Alcatel-Lucent 6850 Switch User Manual

Part No. 060216-10, Rev. E
December 2007
OmniSwitch 6800 Series
OmniSwitch 6850 Series
OmniSwitch 9000 Series
Advanced Routing
Configuration Guide
www.alcatel-lucent.com
This user guide documents release 6.3.1 of the OmniSwitch 6800 Series, OmniSwitch 6850
Series, and OmniSwitch 9000 Series.
The functionality described in this guide is subject to change without notice.
Copyright © 2007 by Alcatel-Lucent. All rights reserved. This document may not be reproduced in whole
or in part without the express written permission of Alcatel-Lucent.
Alcatel-Lucent® and the Alcatel-Lucent logo are registered trademarks of Alcatel-Lucent. Xylan®,
OmniSwitch®, OmniStack®, and Alcatel-Lucent OmniVista® are registered trademarks of Alcatel-Lucent.
OmniAccess™, Omni Switch/Router™, PolicyView™, RouterView™, SwitchManager™, VoiceView™,
WebView™, X-Cell™, X-Vision™, and the Xylan logo are trademarks of Alcatel-Lucent.
This OmniSwitch product contains components which may be covered by one or more of the following
U.S. Patents:
• U.S. Patent No. 6,339,830
• U.S. Patent No. 6,070,243
• U.S. Patent No. 6,061,368
• U.S. Patent No. 5,394,402
• U.S. Patent No. 6,047,024
• U.S. Patent No. 6,314,106
• U.S. Patent No. 6,542,507
• U.S. Patent No. 6,874,090
26801 West Agoura Road
Calabasas, CA 91301
(818) 880-3500 FAX (818) 880-3505
support@ind.alcatel.com
US Customer Support—(800) 995-2696
International Customer Support—(818) 878-4507
Internet—service.esd.alcatel-lucent.com
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Contents
About This Guide .......................................................................................................... xi
Supported Platforms .......................................................................................................... xi
Who Should Read this Manual? ....................................................................................... xii
When Should I Read this Manual? ................................................................................... xii
What is in this Manual? .................................................................................................... xii
What is Not in this Manual? ............................................................................................. xii
How is the Information Organized? ................................................................................xiii
Documentation Roadmap ................................................................................................xiii
Related Documentation .................................................................................................... xv
User Manual CD ............................................................................................................ xvii
Technical Support .......................................................................................................... xvii
Chapter 1
Configuring OSPF ....................................................................................................... 1-1
In This Chapter ................................................................................................................1-1
OSPF Specifications ........................................................................................................1-2
OSPF Defaults Table .......................................................................................................1-3
OSPF Quick Steps ...........................................................................................................1-4
OSPF Overview ..............................................................................................................1-7
OSPF Areas ..............................................................................................................1-8
Classification of Routers ..........................................................................................1-9
Virtual Links ............................................................................................................1-9
Stub Areas ..............................................................................................................1-10
Not-So-Stubby-Areas ......................................................................................1-11
Totally Stubby Areas .......................................................................................1-11
Equal Cost Multi-Path (ECMP) Routing ...............................................................1-12
Non Broadcast OSPF Routing ................................................................................1-12
Graceful Restart on Stacks with Redundant Switches ...........................................1-13
Graceful Restart on Switches with Redundant CMMs ..........................................1-14
Configuring OSPF .........................................................................................................1-15
Preparing the Network for OSPF ...........................................................................1-16
Activating OSPF ....................................................................................................1-16
Creating an OSPF Area ..........................................................................................1-17
Configuring Stub Area Default Metrics .................................................................1-19
Creating OSPF Interfaces .......................................................................................1-20
Interface Authentication .........................................................................................1-21
Creating Virtual Links ............................................................................................1-22
Configuring Redistribution ....................................................................................1-23
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Contents
Using Route Maps ...........................................................................................1-24
Configuring Route Map Redistribution ...........................................................1-28
Route Map Redistribution Example ................................................................1-29
Configuring Router Capabilities ............................................................................1-30
Configuring Static Neighbors .................................................................................1-31
Configuring Redundant Switches in a Stack for Graceful Restart .........................1-32
Configuring Redundant CMMs for Graceful Restart .............................................1-33
OSPF Application Example ..........................................................................................1-34
Step 1: Prepare the Routers .............................................................................1-35
Step 2: Enable OSPF .......................................................................................1-36
Step 3: Create the Areas and Backbone ..........................................................1-36
Step 4: Create, Enable, and Assign Interfaces .................................................1-37
Step 5: Examine the Network ..........................................................................1-38
Verifying OSPF Configuration .....................................................................................1-39
Chapter 2
Configuring OSPFv3 ................................................................................................... 2-1
In This Chapter ................................................................................................................2-1
OSPFv3 Specifications ....................................................................................................2-2
OSPFv3 Defaults Table ...................................................................................................2-3
OSPFv3 Quick Steps .......................................................................................................2-4
OSPFv3 Overview ..........................................................................................................2-8
OSPFv3 Areas ..........................................................................................................2-9
Classification of Routers ........................................................................................2-10
Virtual Links ..........................................................................................................2-10
Stub Areas ..............................................................................................................2-11
Equal Cost Multi-Path (ECMP) Routing ...............................................................2-12
Configuring OSPFv3 .....................................................................................................2-13
Preparing the Network for OSPFv3 .......................................................................2-14
Activating OSPFv3 ................................................................................................2-14
Creating an OSPFv3 Area ......................................................................................2-15
Configuring Stub Area Default Metrics .................................................................2-16
Creating OSPFv3 Interfaces ...................................................................................2-16
Creating Virtual Links ............................................................................................2-17
Configuring Redistribution ....................................................................................2-18
Using Route Maps ...........................................................................................2-19
Configuring Route Map Redistribution ...........................................................2-22
Configuring Router Capabilities ............................................................................2-24
OSPFv3 Application Example ......................................................................................2-25
Step 1: Prepare the Routers .............................................................................2-26
Step 2: Load OSPFv3 ......................................................................................2-27
Step 3: Create the Areas and Backbone ..........................................................2-28
Step 5: Examine the Network ..........................................................................2-29
Verifying OSPFv3 Configuration .................................................................................2-30
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Chapter 3
Configuring IS-IS ........................................................................................................ 3-1
In This Chapter ................................................................................................................3-1
IS-IS Specifications .........................................................................................................3-2
IS-IS Defaults Table ........................................................................................................3-3
IS-IS Quick Steps ............................................................................................................3-5
IS-IS Overview ................................................................................................................ 3-8
IS-IS Packet Types .................................................................................................3-10
IS-IS Areas .............................................................................................................3-10
Graceful Restart on Stacks with Redundant Switches ...........................................3-12
Configuring IS-IS ..........................................................................................................3-14
Preparing the Network for IS-IS ............................................................................3-14
Activating IS-IS ......................................................................................................3-15
Creating an IS-IS Area ID ......................................................................................3-16
Creating IS-IS Interfaces ........................................................................................3-16
Configuring the IS-IS Level ...................................................................................3-16
Enabling Summarization ........................................................................................3-18
Enabling IS-IS Authentication ...............................................................................3-18
Modifying Interface Parameters .............................................................................3-22
Configuring Redistribution Using Route Maps .....................................................3-24
Using Route Maps ...........................................................................................3-24
Configuring Route Map Redistribution ...........................................................3-28
Route Map Redistribution Example ................................................................3-29
Configuring Router Capabilities ............................................................................3-30
Configuring Redundant Switches in a Stack for Graceful Restart .........................3-31
IS-IS Application Example ...........................................................................................3-32
Step 1: Prepare the Routers .............................................................................3-32
Step 2: Enable IS-IS ........................................................................................3-33
Step 3: Create and Enable Area ID ..................................................................3-33
Step 4: Configuring IS-IS Level Capability ....................................................3-33
Step 5: Create, Enable, and Assign Interfaces .................................................3-33
Step 6: Examine the Network ..........................................................................3-34
Verifying IS-IS Configuration ......................................................................................3-34
Chapter 4
Configuring BGP ......................................................................................................... 4-1
In This Chapter .........................................................................................................4-1
BGP Specifications ........................................................................................................4-3
Quick Steps for Using BGP ............................................................................................4-4
BGP Overview ................................................................................................................4-5
Autonomous Systems (ASs) .....................................................................................4-6
Internal vs. External BGP .........................................................................................4-7
Communities ............................................................................................................4-8
Route Reflectors .......................................................................................................4-9
BGP Confederations ...............................................................................................4-11
Policies ...................................................................................................................4-12
Regular Expressions ........................................................................................4-13
The Route Selection Process ..................................................................................4-16
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Contents
Route Dampening ...................................................................................................4-17
CIDR Route Notation .............................................................................................4-17
BGP Configuration Overview .......................................................................................4-18
Starting BGP .................................................................................................................4-19
Disabling BGP ........................................................................................................4-19
Setting Global BGP Parameters ....................................................................................4-20
Setting the Router AS Number ...............................................................................4-21
Setting the Default Local Preference .....................................................................4-21
Enabling AS Path Comparison ...............................................................................4-22
Controlling the use of MED Values .......................................................................4-23
Synchronizing BGP and IGP Routes .....................................................................4-24
Displaying Global BGP Parameters .......................................................................4-25
Configuring a BGP Peer ................................................................................................4-26
Creating a Peer .......................................................................................................4-28
Restarting a Peer .....................................................................................................4-29
Setting the Peer Auto Restart .................................................................................4-29
Changing the Local Router Address for a Peer Session .........................................4-30
Clearing Statistics for a Peer ..................................................................................4-30
Setting Peer Authentication ....................................................................................4-31
Setting the Peer Route Advertisement Interval ......................................................4-31
Configuring a BGP Peer with the Loopback0 Interface ..................................4-31
Configuring Aggregate Routes .....................................................................................4-32
Configuring Local Routes (Networks) ..........................................................................4-33
Adding the Network ........................................................................................4-33
Configuring Network Parameters ....................................................................4-34
Viewing Network Settings ..............................................................................4-35
Controlling Route Flapping Through Route Dampening ..............................................4-36
Example: Flapping Route Suppressed, then Unsuppressed ............................4-36
Enabling Route Dampening ............................................................................4-37
Configuring Dampening Parameters ...............................................................4-37
Clearing the History ........................................................................................4-39
Displaying Dampening Settings and Statistics ................................................4-39
Setting Up Route Reflection .........................................................................................4-40
Configuring Route Reflection ................................................................................4-42
Redundant Route Reflectors ...................................................................................4-42
Working with Communities ..........................................................................................4-43
Creating a Confederation ..............................................................................................4-44
Routing Policies ............................................................................................................4-45
Creating a Policy ....................................................................................................4-45
Assigning a Policy to a Peer ...................................................................................4-50
Displaying Policies .................................................................................................4-52
Configuring Redistribution ...........................................................................................4-53
Using Route Maps ...........................................................................................4-53
Configuring Route Map Redistribution ...........................................................4-57
Route Map Redistribution Example ................................................................4-58
Configuring Redundant CMMs for Graceful Restart .............................................4-59
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Contents
Application Example .....................................................................................................4-60
AS 100 .............................................................................................................4-60
AS 200 .............................................................................................................4-61
AS 300 .............................................................................................................4-62
Displaying BGP Settings and Statistics ........................................................................4-63
BGP for IPv6 Overview ................................................................................................4-64
Quick Steps for Using BGP for IPv6 ............................................................................4-66
Configuring BGP for IPv6 ............................................................................................4-68
Enabling/Disabling IPv6 BGP Unicast ..................................................................4-68
Configuring an IPv6 BGP Peer ..............................................................................4-68
Changing the Local Router Address for an IPv6 Peer Session .......................4-71
Optional IPv6 BGP Peer Parameters ...............................................................4-72
Configuring IPv6 BGP Networks ..........................................................................4-73
Adding a Network ...........................................................................................4-73
Enabling a Network .........................................................................................4-73
Configuring Network Parameters ....................................................................4-73
Viewing Network Settings ..............................................................................4-75
Configuring IPv6 Redistribution ...................................................................................4-76
Using Route Maps for IPv6 Redistribution ............................................................4-76
Configuring IPv6 Route Map Redistribution ..................................................4-76
IPv6 BGP Application Example ...................................................................................4-78
AS 100 .............................................................................................................4-78
AS 200 .............................................................................................................4-80
AS 300 .............................................................................................................4-81
Displaying IPv6 BGP Settings and Statistics ................................................................4-82
Chapter 5
Configuring Multicast Address Boundaries ........................................................ 5-1
In This Chapter ................................................................................................................5-1
Multicast Boundary Specifications .................................................................................5-2
Quick Steps for Configuring Multicast Address Boundaries ..........................................5-2
Using Existing IP Interfaces ..............................................................................5-2
On New IP Interface ..........................................................................................5-2
Multicast Address Boundaries Overview ........................................................................5-4
Multicast Addresses and the IANA ..........................................................................5-4
Administratively Scoped Multicast Addresses ..................................................5-4
Source-Specific Multicast Addresses ................................................................5-4
Multicast Address Boundaries .................................................................................5-5
Concurrent Multicast Addresses ..............................................................................5-6
Configuring Multicast Address Boundaries ....................................................................5-7
Basic Multicast Address Boundary Configuration ...................................................5-7
Creating a Multicast Address Boundary ..................................................................5-7
Deleting a Multicast Address Boundary ..................................................................5-7
Verifying the Multicast Address Boundary Configuration .............................................5-8
Application Example for Configuring Multicast Address Boundaries ...........................5-8
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Contents
Chapter 6
Configuring DVMRP ................................................................................................... 6-1
In This Chapter ................................................................................................................6-1
DVMRP Specifications ...................................................................................................6-2
DVMRP Defaults ............................................................................................................6-2
Quick Steps for Configuring DVMRP ............................................................................6-3
DVMRP Overview ..........................................................................................................6-5
Reverse Path Multicasting ........................................................................................6-5
Neighbor Discovery .................................................................................................6-6
Multicast Source Location, Route Report Messages, and Metrics ..........................6-7
Dependent Downstream Routers and Poison Reverse .............................................6-7
Pruning Multicast Traffic Delivery ..........................................................................6-8
Grafting Branches Back onto the Multicast Delivery Tree ......................................6-8
DVMRP Tunnels ......................................................................................................6-9
Configuring DVMRP ....................................................................................................6-10
Enabling DVMRP on the Switch ...........................................................................6-10
Loading DVMRP into Memory .......................................................................6-10
Enabling DVMRP on a Specific Interface ......................................................6-11
Viewing DVMRP Status and Parameters for a Specific Interface ..................6-12
Globally Enabling DVMRP on the Switch .....................................................6-12
Checking the Current Global DVMRP Status .................................................6-12
Automatic Loading and Enabling of DVMRP Following a System Boot ......6-13
Neighbor Communications ....................................................................................6-13
Routes .....................................................................................................................6-14
Pruning ...................................................................................................................6-15
More About Prunes ..........................................................................................6-15
Grafting ..................................................................................................................6-17
Tunnels ...................................................................................................................6-17
Verifying the DVMRP Configuration ...........................................................................6-18
Chapter 7
Configuring PIM .......................................................................................................... 7-1
In This Chapter ................................................................................................................7-1
PIM Specifications ..........................................................................................................7-3
PIM Defaults ...................................................................................................................7-4
Quick Steps for Configuring PIM-DM ...........................................................................7-6
PIM Overview .................................................................................................................7-8
PIM-Sparse Mode (PIM-SM) ...................................................................................7-8
Rendezvous Points (RPs) ..................................................................................7-8
Bootstrap Routers (BSRs) .................................................................................7-9
Designated Routers (DRs) .................................................................................7-9
Shared (or RP) Trees .........................................................................................7-9
Avoiding Register Encapsulation ....................................................................7-12
PIM-Dense Mode (PIM-DM) .................................................................................7-12
RP Initiation of (S, G) Source-Specific Join Message ...........................................7-13
SPT Switchover ......................................................................................................7-15
Configuring PIM ...........................................................................................................7-18
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Enabling PIM on the Switch ..................................................................................7-18
Verifying the Software ....................................................................................7-18
Loading PIM into Memory ..............................................................................7-19
Enabling IPMS ................................................................................................7-19
Enabling PIM on a Specific Interface ....................................................................7-20
Disabling PIM on a Specific Interface ............................................................7-20
Viewing PIM Status and Parameters for a Specific Interface .........................7-21
Enabling PIM Mode on the Switch ........................................................................7-21
Disabling PIM Mode on the Switch ................................................................7-21
Checking the Current Global PIM Status ........................................................7-21
Mapping an IP Multicast Group to a PIM Mode ...................................................7-22
Mapping an IP Multicast Group to PIM-DM ..................................................7-22
Mapping an IP Multicast Group to PIM-SSM ................................................7-22
Verifying Group Mapping ...............................................................................7-23
Automatic Loading and Enabling of PIM following a System Boot .....................7-23
PIM Bootstrap and RP Discovery ..........................................................................7-24
Configuring a C-RP .........................................................................................7-24
Specifying the Maximum Number of RPs ......................................................7-25
Candidate Bootstrap Routers (C-BSRs) ..........................................................7-25
Bootstrap Routers (BSRs) ...............................................................................7-26
Configuring Static RP Groups .........................................................................7-27
Group-to-RP Mapping .....................................................................................7-28
Configuring Keepalive Period ................................................................................7-28
Verifying Keepalive Period .............................................................................7-28
Configuring Notification Period .............................................................................7-29
Verifying the Notification Period ....................................................................7-29
PIM-SSM Support .........................................................................................................7-31
Source-Specific Multicast Addresses .....................................................................7-31
PIM-SSM Specifications ........................................................................................7-31
Verifying PIM Configuration ........................................................................................7-32
PIM for IPv6 Overview .................................................................................................7-33
Quick Steps for Configuring IPv6 PIM-DM .................................................................7-33
Configuring IPv6 PIM ...................................................................................................7-35
Enabling IPv6 PIM on a Specific Interface ............................................................7-35
Disabling IPv6 PIM on a Specific Interface ....................................................7-35
Viewing IPv6 PIM Status and Parameters for a Specific Interface .................7-35
Enabling IPv6 PIM Mode on the Switch .........................................................7-35
Disabling IPv6 PIM Mode on the Switch ........................................................7-36
Checking the Current Global IPv6 PIM Status ...............................................7-36
Mapping an IPv6 Multicast Group to a PIM mode ................................................7-36
Mapping an IPv6 Multicast Group to PIM-DM ..............................................7-36
Mapping an IPv6 Multicast Group to PIM-SSM ............................................7-37
Verifying Group Mapping ...............................................................................7-37
IPv6 PIM Bootstrap and RP Discovery ..................................................................7-38
Configuring a C-RP for IPv6 PIM ...................................................................7-38
Configuring Candidate Bootstrap Routers (C-BSRs) for IPv6 PIM ...............7-39
Bootstrap Routers (BSRs) ...............................................................................7-39
Configuring Static RP Groups for IPv6 PIM ..................................................7-40
Group-to-RP Mapping .....................................................................................7-41
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Contents
Configuring RP-Switchover for IPv6 PIM .............................................................7-41
Verifying RP-Switchover ................................................................................7-42
IPv6 PIM-SSM Support ................................................................................................7-42
Source-Specific Multicast Addresses .....................................................................7-42
PIM-SSM Specifications ........................................................................................7-42
Verifying IPv6 PIM Configuration ...............................................................................7-43
Appendix A
Software License and Copyright Statements ......................................................A-1
Alcatel-Lucent License Agreement ................................................................................ A-1
ALCATEL-LUCENT SOFTWARE LICENSE AGREEMENT ............................ A-1
Third Party Licenses and Notices .................................................................................. A-4
A. Booting and Debugging Non-Proprietary Software .......................................... A-4
B. The OpenLDAP Public License: Version 2.4, 8 December 2000 ..................... A-4
C. Linux .................................................................................................................. A-5
D. GNU GENERAL PUBLIC LICENSE: Version 2, June 1991 .......................... A-5
E. University of California ................................................................................... A-10
F. Carnegie-Mellon University ............................................................................ A-10
G. Random.c ......................................................................................................... A-10
H. Apptitude, Inc. ................................................................................................. A-11
I. Agranat ............................................................................................................. A-11
J. RSA Security Inc. ............................................................................................ A-11
K. Sun Microsystems, Inc. .................................................................................... A-11
L. Wind River Systems, Inc. ................................................................................ A-12
M. Network Time Protocol Version 4 ................................................................... A-12
Index ...................................................................................................................... Index-1
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About This Guide
This OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide describes how to set up and
monitor advanced routing protocols for operation in a live network environment. The routing protocols
described in this manual are purchased as an add-on package to the base switch software.
Supported Platforms
This information in this guide applies to the following products:
• OmniSwitch 9600 (with Jadvrout.img file installed)
• OmniSwitch 9700 (with Jadvrout.img file installed)
• OmniSwitch 9800 (with Jadvrout.img file installed)
• OmniSwitch 6800 Series (with Kadvrout.img file installed)
• OmniSwitch 6850 Series (with Kadvrout.img file installed)
Note. This OmniSwitch CLI Reference Guide covers Release 6.3.1, which is supported on the OmniSwitch
6800 Series, OmniSwitch 6850 Series, and OmniSwitch 9000 Series switches. OmniSwitch 6600 Family,
OmniSwitch 7700/7800, and OmniSwitch 8800 switches use Release 5.x. Please refer to the 5.x user
guides for those switches.
Unsupported Platforms
The information in this guide does not apply to the following products:
• OmniSwitch (original version with no numeric model name)
• OmniSwitch 6600 Family
• OmniSwitch 7700/7800
• OmniSwitch 8800
• Omni Switch/Router
• OmniStack
• OmniAccess
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
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page -xi
Who Should Read this Manual?
The audience for this user guide is network administrators and IT support personnel who need to configure, maintain, and monitor switches and routers in a live network. However, anyone wishing to gain
knowledge on how advanced routing software features are implemented in the OmniSwitch 6800 Series,
OmniSwitch 6850 Series, and OmniSwitch 9000 Series switches will benefit from the material in this
configuration guide.
When Should I Read this Manual?
Read this guide as soon as you are ready to integrate your OmniSwitch into your network and you are
ready to set up advanced routing protocols. You should already be familiar with the basics of managing a
single OmniSwitch as described in the OmniSwitch 6800/6850/9000 Switch Management Guide.
The topics and procedures in this manual assume an understanding of the OmniSwitch directory structure
and basic switch administration commands and procedures. This manual will help you set up your
switches to route on the network using routing protocols, such as OSPF.
What is in this Manual?
This configuration guide includes information about configuring the following features:
• Open Shortest Path First (OSPF) protocol
• Border Gateway Protocol (BGP)
• Multicast routing boundaries
• Distance Vector Multicast Routing Protocol (DVMRP)
• Protocol-Independent Multicast, Sparse Mode (PIM-SM) protocol
What is Not in this Manual?
The configuration procedures in this manual use Command Line Interface (CLI) commands in all examples. CLI commands are text-based commands used to manage the switch through serial (console port)
connections or via Telnet sessions. Procedures for other switch management methods, such as web-based
(WebView or OmniVista) or SNMP, are outside the scope of this guide.
For information on WebView and SNMP switch management methods consult the OmniSwitch 6800/
6850/9000 Switch Management Guide. Information on using WebView and OmniVista can be found in the
context-sensitive on-line help available with those network management applications.
This guide provides overview material on software features, how-to procedures, and application examples
that will enable you to begin configuring your OmniSwitch. It is not intended as a comprehensive reference to all CLI commands available in the OmniSwitch. For such a reference to all OmniSwitch CLI
commands, consult the OmniSwitch CLI Reference Guide.
page -xii
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December 2007
How is the Information Organized?
Chapters in this guide are broken down by software feature. The titles of each chapter include protocol or
feature names (e.g., OSPF, PIM-SM) with which most network professionals will be familiar.
Each software feature chapter includes sections that will satisfy the information requirements of casual
readers, rushed readers, serious detail-oriented readers, advanced users, and beginning users.
Quick Information. Most chapters include a specifications table that lists RFCs and IEEE specifications
supported by the software feature. In addition, this table includes other pertinent information such as minimum and maximum values and sub-feature support. Most chapters also include a defaults table that lists
the default values for important parameters along with the CLI command used to configure the parameter.
Many chapters include a Quick Steps section, which is a procedure covering the basic steps required to get
a software feature up and running.
In-Depth Information. All chapters include overview sections on the software feature as well as on
selected topics of that software feature. Topical sections may often lead into procedure sections that
describe how to configure the feature just described. Serious readers and advanced users will also find the
many application examples, located near the end of chapters, helpful. Application examples include
diagrams of real networks and then provide solutions using the CLI to configure a particular feature, or
more than one feature, within the illustrated network.
Documentation Roadmap
The OmniSwitch user documentation suite was designed to supply you with information at several critical
junctures of the configuration process. The following section outlines a roadmap of the manuals that will
help you at each stage of the configuration process. Under each stage, we point you to the manual or
manuals that will be most helpful to you.
Stage 1: Using the Switch for the First Time
Pertinent Documentation: Getting Started Guide
Release Notes
A hard-copy Getting Started Guide is included with your switch; this guide provides all the information
you need to get your switch up and running the first time. It provides information on unpacking the switch,
rack mounting the switch, installing NI modules, unlocking access control, setting the switch’s IP address,
and setting up a password. It also includes succinct overview information on fundamental aspects of the
switch, such as hardware LEDs, the software directory structure, CLI conventions, and web-based
management.
At this time you should also familiarize yourself with the Release Notes that accompanied your switch.
This document includes important information on feature limitations that are not included in other user
guides.
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page -xiii
Stage 2: Gaining Familiarity with Basic Switch Functions
Pertinent Documentation: Hardware Users Guide
Switch Management Guide
Once you have your switch up and running, you will want to begin investigating basic aspects of its hardware and software. Information about switch hardware is provided in the Hardware Users Guide. This
guide provide specifications, illustrations, and descriptions of all hardware components, such as chassis,
power supplies, Chassis Management Modules (CMMs), Network Interface (NI) modules, and cooling
fans. It also includes steps for common procedures, such as removing and installing switch components.
The Switch Management Guide is the primary users guide for the basic software features on a single
switch. This guide contains information on the switch directory structure, basic file and directory utilities,
switch access security, SNMP, and web-based management. It is recommended that you read this guide
before connecting your switch to the network.
Stage 3: Integrating the Switch Into a Network
Pertinent Documentation: Network Configuration Guide
Advanced Routing Configuration Guide
When you are ready to connect your switch to the network, you will need to learn how the OmniSwitch
implements fundamental software features, such as 802.1Q, VLANs, Spanning Tree, and network routing
protocols. The Network Configuration Guide contains overview information, procedures, and examples on
how standard networking technologies are configured in the OmniSwitch.
The Advanced Routing Configuration Guide includes configuration information for networks using
advanced routing technologies (OSPF and BGP) and multicast routing protocols (DVMRP and PIM-SM).
Anytime
The OmniSwitch CLI Reference Guide contains comprehensive information on all CLI commands
supported by the switch. This guide includes syntax, default, usage, example, related CLI command, and
CLI-to-MIB variable mapping information for all CLI commands supported by the switch. This guide can
be consulted anytime during the configuration process to find detailed and specific information on each
CLI command.
page -xiv
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Related Documentation
The following are the titles and descriptions of all the related OmniSwitch 6800/6850/9000 user manuals:
• OmniSwitch 6800 Series Getting Started Guide
Describes the hardware and software procedures for getting an OmniSwitch 6800 Series switch up and
running. Also provides information on fundamental aspects of OmniSwitch software and stacking
architecture.
• OmniSwitch 6850 Series Getting Started Guide
Describes the hardware and software procedures for getting an OmniSwitch 6850 Series switch up and
running. Also provides information on fundamental aspects of OmniSwitch software and stacking
architecture.
• OmniSwitch 6800 Series Hardware Users Guide
Detailed technical specifications and procedures for the OmniSwitch 6800 Series chassis and components. Also includes comprehensive information on assembling and managing stacked configurations.
• OmniSwitch 6850 Series Hardware User Guide
Complete technical specifications and procedures for all OmniSwitch 6850 Series chassis, power
supplies, and fans. Also includes comprehensive information on assembling and managing stacked
configurations.
• OmniSwitch 9000 Series Getting Started Guide
Describes the hardware and software procedures for getting an OmniSwitch 9000 Series up and
running. Also provides information on fundamental aspects of OmniSwitch software architecture.
• OmniSwitch 9000 Series Hardware Users Guide
Complete technical specifications and procedures for all OmniSwitch 9000 Series chassis, power
supplies, fans, and Network Interface (NI) modules.
• OmniSwitch CLI Reference Guide
Complete reference to all CLI commands supported on the OmniSwitch 6800, 6850, and 9000.
Includes syntax definitions, default values, examples, usage guidelines and CLI-to-MIB variable
mappings.
• OmniSwitch 6800/6850/9000 Switch Management Guide
Includes procedures for readying an individual switch for integration into a network. Topics include
the software directory architecture, image rollback protections, authenticated switch access, managing
switch files, system configuration, using SNMP, and using web management software (WebView).
• OmniSwitch 6800/6850/9000 Network Configuration Guide
Includes network configuration procedures and descriptive information on all the major software
features and protocols included in the base software package. Chapters cover Layer 2 information
(Ethernet and VLAN configuration), Layer 3 information (routing protocols, such as RIP), security
options (authenticated VLANs), Quality of Service (QoS), and link aggregation.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page -xv
• OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
Includes network configuration procedures and descriptive information on all the software features and
protocols included in the advanced routing software package. Chapters cover multicast routing
(DVMRP and PIM-SM), and OSPF.
• OmniSwitch Transceivers Guide
Includes information on Small Form Factor Pluggable (SFPs) and 10 Gbps Small Form Factor Pluggables (XFPs) transceivers.
• Technical Tips, Field Notices
Includes information published by Alcatel-Lucent’s Customer Support group.
• Release Notes
Includes critical Open Problem Reports, feature exceptions, and other important information on the
features supported in the current release and any limitations to their support.
page -xvi
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
User Manual CD
All user guides are included on the User Manual CD that accompanied your switch. This CD also includes
user guides for other Alcatel-Lucent data enterprise products. In addition, it contains a stand-alone version
of the on-line help system that is embedded in the OmniVista network management application.
Besides the OmniVista documentation, all documentation on the User Manual CD is in PDF format and
requires the Adobe Acrobat Reader program for viewing. Acrobat Reader freeware is available at
www.adobe.com.
Note. In order to take advantage of the documentation CD’s global search feature, it is recommended that
you select the option for searching PDF files before downloading Acrobat Reader freeware.
To verify that you are using Acrobat Reader with the global search option, look for the following button in
the toolbar:
Note. When printing pages from the documentation PDFs, de-select Fit to Page if it is selected in your
print dialog. Otherwise pages may print with slightly smaller margins.
Technical Support
An Alcatel-Lucent service agreement brings your company the assurance of 7x24 no-excuses technical
support. You’ll also receive regular software updates to maintain and maximize your Alcatel-Lucent product’s features and functionality and on-site hardware replacement through our global network of highly
qualified service delivery partners. Additionally, with 24-hour-a-day access to Alcatel-Lucent’s Service
and Support web page, you’ll be able to view and update any case (open or closed) that you have reported
to Alcatel-Lucent’s technical support, open a new case or access helpful release notes, technical bulletins,
and manuals. For more information on Alcatel-Lucent’s Service Programs, see our web page at
service.esd.alcatel-lucent.com, call us at 1-800-995-2696, or email us at support@ind.alcatel.com.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page -xvii
page -xviii
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
1
Configuring OSPF
Open Shortest Path First routing (OSPF) is a shortest path first (SPF), or link state, protocol. OSPF is an
interior gateway protocol (IGP) that distributes routing information between routers in a single Autonomous System (AS). OSPF chooses the least-cost path as the best path. OSPF is suitable for complex
networks with large numbers of routers since it provides faster convergence where multiple flows to a
single destination can be forwarded on one or more interfaces simultaneously.
In This Chapter
This chapter describes the basic components of OSPF and how to configure them through the Command
Line Interface (CLI). CLI commands are used in the configuration examples; for more details about the
syntax of commands, see the OmniSwitch CLI Reference Guide.
Configuration procedures described in this chapter include:
• Loading and enabling OSPF (see page 1-16).
• Creating OSPF areas (see page 1-17).
• Creating OSPF interfaces (see page 1-20).
• Creating virtual links (see page 1-22).
• Configuring redistribution using route maps (see page 1-23).
For information on creating and managing VLANs, see “Configuring VLANs” in the OmniSwitch 6800/
6850/9000 Network Configuration Guide.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 1-1
OSPF Specifications
Configuring OSPF
OSPF Specifications
RFCs Supported
1370—Applicability Statement for OSPF
1850—OSPF Version 2 Management Information
Base
2328—OSPF Version 2
2370—The OSPF Opaque LSA Option
3101—The OSPF Not-So-Stubby Area (NSSA)
Option
3623—Graceful OSPF Restart
Maximum number of Areas (per router)
32
Maximum number of Interfaces (per router) 3200
Maximum number of Interfaces (per area)
100
Maximum number of Link State Database
entries (per router)
96K
Maximum number of adjacencies (per
router)
254
Maximum number of adjacencies (per area) 128
Maximum number of ECMP gateways (per
destination)
4
Maximum number of neighbors (per router) 64
Maximum number of routes (per router)
page 1-2
96K (Depending on the number of interfaces/
neighbors, this value may vary.)
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring OSPF
OSPF Defaults Table
OSPF Defaults Table
The following table shows the default settings of the configurable OSPF parameters:
Parameter Description
Command
Default Value/Comments
Enables OSPF.
ip ospf status
disabled
Enables an interface.
ip ospf interface status
disabled
Enables OSPF redistribution.
ip ospf redist status
disabled
Sets the overflow interval value.
ip ospf exit-overflow-interval
0
Assigns a limit to the number of
External Link-State Database
(LSDB) entries.
ip ospf extlsdb-limit
-1
Configures timers for Shortest Path
First (SPF) calculation.
ip ospf spf-timer
delay: 5
hold: 10
Creates or deletes an area default
metric.
ip ospf area default-metric
ToS: 0
Type: OSPF
Cost: 1
Configures OSPF interface dead
interval.
ip ospf interface dead-interval
40 seconds (broadcast and
point-to-point)
120 seconds (NBMA and
point-to-multipoint)
Configures OSPF interface hello
interval.
ip ospf interface hello-interval
10 seconds (broadcast and
point-to-point)
30 seconds (NBMA and pointto-multipoint)
Configures the OSPF interface cost. ip ospf interface cost
1
Configures the OSPF poll interval.
ip ospf interface poll-interval
120 seconds
Configures the OSPF interface priority.
ip ospf interface priority
1
Configures OSPF interface retransmit interval.
ip ospf interface retrans-interval 5 seconds
Configures the OSPF interface tran- ip ospf interface transit-delay
sit delay.
1 second
Configures the OSPF interface type. ip ospf interface type
broadcast
Configures graceful restart on
switches in a stack/redundant
CMMs.
disabled
ip ospf restart-support
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 1-3
OSPF Quick Steps
Configuring OSPF
OSPF Quick Steps
The followings steps are designed to show the user the necessary set of commands for setting up a router
to use OSPF:
1 Create a VLAN using the vlan command. For example:
-> vlan 5
-> vlan 5 enable
2 Assign a router IP address and subnet mask to the VLAN using the ip interface command. For example:
-> ip interface vlan-5 vlan 5 address 120.1.4.1 mask 255.0.0.0
3 Assign a port to the created VLANs using the vlan command. For example:
-> vlan 5 port default 2/1
Note. The port will be statically assigned to the VLAN, as a VLAN must have a physical port assigned to
it in order for the router port to function. However, the router could be set up in such a way that mobile
ports are dynamically assigned to VLANs using VLAN rules. See the chapter titled “Defining VLAN
Rules” in the OmniSwitch 6800/6850/9000 Network Configuration Guide.
4 Assign a router ID to the router using the ip router router-id command. For example:
-> ip router router-id 1.1.1.1
5 Load and enable OSPF using the ip load ospf and the ip ospf status commands. For example:
-> ip load ospf
-> ip ospf status enable
6 Create a backbone to connect this router to others, and an area for the router’s traffic, using the ip ospf
area command. (Backbones are always labeled area 0.0.0.0.) For example:
-> ip ospf area 0.0.0.0
-> ip ospf area 0.0.0.1
page 1-4
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring OSPF
OSPF Quick Steps
7 Create an OSPF interface for each VLAN created in Step 1, using the ip ospf interface command. The
OSPF interface should use the same interface name used for the VLAN router IP created in Step 2. For
example:
-> ip ospf interface vlan-5
Note. The interface name cannot have spaces.
8 Assign the OSPF interface to the area and the backbone using the ip ospf interface area command.
For example:
-> ip ospf interface vlan-5 area 0.0.0.0
9 Enable the OSPF interfaces using the ip ospf interface status command. For example:
-> ip ospf interface vlan-5 status enable
10 You can now display the router OSPF settings by using the show ip ospf command. The output gener-
ated is similar to the following:
-> show ip ospf
Router Id
= 1.1.1.1,
OSPF Version Number
= 2,
Admin Status
= Enabled,
Area Border Router?
= Yes,
AS Border Router Status
= Disabled,
Route Redistribution Status
= Disabled,
Route Tag
= 0,
SPF Hold Time (in seconds)
= 10,
SPF Delay Time (in seconds)
= 5,
MTU Checking
= Disabled,
# of Routes
= 0,
# of AS-External LSAs
= 0,
# of self-originated LSAs
= 0,
# of LSAs received
= 0,
External LSDB Limit
= -1,
Exit Overflow Interval
= 0,
# of SPF calculations done
= 1,
# of Incr SPF calculations done = 0,
# of Init State Nbrs
= 0,
# of 2-Way State Nbrs
= 0,
# of Exchange State Nbrs
= 0,
# of Full State Nbrs
= 0,
# of attached areas
= 2,
# of Active areas
= 2,
# of Transit areas
= 0,
# of attached NSSAs
= 0
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
Router ID
As set in Step 4
December 2007
page 1-5
OSPF Quick Steps
Configuring OSPF
11 You can display OSPF area settings using the show ip ospf area command. For example:
-> show ip ospf area 0.0.0.0
Area Identifier
Admin Status
Operational Status
Area Type
Area Summary
Time since last SPF Run
# of Area Border Routers known
# of AS Border Routers known
# of LSAs in area
# of SPF Calculations done
# of Incremental SPF Calculations done
# of Neighbors in Init State
# of Neighbors in 2-Way State
# of Neighbors in Exchange State
# of Neighbors in Full State
# of Interfaces attached
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
0.0.0.0,
Enabled,
Up,
normal,
Enabled,
00h:08m:37s,
1,
0,
1,
1,
0,
0,
0,
0,
0,
1
Area ID
As set in Step 6
12 You can display OSPF interface settings using the show ip ospf interface command. For example:
-> show ip ospf interface vlan-5
Interface IP Name
VLAN Id
Interface IP Address
Interface IP Mask
Admin Status
Operational Status
OSPF Interface State
Interface Type
Area Id
Designated Router IP Address
Designated Router RouterId
Backup Designated Router IP Address
Backup Designated Router RouterId
MTU (bytes)
Metric Cost
Priority
Hello Interval (seconds)
Transit Delay (seconds)
Retrans Interval (seconds)
Dead Interval (seconds)
Poll Interval (seconds)
Link Type
Authentication Type
Authentication Key
# of Events
# of Init State Neighbors
# of 2-Way State Neighbors
# of Exchange State Neighbors
# of Full State Neighbors
page 1-6
= vlan-3
= 5,
= 120.1.4.1,
= 255.0.0.0,
= Enabled,
= Down,
= Down,
= Broadcast,
= 0.0.0.0,
= 0.0.0.0,
= 0.0.0.0,
= 0.0.0.0,
= 0.0.0.0,
= 1500,
= 1,
= 1,
= 10,
= 1,
= 5,
= 40,
= 120,
= Broadcast,
= simple,
= Set,
= 0,
= 0,
= 0,
= 0,
= 0
VLAN ID
As set in Step 1
Interface ID
As set in Step 2
Interface Status
As set in Step 10
Area ID
As set in Step 6
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring OSPF
OSPF Overview
OSPF Overview
Open Shortest Path First routing (OSPF) is a shortest path first (SPF), or link-state, protocol. OSPF is an
interior gateway protocol (IGP) that distributes routing information between routers in a Single Autonomous System (AS). OSPF chooses the least-cost path as the best path.
Each participating router distributes its local state (i.e., the router’s usable interfaces, local networks, and
reachable neighbors) throughout the AS by flooding. In a link-state protocol, each router maintains a database describing the entire topology. This database is built from the collected link state advertisements of
all routers. Each multi-access network that has at least two attached routers has a designated router and a
backup designated router. The designated router floods a link state advertisement for the multi-access
network.
When a router starts, it uses the OSPF Hello Protocol to discover neighbors. The router sends Hello packets to its neighbors, and in turn receives their Hello packets. On broadcast and point-to-point networks, the
router dynamically detects its neighboring routers by sending Hello packets to a multicast address. On
non-broadcast and point-to-multipoint networks, some configuration information is necessary in order to
configure neighbors. On all networks (broadcast or non-broadcast), the Hello Protocol also elects a designated router for the network.
Hello. Please respond...
Hello. Please respond...
Are you a neighbor...
Are you a neighbor...
My link state is...
My link state is...
OSPF Hello Protocol
The router will attempt to form full adjacencies with all of its newly acquired neighbors. Only some pairs,
however, will be successful in forming full adjacencies. Topological databases are synchronized between
pairs of fully adjacent routers.
Adjacencies control the distribution of routing protocol packets. Routing protocol packets are sent and
received only on adjacencies. In particular, distribution of topological database updates proceeds along
adjacencies.
Link state is also advertised when a router’s state changes. A router’s adjacencies are reflected in the
contents of its link state advertisements. This relationship between adjacencies and link state allows the
protocol to detect downed routers in a timely fashion.
Link state advertisements are flooded throughout the AS. The flooding algorithm ensures that all routers
have exactly the same topological database. This database consists of the collection of link state advertisements received from each router belonging to the area. From this database each router calculates a shortest-path tree, with itself as root. This shortest-path tree in turn yields a routing table for the protocol.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 1-7
OSPF Overview
Configuring OSPF
OSPF Areas
OSPF allows collections of contiguous networks and hosts to be grouped together as an area. Each area
runs a separate copy of the basic link-state routing algorithm (usually called SPF). This means that each
area has its own topological database, as explained in the previous section.
Inter-Area Routing
Intra-Area
Routing
Intra-Area
Routing
Router 3
Backbone
Router 1
Link State
Messages
Link State
Messages
Router 2
Router 4
Area 1
Area 2
OSPF Intra-Area and Inter-Area Routing
An area’s topology is visible only to the members of the area. Conversely, routers internal to a given area
know nothing of the detailed topology external to the area. This isolation of knowledge enables the protocol to reduce routing traffic by concentrating on small areas of an AS, as compared to treating the entire
AS as a single link-state domain.
Areas cause routers to maintain a separate topological database for each area to which they are connected.
(Routers connected to multiple areas are called area border routers). Two routers belonging to the same
area have identical area topological databases.
Different areas communicate with each other through a backbone. The backbone consists of routers with
contacts between multiple areas. A backbone must be contiguous (i.e., it must be linked to all areas).
The backbone is responsible for distributing routing information between areas. The backbone itself has all
of the properties of an area. The topology of the backbone is invisible to each of the areas, while the backbone itself knows nothing of the topology of the areas.
All routers in an area must agree on that area’s parameters. Since a separate copy of the link-state algorithm is run in each area, most configuration parameters are defined on a per-router basis. All routers
belonging to an area must agree on that area’s configuration. Misconfiguration will keep neighbors from
forming adjacencies between themselves, and OSPF will not function.
page 1-8
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring OSPF
OSPF Overview
Classification of Routers
When an AS is split into OSPF areas, the routers are further divided according to function into the following four overlapping categories:
• Internal routers. A router with all directly connected networks belonging to the same area. These
routers run a single copy of the SPF algorithm.
• Area border routers. A router that attaches to multiple areas. Area border routers run multiple copies
of the SPF algorithm, one copy for each attached area. Area border routers condense the topological
information of their attached areas for flooding to other areas.
• Backbone routers. A router that has an interface to the backbone. This includes all routers that inter-
face to more than one area (i.e., area border routers). However, backbone routers do not have to be area
border routers. Routers with all interfaces connected to the backbone are considered to be internal routers.
• AS boundary routers. A router that exchanges routing information with routers belonging to other
Autonomous Systems. Such a router has AS external routes that are advertised throughout the Autonomous System. The path to each AS boundary router is known by every router in the AS. This classification is completely independent of the previous classifications (i.e., internal, area border, and
backbone routers). AS boundary routers may be internal or area border routers, and may or may not
participate in the backbone.
Virtual Links
It is possible to define areas in such a way that the backbone is no longer contiguous. (This is not an ideal
OSPF configuration, and maximum effort should be made to avoid this situation.) In this case the system
administrator must restore backbone connectivity by configuring virtual links.
Virtual links can be configured between any two backbone routers that have a connection to a common
non-backbone area. The protocol treats two routers joined by a virtual link as if they were connected by an
unnumbered point-to-point network. The routing protocol traffic that flows along the virtual link uses
intra-area routing only, and the physical connection between the two routers is not managed by the
network administrator (i.e., there is no dedicated connection between the routers as there is with the OSPF
backbone).
Router B
Router A
Area 1
Backbone
Virtual Link
Backbone
OSPF Routers Connected with a Virtual Link
In the above diagram, Router A and Router B are connected via a virtual link in Area 1, which is known as
a transit area. See “Creating Virtual Links” on page 1-22 for more information.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 1-9
OSPF Overview
Configuring OSPF
Stub Areas
OSPF allows certain areas to be configured as stub areas. A stub area is an area with routers that have no
AS external Link State Advertisements (LSAs).
In order to take advantage of the OSPF stub area support, default routing must be used in the stub area.
This is accomplished by configuring only one of the stub area’s border routers to advertise a default route
into the stub area. The default routes will match any destination that is not explicitly reachable by an intraarea or inter-area path (i.e., AS external destinations).
Backbone
Backbone
Area 1
(stub)
Area 2
Area 3
(stub)
OSPF Stub Area
Area 1 and Area 3 could be configured as stub areas. Stub areas are configured using the OSPF ip ospf area
command, described in “Creating an Area” on page 1-17. For more overview information on areas, see “OSPF
Areas” on page 1-8.
The OSPF protocol ensures that all routers belonging to an area agree on whether the area has been configured as a stub. This guarantees that no confusion will arise in the flooding of AS external advertisements.
Two restrictions on the use of stub areas are:
• Virtual links cannot be configured through stub areas.
• AS boundary routers cannot be placed internal to stub areas.
page 1-10
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring OSPF
OSPF Overview
Not-So-Stubby-Areas
NSSA, or not-so-stubby area, is an extension to the base OSPF specification and is defined in RFC 1587.
An NSSA is similar to a stub area in many ways: AS-external LSAs are not flooded into an NSSA and
virtual links are not allowed in an NSSA. The primary difference is that selected external routing information can be imported into an NSSA and then redistributed into the rest of the OSPF routing domain. These
routes are imported into the NSSA using a new LSA type: Type-7 LSA. Type-7 LSAs are flooded within
the NSSA and are translated at the NSSA boundary into AS-external LSAs so as to convey the external
routing information to other areas.
NSSAs enable routers with limited resources to participate in OSPF routing while also allowing the import
of a selected number of external routes into the area. For example, an area which connects to a small
external routing domain running RIP may be configured as an NSSA. This will allow the import of RIP
routes into this area and the rest of the OSPF routing domain and at the same time, prevent the flooding of
other external routing information (learned, for example, through RIP) into this area.
All routers in an NSSA must have their OSPF area defined as an NSSA. To configure otherwise will
ensure that the router will be unsuccessful in establishing an adjacent in the OSPF domain.
Totally Stubby Areas
In Totally Stubby Areas the ABR advertises a default route to the routers in the totally stubby area but
does not advertise any inter-area or external LSAs. As a result, routers in a totally stubby area know only
the routes for destination networks in the stub area and have a default route for any other destination
outside the stub.
Note. Virtual links cannot be configured through totally stubby areas.
The router memory is saved when using stub area networks by filtering Type 4 and 5 LSAs. This concept
has been extended with Totally Stubby Areas by filtering Type 3 LSAs (Network Summary LSA) in addition to Type 4 and 5 with the exception of one single Type 3 LSA used to advertise a default route within
the area.
The following is an example of a simple totally stubby configuration with Router B being an ABR
between the backbone area 0 and the stub area 1. Router A is in area 1.1.1.1, totally stubby area:
OSPF Area 0
192.168.50.0/24
192.168.12.1
OSPF Area 1
Totally Stubby
192.168.12.2
Router A
Router B
Totally Stubby Area Example
Note. See “Configuring a Totally Stubby Area” on page 1-19 for information on configuring Totally
Stubby Areas.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 1-11
OSPF Overview
Configuring OSPF
Equal Cost Multi-Path (ECMP) Routing
Using information from its continuously updated databases, OSPF calculates the shortest path to a given
destination. Shortest path is determined from metric values at each hop along a path. At times, two or more
paths to the same destination will have the same metric cost.
In the network illustration below, there are two paths from Source router A to Destination router B. One
path traverses two hops at routers X and Y and the second path traverses two hops at M and N. If the total
cost through X and Y to B is the same as the cost via M and N to B, then these two paths have equal cost.
In this version of OSPF both paths will be stored and used to transmit data.
X
Y
A-> X-> Y-> B = A-> M-> N-> B
Source (A)
Destination (B)
M
N
Multiple Equal Cost Paths
Delivery of packets along equal paths is based on flows rather than a round-robin scheme. Equal cost is
determined based on standard routing metrics. However, other variables, such as line speed, are not
considered. So it is possible for OSPF to decide two paths have an equal cost even though one may contain
faster links than another.
Non Broadcast OSPF Routing
OSPF can operate in two modes on non-broadcast networks: NBMA and point-to-multipoint. The interface type for the corresponding network segment should be set to non-broadcast or point-to-multipoint,
respectively.
For non-broadcast networks neighbors should be statically configured. For NBMA neighbors the eligibility option must be enabled for the neighboring router to participate in Designated Router (DR) election.
For the correct working of an OSPF NBMA network, a fully meshed network is mandatory. Also, the
neighbor eligibility configuration for a router on every other router should match the routers interface
priority configuration.
See “Configuring Static Neighbors” on page 1-31 for more information and setting up static neighbors.
page 1-12
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring OSPF
OSPF Overview
Graceful Restart on Stacks with Redundant Switches
OmniSwitch 6800 and OmniSwitch 6850 stacks with two or more switches can support redundancy where
if the primary switch fails or goes offline for any reason, the secondary switch is instantly notified. The
secondary switch automatically assumes the primary role. This switch between the primary and secondary
switches is known as takeover.
When a takeover occurs, which can be planned (e.g., the users performs the takeover) or unplanned (e.g.,
the primary switch unexpectedly fails), an OSPF router must reestablish full adjacencies with all its previously fully adjacent neighbors. This time period between the restart and the reestablishment of adjacencies is termed graceful restart.
In the network illustration below, a helper router, Router Y, monitors the network for topology changes.
As long as there are none, it continues to advertise its LSAs as if the restarting router, Router X, had
remained in continuous OSPF operation (i.e., Router Y’s LSAs continue to list an adjacency to Router X
over network segment S, regardless of the adjacency’s current synchronization state).
Router B
Restarting Router X
Helping Router Y
Network Segment S
Router C
Router A
OSPF Graceful Restart Helping and Restarting Router Example
If the restarting router, Router X, was the Designated Router (DR) on network segment S when the helping relationship began, the helper neighbor, Router Y, maintains Router X as the DR until the helping relationship is terminated. If there are multiple adjacencies with the restarting Router X, Router Y will act as a
helper on all other adjacencies.
Continuous forwarding during a graceful restart depends on several factors. If the secondary module has a
different router MAC than the primary module, or if one or more ports of a VLAN belonged to the
primary module, spanning tree re-convergence might disrupt forwarding state, even though OSPF
performs a graceful restart.
Note. See “Configuring Redundant Switches in a Stack for Graceful Restart” on page 1-32 for more information on configuring graceful restart.
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OSPF Overview
Configuring OSPF
Graceful Restart on Switches with Redundant CMMs
OmniSwitch 9000 chassis with two Chassis management Modules (CMMs) can support redundancy where
if the primary CMM fails or goes offline for any reason, the secondary CMM is instantly notified. The
secondary CMM automatically assumes the primary role. This switch between the primary and secondary
CMMs is known as takeover.
When a takeover occurs, which can be planned (e.g., the users performs the takeover) or unplanned (e.g.,
the primary CMM unexpectedly fails), an OSPF router must reestablish full adjacencies with all its previously fully adjacent neighbors. This time period between the restart and the reestablishment of adjacencies is termed graceful restart.
In the network illustration below, a helper router, Router Y, monitors the network for topology changes.
As long as there are none, it continues to advertise its LSAs as if the restarting router, Router X, had
remained in continuous OSPF operation (i.e., Router Y’s LSAs continue to list an adjacency to Router X
over network segment S, regardless of the adjacency’s current synchronization state).
Router B
Restarting router X
Helping router Y
Network Segment S
Router A
Router C
OSPF Graceful Restart Helping and Restarting Router Example
If the restarting router, Router X, was the Designated Router (DR) on network segment S when the helping relationship began, the helper neighbor, Router Y, maintains Router X as the DR until the helping relationship is terminated. If there are multiple adjacencies with the restarting Router X, Router Y will act as a
helper on all other adjacencies.
Note. See “Configuring Redundant CMMs for Graceful Restart” on page 1-33 for more information on
configuring graceful restart.
page 1-14
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Configuring OSPF
Configuring OSPF
Configuring OSPF
Configuring OSPF on a router requires several steps. Depending on your requirements, you may not need
to perform all of the steps listed below.
By default, OSPF is disabled on the router. Configuring OSPF consists of these tasks:
• Set up the basics of the OSPF network by configuring the required VLANs, assigning ports to the
VLANs, and assigning router identification numbers to the routers involved. This is described in
“Preparing the Network for OSPF” on page 1-16.
• Enable OSPF. When the image file for advanced routing is installed, you must load the code and
enable OSPF. The commands for enabling OSPF are described in “Activating OSPF” on page 1-16.
• Create an OSPF area and the backbone. The commands to create areas and backbones are described in
“Creating an OSPF Area” on page 1-17.
• Set area parameters (optional). OSPF will run with the default area parameters, but different networks
may benefit from modifying the parameters. Modifying area parameters is described in “Configuring
Stub Area Default Metrics” on page 1-19.
• Create OSPF interfaces. OSPF interfaces are created and assigned to areas. Creating interfaces is
described in “Creating an Interface” on page 1-20, and assigning interfaces is described in “Assigning
an Interface to an Area” on page 1-20.
• Set interface parameters (optional). OSPF will run with the default interface parameters, but different
networks may benefit from modifying the parameters. Also, it is possible to set authentication on an
interface. Setting interface authentication is described in “Interface Authentication” on page 1-21, and
modifying interface parameters is described in “Modifying Interface Parameters” on page 1-22.
• Configure virtual links (optional). A virtual link is used to establish backbone connectivity when two
backbone routers are not physically contiguous. To create a virtual link, see “Creating Virtual Links”
on page 1-22.
• Create a redistribution policy and enable the same using route maps (optional). To create route maps,
see “Configuring Redistribution” on page 1-23.
• Configure router capabilities (optional). There are several commands that influence router operation.
These are covered briefly in a table in “Configuring Router Capabilities” on page 1-30.
• Create static neighbors (optional). These commands allow you to statically configure neighbors. See
“Configuring Static Neighbors” on page 1-31.
• Configure redundant switches for graceful OSPF restart (optional). Configuring switches with redun-
dant switches for graceful restart is described in “Configuring Redundant Switches in a Stack for
Graceful Restart” on page 1-32.
• Configure redundant CMMs for graceful OSPF restart (optional). Configuring switches with redun-
dant switches for graceful restart is described in “Configuring Redundant CMMs for Graceful Restart”
on page 1-33.
At the end of the chapter is a simple OSPF network diagram with instructions on how it was created on a
router-by-router basis. See “OSPF Application Example” on page 1-34 for more information.
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Configuring OSPF
Configuring OSPF
Preparing the Network for OSPF
OSPF operates on top of normal switch functions, using existing ports, virtual ports, VLANs, etc. The
following network components should already be configured:
• Configure VLANs that are to be used in the OSPF network. VLANS should be created for both the
backbone interfaces and all other connected devices that will participate in the OSPF network. A
VLAN should exist for each instance in which the backbone connects two routers. VLAN configuration is described in “Configuring VLANs,” in the OmniSwitch 6800/6850/9000 Network Configuration
Guide.
• Assign IP interfaces to the VLANs. IP interfaces, or router ports, must be assigned to the VLAN.
Assigning IP interfaces is described in “Configuring VLANs,” in the OmniSwitch 6800/6850/9000
Network Configuration Guide.
• Assign ports to the VLANs. The physical ports participating in the OSPF network must be assigned to
the created VLANs. Assigning ports to a VLAN is described in “Assigning Ports to VLANs,” in the
OmniSwitch 6800/6850/9000 Network Configuration Guide.
• Set the router identification number. (optional) The routers participating in the OSPF network must
be assigned a router identification number. This number can be any number, as long as it is in standard
dotted decimal format (e.g., 1.1.1.1). Router identification number assignment is discussed in “Configuring IP,” in the OmniSwitch 6800/6850/9000 Network Configuration Guide. If this is not done, the
router identification number is automatically the primary interface address.
Activating OSPF
For OSPF to run on the router, the advanced routing image must be installed. (For information on how to
install image files, see the OmniSwitch 6800/6850/9000 Switch Management Guide.)
After the image file has been installed onto the router, you will need to load the OSPF software into
memory and enable it, as described below.
Loading the Software
To load the OSPF software into the router’s running configuration, enter the ip load ospf command at the
system prompt:
-> ip load ospf
The OPSF software is now loaded into memory, and can be enabled.
Enabling OSPF
Once the OSPF software has been loaded into the router’s running configuration (either through the CLI or
on startup), it must be enabled. To enable OSPF on a router, enter the ip ospf status command at the CLI
prompt, as shown:
-> ip ospf status enable
Once OSPF is enabled, you can begin to set up OSPF parameters. To disable OSPF, enter the following:
-> ip ospf status disable
page 1-16
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Configuring OSPF
Configuring OSPF
Removing OSPF from Memory
To remove OSPF from the router memory, it is necessary to manually edit the boot.cfg file. The boot.cfg
file is an ASCII text-based file that controls many of the switch parameters. Open the file and delete all
references to OSPF.
For the operation to take effect the switch needs to be rebooted.
Creating an OSPF Area
OSPF allows a set of network devices in an AS system to be grouped together in areas.
There can be more than one router in an area. Likewise, there can be more than one area on a single router
(in effect, making the router the Area Border Router (ABR) for the areas involved), but standard networking design does not recommended that more than three areas be handled on a single router.
Areas are named using 32-bit dotted decimal format (e.g., 1.1.1.1). Area 0.0.0.0 is reserved for the backbone.
Creating an Area
To create an area and associate it with a router, enter the ip ospf area command with the area identification number at the CLI prompt, as shown:
-> ip ospf area 1.1.1.1
Area 1.1.1.1 will now be created on the router with the default parameters.
The backbone is always area 0.0.0.0. To create this area on a router, you would use the above command,
but specify the backbone, as shown:
-> ip ospf area 0.0.0.0
The backbone would now be attached to the router, making it an Area Border Router (ABR).
Specifying an Area Type
When creating areas, an area type can be specified (normal, stub, or NSSA). Area types are described
above in “OSPF Areas” on page 1-8. To specify an area type, use the ip ospf area command as shown:
-> ip ospf area 1.1.1.1 type stub
Note. By default, an area is a normal area. The type keyword would be used to change a stub or NSSA
area into a normal area.
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Configuring OSPF
Configuring OSPF
Enabling and Disabling Summarization
Summarization can also be enabled or disabled when creating an area. Enabling summarization allows for
ranges to be used by Area Border Routers (ABRs) for advertising routes as a single route rather than
multiple routes, while disabling summarization prevents set ranges from functioning in stub and NSSA
areas. (Configuring ranges is described in “Setting Area Ranges” on page 1-19.)
For example, to enable summarization for Area 1.1.1.1, enter the following:
-> ip ospf area 1.1.1.1 summary enable
To disable summarization for the same area, enter the following:
-> ip ospf area 1.1.1.1 summary disable
Note. By default, an area has summarization enabled. Disabling summarization for an area is useful when
ranges need to be deactivated, but not deleted.
Displaying Area Status
You can check the status of the newly created area by using the show command, as demonstrated:
-> show ip ospf area 1.1.1.1
or
-> show ip ospf area
The first example gives specifics about area 1.1.1.1, and the second example shows all areas configured on
the router.
To display a stub area’s parameters, use the show ip ospf area stub command as follows:
-> show ip ospf area 1.1.1.1 stub
Deleting an Area
To delete an area, enter the ip ospf area command as shown:
-> no ip ospf area 1.1.1.1
page 1-18
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Configuring OSPF
Configuring OSPF
Configuring Stub Area Default Metrics
The default metric configures the type of cost metric that a default area border router (ABR) will advertise in the default summary Link State Advertisement (LSA). Use the ip ospf area default-metric
command to create or delete a default metric for stub or Not So Stubby Area (NSSA) area. Specify the
stub area and select a cost value or a route type, as shown:
-> ip ospf area 1.1.1.1 default-metric 0 cost 50
or
-> ip ospf area 1.1.1.1 default-metric 0 type type1
A route has a preset metric associated to it depending on its type. The first example, the stub area is given
a default metric of 0 (this is Type of Service 0) and a cost of 50 added to routes from the area. The second
example specifies that the cost associated with Type 1 routes should be applied to routes from the area.
Note. At this time, only the default metric of ToS 0 is supported.
To remove the area default-metric setting, enter the ip ospf area default-metric command using the no
command, as shown:
-> no ip ospf area 1.1.1.1 default-metric 0
Setting Area Ranges
Area ranges are used to summarize many area routes into a single advertisement at an area boundary.
Ranges are advertised as summaries or NSSAs. Ranges also act as filters that either allow the summary to
be advertised or not. Ranges are created using the ip ospf area range command. An area and the summary
IP address and IP mask must be specified. For example, to create a summary range with IP address
192.5.40.1 and an IP mask of 255.255.255.0 for area 1.1.1.1, the following commands would be entered at
the CLI prompt:
-> ip ospf area 1.1.1.1 range summary 192.5.40.1 255.255.255.0
-> ip ospf area 1.1.1.1 range summary 192.5.40.1 255.255.255.0 effect noMatching
To view the configured ranges for an area, use the show ip ospf area range command as demonstrated:
-> show ip ospf area 1.1.1.1 range
Configuring a Totally Stubby Area
In order to configure a totally stubby area you need to configure the area as stub on the ABR and disable
summarization. By doing so the ABR will generate a default route in the totally stubby area. In addition,
the other routers within the totally stubby area must only have their area configured as stub.
For example, to configure the simple totally stubby configuration shown in the figure in “Configuring a
Totally Stubby Area” on page 1-19 where Router B is an ABR between the backbone area 0 and the stub
area 1 and Router A is in Totally Stubby Area 1.1.1.1 follow the steps below:
1 Enter the following commands on Router B:
->
->
->
->
ip
ip
ip
ip
load
ospf
ospf
ospf
ospf
area 0.0.0.0
area 1.1.1.1
area 1.1.1.1 type stub
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page 1-19
Configuring OSPF
->
->
->
->
->
->
->
->
->
ip
ip
ip
ip
ip
ip
ip
ip
ip
ospf
ospf
ospf
ospf
ospf
ospf
ospf
ospf
ospf
Configuring OSPF
area 1.1.1.1 summary disable
area 1.1.1.1 default-metric 0
interface vlan-5
interface vlan-5 area 1.1.1.1
interface vlan-5 status enable
interface vlan-6
interface vlan-6 area 0.0.0.0
interface vlan-6 status enable
status enable
2 Enter the following on Router A:
->
->
->
->
->
->
->
ip
ip
ip
ip
ip
ip
ip
load
ospf
ospf
ospf
ospf
ospf
ospf
ospf
area 1.1.1.1
area 1.1.1.1 type stub
interface vlan-3
interface vlan-3 area 1.1.1.1
interface vlan-3 status enable
status enable
Creating OSPF Interfaces
Once areas have been established, interfaces need to be created and assigned to the areas.
Creating an Interface
To create an interface, enter the ip ospf interface command with an interface name, as shown:
-> ip ospf interface vlan-213
Note. The interface name cannot have spaces.
The interface can be deleted the by using the no keyword, as shown:
-> no ip ospf interface vlan-213
Assigning an Interface to an Area
Once an interface is created, it must be assigned to an area. (Creating areas is described in “Creating an
Area” on page 1-17 above.)
To assign an interface to an area, enter the ip ospf interface area command with the interface name and
area identification number at the CLI prompt. For example to add interface vlan-213 to area 1.1.1.1, enter
the following:
-> ip ospf interface vlan-213 area 1.1.1.1
An interface can be removed from an area by reassigning it to a new area.
Once an interface has been created and enabled, you can check its status and configuration by using the
show ip ospf interface command, as demonstrated:
-> show ip ospf interface vlan-213
Instructions for configuring authentication are given in “Interface Authentication” on page 1-21, and interface parameter options are described in “Modifying Interface Parameters” on page 1-22.
page 1-20
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Configuring OSPF
Configuring OSPF
Activating an Interface
Once the interface is created and assigned to an area, it must be activated using the ip ospf interface
status command with the interface name, as shown:
-> ip ospf interface vlan-213 status enable
The interface can be disabled using the disable keyword in place of the enable keyword.
Interface Authentication
OSPF allows for the use of authentication on configured interfaces. When authentication is enabled, only
neighbors using the same type of authentication and the matching passwords or keys can communicate.
There are two types of authentication: simple and MD5. Simple authentication requires only a text string
as a password, while MD5 is a form of encrypted authentication that requires a key and a password. Both
types of authentication require the use of more than one command.
Simple Authentication
To enable simple authentication on an interface, enter the ip ospf interface auth-type command with the
interface name, as shown:
-> ip ospf interface vlan-213 auth-type simple
Once simple authentication is enabled, the password must be set with the ip ospf interface auth-key
command, as shown:
-> ip ospf interface vlan-213 auth-key test
In the above instance, only other interfaces with simple authentication and a password of “test” will be
able to use the configured interface.
MD5 Encryption
To configure the same interface for MD5 encryption, enter the ip ospf interface auth-type as shown:
-> ip ospf interface vlan-213 auth-type md5
Once MD5 authentication is set, a key identification and key string must be set with the ip ospf interface
md5 key command. For example to set interface 120.5.80.1 to use MD5 authentication with a key identification of 7 and key string of “test”, enter:
-> ip ospf interface vlan-213 md5 7
and
-> ip ospf interface vlan-213 md5 7 key "test"
Note that setting the key ID and key string must be done in two separate commands. Once the key ID and
key string have been set, MD5 authentication is enabled. To disable it, use the ip ospf interface md5
command, as shown:
-> ip ospf interface vlan-213 md5 7 disable
To remove all authentication, enter the ip ospf interface auth-type as follows:
-> ip ospf interface vlan-213 auth-type none
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page 1-21
Configuring OSPF
Configuring OSPF
Modifying Interface Parameters
There are several interface parameters that can be modified on a specified interface. Most of these deal
with timer settings.
The cost parameter and the priority parameter help to determine the cost of the route using this interface,
and the chance that this interface’s router will become the designated router, respectively.
The following table shows the various interface parameters that can be set:
ip ospf interface dead-interval
Configures OSPF interface dead interval. If no hello packets are
received in this interval from a neighboring router the neighbor is considered dead.
ip ospf interface hello-interval
Configures the OSPF interface interval for NBMA segments.
ip ospf interface cost
Configures the OSPF interface cost. A cost metric refers to the network path preference assigned to certain types of traffic.
ip ospf interface poll-interval
Configures the OSPF poll interval.
ip ospf interface priority
Configures the OSPF interface priority. The priority number helps
determine if this router will become the designated router.
ip ospf interface retrans-interval Configures OSPF interface retransmit interval. The number of seconds between link state advertisement retransmissions for adjacencies
belonging to this interface.
ip ospf interface transit-delay
Configures the OSPF interface transit delay. The estimated number of
seconds required to transmit a link state update over this interface.
These parameters can be added any time. (See “Creating OSPF Interfaces” on page 1-20 for more information.) For example, to set an the dead interval to 50 and the cost to 100 on interface vlan-213, enter the
following:
-> ip ospf interface vlan-213 dead-interval 50 cost 100
To set an the poll interval to 25, the priority to 100, and the retransmit interval to 10 on interface vlan-213,
enter the following:
-> ip ospf interface vlan-213 poll-interval 25 priority 100 retrans-interval 10
To set the hello interval to 5000 on interface vlan-213, enter the following:
-> ip ospf interface vlan-213 hello-interval 5000
To reset any parameter to its default value, enter the keyword with no parameter value, as shown:
-> ip ospf interface vlan-213 dead-interval
Note. Although you can configure several parameters at once, you can only reset them to the default one at
a time.
Creating Virtual Links
A virtual link is a link between two backbones through a transit area. Use the ip ospf virtual-link
command to create or delete a virtual link.
page 1-22
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Configuring OSPF
Configuring OSPF
Accepted network design theory states that virtual links are the option of last resort. For more information
on virtual links, see “Virtual Links” on page 1-9 and refer to the figure on page 1-9.
Creating a Virtual Link
To create a virtual link, commands must be submitted to the routers at both ends of the link. The router
being configured should point to the other end of the link, and both routers must have a common area.
When entering the ip ospf virtual-link command, it is necessary to enter the Router ID of the far end of
the link, and the area ID that both ends of the link share.
For example, a virtual link needs to be created between Router A (router ID 1.1.1.1) and Router B (router
ID 2.2.2.2). We must:
1 Establish a transit area between the two routers using the commands discussed in “Creating an OSPF
Area” on page 1-17 (in this example, we will use Area 0.0.0.1).
2 Then use the ip ospf virtual-link command on Router A as shown:
-> ip ospf virtual-link 0.0.0.1 2.2.2.2
3 Next, enter the following command on Router B:
-> ip ospf virtual-link 0.0.0.1 1.1.1.1
Now there is a virtual link across Area 0.0.0.1 linking Router A and Router B.
4 To display virtual links configured on a router, enter the following show command:
-> show ip ospf virtual-link
5 To delete a virtual link, enter the ip ospf virtual-link command with the area and far end router infor-
mation, as shown:
-> no ip ospf virtual-link 0.0.0.1 2.2.2.2
Modifying Virtual Link Parameters
There are several parameters for a virtual link (such as authentication type and cost) that can be modified
at the time of the link creation. They are described in the ip ospf virtual-link command description. These
parameters are identical in function to their counterparts in the section “Modifying Interface Parameters”
on page 1-22.
Configuring Redistribution
It is possible to learn and advertise IPv4 routes between different protocols. Such a process is referred to
as route redistribution and is configured using the ip redist command.
Redistribution uses route maps to control how external routes are learned and distributed. A route map
consists of one or more user-defined statements that can determine which routes are allowed or denied
access to the network. In addition a route map may also contain statements that modify route parameters
before they are redistributed.
When a route map is created, it is given a name to identify the group of statements that it represents. This
name is required by the ip redist command. Therefore, configuring route redistribution involves the
following steps:
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page 1-23
Configuring OSPF
Configuring OSPF
1 Create a route map, as described in “Using Route Maps” on page 1-24.
2 Configure redistribution to apply a route map, as described in “Configuring Route Map Redistribution” on page 1-28.
Note. An OSPF router automatically becomes an Autonomous System Border Router (ASBR) when redistribution is configured on the router.
Using Route Maps
A route map specifies the criteria that are used to control redistribution of routes between protocols. Such
criteria is defined by configuring route map statements. There are three different types of statements:
• Action. An action statement configures the route map name, sequence number, and whether or not
redistribution is permitted or denied based on route map criteria.
• Match. A match statement specifies criteria that a route must match. When a match occurs, then the
action statement is applied to the route.
• Set. A set statement is used to modify route information before the route is redistributed into the
receiving protocol. This statement is only applied if all the criteria of the route map is met and the
action permits redistribution.
The ip route-map command is used to configure route map statements and provides the following action,
match, and set parameters:
ip route-map action ...
ip route-map match ...
ip route-map set ...
permit
deny
ip-address
ip-nexthop
ipv6-address
ipv6-nexthop
tag
ipv4-interface
ipv6-interface
metric
route-type
metric
metric-type
tag
community
local-preference
level
ip-nexthop
ipv6-nexthop
Refer to the “IP Commands” chapter in the OmniSwitch CLI Reference Guide for more information about
the ip route-map command parameters and usage guidelines.
Once a route map is created, it is then applied using the ip redist command. See “Configuring Route Map
Redistribution” on page 1-28 for more information.
Creating a Route Map
When a route map is created, it is given a name (up to 20 characters), a sequence number, and an action
(permit or deny). Specifying a sequence number is optional. If a value is not configured, then the number
50 is used by default.
To create a route map, use the ip route-map command with the action parameter. For example,
-> ip route-map ospf-to-bgp sequence-number 10 action permit
The above command creates the ospf-to-bgp route map, assigns a sequence number of 10 to the route
map, and specifies a permit action.
page 1-24
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Configuring OSPF
Configuring OSPF
To optionally filter routes before redistribution, use the ip route-map command with a match parameter
to configure match criteria for incoming routes. For example,
-> ip route-map ospf-to-bgp sequence-number 10 match tag 8
The above command configures a match statement for the ospf-to-bgp route map to filter routes based on
their tag value. When this route map is applied, only OSPF routes with a tag value of eight are redistributed into the BGP network. All other routes with a different tag value are dropped.
Note. Configuring match statements is not required. However, if a route map does not contain any match
statements and the route map is applied using the ip redist command, the router redistributes all routes
into the network of the receiving protocol.
To modify route information before it is redistributed, use the ip route-map command with a set parameter. For example,
-> ip route-map ospf-to-bgp sequence-number 10 set tag 5
The above command configures a set statement for the ospf-to-bgp route map that changes the route tag
value to five. Because this statement is part of the ospf-to-bgp route map, it is only applied to routes that
have an existing tag value equal to eight.
The following is a summary of the commands used in the above examples:
-> ip route-map ospf-to-bgp sequence-number 10 action permit
-> ip route-map ospf-to-bgp sequence-number 10 match tag 8
-> ip route-map ospf-to-bgp sequence-number 10 set tag 5
To verify a route map configuration, use the show ip route-map command:
-> show ip route-map
Route Maps: configured: 1 max: 200
Route Map: ospf-to-bgp Sequence Number: 10 Action permit
match tag 8
set tag 5
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page 1-25
Configuring OSPF
Configuring OSPF
Deleting a Route Map
Use the no form of the ip route-map command to delete an entire route map, a route map sequence, or a
specific statement within a sequence.
To delete an entire route map, enter no ip route-map followed by the route map name. For example, the
following command deletes the entire route map named redistipv4:
-> no ip route-map redistipv4
To delete a specific sequence number within a route map, enter no ip route-map followed by the route
map name, then sequence-number followed by the actual number. For example, the following command
deletes sequence 10 from the redistipv4 route map:
-> no ip route-map redistipv4 sequence-number 10
Note that in the above example, the redistripv4 route map is not deleted. Only those statements associated
with sequence 10 are removed from the route map.
To delete a specific statement within a route map, enter no ip route-map followed by the route map name,
then sequence-number followed by the sequence number for the statement, then either match or set and
the match or set parameter and value. For example, the following command deletes only the match tag 8
statement from route map redistipv4 sequence 10:
-> no ip route-map redistipv4 sequence-number 10 match tag 8
Configuring Route Map Sequences
A route map may consist of one or more sequences of statements. The sequence number determines which
statements belong to which sequence and the order in which sequences for the same route map are
processed.
To add match and set statements to an existing route map sequence, specify the same route map name and
sequence number for each statement. For example, the following series of commands creates route map
rm_1 and configures match and set statements for the rm_1 sequence 10:
-> ip route-map rm_1 sequence-number 10 action permit
-> ip route-map rm_1 sequence-number 10 match tag 8
-> ip route-map rm_1 sequence-number 10 set metric 1
To configure a new sequence of statements for an existing route map, specify the same route map name
but use a different sequence number. For example, the following command creates a new sequence 20 for
the rm_1 route map:
-> ip route-map rm_1 sequence-number 20 action permit
-> ip route-map rm_1 sequence-number 20 match ipv4-interface to-finance
-> ip route-map rm_1 sequence-number 20 set metric 5
The resulting route map appears as follows:
-> show ip route-map rm_1
Route Map: rm_1 Sequence Number: 10 Action permit
match tag 8
set metric 1
Route Map: rm_1 Sequence Number: 20 Action permit
match ip6 interface to-finance
set metric 5
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Configuring OSPF
Configuring OSPF
Sequence 10 and sequence 20 are both linked to route map rm_1 and are processed in ascending order
according to their sequence number value. Note that there is an implied logical OR between sequences. As
a result, if there is no match for the tag value in sequence 10, then the match interface statement in
sequence 20 is processed. However, if a route matches the tag 8 value, then sequence 20 is not used. The
set statement for whichever sequence was matched is applied.
A route map sequence may contain multiple match statements. If these statements are of the same kind
(e.g., match tag 5, match tag 8, etc.) then a logical OR is implied between each like statement. If the match
statements specify different types of matches (e.g. match tag 5, match ip4 interface to-finance, etc.), then a
logical AND is implied between each statement. For example, the following route map sequence will
redistribute a route if its tag is either 8 or 5:
-> ip route-map rm_1 sequence-number 10 action permit
-> ip route-map rm_1 sequence-number 10 match tag 5
-> ip route-map rm_1 sequence-number 10 match tag 8
The following route map sequence will redistribute a route if the route has a tag of 8 or 5 and the route
was learned on the IPv4 interface to-finance:
->
->
->
->
ip
ip
ip
ip
route-map
route-map
route-map
route-map
rm_1
rm_1
rm_1
rm_1
sequence-number
sequence-number
sequence-number
sequence-number
10
10
10
10
action permit
match tag 5
match tag 8
match ipv4-interface to-finance
Configuring Access Lists
An IP access list provides a convenient way to add multiple IPv4 or IPv6 addresses to a route map. Using
an access list avoids having to enter a separate route map statement for each individual IP address. Instead,
a single statement is used that specifies the access list name. The route map is then applied to all the
addresses contained within the access list.
Configuring an IP access list involves two steps: creating the access list and adding IP addresses to the list.
To create an IP access list, use the ip access-list command (IPv4) or the ipv6 access-list command (IPv6)
and specify a name to associate with the list. For example,
-> ip access-list ipaddr
-> ipv6 access-list ip6addr
To add addresses to an access list, use the ip access-list address (IPv4) or the ipv6 access-list address
(IPv6) command. For example, the following commands add addresses to an existing access list:
-> ip access-list ipaddr address 16.24.2.1/16
-> ipv6 access-list ip6addr address 2001::1/64
Use the same access list name each time the above commands are used to add additional addresses to the
same access list. In addition, both commands provide the ability to configure if an address and/or its
matching subnet routes are permitted (the default) or denied redistribution. For example:
-> ip access-list ipaddr address 16.24.2.1/16 action deny redist-control allsubnets
-> ipv6 access-list ip6addr address 2001::1/64 action permit redist-control nosubnets
For more information about configuring access list commands, see the “IP Commands” chapter in the
OmniSwitch CLI Reference Guide.
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page 1-27
Configuring OSPF
Configuring OSPF
Configuring Route Map Redistribution
The ip redist command is used to configure the redistribution of routes from a source protocol into the
destination protocol. This command is used on the router that will perform the redistribution.
Note. An OSPF router automatically becomes an Autonomous System Border Router (ASBR) when redistribution is configured on the router.
A source protocol is a protocol from which the routes are learned. A destination protocol is the one into
which the routes are redistributed. Make sure that both protocols are loaded and enabled before configuring redistribution.
Redistribution applies criteria specified in a route map to routes received from the source protocol. Therefore, configuring redistribution requires an existing route map. For example, the following command
configures the redistribution of OSPF routes into the BGP network using the ospf-to-bgp route map:
-> ip redist ospf into bgp route-map ospf-to-bgp
OSPF routes received by the router interface are processed based on the contents of the ospf-to-bgp route
map. Routes that match criteria specified in this route map are either allowed or denied redistribution into
the BGP network. The route map may also specify the modification of route information before the route
is redistributed. See “Using Route Maps” on page 1-24 for more information.
To remove a route map redistribution configuration, use the no form of the ip redist command. For example:
-> no ip ospf into bgp route-map ospf-to-bgp
Use the show ip redist command to verify the redistribution configuration:
-> show ip redist
Source
Destination
Protocol
Protocol
Status
Route Map
------------+------------+---------+-------------------LOCAL4
RIP
Enabled
rip_1
LOCAL4
OSPF
Enabled
ospf_2
LOCAL4
BGP
Enabled
bgp_3
BGP
OSPF
Enabled
ospf-to-bgp
Configuring the Administrative Status of the Route Map Redistribution
The administrative status of a route map redistribution configuration is enabled by default. To change the
administrative status, use the status parameter with the ip redist command. For example, the following
command disables the redistribution administrative status for the specified route map:
-> ip redist ospf into bgp route-map ospf-to-bgp status disable
The following command example enables the administrative status:
-> ip redist ospf into bgp route-map ospf-to-bgp status enable
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Configuring OSPF
Configuring OSPF
Route Map Redistribution Example
The following example configures the redistribution of OSPF routes into a BGP network using a route
map (ospf-to-bgp) to filter specific routes:
-> ip route-map ospf-to-bgp sequence-number 10 action deny
-> ip route-map ospf-to-bgp sequence-number 10 match tag 5
-> ip route-map ospf-to-bgp sequence-number 10 match route-type external type2
-> ip route-map ospf-to-bgp sequence-number 20 action permit
-> ip route-map ospf-to-bgp sequence-number 20 match ipv4-interface intf_ospf
-> ip route-map ospf-to-bgp sequence-number 20 set metric 255
-> ip route-map ospf-to-bgp sequence-number 30 action permit
-> ip route-map ospf-to-bgp sequence-number 30 set tag 8
-> ip redist ospf into bgp route-map ospf-to-bgp
The resulting ospf-to-bgp route map redistribution configuration does the following:
• Denies the redistribution of Type 2 external OSPF routes with a tag set to five.
• Redistributes into BGP all routes learned on the intf_ospf interface and sets the metric for such routes
to 255.
• Redistributes into BGP all other routes (those not processed by sequence 10 or 20) and sets the tag for
such routes to eight.
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page 1-29
Configuring OSPF
Configuring OSPF
Configuring Router Capabilities
The following list shows various commands that can be useful in tailoring a router’s performance capabilities. All of the listed parameters have defaults that are acceptable for running an OSPF network.
ip ospf exit-overflow-interval
Sets the overflow interval value. The overflow interval is the time
whereby the router will wait before attempting to leave the database
overflow state.
ip ospf extlsdb-limit
Sets a limit to the number of external Link State Databases entries
learned by the router. An external LSDB entry is created when the
router learns a link address that exists outside of its Autonomous System
(AS).
ip ospf host
Creates and deletes an OSPF entry for directly attached hosts.
ip ospf mtu-checking
Enables or disables the use of Maximum Transfer Unit (MTU) checking
on received OSPF database description packets.
ip ospf default-originate
Configures a default external route into the OSPF routing domain.
ip ospf route-tag
Configures a tag value for OSPF routes injected into the IP routing table
that can be used for redistribution.
ip ospf spf-timer
Configures timers for Shortest Path First (SPF) calculation.
To configure a router parameter, enter the parameter at the CLI prompt with the new value or required
variables. For example to set the exit overflow interval to 40, enter:
-> ip ospf exit-overflow-interval 40
To enable MTU checking, enter:
-> ip ospf mtu-checking
To advertise a default external route into OSPF regardless of whether the routing table has a default route,
enter:
-> ip ospf default-originate always
To set the route tag to 5, enter:
-> ip ospf route-tag 5
To set the SPF timer delay to 3 and the hold time to 6, enter:
-> ip ospf spf-timer delay 3 hold 6
To return a parameter to its default setting, enter the command with no parameter value, as shown:
-> ip ospf spf-timer
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Configuring OSPF
Configuring OSPF
Configuring Static Neighbors
It is possible to configure neighbors statically on Non Broadcast Multi Access (NBMA), point-to-point,
and point-to-multipoint networks.
NBMA requires all routers attached to the network to communicate directly (unicast), and every attached
router in this network becomes aware of all of its neighbors through configuration. It also requires a
Designated Router (DR) “eligibility” flag to be set for every neighbor.
To set up a router to use NBMA routing, follow the following steps:
1 Create an OSPF interface using the CLI command ip ospf interface and perform all the normal config-
uration for the interface as with broadcast networks (attaching it to an area, enabling the status, etc.).
2 The OSPF interface type for this interface should be set to non-broadcast using the CLI
ip ospf interface type command. For example, to set interface vlan-213 to be an NBMA interface, enter
the following:
-> ip ospf interface vlan-213 type non-broadcast
3 Configure static neighbors for every OSPF router in the network using the ip ospf neighbor command.
For example, to create an OSPF neighbor with an IP address of 1.1.1.8 to be a static neighbor, enter the
following:
-> ip ospf neighbor 1.1.1.8 eligible
The neighbor attaches itself to the right interface by matching the network address of the neighbor and the
interface. If the interface has not yet been created, the neighbor gets attached to the interface as and when
the interface comes up.
If this neighbor is not required to participate in DR election, configure it as ineligible. The eligibility can
be changed at any time as long as the interface it is attached to is in the disabled state.
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page 1-31
Configuring OSPF
Configuring OSPF
Configuring Redundant Switches in a Stack for Graceful Restart
By default, OSPF graceful restart is disabled. To enable OSPF graceful restart support on OmniSwitch
6800 and OmniSwitch 6850 switches, use the ip ospf restart-support command by entering ip ospf
restart-support followed by planned-unplanned.
For example, to enable OSPF graceful restart to support planned and unplanned restarts enter:
-> ip ospf restart-support planned-unplanned
To disable OSPF graceful restart, use the no form of the ip ospf restart-support command by entering:
-> no ip ospf restart-support
On OmniSwitch 6800 and OmniSwitch 6850 switches only, continuous forwarding during a graceful
restart depends on several factors. If the secondary module has a different router MAC than the primary
module or if one or more ports of a VLAN belonged to the primary module, Spanning Tree re-convergence might disrupt the forwarding state, even though OSPF performs a graceful restart.
Note. Graceful restart is only supported on active ports (i.e., interfaces), which are on the secondary or idle
switches in a stack during a takeover. It is not supported on ports on a primary switch in a stack.
Optionally, you can configure graceful restart parameters with the following CLI commands:
ip ospf restart-interval
Configures the grace period for achieving a graceful OSPF restart.
ip ospf restart-helper status
Administratively enables and disables the capability of an OSPF router
to operate in helper mode in response to a router performing a graceful
restart.
ip ospf restart-helper strict-lsa- Administratively enables and disables whether or not a changed Link
checking status
State Advertisement (LSA) will result in termination of graceful restart
by a helping router.
ip ospf restart initiate
Initiates a planned graceful restart.
For more information about graceful restart commands, see the “OSPF Commands” chapter in the
OmniSwitch CLI Reference Guide.
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Configuring OSPF
Configuring OSPF
Configuring Redundant CMMs for Graceful Restart
By default, OSPF graceful restart is disabled. To enable OSPF graceful restart on OmniSwitch 9000
switches, use the ip ospf restart-support command by entering ip ospf restart-support followed by
planned-unplanned.
For example, to enable OSPF graceful restart to support planned and unplanned restarts enter:
-> ip ospf restart-support planned-unplanned
To disable OSPF graceful restart use the no form of the ip ospf restart-support command by entering:
-> no ip ospf restart-support
Optionally, you can configure graceful restart parameters with the following CLI commands:
ip ospf restart-interval
Configures the grace period for achieving a graceful OSPF restart.
ip ospf restart-helper status
Administratively enables and disables the capability of an OSPF router
to operate in helper mode in response to a router performing a graceful
restart.
ip ospf restart-helper strict-lsa- Administratively enables and disables whether or not a changed Link
checking status
State Advertisement (LSA) will result in termination of graceful restart
by a helping router.
ip ospf restart initiate
Initiates a planned graceful restart.
For more information about graceful restart commands, see the “OSPF Commands” chapter in the
OmniSwitch CLI Reference Guide.
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page 1-33
OSPF Application Example
Configuring OSPF
OSPF Application Example
This section will demonstrate how to set up a simple OSPF network. It uses three routers, each with an
area. Each router uses three VLANs. A backbone connects all the routers. This section will demonstrate
how to set it up by explaining the necessary commands for each router.
The following diagram is a simple OSPF network. It will be created by the steps listed on the following
pages:
VLAN 10
Interface 10.0.0.1
Area 0.0.0.1
Router 1
Router ID 1.1.1.1
VLAN 31
Interface 31.x.x.x
VLAN 12
Interface 12.x.x.x
Backbone Area
(Area 0.0.0.0)
VLAN 23
Interface 23.x.x.x
Area 0.0.0.2
Router 2
Router ID 20.0.0.1
Area 0.0.0.3
Router 3
Router ID 3.3.3.3
VLAN 20
Interface 20.0.0.1
VLAN 30
Interface 30.0.0.1
Three Area OSPF Network
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Configuring OSPF
OSPF Application Example
Step 1: Prepare the Routers
The first step is to create the VLANs on each router, add an IP interface to the VLAN, assign a port to the
VLAN, and assign a router identification number to the routers. For the backbone, the network design in
this case uses slot 2, port 1 as the egress port and slot 2, port 2 as ingress port on each router. Router 1
connects to Router 2, Router 2 connects to Router 3, and Router 3 connects to Router 1 using 10/100
Ethernet cables.
Note. The ports will be statically assigned to the router, as a VLAN must have a physical port assigned to
it in order for the router port to function. However, the router could be set up in such a way that mobile
ports are dynamically assigned to VLANs using VLAN rules. See the chapter titled “Defining VLAN
Rules” in the OmniSwitch 6800/6850/9000 Network Configuration Guide.
The commands setting up VLANs are shown below:
Router 1 (using ports 2/1 and 2/2 for the backbone, and ports 2/3-5 for end devices):
-> vlan 31
-> ip interface vlan-31 vlan 31 address 31.0.0.1 mask 255.0.0.0
-> vlan 31 port default 2/1
-> vlan 12
-> ip interface vlan-12 vlan 12 address 12.0.0.1 mask 255.0.0.0
-> vlan 12 port default 2/2
-> vlan 10
-> ip interface vlan-10 vlan 10 address 10.0.0.1 mask 255.0.0.0
-> vlan 10 port default 2/3-5
-> ip router router-id 1.1.1.1
These commands created VLANs 31, 12, and 10.
• VLAN 31 handles the backbone connection from Router 1 to Router 3, using the IP router port
31.0.0.1 and physical port 2/1.
• VLAN 12 handles the backbone connection from Router 1 to Router 2, using the IP router port
12.0.0.1 and physical port 2/2.
• VLAN 10 handles the device connections to Router 1, using the IP router port 10.0.0.1 and physical
ports 2/3-5. More ports could be added at a later time if necessary.
The router was assigned the Router ID of 1.1.1.1.
Router 2 (using ports 2/1 and 2/2 for the backbone, and ports 2/3-5 for end devices):
-> vlan 12
-> ip interface vlan-12 vlan 12 address 12.0.0.2 mask 255.0.0.0
-> vlan 12 port default 2/1
-> vlan 23
-> ip interface vlan-23 vlan 23 address 23.0.0.2 mask 255.0.0.0
-> vlan 23 port default 2/2
-> vlan 20
-> ip interface vlan-20 vlan 20 address 20.0.0.2 mask 255.0.0.0
-> vlan 20 port default 2/3-5
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page 1-35
OSPF Application Example
Configuring OSPF
-> ip router router-id 2.2.2.2
These commands created VLANs 12, 23, and 20.
• VLAN 12 handles the backbone connection from Router 1 to Router 2, using the IP router port 12.0.0.2
and physical port 2/1.
• VLAN 23 handles the backbone connection from Router 2 to Router 3, using the IP router port 23.0.0.2
and physical port 2/2.
• VLAN 20 handles the device connections to Router 2, using the IP router port 20.0.0.2 and physical
ports 2/3-5. More ports could be added at a later time if necessary.
The router was assigned the Router ID of 2.2.2.2.
Router 3 (using ports 2/1 and 2/2 for the backbone, and ports 2/3-5 for end devices):
-> vlan 23
-> ip interface vlan-23 vlan 23 address 23.0.0.3 mask 255.0.0.0
-> vlan 23 port default 2/1
-> vlan 31
-> ip interface vlan-31 vlan 31 address 31.0.0.3 mask 255.0.0.0
-> vlan 31 port default 2/2
-> vlan 30
-> ip interface vlan-30 vlan 30 address 30.0.0.3 mask 255.0.0.0
-> vlan 30 port default 2/3-5
-> ip router router-id 3.3.3.3
These commands created VLANs 23, 31, and 30.
• VLAN 23 handles the backbone connection from Router 2 to Router 3, using the IP router port 23.0.0.3
and physical port 2/1.
• VLAN 31 handles the backbone connection from Router 3 to Router 1, using the IP router port 31.0.0.3
and physical port 2/2.
• VLAN 30 handles the device connections to Router 3, using the IP router port 30.0.0.3 and physical
ports 2/3-5. More ports could be added at a later time if necessary.
The router was assigned the Router ID of 3.3.3.3.
Step 2: Enable OSPF
The next step is to load and enable OSPF on each router. The commands for this step are below (the
commands are the same on each router):
-> ip load ospf
-> ip ospf status enable
Step 3: Create the Areas and Backbone
Now the areas should be created. In this case, we will create an area for each router, and a backbone (area
0.0.0.0) that connects the areas.
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Configuring OSPF
OSPF Application Example
The commands for this step are below:
Router 1
-> ip ospf area 0.0.0.0
-> ip ospf area 0.0.0.1
These commands created area 0.0.0.0 (the backbone) and area 0.0.0.1 (the area
for Router 1). Both of these areas are also enabled.
Router 2
-> ip ospf area 0.0.0.0
-> ip ospf area 0.0.0.2
These commands created Area 0.0.0.0 (the backbone) and Area 0.0.0.2 (the area
for Router 2). Both of these areas are also enabled.
Router 3
-> ip ospf area 0.0.0.0
-> ip ospf area 0.0.0.3
These commands created Area 0.0.0.0 (the backbone) and Area 0.0.0.3 (the area
for Router 3). Both of these areas are also enabled.
Step 4: Create, Enable, and Assign Interfaces
Next, OSPF interfaces must be created, enabled, and assigned to the areas. The OSPF interfaces should
have the same interface name as the IP router ports created above in “Step 1: Prepare the Routers” on
page 1-35.
Router 1
-> ip ospf interface vlan-31
-> ip ospf interface vlan-31 area 0.0.0.0
-> ip ospf interface vlan-31 status enable
-> ip ospf interface vlan-12
-> ip ospf interface vlan-12 area 0.0.0.0
-> ip ospf interface vlan-12 status enable
-> ip ospf interface
-> ip ospf interface
-> ip ospf interface
vlan-10
vlan-10 area 0.0.0.1
vlan-10 status enable
IP router port 31.0.0.1 was associated to OSPF interface vlan-31, enabled, and assigned to the backbone.
IP router port 12.0.0.1 was associated to OSPF interface vlan-12, enabled, and assigned to the backbone.
IP router port 10.0.0.1 which connects to end stations and attached network devices, was associated to
OSPF interface vlan-10, enabled, and assigned to Area 0.0.0.1.
Router 2
-> ip ospf interface vlan-12
-> ip ospf interface vlan-12 area 0.0.0.0
-> ip ospf interface vlan-12 status enable
-> ip ospf interface vlan-23
-> ip ospf interface vlan-23 area 0.0.0.0
-> ip ospf interface vlan-23 status enable
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
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page 1-37
OSPF Application Example
Configuring OSPF
-> ip ospf interface vlan-20
-> ip ospf interface vlan-20 area 0.0.0.2
-> ip ospf interface vlan-20 status enable
IP router port 12.0.0.2 was associated to OSPF interface vlan-12, enabled, and assigned to the backbone.
IP router port 23.0.0.2 was associated to OSPF interface vlan-23, enabled, and assigned to the backbone.
IP router port 20.0.0.2, which connects to end stations and attached network devices, was associated to
OSPF interface vlan-20, enabled, and assigned to Area 0.0.0.2.
Router 3
-> ip ospf interface vlan-23
-> ip ospf interface vlan-23 area 0.0.0.0
-> ip ospf interface vlan-23 status enable
-> ip ospf interface vlan-31
-> ip ospf interface vlan-31 area 0.0.0.0
-> ip ospf interface vlan-31 status enable
-> ip ospf interface vlan-30
-> ip ospf interface vlan-30 area 0.0.0.3
-> ip ospf interface vlan-30 status enable
IP router port 23.0.0.3 was associated to OSPF interface vlan-23, enabled, and assigned to the backbone.
IP router port 31.0.0.3 was associated to OSPF interface vlan-31, enabled, and assigned to the backbone.
IP router port 30.0.0.3, which connects to end stations and attached network devices, was associated to
OSPF interface vlan-30, enabled, and assigned to Area 0.0.0.3.
Step 5: Examine the Network
After the network has been created, you can check various aspects of it using show commands:
• For OSPF in general, use the show ip ospf command.
• For areas, use the show ip ospf area command.
• For interfaces, use the show ip ospf interface command.
• To check for adjacencies formed with neighbors, use the show ip ospf neighbor command.
• For routes, use the show ip ospf routes command.
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Configuring OSPF
Verifying OSPF Configuration
Verifying OSPF Configuration
To display information about areas, interfaces, virtual links, redistribution, or OPSF in general, use the
show commands listed in the following table:
show ip ospf
Displays OSPF status and general configuration parameters.
show ip ospf border-routers
Displays information regarding all or specified border routers.
show ip ospf ext-lsdb
Displays external Link State Advertisements from the areas to which the
router is attached.
show ip ospf host
Displays information on directly attached hosts.
show ip ospf lsdb
Displays LSAs in the Link State Database associated with each area.
show ip ospf neighbor
Displays information on OSPF non-virtual neighbor routers.
show ip redist
Displays the route map redistribution configuration.
show ip ospf routes
Displays OSPF routes known to the router.
show ip ospf virtual-link
Displays virtual link information.
show ip ospf virtual-neighbor
Displays OSPF virtual neighbors.
show ip ospf area
Displays either all OSPF areas, or a specified OSPF area.
show ip ospf area range
Displays all or specified configured area address range summaries for
the given area.
show ip ospf area stub
Displays stub area status.
show ip ospf interface
Displays OSPF interface information.
show ip ospf restart
Displays the OSPF graceful restart related configuration and status.
For more information about the resulting displays form these commands, see the “OSPF Commands”
chapter in the OmniSwitch CLI Reference Guide.
Examples of the show ip ospf, show ip ospf area, and show ip ospf interface command outputs are given
in the section “OSPF Quick Steps” on page 1-4.
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Verifying OSPF Configuration
page 1-40
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
Configuring OSPF
December 2007
2
Configuring OSPFv3
Open Shortest Path First version 3 (OSPFv3) is an extension of OSPF version 2 that provides support for
networks using the IPv6 protocol. OSPFv2 is for IPv4 networks (see Chapter 1, “Configuring OSPF,” for
more information about OSPFv2).
In This Chapter
This chapter describes the basic components of OSPFv3 and how to configure them through the Command
Line Interface (CLI). CLI commands are used in the configuration examples; for more details about the
syntax of commands, see the OmniSwitch CLI Reference Guide.
Configuration procedures described in this chapter include:
• Loading and enabling OSPFv3. See “Activating OSPFv3” on page 2-14.
• Creating OSPFv3 areas. See “Creating an OSPFv3 Area” on page 2-15.
• Creating OSPFv3 interfaces. See “Creating OSPFv3 Interfaces” on page 2-16.
• Creating virtual links. See “Creating Virtual Links” on page 2-17.
• Configuring redistribution using route map. See “Configuring Redistribution” on page 2-18.
For information on creating and managing VLANs, see “Configuring VLANs” in the OmniSwitch 6800/
6850/9000 Network Configuration Guide.
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December 2007
page 2-1
OSPFv3 Specifications
Configuring OSPFv3
OSPFv3 Specifications
RFCs Supported
RFC 1826—IP Authentication Header
RFC 1827—IP Encapsulating Security Payload
RFC 2553—Basic Socket Interface Extensions for
IPv6
RFC 2373—IPv6 Addressing Architecture
RFC 2374—An IPv6 Aggregatable Global Unicast
Address Format
RFC 2460—IPv6 base specification
RFC 2470—OSPF for IPv6
draft-ietf-ospf-ospfv3-update-11—OSPF for IPv6
draft-ietf-ospf-ospfv3-mib-09—MIB for OSPFv3
Maximum number of Areas (per router)
5
Maximum number of Interfaces (per router) 20
Maximum number of Link State Database
entries (per router)
5K
Maximum number of adjacencies (per
router)
20
Maximum number of ECMP gateways (per
destination)
4
Maximum number of neighbors (per router) 16
Maximum number of routes (per router)
page 2-2
Up to 50000 (Depending on the number of interfaces/neighbors, this value may vary.)
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Configuring OSPFv3
OSPFv3 Defaults Table
OSPFv3 Defaults Table
The following table shows the default settings of the configurable OSPFv3 parameters.
Parameter Description
Command
Default Value/Comments
Configures the OSPFv3 administra- ipv6 ospf status
tive status.
enabled
Configures the administrative status ipv6 ospf interface status
for an OSPF interface.
enabled
Enables OSPFv3 redistribution.
ipv6 redist
disabled
Configures timers for Shortest Path
First (SPF) calculation.
ipv6 ospf spf-timer
delay: 5
hold: 10
Creates or deletes an area default
metric.
ipv6 ospf area
0
Configures OSPFv3 interface dead
interval.
ipv6 ospf interface dead-interval 40 seconds
Configures OSPFv3 interface hello
interval.
ipv6 ospf interface hello-interval 10 seconds
Configures the OSPFv3 interface
cost.
ipv6 ospf interface cost
1
Configures the OSPFv3 interface
priority.
ipv6 ospf interface priority
1
Configures OSPFv3 interface
retransmit interval.
ipv6 ospf interface retrans-inter- 5 seconds
val
Configures the OSPFv3 interface
transit delay.
ipv6 ospf interface transit-delay 1 second
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
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page 2-3
OSPFv3 Quick Steps
Configuring OSPFv3
OSPFv3 Quick Steps
The followings steps are designed to show the user the necessary set of commands for setting up a router
to use OSPFv3:
1 Create a VLAN using the vlan command. For example:
-> vlan 5
-> vlan 5 enable
2 Create an IPv6 interface on the vlan using the ipv6 interface command. For example:
-> ipv6 interface test vlan 1
3 Configure an IPv6 address on the vlan using the ipv6 address command. For example:
-> ipv6 address 2001::/64 eui-64 test
4 Assign a port to the VLAN created in Step 1 using the vlan port default command. For example:
-> vlan 1 port default 2/1
Note. The port will be statically assigned to the VLAN, as a VLAN must have a physical port assigned to
it in order for the router port to function. However, the router could be set up in such a way that mobile
ports are dynamically assigned to VLANs using VLAN rules. See the chapter titled “Defining VLAN
Rules” in the OmniSwitch 6800/6850/9000 Network Configuration Guide.
5 Assign a router ID to the router using the ip router router-id command. For example:
-> ip router router-id 5.5.5.5
6 Load OSPFv3 using the ipv6 load ospf command. For example:
-> ipv6 load ospf
7 Create a backbone to connect this router to others, and an area for the router’s traffic using the
ipv6 ospf area command. (Backbones are always labeled area 0.0.0.0.) For example:
-> ipv6 ospf area 0.0.0.0
-> ipv6 ospf area 0.0.0.1
8 Create an OSPFv3 interface for the VLAN created in Step 1 and assign the interface to an area identi-
fier using the ipv6 ospf interface area command. The OSPFv3 interface should use the same interface
name used for the VLAN router IP created in Step 2. For example:
-> ipv6 ospf interface test area 0.0.0.0
Note. The interface name cannot have spaces.
page 2-4
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Configuring OSPFv3
OSPFv3 Quick Steps
9 You can now display the router OSPFv3 settings by using the show ipv6 ospf command. The output
generated is similar to the following:
-> show ipv6 ospf
Status
Router ID
# Areas
# Interfaces
Area Border Router
AS Border Router
External Route Tag
SPF Hold (seconds)
SPF Delay (seconds)
MTU checking
# SPF calculations performed
Last SPF run (seconds ago)
# of neighbors that are in:
Full state
Loading state
Exchange state
Exstart state
2way state
Init state
Attempt state
Down state
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
Router ID
As set in Step 5
Enabled,
5.5.5.5,
2,
4,
Yes,
No,
0,
10,
5,
Enabled,
3,
N/A,
3,
0,
0,
0,
0,
0,
0,
0
10 You can display OSPFv3 area settings using the show ipv6 ospf area command. For example:
-> show ipv6 ospf area
Stub
Number of
Area ID
Type
Metric Interfaces
---------------+-------+------+-----------------------0.0.0.0
Normal NA
2
0.0.0.1
Normal NA
2
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Area ID
As set in Step 6
page 2-5
OSPFv3 Quick Steps
Configuring OSPFv3
11 You can display OSPFv3 interface settings using the show ipv6 ospf interface command.
For example:
-> show ipv6 ospf interface test
Name
Type
Admin Status
IPv6 Interface Status
Oper Status
State
Area
Priority
Cost
Designated Router
Backup Designated Router
Hello Interval
Router Dead Interval
Retransmit Interval
Transit Delay
Ifindex
IPv6 'ifindex'
MTU
# of attached neighbors
Globally reachable prefix #0
page 2-6
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
test
BROADCAST,
Enabled,
Up,
Up,
DR,
0.0.0.0,
100,
1,
3.3.3.3,
0.0.0.0,
1,
4,
5,
1,
17,
2071,
1500,
0,
2071::2/64
Area ID
As set in Step 6
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Configuring OSPFv3
OSPFv3 Quick Steps
12 You can view the contents of the Link-State Database (LDSB) using the show ipv6 ospf lsdb
command. This command displays the topology information that is provided to/from neighbors.
For example:
-> show ipv6 ospf lsdb
Area
Type
Link ID
Advertising Rtr Sequence # Age
----------------+----------+------------+-----------------+----------+--------0.0.0.0
Router
0
172.28.4.28
8000003b
203
0.0.0.0
Router
0
172.28.4.29
80000038
35
0.0.0.0
Network
9
172.28.4.28
80000064
36
0.0.0.0
Intra AP
16393
172.28.4.28
80000063
36
0.0.0.0
Inter AP
1
172.28.4.29
80000032
100
0.0.0.0
Inter AP
2
172.28.4.28
80000032
67
0.0.0.0
Inter AP
2
172.28.4.29
80000032
100
0.0.0.0
Inter AP
3
172.28.4.28
80000032
67
0.0.0.0
Inter AP
3
172.28.4.29
80000033
100
0.0.0.0
Inter AP
4
172.28.4.29
80000032
73
0.0.0.0
Link
6
172.28.4.28
80000032
67
0.0.0.0
Link
7
172.28.4.29
80000033
37
0.0.0.0
Link
9
172.28.4.28
80000033
75
0.0.0.3
Router
0
172.28.4.28
80000037
56
0.0.0.3
Router
0
172.28.4.29
80000038
58
0.0.0.3
Network
5
172.28.4.29
80000062
122
0.0.0.3
Intra AP
1
172.28.4.28
80000032
121
0.0.0.3
Intra AP
1
172.28.4.29
80000032
145
0.0.0.3
Intra AP
16389
172.28.4.29
80000062
122
0.0.0.3
Inter AP
1
172.28.4.29
80000032
100
0.0.0.3
Inter AP
3
172.28.4.29
80000032
100
0.0.0.3
Inter AP
5
172.28.4.28
80000033
30
0.0.0.3
Inter AP
6
172.28.4.28
80000032
29
0.0.0.3
Inter AP
6
172.28.4.29
80000032
22
0.0.0.3
Inter AP
7
172.28.4.28
80000032
29
0.0.0.3
Inter AP
7
172.28.4.29
80000032
22
0.0.0.3
Link
5
172.28.4.29
80000033
145
0.0.0.3
Link
6
172.28.4.28
80000033
121
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page 2-7
OSPFv3 Overview
Configuring OSPFv3
OSPFv3 Overview
Open Shortest Path First version 3 (OSPFv3) routing is a shortest path first (SPF), or link-state, protocol
for IPv6 networks. OSPFv3 is an interior gateway protocol (IGP) that distributes routing information
between routers in a Single Autonomous System (AS). OSPFv3 chooses the least-cost path as the best
path.
Each participating router distributes its local state (i.e., the router’s usable interfaces, local networks, and
reachable neighbors) throughout the AS by flooding Link-State Advertisements (LSAs). Each router maintains a link-state database (LSDB) describing the entire topology. The LSDB is built from the collected
LSAs of all routers within the AS. Each multi-access network that has at least two attached routers has a
designated router and a backup designated router. The designated router floods an LSA for the multiaccess network.
When a router starts, it uses the OSPFv3 Hello Protocol to discover neighbors and elect a designated
router for the network. Neighbors are dynamically detected by sending Hello packets to a multicast
address. The router sends Hello packets to its neighbors and in turn receives their Hello packets.
Hello. Please respond...
Hello. Please respond...
Are you a neighbor...
Are you a neighbor...
My link state is...
My link state is...
OSPFv3 Hello Protocol
The router will attempt to form full adjacencies with all of its newly acquired neighbors. Only some pairs,
however, will be successful in forming full adjacencies. Topological databases are synchronized between
pairs of fully adjacent routers.
Adjacencies control the distribution of routing protocol packets. Routing protocol packets are sent and
received only on adjacencies. In particular, distribution of topological database updates proceeds along
adjacencies.
Link state is also advertised when a router’s state changes. A router’s adjacencies are reflected in the
contents of its link state advertisements. This relationship between adjacencies and link state allows the
protocol to detect downed routers in a timely fashion.
AS link state advertisements are flooded throughout the AS, across areas. Area link state advertisements
are flooded to routers within the same area. The flooding algorithm ensures that all routers within a given
area have exactly the same LSDB. This database consists of the collection of link state advertisements
received from each router belonging to the area. From this database each router calculates a shortest-path
tree. This shortest-path tree in turn yields a routing table for the protocol.
page 2-8
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Configuring OSPFv3
OSPFv3 Overview
OSPFv3 Areas
OSPFv3 allows collections of contiguous networks and hosts to be grouped together as an area. Each area
runs a separate copy of the basic link-state routing algorithm (usually called SPF). This means that each
area has its own topological database, as explained in the previous section.
Inter-Area Routing
Intra-Area
Routing
Intra-Area
Routing
Router 3
Backbone
Router 1
Link State
Messages
Link State
Messages
Router 2
Router 4
Area 1
Area 2
OSPFv3 Intra-Area and Inter-Area Routing
An area’s topology is visible only to the members of the area. Conversely, routers internal to a given area
know nothing of the detailed topology external to the area. This isolation of knowledge enables the protocol to reduce routing traffic by concentrating on small areas of an AS, as compared to treating the entire
AS as a single link-state domain.
Each router that participates in a specific area maintains an LSDB containing topological information for
that area. If the router participates in multiple areas, then it will maintain a separate database for each area
to which the router belongs. LSAs are flooded throughout an area to ensure that all participating routers
have an identical LSDB for that area.
A router connected to multiple areas is identified as an area border router (ABR). All ABRs must also
belong to a backbone area (also known as area 0). The backbone is responsible for distributing routing
information between areas. Although the backbone is an area itself, it consists of area border routers and
must also have links to all areas to which it will transfer information.The topology of the backbone area is
invisible to each of the areas, while the backbone itself knows nothing of the topology of the areas.
All routers in an area must agree on that area’s parameters. Since a separate copy of the link-state algorithm is run in each area, most configuration parameters are defined on a per-router basis. All routers
belonging to an area must agree on that area’s configuration. Misconfiguration will keep neighbors from
forming adjacencies between themselves, and OSPFv3 will not function.
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December 2007
page 2-9
OSPFv3 Overview
Configuring OSPFv3
Classification of Routers
When an AS is split into OSPFv3 areas, the routers are further divided according to function into the
following four overlapping categories:
• Internal area router. A router with all directly connected networks belonging to the same area. Each
internal router shares the same LSDB with other routers within the same area.
• Area border router (ABR). A router that attaches to multiple areas and to the backbone area. ABRs
maintain a separate LSDB for each area to which it is connected, in addition to an AS and link-local
database. The topological information from each area LSDB is condensed by the ABR and flooded to
other areas.
• Designated router (DR). An elected router that is responsible for generating LSAs and maintaining
the LSDB for the subnet to which the router is connected. The DR updates the LSDB by exchanging
database updates with adjacent, non-designated routers on the network.
• AS boundary router. A router that exchanges routing information with routers belonging to other
Autonomous Systems. Such a router may also advertise external routes throughout the Autonomous
System. The path to each AS boundary router is known by every router in the AS. This classification is
completely independent of the previous classifications (i.e., internal and area border routers). AS
boundary routers may be internal or area border routers.
Virtual Links
It is possible to define areas in such a way that the backbone is no longer contiguous. (This is not an ideal
OSPFv3 configuration, and maximum effort should be made to avoid this situation.) In this case the
system administrator must restore backbone connectivity by configuring virtual links.
Virtual links can be configured between any two backbone routers that have a connection to a common
non-backbone area. The protocol treats two routers joined by a virtual link as if they were connected by an
unnumbered point-to-point network. The routing protocol traffic that flows along the virtual link uses
intra-area routing only, and the physical connection between the two routers is not managed by the
network administrator (i.e., there is no dedicated connection between the routers as there is with the
OSPFv3 backbone).
Router B
Router A
Area 1
Backbone
Virtual Link
Backbone
OSPFv3 Routers Connected with a Virtual Link
In the above diagram, Router A and Router B are connected via a virtual link in Area 1, which is known as
a transit area. See “Creating Virtual Links” on page 2-17 for more information.
page 2-10
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December 2007
Configuring OSPFv3
OSPFv3 Overview
Stub Areas
OSPFv3 allows certain areas to be configured as stub areas. A stub area is an area with routers that have
no AS external Link State Advertisements (LSAs).
In order to take advantage of the OSPFv3 stub area support, default routing must be used in the stub area.
This is accomplished by configuring one or more of the stub area’s border routers to advertise a default
route into the stub area. The default routes will match any destination that is not explicitly reachable by an
intra-area or inter-area path (i.e., AS external destinations).
Backbone
Virtual Link
Backbone
Area 1
(stub)
Area 3
(stub)
Area 2
OSPFv3 Stub Area
Area 1 and Area 3 could be configured as stub areas. Stub areas are configured using the OSPFv3 ipv6 ospf
area command, described in “Creating an Area” on page 2-15. For more overview information on areas, see
“OSPFv3 Areas” on page 2-9.
The OSPFv3 protocol ensures that all routers belonging to an area agree on whether the area has been
configured as a stub. This guarantees that no confusion will arise in the flooding of AS external advertisements.
Two restrictions on the use of stub areas are:
• Virtual links cannot be configured through stub areas.
• AS boundary routers cannot be placed internal to stub areas.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 2-11
OSPFv3 Overview
Configuring OSPFv3
Equal Cost Multi-Path (ECMP) Routing
Using information from its continuously updated databases, OSPFv3 calculates the shortest path to a given
destination. Shortest path is determined from metric values at each hop along a path. At times, two or more
paths to the same destination will have the same metric cost.
In the network illustration below, there are two paths from Source router A to Destination router B. One
path traverses two hops at routers X and Y and the second path traverses two hops at M and N. If the total
cost through X and Y to B is the same as the cost via M and N to B, then these two paths have equal cost.
In this version of OSPFv3 both paths will be stored and used to transmit data.
X
Y
A-> X-> Y-> B = A-> M-> N-> B
Source (A)
Destination (B)
M
N
Multiple Equal Cost Paths
Delivery of packets along equal paths is based on flows rather than a round-robin scheme. Equal cost is
determined based on standard routing metrics. However, other variables, such as line speed, are not
considered. So it is possible for OSPFv3 to decide two paths have an equal cost even though one may
contain faster links than another.
page 2-12
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December 2007
Configuring OSPFv3
Configuring OSPFv3
Configuring OSPFv3
Configuring OSPFv3 on a router requires several steps. Depending on your requirements, you may not
need to perform all of the steps listed below.
By default, OSPFv3 is enabled on the router. Configuring OSPFv3 consists of these tasks:
• Set up the basics of the OSPFv3 network by configuring the required VLANs, assigning ports to the
VLANs, and assigning router identification numbers to the routers involved. This is described in
“Preparing the Network for OSPFv3” on page 2-14.
• Load OSPFv3. When the image file for advanced routing is installed, you must load the OSPFv3 code.
The commands for loading OSPFv3 are described in “Activating OSPFv3” on page 2-14.
• Create any desired OSPFv3 areas, including the backbone area if one is required. Note that a backbone
area is not necessary if there is only one area. The commands to create areas and backbone areas are
described in “Creating an OSPFv3 Area” on page 2-15.
• Set area parameters (optional). OSPFv3 will run with the default area parameters, but different
networks may benefit from modifying the parameters. Modifying area parameters is described in
“Configuring Stub Area Default Metrics” on page 2-16.
• Create OSPFv3 interfaces. OSPFv3 interfaces are created and assigned to areas. Creating interfaces is
described in “Creating an Interface” on page 1-20, and assigning interfaces is described in “Assigning
an Interface to an Area” on page 1-20.
• Set interface parameters (optional). OSPFv3 will run with the default interface parameters, but differ-
ent networks may benefit from modifying the parameters. Also, it is possible to set authentication on
an interface.
• Configure virtual links (optional). A virtual link is used to establish backbone connectivity when two
backbone routers are not physically contiguous. To create a virtual link, see “Creating Virtual Links”
on page 2-17.
• Configure redistribution using route maps (optional). Redistribution allows the control of how routes
are advertised into the OSPFv3 network from outside the Autonomous System. Configuring redistribution is described in “Configuring Redistribution” on page 2-18.
• Configure router capabilities (optional). There are several commands that influence router operation.
These are covered briefly in a table in “Configuring Router Capabilities” on page 2-24.
At the end of the chapter is a simple OSPFv3 network diagram with instructions on how it was created on
a router-by-router basis. See “OSPFv3 Application Example” on page 2-25 for more information.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 2-13
Configuring OSPFv3
Configuring OSPFv3
Preparing the Network for OSPFv3
OSPFv3 operates on top of normal switch functions, using existing ports, virtual ports, VLANs, etc. The
following network components should already be configured:
• Configure VLANs that are to be used in the OSPFv3 network. VLANS should be created for inter-
faces that will participate in the OSPFv3 network. VLAN configuration is described in “Configuring
VLANs,” in the OmniSwitch 6800/6850/9000 Network Configuration Guide.
• Assign IPv6 interfaces to the VLANs. IPv6 interfaces must be assigned to the VLAN. Assigning IPv6
interfaces is described in “Configuring VLANs,” in the OmniSwitch 6800/6850/9000 Network Configuration Guide.
• Assign ports to the VLANs. The physical ports participating in the OSPFv3 network must be assigned
to the created VLANs. Assigning ports to a VLAN is described in “Assigning Ports to VLANs,” in the
OmniSwitch 6800/6850/9000 Network Configuration Guide.
• Set the router identification number. (optional) The routers participating in the OSPFv3 network
must be assigned a router identification number. This number is specified using the standard dotted
decimal format (e.g., 1.1.1.1) but may not consist of all zeros (0.0.0.0). Router identification number
assignment is discussed in “Configuring IP,” in the OmniSwitch 6800/6850/9000 Network Configuration Guide. If this is not done, the router identification number is automatically the primary interface
address.
Activating OSPFv3
For OSPFv3 to run on the router, the advanced routing image must be installed. (For information on how
to install image files, see the OmniSwitch 6800/6850/9000 Switch Management Guide.)
After the image file has been installed onto the router, you will need to load the OSPFv3 software into
memory as described below:
Loading the Software
To load the OSPFv3 software into the router’s running configuration, enter the ipv6 load ospf command at
the system prompt:
-> ipv6 load OSPF
The OPSFv3 software is now loaded into memory.
Configuring the OSPFv3 Administrative Status
When the OSPFv3 software is loaded into the router’s running configuration (either through the CLI or on
startup), it is administratively enabled by default. To change the OSPFv3 administrative status, use the
ipv6 ospf status command. For example, the following commands disable and enable OSPFv3 on the
router:
-> ipv6 ospf status disable
-> ipv6 ospf status enable
page 2-14
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December 2007
Configuring OSPFv3
Configuring OSPFv3
Removing OSPFv3 from Memory
To remove OSPFv3 from the router memory, it is necessary to manually edit the boot.cfg file. The
boot.cfg file is an ASCII text-based file that controls many of the switch parameters. Open the file and
delete all references to OSPFv3.
For the operation to take effect the switch needs to be rebooted.
Creating an OSPFv3 Area
OSPFv3 allows a set of network devices in an Autonomous System (AS) to be grouped together in areas.
There can be more than one router in an area. Likewise, there can be more than one area on a single router
(in effect, making the router the Area Border Router (ABR) for the areas involved), but standard networking design does not recommended that more than three areas be handled on a single router.
Note that configuring a backbone area for a router is required if the router is going to participate in more
than one area.
Areas are named using 32-bit dotted decimal format (e.g., 1.1.1.1). Area 0.0.0.0 is reserved for the backbone.
Creating an Area
To create an area and associate it with a router, enter the ipv6 ospf area command with the area identification number at the CLI prompt, as shown:
-> ipv6 ospf area 1.1.1.1
Area 1.1.1.1 will now be created on the router with the default parameters.
The backbone is always area 0.0.0.0. To create this area on a router, you would use the above command,
but specify the backbone, as shown:
-> ipv6 ospf area 0.0.0.0
The backbone would now be attached to the router, making it an Area Border Router (ABR).
Specifying an Area Type
When creating areas, an area type can be specified (normal or stub). Area types are described above in
“OSPFv3 Areas” on page 2-9. To specify an area type, use the ipv6 ospf area command as shown:
-> ipv6 ospf area 1.1.1.1 type stub
Note. By default, an area is a normal area. The type keyword would be used to change a normal area into
stub.
Displaying Area Status
You can check the status of the newly created area by using the show command, as demonstrated:
-> show ipv6 ospf area 1.1.1.1
or
-> show ipv6 ospf area
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Configuring OSPFv3
Configuring OSPFv3
The first example gives specifics about area 1.1.1.1, and the second example shows all areas configured on
the router.
To display the parameters of an area, use the show ipv6 ospf area command as follows:
-> show ipv6 ospf area 1.1.1.1
Deleting an Area
To delete an area, enter the ipv6 ospf area command as shown:
-> no ipv6 ospf area 1.1.1.1
Configuring Stub Area Default Metrics
The default metric configures the metric that an area border router (ABR) will advertise into the stub area.
Use the ipv6 ospf area command to modify the default metric for a stub area. Specify the stub area and
select a cost value or a route type, as shown:
-> ipv6 ospf area 1.1.1.1 type stub default-metric 10
Creating OSPFv3 Interfaces
Once areas have been established, interfaces need to be created and assigned to the areas. (Creating areas
is described in “Creating an Area” on page 2-15 above.)
To create an interface and assign it to an area, enter the ipv6 ospf interface area command with an interface name and an area identification number, as shown:
-> ipv6 ospf interface vlan-213 area 1.1.1.1
Note. The interface name cannot have spaces.
The interface can be deleted by using the no keyword, as shown:
-> no ipv6 ospf interface vlan-213
An interface can be removed from an area by reassigning it to a new area.
Once an interface has been created, you can check its status and configuration by using the show ipv6 ospf
interface command, as demonstrated:
-> show ipv6 ospf interface vlan-213
Instructions for interface parameter options are described in “Modifying Interface Parameters” on
page 2-17.
Configuring the Interface Administrative Status
When an OSPFv3 interface is created and assigned an area, it is administratively enabled by default. To
change the administrative status of the interface, use the ipv6 ospf interface status command with the
interface IP address or interface name, as shown:
-> ipv6 ospf interface vlan-213 status disable
-> ipv6 ospf interface vlan-213 status enable
page 2-16
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Configuring OSPFv3
Configuring OSPFv3
Modifying Interface Parameters
There are several interface parameters that can be modified on a specified interface. Most of these deal
with timer settings.
The cost parameter and the priority parameter help to determine the cost of the route using this interface,
and the chance that this interface’s router will become the designated router, respectively.
The following table shows the various interface parameters that can be set:
ipv6 ospf interface dead-interval Configures the OSPFv3 interface dead interval. If no hello packets are
received in this interval from a neighboring router, the neighbor is
considered dead.
ipv6 ospf interface hello-interval Configures the OSPFv3 hello interval.
ipv6 ospf interface cost
Configures the OSPFv3 interface cost. A cost metric refers to the network path preference assigned to certain types of traffic.
ipv6 ospf interface priority
Configures the OSPFv3 interface priority. The priority number helps
determine if this router will become the designated router.
ipv6 ospf interface retransinterval
Configures the OSPFv3 interface retransmit interval. The number of
seconds between link state advertisement retransmissions for adjacencies belonging to this interface.
ipv6 ospf interface transit-delay
Configures the OSPFv3 interface transit delay. The estimated number
of seconds required to transmit a link state update over this interface.
These parameters can be added any time. (See “Creating OSPFv3 Interfaces” on page 2-16 for more information.) For example, to set the dead interval to 50 and the cost to 100 on interface vlan-213, enter the
following:
-> ipv6 ospf interface vlan-213 dead-interval 50 cost 100
To set the poll interval to 25, the priority to 100, and the retransmit interval to 10 on interface
vlan-213, enter the following:
-> ipv6 ospf interface vlan-213 poll-interval 25 priority 100 retrans-interval
10
To set the hello interval to 5000 on interface vlan-213, enter the following:
-> ipv6 ospf interface vlan-213 hello-interval 5000
Creating Virtual Links
To create a virtual link, commands must be submitted to the routers at both ends of the link. The router
being configured should point to the other end of the link, and both routers must have a common area.
When entering the ipv6 ospf virtual-link command, it is necessary to enter the Router ID of the far end of
the link, and the area ID that both ends of the link share.
For example, a virtual link needs to be created between Router A (router ID 1.1.1.1) and Router B (router
ID 2.2.2.2). We must:
1 Establish a transit area between the two routers using the commands discussed in “Creating an OSPFv3
Area” on page 2-15 (in this example, we will use Area 0.0.0.1).
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Configuring OSPFv3
Configuring OSPFv3
2 Then use the ipv6 ospf virtual-link command on Router A as shown:
-> ipv6 ospf virtual-link area 0.0.0.1 router 2.2.2.2
3 Next, enter the following command on Router B:
-> ipv6 ospf virtual-link area 0.0.0.1 router 1.1.1.1
Now there is a virtual link across Area 0.0.0.1 linking Router A and Router B.
4 To display virtual links configured on a router, enter the following show command:
-> show ipv6 ospf virtual-link
5 To delete a virtual link, enter the ipv6 ospf virtual-link command with the area and far end router
information, as shown:
-> no ipv6 ospf virtual-link area 0.0.0.1 router 2.2.2.2
Modifying Virtual Link Parameters
There are several parameters for a virtual link (such as hello-interval and dead-interval that can be modified at the time of the link creation. They are described in the ipv6 ospf virtual-link command description. These parameters are identical in function to their counterparts in the section “Modifying Interface
Parameters” on page 2-17.
Configuring Redistribution
It is possible to learn and advertise IPv6 routes between different protocols. Such a process is referred to as
route redistribution and is configured using the ipv6 redist command.
Redistribution uses route maps to control how external routes are learned and distributed. A route map
consists of one or more user-defined statements that can determine which routes are allowed or denied
access to the network. In addition a route map may also contain statements that modify route parameters
before they are redistributed.
When a route map is created, it is given a name to identify the group of statements that it represents. This
name is required by the ipv6 redist command. Therefore, configuring route redistribution involves the
following steps:
1 Create a route map, as described in “Using Route Maps” on page 2-19.
2 Configure redistribution to apply a route map, as described in “Configuring Route Map Redistribution” on page 2-22.
Note. An OSPFv3 router automatically becomes an Autonomous System Border Router (ASBR) when
redistribution is configured on the router.
page 2-18
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Configuring OSPFv3
Configuring OSPFv3
Using Route Maps
A route map specifies the criteria that are used to control redistribution of routes between protocols. Such
criteria is defined by configuring route map statements. There are three different types of statements:
• Action. An action statement configures the route map name, sequence number, and whether or not
redistribution is permitted or denied based on route map criteria.
• Match. A match statement specifies criteria that a route must match. When a match occurs, then the
action statement is applied to the route.
• Set. A set statement is used to modify route information before the route is redistributed into the
receiving protocol. This statement is only applied if all the criteria of the route map is met and the
action permits redistribution.
The ip route-map command is used to configure route map statements and provides the following action,
match, and set parameters:
ip route-map action ...
ip route-map match ...
ip route-map set ...
permit
deny
ip-address
ip-nexthop
ipv6-address
ipv6-nexthop
tag
ipv4-interface
ipv6-interface
metric
route-type
metric
metric-type
tag
community
local-preference
level
ip-nexthop
ipv6-nexthop
Refer to the “IP Commands” chapter in the OmniSwitch CLI Reference Guide for more information about
the ip route-map command parameters and usage guidelines.
Once a route map is created, it is then applied using the ipv6 redist command. See “Configuring Route
Map Redistribution” on page 2-22 for more information.
Creating a Route Map
When a route map is created, it is given a name (up to 20 characters), a sequence number, and an action
(permit or deny). Specifying a sequence number is optional. If a value is not configured, then the number
50 is used by default.
To create a route map, use the ip route-map command with the action parameter. For example,
-> ip route-map ospf-to-rip sequence-number 10 action permit
The above command creates the ospf-to-rip route map, assigns a sequence number of 10 to the route
map, and specifies a permit action.
To optionally filter routes before redistribution, use the ip route-map command with a match parameter
to configure match criteria for incoming routes. For example,
-> ip route-map ospf-to-rip sequence-number 10 match tag 8
The above command configures a match statement for the ospf-to-rip route map to filter routes based on
their tag value. When this route map is applied, only OSPFv3 routes with a tag value of eight are redistributed into the RIPng network. All other routes with a different tag value are dropped.
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Configuring OSPFv3
Configuring OSPFv3
Note. Configuring match statements is not required. However, if a route map does not contain any match
statements and the route map is applied using the ipv6 redist command, the router redistributes all routes
into the network of the receiving protocol.
To modify route information before it is redistributed, use the ip route-map command with a set parameter. For example,
-> ip route-map ospf-to-rip sequence-number 10 set tag 5
The above command configures a set statement for the ospf-to-rip route map that changes the route tag
value to five. Because this statement is part of the ospf-to-rip route map, it is only applied to routes that
have an existing tag value equal to eight.
The following is a summary of the commands used in the above examples:
-> ip route-map ospf-to-rip sequence-number 10 action permit
-> ip route-map ospf-to-rip sequence-number 10 match tag 8
-> ip route-map ospf-to-rip sequence-number 10 set tag 5
To verify a route map configuration, use the show ip route-map command:
-> show ip route-map
Route Maps: configured: 1 max: 200
Route Map: ospf-to-rip Sequence Number: 10 Action permit
match tag 8
set tag 5
Deleting a Route Map
Use the no form of the ip route-map command to delete an entire route map, a route map sequence, or a
specific statement within a sequence.
To delete an entire route map, enter no ip route-map followed by the route map name. For example, the
following command deletes the entire route map named redistipv6:
-> no ip route-map redistipv6
To delete a specific sequence number within a route map, enter no ip route-map followed by the route
map name, then sequence-number followed by the actual number. For example, the following command
deletes sequence 10 from the redistipv6 route map:
-> no ip route-map redistipv6 sequence-number 10
Note that in the above example, the redistripv6 route map is not deleted. Only those statements associated
with sequence 10 are removed from the route map.
To delete a specific statement within a route map, enter no ip route-map followed by the route map name,
then sequence-number followed by the sequence number for the statement, then either match or set and
the match or set parameter and value. For example, the following command deletes only the match tag 8
statement from route map redistipv6 sequence 10:
-> no ip route-map redistipv6 sequence-number 10 match tag 8
page 2-20
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Configuring OSPFv3
Configuring OSPFv3
Configuring Route Map Sequences
A route map may consist of one or more sequences of statements. The sequence number determines which
statements belong to which sequence and the order in which sequences for the same route map are
processed.
To add match and set statements to an existing route map sequence, specify the same route map name and
sequence number for each statement. For example, the following series of commands creates route map
rm_1 and configures match and set statements for the rm_1 sequence 10:
-> ip route-map rm_1 sequence-number 10 action permit
-> ip route-map rm_1 sequence-number 10 match tag 8
-> ip route-map rm_1 sequence-number 10 set metric 1
To configure a new sequence of statements for an existing route map, specify the same route map name
but use a different sequence number. For example, the following command creates a new sequence 20 for
the rm_1 route map:
-> ip route-map rm_1 sequence-number 20 action permit
-> ip route-map rm_1 sequence-number 20 match ipv6-interface to-finance
-> ip route-map rm_1 sequence-number 20 set metric 5
The resulting route map appears as follows:
-> show ip route-map rm_1
Route Map: rm_1 Sequence Number: 10 Action permit
match tag 8
set metric 1
Route Map: rm_1 Sequence Number: 20 Action permit
match ip6 interface to-finance
set metric 5
Sequence 10 and sequence 20 are both linked to route map rm_1 and are processed in ascending order
according to their sequence number value. Note that there is an implied logical OR between sequences. As
a result, if there is no match for the tag value in sequence 10, then the match interface statement in
sequence 20 is processed. However, if a route matches the tag 8 value, then sequence 20 is not used. The
set statement for whichever sequence was matched is applied.
A route map sequence may contain multiple match statements. If these statements are of the same kind
(e.g., match tag 5, match tag 8, etc.) then a logical OR is implied between each like statement. If the match
statements specify different types of matches (e.g. match tag 5, match ip4 interface to-finance, etc.), then a
logical AND is implied between each statement. For example, the following route map sequence will
redistribute a route if its tag is either 8 or 5:
-> ip route-map rm_1 sequence-number 10 action permit
-> ip route-map rm_1 sequence-number 10 match tag 5
-> ip route-map rm_1 sequence-number 10 match tag 8
The following route map sequence will redistribute a route if the route has a tag of 8 or 5 and the route
was learned on the IPv4 interface to-finance:
->
->
->
->
ip
ip
ip
ip
route-map
route-map
route-map
route-map
rm_1
rm_1
rm_1
rm_1
sequence-number
sequence-number
sequence-number
sequence-number
10
10
10
10
action permit
match tag 5
match tag 8
match ipv4-interface to-finance
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Configuring OSPFv3
Configuring OSPFv3
Configuring Access Lists
An IP access list provides a convenient way to add multiple IPv4 or IPv6 addresses to a route map. Using
an access list avoids having to enter a separate route map statement for each individual IP address. Instead,
a single statement is used that specifies the access list name. The route map is then applied to all the
addresses contained within the access list.
Configuring an IP access list involves two steps: creating the access list and adding IP addresses to the list.
To create an IP access list, use the ip access-list command (IPv4) or the ipv6 access-list command (IPv6)
and specify a name to associate with the list. For example,
-> ip access-list ipaddr
-> ipv6 access-list ip6addr
To add addresses to an access list, use the ip access-list address (IPv4) or the ipv6 access-list address
(IPv6) command. For example, the following commands add addresses to an existing access list:
-> ip access-list ipaddr address 16.24.2.1/16
-> ipv6 access-list ip6addr address 2001::1/64
Use the same access list name each time the above commands are used to add additional addresses to the
same access list. In addition, both commands provide the ability to configure if an address and/or its
matching subnet routes are permitted (the default) or denied redistribution. For example:
-> ip access-list ipaddr address 16.24.2.1/16 action deny redist-control allsubnets
-> ipv6 access-list ip6addr address 2001::1/64 action permit redist-control nosubnets
For more information about configuring access list commands, see the “IP Commands” chapter in the
OmniSwitch CLI Reference Guide.
Configuring Route Map Redistribution
The ipv6 redist command is used to configure the redistribution of routes from a source protocol into the
OSPFv3 destination protocol. This command is used on the OSPFv3 router that will perform the redistribution.
Note. A router automatically becomes an Autonomous System Border Router (ASBR) when redistribution is configured on the router.
A source protocol is a protocol from which the routes are learned. A destination protocol is the one into
which the routes are redistributed. Make sure that both protocols are loaded and enabled before configuring redistribution.
Redistribution applies criteria specified in a route map to routes received from the source protocol. Therefore, configuring redistribution requires an existing route map. For example, the following command
configures the redistribution of OSPFv3 routes into the RIPng network using the ospf-to-rip route map:
-> ipv6 redist ospf into rip route-map ospf-to-rip
OSPFv3 routes received by the router interface are processed based on the contents of the ospf-to-rip route
map. Routes that match criteria specified in this route map are either allowed or denied redistribution into
the RIPng network. The route map may also specify the modification of route information before the route
is redistributed. See “Using Route Maps” on page 2-19 for more information.
page 2-22
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Configuring OSPFv3
Configuring OSPFv3
To remove a route map redistribution configuration, use the no form of the ipv6 redist command. For
example:
-> no ipv6 redist ospf into rip route-map ospf-to-rip
Use the show ipv6 redist command to verify the redistribution configuration:
-> show ipv6 redist
Source
Destination
Protocol
Protocol
Status
Route Map
------------+------------+---------+-------------------localIPv6
RIPng
Enabled
ipv6rm
OSPFv3
RIPng
Enabled
ospf-to-rip
Configuring the Administrative Status of the Route Map Redistribution
The administrative status of a route map redistribution configuration is enabled by default. To change the
administrative status, use the status parameter with the ipv6 redist command. For example, the following
command disables the redistribution administrative status for the specified route map:
-> ipv6 redist ospf into rip route-map ospf-to-rip status disable
The following command example enables the administrative status:
-> ipv6 redist ospf into rip route-map ospf-to-rip status enable
Route Map Redistribution Example
The following example configures the redistribution of OSPFv3 routes into a RIPng network using a route
map (ospf-to-rip) to filter specific routes:
-> ip route-map ospf-to-rip sequence-number 10 action deny
-> ip route-map ospf-to-rip sequence-number 10 match tag 5
-> ip route-map ospf-to-rip sequence-number 10 match route-type external type2
-> ip route-map ospf-to-rip sequence-number 20 action permit
-> ip route-map ospf-to-rip sequence-number 20 match ipv6-interface intf_ospf
-> ip route-map ospf-to-rip sequence-number 20 set metric 255
->ip route-map ospf-to-rip sequence-number 30 action permit
->ip route-map ospf-to-rip sequence-number 30 set tag 8
-> ipv6 redist ospf into rip route-map ospf-to-rip
The resulting ospf-to-rip route map redistribution configuration does the following
• Denies the redistribution of Type 2 external OSPF routes with a tag set to five.
• Redistributes into RIPng all routes learned on the intf_ospf interface and sets the metric for such routes
to 255.
• Redistributes into RIPng all other routes (those not processed by sequence 10 or 20) and sets the tag for
such routes to eight.
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Configuring OSPFv3
Configuring OSPFv3
Configuring Router Capabilities
The following list shows various commands that can be useful in tailoring a router’s performance capabilities. All of the listed parameters have defaults that are acceptable for running an OSPFv3 network.
ipv6 ospf host
Creates and deletes an OSPFv3 entry for directly attached hosts.
ipv6 ospf mtu-checking
Enables or disables the use of Maximum Transfer Unit (MTU) checking
on received OSPFv3 database description packets.
ipv6 ospf route-tag
Configures a tag value for Autonomous System External (ASE) routes
created.
ipv6 ospf spf-timer
Configures timers for Shortest Path First (SPF) calculation.
To enable MTU checking, enter:
-> ipv6 ospf mtu-checking
To set the route tag to 5, enter:
-> ipv6 ospf route-tag 5
To set the SPF timer delay to 3 and the hold time to 6, enter:
-> ipv6 ospf spf-timer delay 3 hold 6
To return a parameter to its default setting, enter the command with no parameter value, as shown:
-> ipv6 ospf spf-timer
page 2-24
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Configuring OSPFv3
OSPFv3 Application Example
OSPFv3 Application Example
This section will demonstrate how to set up a simple OSPFv3 network. It uses three routers, each with an
area. Each router uses three VLANs. A backbone connects all the routers. This section will demonstrate
how to set it up by explaining the necessary commands for each router.
The following diagram is a simple OSPFv3 network. It will be created by the steps listed on the following
pages.
VLAN 10
Area 0.0.0.1
Router 1
Router ID 1.1.1.1
VLAN 12
VLAN 31
Backbone Area
(Area 0.0.0.0)
VLAN 23
Area 0.0.0.2
Router 2
Router ID 20.0.0.1
Area 0.0.0.3
Router 3
Router ID 3.3.3.3
VLAN 20
VLAN 30
Three Area OSPFv3 Network
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page 2-25
OSPFv3 Application Example
Configuring OSPFv3
Step 1: Prepare the Routers
The first step is to create the VLANs on each router, add an IP interface to the VLAN, assign a port to the
VLAN, and assign a router identification number to the routers. For the backbone, the network design in
this case uses slot 2, port 1 as the egress port and slot 2, port 2 as ingress port on each router. Router 1
connects to Router 2, Router 2 connects to Router 3, and Router 3 connects to Router 1 using 10/100
Ethernet cables.
Note. The ports will be statically assigned to the router, as a VLAN must have a physical port assigned to
it in order for the router port to function. However, the router could be set up in such a way that mobile
ports are dynamically assigned to VLANs using VLAN rules. See the chapter titled “Defining VLAN
Rules” in the OmniSwitch 6800/6850/9000 Network Configuration Guide.
The commands setting up VLANs are shown below:
Router 1 (using ports 2/1 and 2/2 for the backbone, and ports 2/3-5 for end devices):
->
->
->
->
vlan
ipv6
ipv6
vlan
31
interface vlan-31 vlan 31
address 2001:1::1/64 vlan-31
31 port default 2/1
->
->
->
->
vlan
ipv6
ipv6
vlan
12
interface vlan-12 vlan 12
address 2001:2::1/64 vlan-12
12 port default 2/2
->
->
->
->
vlan
ipv6
ipv6
vlan
10
interface vlan-10 vlan 10
address 2001:3::1/64 vlan-10
10 port default 2/3-5
-> ip router router-id 1.1.1.1
These commands created VLANs 31, 12, and 10.
• VLAN 31 handles the backbone connection from Router 1 to Router 3, using the IP router port
2001:1::1/64 and physical port 2/1.
• VLAN 12 handles the backbone connection from Router 1 to Router 2, using the IP router port
2001:2::1/64 and physical port 2/2.
• VLAN 10 handles the device connections to Router 1, using the IP router port 2001:3::1/64 and
physical ports 2/3-5. More ports could be added at a later time if necessary.
The router was assigned the Router ID of 1.1.1.1.
Router 2 (using ports 2/1 and 2/2 for the backbone, and ports 2/3-5 for end devices):
->
->
->
->
vlan
ipv6
ipv6
vlan
12
interface vlan-12 vlan 12
address 2001:2::2/64 vlan-12
12 port default 2/1
->
->
->
->
vlan
ipv6
ipv6
vlan
23
interface vlan-23 vlan 23
address 2001:5::1/64 vlan-23
23 port default 2/2
page 2-26
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Configuring OSPFv3
->
->
->
->
vlan
ipv6
ipv6
vlan
OSPFv3 Application Example
20
interface vlan-20 vlan 20
address 2001:4::1/64 vlan-20
20 port default 2/3-5
-> ipv6 router router-id 2.2.2.2
These commands created VLANs 12, 23, and 20.
• VLAN 12 handles the backbone connection from Router 1 to Router 2, using the IP router port
2001:2::2/64 and physical port 2/1.
• VLAN 23 handles the backbone connection from Router 2 to Router 3, using the IP router port
2001:5::1/64 and physical port 2/2.
• VLAN 20 handles the device connections to Router 2, using the IP router port 2001:4::1/64 and
physical ports 2/3-5. More ports could be added at a later time if necessary.
The router was assigned the Router ID of 2.2.2.2.
Router 3 (using ports 2/1 and 2/2 for the backbone, and ports 2/3-5 for end devices):
->
->
->
->
vlan
ipv6
ipv6
vlan
23
interface vlan-23 vlan 23
address 2001:5::2/64 vlan-23
23 port default 2/1
->
->
->
->
vlan
ipv6
ipv6
vlan
31
interface vlan-31 vlan 31
address 2001:1::2/64 vlan-31
31 port default 2/2
->
->
->
->
vlan
ipv6
ipv6
vlan
30
interface vlan-30 vlan 30
address 2001:6::2/64 vlan-30
30 port default 2/3-5
-> ipv6 router router-id 3.3.3.3
These commands created VLANs 23, 31, and 30.
• VLAN 23 handles the backbone connection from Router 2 to Router 3, using the IP router port
2001:5::2/64 and physical port 2/1.
• VLAN 31 handles the backbone connection from Router 3 to Router 1, using the IP router port
2001:1::2/64 and physical port 2/2.
• VLAN 30 handles the device connections to Router 3, using the IP router port 2001:6::2/64 and
physical ports 2/3-5. More ports could be added at a later time if necessary.
The router was assigned the Router ID of 3.3.3.3.
Step 2: Load OSPFv3
The next step is to load OSPFv3 on each router. The commands for this step are below (the commands are
the same on each router):
-> ipv6 load ospf
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page 2-27
OSPFv3 Application Example
Configuring OSPFv3
Step 3: Create the Areas and Backbone
Now the areas should be created. In this case, we will create an area for each router, and a backbone (area
0.0.0.0) that connects the areas.
The commands for this step are below:
Router 1
-> ipv6 ospf area 0.0.0.0
-> ipv6 ospf area 0.0.0.1
These commands created and enabled area 0.0.0.0 (the backbone) and area 0.0.0.1 (the area for Router 1).
Router 2
-> ipv6 ospf area 0.0.0.0
-> ipv6 ospf area 0.0.0.2
These commands created and enabled Area 0.0.0.0 (the backbone) and Area 0.0.0.2 (the area for Router
2).
Router 3
-> ipv6 ospf area 0.0.0.0
-> ipv6 ospf area 0.0.0.3
These commands created and enabled Area 0.0.0.0 (the backbone) and Area 0.0.0.3 (the area for Router
3).
Step 4: Create, Enable, and Assign Interfaces
Next, OSPFv3 interfaces must be created, enabled, and assigned to the areas. The OSPFv3 interfaces
should have the same interface name as the IPv6 router interfaces created above in “Step 1: Prepare the
Routers” on page 2-26.
Router 1
-> ipv6 ospf interface vlan-31 area 0.0.0.0
-> ipv6 ospf interface vlan-12 area 0.0.0.0
-> ipv6 ospf interface vlan-10 area 0.0.0.1
IPv6 router interface vlan-31 was associated with OSPFv3 interface vlan-31, enabled, and assigned to the
backbone. IPv6 router interface vlan-12 was associated with OSPFv3 interface vlan-12, enabled, and
assigned to the backbone. IPv6 router interface vlan-10, which connects to end stations and attached
network devices, was associated with OSPFv3 interface vlan-10, enabled, and assigned to Area 0.0.0.1.
Router 2
-> ipv6 ospf interface vlan-12 area 0.0.0.0
-> ipv6 ospf interface vlan-23 area 0.0.0.0
-> ipv6 ospf interface vlan-20 area 0.0.0.2
page 2-28
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring OSPFv3
OSPFv3 Application Example
IPv6 router interface vlan-12 was associated with OSPFv3 interface vlan-12, enabled, and assigned to the
backbone. IPv6 router interface vlan-23 was associated with OSPFv3 interface vlan-23, enabled, and
assigned to the backbone. IPv6 router interface vlan-20, which connects to end stations and attached
network devices, was associated with OSPFv3 interface vlan-20, enabled, and assigned to Area 0.0.0.2.
Router 3
-> ipv6 ospf interface vlan-23 area 0.0.0.0
-> ipv6 ospf interface vlan-31 area 0.0.0.0
-> ipv6 ospf interface vlan-30 area 0.0.0.3
IPv6 router interface vlan-23 was associated with OSPFv3 interface vlan-23, enabled, and assigned to the
backbone. IPv6 router interface vlan-31 was associated with OSPFv3 interface vlan-31, enabled, and
assigned to the backbone. IPv6 router interface vlan-30, which connects to end stations and attached
network devices, was associated with OSPFv3 interface vlan-30, enabled, and assigned to Area 0.0.0.3.
Step 5: Examine the Network
After the network has been created, you can check the various aspects using show commands:
• For OSPFv3 in general, use the show ipv6 ospf command.
• For areas, use the show ipv6 ospf area command.
• For interfaces, use the show ipv6 ospf interface command.
• To check for adjacencies formed with neighbors, use the show ipv6 ospf neighbor command.
• For routes, use the show ipv6 ospf routes command.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 2-29
Verifying OSPFv3 Configuration
Configuring OSPFv3
Verifying OSPFv3 Configuration
To display information about areas, interfaces, virtual links, redistribution, or OPSFv3 in general, use the
show commands listed in the following table:
show ipv6 ospf
Displays the OSPFv3 status and general configuration parameters.
show ipv6 redist
Displays the route map redistribution configuration.
show ipv6 ospf border-routers Displays information regarding all or specified border routers.
show ipv6 ospf host
Displays information on directly attached hosts.
show ipv6 ospf lsdb
Displays LSAs in the LSDB associated with each area.
show ipv6 ospf neighbor
Displays information on OSPFv3 non-virtual neighbors.
show ipv6 ospf routes
Displays the OSPFv3 routes known to the router.
show ipv6 ospf virtual-link
Displays virtual link information.
show ipv6 ospf area
Displays either all OSPFv3 areas, or a specified OSPFv3 area.
show ipv6 ospf interface
Displays OSPFv3 interface information.
For more information about the resulting displays from these commands, see the “OSPFv3 Commands”
chapter in the OmniSwitch CLI Reference Guide.
Examples of the show ipv6 ospf, show ipv6 ospf area, and show ipv6 ospf interface command outputs
are given in the section “OSPFv3 Quick Steps” on page 2-4.
page 2-30
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
3
Configuring IS-IS
Intermediate System-to-Intermediate System (IS-IS) is an International Organization for Standardization
(ISO) dynamic routing specification.
IS-IS is a shortest path first (SPF), or link state protocol. It is an interior gateway protocol (IGP) that
distributes routing information between routers in a single Autonomous System (AS) in IP as well as in
OSI environments. IS-IS chooses the least-cost path as the best path. IS-IS is suitable for complex
networks with large number of routers since it provides faster convergence where multiple flows to a
single destination can be forwarded through one or more interfaces simultaneously.
IS-IS is also an ISO Connectionless Network Protocol (CLNP). It communicates with its peers using the
Connectionless Mode Network Service (CLNS) PDU packets, which means that even in an IP-only environment the IS-IS router must have an ISO address. ISO network-layer addressing is done through
Network Service Access Point (NSAP) addresses that identify any system in the OSI network.
Note. IS-IS is supported only on OmniSwitch 6850 and 9000 Series switches in Release 6.3.1.
In This Chapter
This chapter describes the basic components of IS-IS and how to configure them through the Command
Line Interface (CLI). CLI commands are used in the configuration examples; for more details about the
syntax of commands, refer the OmniSwitch CLI Reference Guide.
The configuration procedures described in this chapter include:
• Loading and enabling IS-IS (see page 3-15).
• Creating IS-IS areas (see page 3-16).
• Creating IS-IS interfaces (see page 3-16).
• Enabling IS-IS authentication (see page 3-18).
• Creating redistribution policies using route maps (see page 3-24).
For information on creating and managing VLANs, see “Configuring VLANs” in the OmniSwitch 6800/
6850/9000 Network Configuration Guide.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 3-1
IS-IS Specifications
Configuring IS-IS
IS-IS Specifications
RFCs Supported
1142-OSI IS-IS Intra-domain Routing Protocol
1195-OSI IS-IS for Routing in TCP/IP and Dual
Environments
3373-Three-Way Handshake for Intermediate
System to Intermediate System (IS-IS) Pointto-Point Adjacencies
3567-Intermediate System to Intermediate
System (IS-IS) Cryptographic Authentication
2966-Prefix Distribution with two-level IS-IS
(Route Leaking) support
2763-Dynamic Host name exchange support
3719-Recommendations for Interoperable
Networks using IS-IS
3787-Recommendations for Interoperable IP
Networks using IS-IS
draft-ietf-isis-igp-p2p-over-lan-05.txt-Point-topoint operation over LAN in link-state rout
ing protocols
Maximum number of areas (per router)
3
Maximum number of L1 adjacencies per
interface (per router)
70
Maximum number of L2 adjacencies per
interface (per router)
70
Maximum number of IS-IS interfaces (per
router)
70
Maximum number of Link State Packet
entries (per adjacency)
255
Maximum number of IS-IS routes
24000
Maximum number of IS-IS L1 routes
12000
Maximum number of IS-IS L2 routes
12000
page 3-2
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring IS-IS
IS-IS Defaults Table
IS-IS Defaults Table
The following table shows the default settings of the configurable IS-IS parameters.
Parameter Description
Command
Default Value/Comments
Administrative status of IS-IS
ip isis status
disabled
Global level of IS-IS
ip isis level-capability
Level-1/2
IS-IS authentication type
ip isis auth-type
none
Global CSNP authentication
ip isis csnp-auth
enabled
Global Hello authentication
ip isis hello-auth
enabled
Global PSNP authentication
ip isis psnp-auth
enabled
Link State Packet (LSP) timer
ip isis lsp-lifetime
1200 seconds
LSP wait interval
ip isis lsp-wait
5 seconds (max-wait)
0 (initial-wait)
1 (second-wait)
SPF time interval
ip isis spf-wait
10 seconds (max-wait)
1000 milliseconds (initial-wait)
1000 milliseconds (secondwait)
IS-IS Overload state
ip isis overload
disabled (Overload state)
infinity (timeout interval)
IS-IS Overload state after bootup
ip isis overload-on-boot
disabled (Overload state after
bootup)
infinity (timeout interval)
IS-IS graceful restart
ip isis graceful-restart
disabled
IS-IS graceful restart helper mode
ip isis graceful-restart helper
enabled
IS-IS system wait-time
ip isis strict-adjacency-check
60 seconds
IS-IS adjacency check configuration ip isis strict-adjacency-check
disable
Authentication type (per IS-IS level) ip isis level auth-type
none
Hello authentication (per IS-IS
level)
ip isis level hello-auth
enabled
CSNP authentication (per IS-IS
level)
ip isis level csnp-auth
enabled
PSNP authentication (per IS-IS
level)
ip isis level psnp-auth
enabled
Wide metrics (per IS-IS level)
ip isis level wide-metrics-only
disabled
IS-IS interface status
ip isis interface status
disable
IS-IS interface type
ip isis interface interface-type
broadcast
Hello authentication (per interface)
ip isis interface hello-auth-type
none
CSNP time interval (per interface)
ip isis interface csnp-interval
10 seconds (broadcast)
5 seconds (point-to-point)
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 3-3
IS-IS Defaults Table
Configuring IS-IS
Parameter Description
Command
Default Value/Comments
IS-IS level (per interface)
ip isis interface level-capability
Level-1/2
IS-IS authentication check
ip isis auth-check
enabled
LSP time interval (per interface)
ip isis interface lsp-pacing-inter- 100 milliseconds
val
IS-IS passive interface
ip isis interface passive
Retransmission time of LSP on a
point-to-point interface
ip isis interface retransmit-inter- 5 seconds
val
Hello authentication for the specified IS-IS level of an interface
ip isis interface level hello-auth- none
type
disabled
Hello time interval for the specified ip isis interface level hello-inter- designated routers: 3 seconds
IS-IS level of an interface
val
non-designated routers:
9 seconds
Number of missing Hello PDUs
from a neighbor
ip isis interface level hello-multi- 3
plier
Metric value of the specified IS-IS
level of the interface
ip isis interface level metric
10
IS-IS passive interface (per IS-IS
level)
ip isis interface level passive
disabled
Interface level priority
ip isis interface level priority
64
page 3-4
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring IS-IS
IS-IS Quick Steps
IS-IS Quick Steps
The following steps are designed to show the user the necessary set of commands for setting up a router to
use IS-IS:
1 Create a VLAN using the vlan command. For example:
-> vlan 5 name "vlan-5"
2 Assign an IP address to the VLAN using the ip interface command. For example:
-> ip interface vlan-5 address 120.1.4.1 mask 255.0.0.0 vlan 5
3 Assign a port to the VLAN using the vlan command. For example:
-> vlan 5 port default 2/1
4 Load IS-IS using the ip load isis command. For example:
-> ip load isis
5 Enable IS-IS using the ip isis status command. For example:
-> ip isis status enable
6 Create an area ID using the ip isis area-id command. For example:
-> ip isis area-id 49.0001
7 Create an IS-IS interface on the given VLAN using the ip isis interface command. For example:
-> ip isis interface vlan-5
8 Enable the interface for IS-IS routing using the ip isis interface status command. For example:
-> ip isis interface vlan-5 status enable
9 You can now display the router’s IS-IS settings by using the show ip isis status command. The output
generated is similar to the following:
-> show ip isis status
==========================================================
ISIS Status
==========================================================
System Id : 0050.0500.5001
Admin State
: UP
Last Enabled
: WED OCT 24 10:05:55 2007
Level Capability
: L1L2
Authentication Check
: True
Authentication Type
: None
Graceful Restart
: Disabled
GR helper-mode
: Disabled
LSP Lifetime
: 1200
LSP Wait
: Max :5 sec, Initial :0 sec, Second :1 sec
Adjacency Check
: Loose
L1 Auth Type
: None
L2 Auth Type
: None
L1 Wide Metrics-only
: Disabled
L2 Wide Metrics-only
: Disabled
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 3-5
IS-IS Quick Steps
Configuring IS-IS
L1 LSDB Overload
: Disabled
L2 LSDB Overload
: Disabled
L1 LSPs
: 177
L2 LSPs
: 177
Last SPF
: FRI OCT 26 05:04:09 2007
SPF Wait
: Max :10000 ms, Initial :1000 ms, Second :1000 ms
Hello-Auth Check
: Enabled
Csnp-Auth Check
: Enabled
Psnp-Auth Check
: Enabled
L1 Hello-Auth Check
: Enabled
L1 Csnp-Auth Check
: Enabled
L1 Psnp-Auth Check
: Enabled
L2 Hello-Auth Check
: Enabled
L2 Csnp-Auth Check
: Enabled
L2 Psnp-Auth Check
: Enabled
Area Address
: 49.0000
===========================================================
10 You can display the information pertaining to interface using the show ip isis interface command. The
output generated is similar to the following:
-> show ip isis interface
=========================================================================
ISIS Interfaces
===============================================================================
Interface
Level
CircID
Oper-state
Admin-state L1/L2-Metric
------------------------------------------------------------------------------system
L1L2
1
Up
Up
10/10
if2/1
L2
8
Up
Up
- /10
if2/2
L1
5
Up
Up
10/if2/3
L1
6
Up
Up
10/if2/4
L1
7
Up
Up
10/if2/5
L2
2
Up
Up
-/10
lag-1
L2
3
Up
Up
-/10
if2/8
L2
4
Up
Up
-/10
------------------------------------------------------------------------------Interfaces : 8
-> show ip isis interface detail
=============================================================================
ISIS Interface
=============================================================================
----------------------------------------------------------------------------Interface
: system
Level Capability : L1L2
Oper State
: UP
Admin State
: UP
Auth-Type
: None
Circuit Id
: 1
Retransmit Int
: 5
Type
: Broadcast
LSP Pacing Int
: 100
Mesh Group
: Inactive
CSNP Int
: 10
Level
Desg IS
Auth Type
Hello Timer
Priority
:
:
:
:
:
L1
1720.2116.1067
None
9
64
Adjacencies
: 0
Metric
Hello Mult
Passive
: 10
: 3
: No
Level
Desg IS
: L2
: 1720.2116.1067
Adjacencies
: 0
page 3-6
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring IS-IS
IS-IS Quick Steps
Auth Type
: None
Metric
: 10
Hello Timer : 9
Hello Mult
: 3
Priority
: 64
Passive
: No
----------------------------------------------------------------------------Interface
: intf2
Level Capability : L2
Oper State
: UP
Admin State
: UP
Auth-Type
: None
Circuit Id
: 0
Retransmit Int
: 5
Type
: Pt-to-Pt
LSP Pacing Int
: 100
Mesh Group
: Inactive
CSNP Int
: 10
Level
: L2
Adjacencies
: 0
Desg IS
: 1720.2116.1067
Auth Type
: None
Metric
: 10
Hello Timer
: 9
Hello Mult
: 3
Priority
: 64
Passive
: No
-----------------------------------------------------------------------------Interfaces : 2
==============================================================================
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 3-7
IS-IS Overview
Configuring IS-IS
IS-IS Overview
IS-IS is an SPF or link state protocol. IS-IS is also an IGP that distributes routing information between
routers in a single AS. It supports pure IP and OSI environments, as well as dual environments (both IP
and OSI). However, it is deployed extensively in IP-only environments.
IS-IS uses a two-level hierarchy to support large routing domains. A large routing domain may be administratively divided into areas, with each router residing in exactly one area. Routing within an area is
referred to as Level-1 routing. A Level-1 Intermediate System (IS) keeps track of routing within its own
area. Routing between areas is referred to as Level-2 routing. A Level-2 IS keeps track of paths to destination areas.
IS-IS identifies a device in the network by the NSAP address. NSAP address is a logical point between
network and transport layers. It consists of the following three fields:
• NSEL field—The N-Selector (NSEL) field is the last byte and it must be specified as a single byte
with two hex digits preceded by a period (.). Normally, the NSEL value is set to 00.The NSAP address
with its NSEL set to 00 is called Network Entity Title (NET). A NET implies the network layer address
of IS-IS.
• System ID— This ID occupies the 6 bytes preceding the NSEL field. It is customary to use either a
MAC address from the router (for Integrated IS-IS) or an IP address (for example, the IP address of a
loopback interface) as part of the system ID.
• Area ID—The area ID occupies the rest of NSAP address.
When a router starts, it uses the IS-IS Hello protocol to discover neighbors and establish adjacencies. The
router sends Hello packets through all IS-IS-enabled interfaces to its neighbors, and in turn receives Hello
packets. In a broadcast network, the Hello protocol elects a Designated Intermediate System (DIS) for the
network.
Hello. Please respond...
Hello. Please respond...
Are you a neighbor...
Are you a neighbor...
My link state is...
My link state is...
IS-IS Hello Protocol
Separate DISs are elected for Level-1 and Level-2 routing. Election of the DIS is based on the highest
interface priority, the default value of which is 64. Priority can also be manually configured, the range
being 1–127. In case of a tie, the router with the highest Subnetwork Point Of Attachment (SNPA) address
(usually the MAC address) for that interface is elected as the DIS.
Routers that share common data links will become IS-IS neighbors if their Hello packets contain data that
meet the requirements for forming an adjacency. The requirements may differ slightly depending on the
type of media being used, which is either point-to-point or broadcast. The primary criteria for forming
adjacencies are authentication match, IS-type, and MTU size.
page 3-8
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring IS-IS
IS-IS Overview
Adjacencies control the distribution of routing protocol packets. Routing protocol packets are sent and
received only on adjacencies. In particular, distribution of topological database updates proceeds along
adjacencies.
After establishing adjacencies, routers will build a link-state packet (LSP) based upon their local interfaces that are configured for IS-IS and prefixes learned from other adjacent routers. Routers flood LSPs to
all adjacent neighbors except the neighbor from which they received the same LSP. Routers construct their
link-state database from these packets.
The link state is also advertised when a router’s state changes. A router’s adjacencies are reflected in the
contents of its link state packets. This relationship between adjacencies and link state allows the protocol
to detect downed routers in a timely fashion.
Link state packets are flooded throughout the AS. The flooding algorithm ensures that all routers have
exactly the same topological database. This database consists of a collection of link state packets received
from each router belonging to the area. From this database, each router calculates the shortest-path tree,
with itself as the root. This shortest-path tree, in turn, yields a routing table for the protocol.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 3-9
IS-IS Overview
Configuring IS-IS
IS-IS Packet Types
IS-IS transmits data in little chunks known as packets. There are four packet types in IS-IS. They are:
• Intermediate System-to-Intermediate System Hello (IIH)—Used by routers to detect neighbors and
form adjacencies.
• Link State Packet (LSP)—Contains all the information about adjacencies, connected IP prefixes, OSI
end system, area address, etc. There are four types of LSPs: Level-1 pseudo node, Level-1 non-pseudo
node, Level-2 pseudo node, and Level-2 non-pseudo node.
• Complete Sequence Number PDU (CSNP)—Contains a list of all the LSPs from the current data-
base. CSNPs are used to inform other routers about LSPs that may be outdated or missing from their
own database. This ensures that all routers have the same information and are synchronized.
• Partial Sequence Number PDU (PSNP)—Used to request an LSP(s) and acknowledge receipt of an
LSP(s).
IS-IS Areas
IS-IS allows collections of contiguous networks and hosts to be grouped together as an area. Each area
runs a separate copy of the basic link state routing algorithm (usually called SPF). This means that each
area has its own topological database as explained in the previous section.
Area 02
Area 01
L1
L1/L2
L1/L2
L1
Area 03
Area 04
L1/L2
L1/L2
L1
L1
IS-IS Areas
page 3-10
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring IS-IS
IS-IS Overview
An area’s topology is visible only to the members of that area. Routers inside a given area do not know the
detailed topology outside the area. This isolation of knowledge enables the protocol to reduce routing traffic by concentrating on small areas of an AS, as compared to treating the entire AS as a single link state
domain. In IS-IS, the router belongs entirely to a single area.
When an AS is split into IS-IS areas, the routers are classified into the following three categories:
• Level-1 routers—These are Intra-area routers and form relationship with other Level-1 or Level-1/2
routers within the same area.
• Level-1/2 routers—These routers form relationship with other Level-1, Level-2, or Level-1/2 routers.
They are used to connect Inter-area routers with Intra-area routers.
• Level-2 routers—These are Inter-area routers and form relationship with other Level-2 or Level-1/2
routers
These Level capabilities can be defined globally on a router or on specific interfaces. Since a separate
copy of the link state algorithm is run in each area, most configuration parameters are defined on a perrouter basis. All routers belonging to an area must agree on that area’s configuration. Misconfiguration
will keep neighbors from forming adjacencies between themselves, and IS-IS will not function.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 3-11
IS-IS Overview
Configuring IS-IS
Graceful Restart on Stacks with Redundant Switches
OmniSwitch 6850 stacks with two or more switches support redundancy, where if the primary switch fails
or goes offline, the secondary switch is instantly notified. The secondary switch automatically assumes the
primary role. This transition from secondary to primary is known as takeover.
When the router is in the graceful restart mode, it informs its neighbors of the restart. The IS-IS Hello
(IIH) messages are modified to signal a graceful restart request. The neighbors respond by sending back
their own IIHs with an acknowledgement of the restart, along with a "Remaining Time" value to indicate
how long they will wait for a restart. The neighbors also continue to send out LSPs with the restarting
router still listed as an adjacency, thus avoiding SPF calculations and enabling traffic to flow to the router
from neighbors.
The restarting router continues to forward LSPs using its pre-restart forwarding tables. When graceful
restart is enabled, the router can either be a helper or a restarting router, or both. In the current release,
only the helper mode is supported. If a helper is enabled on a neighbor, it begins the Link State Database
synchronization process. They send their Complete Sequence Number PDUs (CSNPs) to the restarting
router. The restarting router can then determine the LSPs it needs and request them. After it receives all
requested LSPs, the database is synchronized.
Note. When graceful restart is enabled on the router, the helper mode is automatically enabled by default.
When the graceful restart timer expires, the restarting router runs the SPF calculation to re-compute IS-IS
routes. Only then does it flood LSPs to neighbors and comes back to normal protocol behavior.
In the network illustration below, a helper router, Router Y, monitors the network for topology changes.
As long as there are none, it continues to advertise its LSPs as if the restarting router, Router X, had
remained in continuous IS-IS operation (i.e., Router Y’s LSPs continue to list an adjacency to Router X
over network segment S, regardless of the adjacency’s current synchronization state).
Router B
Restarting Router X
Helper Router Y
Network Segment S
Router C
Router A
IS-IS Graceful Restart Helper and Restarting Router
page 3-12
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring IS-IS
IS-IS Overview
If the restarting router, Router X, is identified as the Designated Router (DIS) on the network segment S at
the beginning of the helping relationship, the helper neighbor, Router Y, will maintain Router X as the
DIS until the helping relationship is terminated. If there are multiple adjacencies with the restarting Router
X, Router Y will act as a helper on all other adjacencies.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 3-13
Configuring IS-IS
Configuring IS-IS
Configuring IS-IS
Configuring IS-IS on a router requires several steps. Depending on your requirements, you may need to
perform all the steps listed below.
By default, IS-IS is disabled on the router. Configuring IS-IS consists of the following tasks:
• Set up the basics of the IS-IS network by configuring the required VLANs and assigning ports to the
VLANs. This is described in “Preparing the Network for IS-IS” on page 3-14.
• Enable IS-IS. When the image file for advanced routing is installed, you must load the code and enable
IS-IS. The commands for enabling IS-IS are described in “Activating IS-IS” on page 3-15.
• Configure an IS-IS area ID. The commands to create areas and backbones are described in “Creating an
IS-IS Area ID” on page 3-16.
• Create IS-IS interfaces. IS-IS interfaces are created and assigned to areas. Creating interfaces is
described in “Creating an Interface” on page 3-16.
• Configure IS-IS levels. Routers are configured at different IS-IS levels. This is described in
“Configuring the IS-IS Level” on page 3-16.
• Enable summarization. Routes can be summarized on routers. This is described in
“Enabling Summarization” on page 3-18.
• Configure IS-IS authentication (optional). This is described in “Enabling IS-IS Authentication” on
page 3-18.
• Configure interface level parameters (optional). The commands to configure interface level parameters
are described in “Modifying Interface Parameters” on page 3-22.
• Create a redistribution policy and enable the same using route maps (optional). To create route maps,
see “Configuring Redistribution Using Route Maps” on page 3-24.
• Configure router capabilities (optional). There are several commands that influence router operation.
These are covered briefly in the table in “Configuring Router Capabilities” on page 3-30.
• Configure redundant switches for graceful IS-IS restart (optional). Configuring switches with redun-
dant switches for graceful restart is described in “Configuring Redundant Switches in a Stack for
Graceful Restart” on page 3-31.
At the end of the chapter is a simple IS-IS network diagram with instructions on how it was created on a
router-by-router basis. See “IS-IS Application Example” on page 3-32 for more information.
Preparing the Network for IS-IS
IS-IS operates over normal switch functions, using existing ports, virtual ports, VLANs, etc. However, the
following network components should already be configured:
• Configure VLANs that are to be used in the IS-IS network. VLANs should be created for all the
connected devices that will participate in the IS-IS network. VLAN configuration is described in
“Configuring VLANs,” in the OmniSwitch 6800/6850/9000 Network Configuration Guide.
• Assign IP interfaces to the VLANs. IP interfaces or router ports, must be assigned to the VLAN.
Assigning IP interfaces is described in “Configuring VLANs,” in the OmniSwitch 6800/6850/9000
Network Configuration Guide.
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Configuring IS-IS
Configuring IS-IS
• Assign ports to the VLANs. The physical ports participating in the IS-IS network must be assigned to
the created VLANs. Assigning ports to a VLAN is described in “Assigning Ports to VLANs,” in the
OmniSwitch 6800/6850/9000 Network Configuration Guide.
• Set the area ID (optional). The routers participating in the IS-IS network must be assigned an area
identification number. The area ID is a part of the Network Service Access Point (NSAP) address,
which identifies a point of connection to the network, such as a router interface. The area identification
number assignment is discussed in “Creating an IS-IS Area ID” on page 3-16.
Activating IS-IS
For IS-IS to run on the router, the advanced routing image must be installed. (For information on how to
install image files, refer to the OmniSwitch 6800/6850/9000 Switch Management Guide.)
After the image file has been installed onto the router, you need to load the IS-IS software into the
memory and enable it, as described below:
Loading the Software
To load the IS-IS software into the router’s running configuration, enter the ip load isis command at the
system prompt:
-> ip load isis
The IS-IS software is now loaded into the memory, and can be enabled. IS-IS is not loaded on the switch
by default.
Enabling IS-IS
Once the IS-IS software has been loaded into the router’s running configuration (either through the CLI or
on startup), it must be enabled. To enable IS-IS on a router, enter the ip isis status command at the CLI
prompt, as shown:
-> ip isis status enable
Once IS-IS is enabled, you can begin to set up IS-IS parameters. To disable IS-IS, enter the following:
-> ip isis status disable
Removing IS-IS
To remove IS-IS from the router memory, it is necessary to manually edit the boot.cfg file. The boot.cfg
file is an ASCII text-based file that controls many of the switch parameters. Open the file and delete all
references to IS-IS.
For the operation to take effect the switch needs to be rebooted.
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Configuring IS-IS
Configuring IS-IS
Creating an IS-IS Area ID
IS-IS allows a set of network devices in an AS to be grouped together in areas. Each area is identified by
an area ID. The area ID is a 1–13 byte variable length integer, which specifies the area address of an IS-IS
routing process.
For creating an IS-IS area first assign area ID to each router present in the network by using the
ip isis area-id command. There can be more than one router in an area.
Note: Each router can have a maximum of 3 area IDs assigned to it.
Creating an Area ID
To create an area ID and associate it with a router, enter the ip isis area-id command with the area
identification number at the CLI prompt, as shown:
-> ip isis area-id 49.0001
Area ID 49.0001 will now be created on the router with the default parameters.
Deleting an Area ID
To delete an area ID, enter the ip isis area-id command, as shown:
-> no ip isis area-id 49.0001
Creating IS-IS Interfaces
Once areas have been created, interfaces need to be created and enabled for IS-IS routing.
Creating an Interface
To create an interface, enter the ip isis interface command with an interface name, as shown:
-> ip isis interface vlan-101
Note. The interface name cannot have spaces.
To delete an interface, use the no form of the ip isis interface, as shown:
-> no ip isis interface vlan-101
Enabling an Interface
Once an interface is created, it must be enabled using the ip isis interface status command, as shown:
-> ip isis interface vlan-101 status enable
Configuring the IS-IS Level
The Autonomous System is divided into multiple areas to reduce the control traffic and size of routing
table. To communicate within an IS-IS area, Level-1 routers are used. To communicate between areas,
Level-2 routers are used. A router can be a configured to be a Level-1 router, a Level-2 router, or both.
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Configuring IS-IS
Configuring IS-IS
The level capability can be configured globally on the router or on specific interfaces. By default, the
router can operate at both levels.
To modify the level capability of the router globally, use the ip isis level-capability command as
explained in the following examples:
To configure a router as a Level-1 router, enter:
-> ip isis level-capability level-1
To configure the router as a Level-2 router, enter:
-> ip isis level-capability level-2
To configure the router to have both Level-1 and Level-2 capabilities, enter:
-> ip isis level-capability level-1/2
To modify the level capability of the router on interface level, use the ip isis interface level-capability
command as explained in the following examples:
To configure an interface named “vlan-2” to have Level-1 capability, enter:
-> ip isis interface vlan-2 level-capability level-1
To configure the interface to have Level-2 capability, enter:
-> ip isis interface vlan-2 level-capability level-2
To configure the interface to have both Level-1 and Level-2 capabilities, enter:
-> ip isis interface vlan-2 level-capability level-1/2
When the level capabilities are configured both globally and on per-interface basis, the combination of the
two settings will decide the potential adjacency. The rules for deciding the potential adjacency is
explained in the following table:
Global Level
Interface
Level
Potential
Adjacency
Level-1/2
Level-1
Level-1
Level-1/2
Level-2
Level-2
Level-1/2
Level-1/2
Level-1 and/or
Level-2
Level-1
Level-1
Level-1
Level-1
Level-1
None
Level-1
Level-1/2
Level-1
Level-2
Level-1
None
Level-2
Level-2
Level-2
Level-2
Level-1/2
Level-2
• When the router is globally configured to act at both levels (Level-1/2) and the interface is configured
to act at any level, the potential adjacency will be the level adjacency of the interface.
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Configuring IS-IS
Configuring IS-IS
• When the router is globally configured to act at Level-1, the potential adjacency will also be Level-1. If
the interface is configured at Level-2 capability, the router will not form potential adjacency with the
neighbor.
• When the router is globally configured to act at Level-2, the potential adjacency will also be at Level-2.
If the interface is configured at Level-1 capability, the router will not form potential adjacency with the
neighbor.
Enabling Summarization
Route summarization in IS-IS reduces the number of routes that a router must maintain, and represents a
series of network numbers in a single summary address.
Summarization can also be enabled or disabled when creating an area. IS-IS routes can be summarized
into Level-2 from the Level-1 database. It is not possible to summarize IS-IS internal routes at Level-1,
although it is possible to summarize external (redistributed) routes. You can summarize level-1, level-2,
level-1/2 IS-IS routes. The metric that is used to advertise the summary address is the smallest metric than
any of the more specific IPv4 routes.
For example, to summarize the routes between 100.1.1.0/24 and 100.1.100.0/24 into one, enter the following command:
-> ip isis summary-address 100.1.0.0/16 level-2
To remove the summary address, enter the following:
-> no ip isis summary-address 100.1.0.0/16 level-2
Note. IS-IS routes are not summarized by default. If you do not specify the level while configuring the
summarization, level-1/2 routes are summarized by default.
Displaying Summary Address
You can view the details of the IS-IS summary address using the show ip isis summary-address
command:
-> show ip isis summary-address
Enabling IS-IS Authentication
IS-IS allows for the use of authentication on a device. When authentication is enabled, only neighbors
using the same type of authentication and the matching keys can communicate.
There are two types of authentication: simple and MD5. Simple authentication requires only a text string
as a password, while MD5 is a form of encrypted authentication that requires a key and a password.
You can use the key parameter to configure the password for Simple or MD5 authentication. Alternatively, you can use the encrypt-key parameter to configure the password by supplying the encrypted form
of the password as the encrypt-key. Configuration snapshot always displays the password in an encrypted
form. You should use only the key parameter during the CLI configuration.
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Configuring IS-IS
If the encrypt-key parameter is used to configure the password through the CLI, then its value should be
the same as the one that appears in the configuration snapshot.
Note. By default, the authentication is disabled and no authentication type is configured
Simple Authentication
Simple authentication works by including the password in the packet. This helps to protect the routers
from a configuration mishap.
To enable simple authentication with plain text key on a router, enter the ip isis auth-type command, as
shown:
-> ip isis auth-type simple key 12345
Here, only routers with simple authentication and simple key “12345” will be able to use the configured
interface.
You can also use the encrypt-key parameter to configure the password by supplying the encrypted form
of the password.
-> ip isis auth-type simple encrypt-key 31fa061a5de5d1a8
If the encrypt-key parameter is used to configure the password through the CLI, then its value should be
the same as the one that appears in the configuration snapshot.
Note. Only valid system generated values are accepted as encrypt-key.
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Configuring IS-IS
Configuring IS-IS
MD5 Authentication
MD5 authentication can be used to protect the system from malicious actions. MD5 authentication can be
used to encrypt information sent over the network. MD5 authentication works by using shared secret key.
Key is used to sign the packets with an MD5 checksum, so that the packets cannot be forged or tampered
with. Since the key is not included in the packet, snooping the key is not possible.
To enable MD5 authentication with plain text key on a router, enter the ip isis auth-type command, as
shown:
-> ip isis auth-type md5 key 12345
Here, only routers with MD5 authentication and password “12345” will be able to use the configured
interface.
You can also use the encrypt-key parameter to configure the password by supplying the encrypted form
of the password.
-> ip isis auth-type md5 encrypt-key 31fa061a5de5d1a8
If the encrypt-key parameter is used to configure the password through the CLI, then its value should be
the same as the one that appears in the configuration snapshot.
Note. Only valid system generated values are accepted as encrypt-key.
Global Authentication
The authentication check for all the IS-IS PDUs can be enabled or disabled globally by using the ip isis
auth-check command.
To enable the authentication check for IS-IS PDUs, enter the following:
-> ip isis auth-check enable
If enabled, IS-IS PDUs that fail to match either of the authentication type and key requirements are
rejected.
To disable the authentication check for IS-IS PDUs, enter the following:
-> ip isis auth-check disable
If disabled, the authentication PDUs are generated and the IS-IS PDUs are authenticated on receipt. An
error message will be generated in case of a mismatch; but PDUs will not be rejected.
Note. By default, authentication check is enabled.
IS-IS authentication can be enabled globally for Hello, CSNP, and PSNP packets.
To enable the authentication of Hello PDUs globally, enter the following:
-> ip isis hello-auth
To enable the authentication of CSNP PDUs globally, enter the following:
-> ip isis csnp-auth
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Configuring IS-IS
Configuring IS-IS
To enable the authentication of PSNP PDUs globally, enter the following:
-> ip isis psnp-auth
Level Authentication
You can enable authentication and configure the authentication types for specific IS-IS levels globally
using ip isis level auth-type command. For example:
-> ip isis level 2 auth-type md5 encrypt-key 7a1e441a014b4030
The above example configures the authentication type as MD5 for level 2 IS-IS PDUs and the key.
Note. You can configure the authentication of either simple or MD5 type with the password specified
either in plain text or in encrypted form. For the explanations about the authentication types and the key
types refer Simple authentication and MD5 authentication.
IS-IS authentication can be enabled for specific IS-IS PDUs such as Hello, CSNP, and PSNP packets at
specific IS-IS levels (Level-1, Level-2, or Level-1/2). Enabling authentication on specific IS-IS levels
over-rides the global authentication.
To enable the authentication of Hello PDUs for IS-IS Level-1, enter the following:
-> ip isis level 1 hello-auth
To enable the authentication of CSNP PDUs for IS-IS Level-2, enter the following:
-> ip isis level 2 csnp-auth
To enable the authentication of PSNP PDUs for IS-IS Level-2, enter the following:
-> ip isis level 2 psnp-auth
Interface Authentication
IS-IS authentication can be enabled for Hello packets on specific interfaces using ip isis interface helloauth-type.
For example, to enable MD5 authentication of Hello PDUs on the interface VLAN 100, enter the following:
-> ip isis interface vlan-100 hello-auth-type md5 key 12345
IS-IS authentication can also be enabled for Hello packets at different levels on specific interfaces using ip
isis interface hello-auth-type.
For example, to enable simple authentication of Hello PDUs on the interface VLAN 100 at Level-2, enter
the following:
-> ip isis interface vlan-100 level 2 hello-auth-type simple encrypt-key
7a1e441a014b4030
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Configuring IS-IS
Configuring IS-IS
Note. Both the ip isis interface hello-auth-type and ip isis interface level hello-auth-type can be configured for the authentication of either simple or MD5 type with the password specified either in plain text or
in encrypted form. For the explanations about the authentication types and the key types refer Simple
authentication and MD5 authentication.
Modifying Interface Parameters
To configure the interval between the successive Hello PDUs at the given IS-IS level on an interface, enter
the ip isis interface level hello-interval command, as shown:
-> ip isis interface man-1 level 1 hello-interval 50
To configure the number of Hello PDUs before the router declares the adjacency as down, use the ip isis
interface level hello-multiplier command, as shown:
-> ip isis interface lan-1 level 1 hello-multiplier 10
To configure the metric value of the IS-IS level of the interface, enter the ip isis interface level metric
command, as shown:
-> ip isis interface interface-1 level 1 metric 25
Configuring an interface as passive suppresses IS-IS packets from being sent or received on the interface.
For example, to configure the interface from receiving Level-1 IS-IS packets, enter the
ip isis interface level passive command, as shown:
-> ip isis interface lan-5 level 1 passive
Configuring the priority value helps to determine a DIS in a multi-access network. To configure the priority of the IS-IS router interface for the election of a DIS in a multi-access network, enter the
ip isis interface level priority command, as shown:
-> ip isis interface vlan-isis level 1 priority 4
There are several other interface parameters that can be modified on a specified interface. Most of these
deal with timer settings.
The following table shows the various interface parameters that can be set:
ip isis interface csnp-interval
Configures the time interval in seconds to send Complete Sequence
Number PDUs (CSNP) from the specified interface.
ip isis interface lsp-pacinginterval
Configures the interval between IS-IS Link State PDUs (LSP) sent
from the specified interface.
ip isis interface retransmitinterval
Configures the minimum time between Link State PDU (LSP) transmissions on a point-to-point interface.
ip isis interface default-type
Configures the interface type to default (Broadcast).
These parameters can be added any time. In broadcast networks, the DIS sends CSNP packets to maintain
database synchronization. For example, to configure the CSNP PDUs time interval to 50 seconds, enter the
following:
-> ip isis interface vlan-101 csnp-interval 50
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Configuring IS-IS
Configuring IS-IS
To set the LSP interval to 120 seconds, enter the following:
-> ip isis interface vlan-101 lsp-pacing-interval 120
To set the LSP retransmit interval to 100 seconds, enter the following:
-> ip isis interface lan-3 retransmit-interval 100
Note. The retransmit interval should be greater than the expected round-trip delay between two
devices.This will avoid any needless retransmission of PDUs.
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Configuring IS-IS
Configuring IS-IS
Configuring Redistribution Using Route Maps
It is possible to configure the IS-IS protocol to advertise routes learned from other routing protocols (ASexternal routes) into the IS-IS network. Such a process is referred to as route redistribution and is configured using the ip redist command.
IS-IS redistribution uses route maps to control how external routes are learned and distributed. A route
map consists of one or more user-defined statements that can determine which routes are allowed or
denied access to the IS-IS network. In addition a route map may also contain statements that modify route
parameters before they are redistributed.
When a route map is created, it is given a name to identify the group of statements that it represents. This
name is required by the ip redist command. Therefore, configuring IS-IS route redistribution involves the
following steps:
1 Create a route map, as described in “Using Route Maps” on page 3-24.
2 Configure redistribution to apply a route map, as described in “Configuring Route Map Redistribution” on page 3-28.
Using Route Maps
A route map specifies the criteria that are used to control redistribution of routes between protocols. Such
criteria are defined by configuring route map statements. There are three different types of statements:
• Action—An action statement configures the route map name, sequence number, and whether or not
redistribution is permitted or denied based on route map criteria.
• Match—A match statement specifies criteria that a route must match. When a match occurs, then the
action statement is applied to the route.
• Set—A set statement is used to modify route information before the route is redistributed into the
receiving protocol. This statement is applied only if all the criteria of the route map is met and the
action permits redistribution.
The ip route-map command is used to configure route map statements and provides the following action,
match, and set parameters:
ip route-map action ...
ip route-map match ...
ip route-map set ...
permit
deny
ip address
ip next-hop
ipv6 address
ipv6 next-hop
tag
ipv4-interface
ipv6-interface
metric
route-type
metric
metric-type
tag
community
local-preference
level
ip-nexthop
ipv6-nexthop
Note. The tag parameter is not supported in the current release.
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Configuring IS-IS
Configuring IS-IS
Refer to the “IP Commands” chapter in the OmniSwitch CLI Reference Guide for more information about
the ip route-map command parameters and usage guidelines.
Once a route map is created, it is then applied using the ip redist command. See “Configuring Route Map
Redistribution” on page 3-28 for more information.
Creating a Route Map
When a route map is created, it is given a name (up to 20 characters), a sequence number, and an action
(permit or deny). Specifying a sequence number is optional. If a value is not configured, then the number
50 is used by default.
To create a route map, use the ip route-map command with the action parameter. For example,
-> ip route-map rip-to-isis sequence-number 10 action permit
The above command creates the rip-to-isis route map, assigns a sequence number of 10 to the route map,
and specifies a permit action.
To optionally filter routes before redistribution, use the ip route-map command with a match parameter
to configure match criteria for incoming routes. For example,
-> ip route-map rip-to-isis sequence-number 10 match metric 8
The above command configures a match statement for the rip-to-isis route map to filter routes based on
their metric value. When this route map is applied, only RIP routes with a metric value of eight are redistributed into the IS-IS network. All other routes with a different metric value are dropped.
Note. Configuring match statement is not required. However, if a route map does not contain any match
statement and the route map is applied using the ip redist command, the router redistributes all routes into
the network of the receiving protocol.
To modify route information before it is redistributed, use the ip route-map command with a set parameter. For example,
-> ip route-map rip-to-isis sequence-number 10 set metric 5
The above command configures a set statement for the rip-to-isis route map that changes the metric value
to five. Because this statement is part of the rip-to-isis route map, it is only applied to routes that have an
existing metric value equal to eight.
The following is a summary of the commands used in the above examples:
-> ip route-map rip-to-isis sequence-number 10 action permit
-> ip route-map rip-to-isis sequence-number 10 match metric 8
-> ip route-map rip-to-isis sequence-number 10 set metric 5
To verify a route map configuration, use the show ip route-map command:
-> show ip route-map
Route Maps: configured: 1 max: 200
Route Map: rip-to-isis Sequence Number: 10 Action permit
match metric 8
set metric 5
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Configuring IS-IS
Configuring IS-IS
Deleting a Route Map
Use the no form of the ip route-map command to delete an entire route map, a route map sequence, or a
specific statement within a sequence.
To delete an entire route map, enter no ip route-map followed by the route map name. For example, the
following command deletes the entire route map named rip-to-isis:
-> no ip route-map rip-to-isis
To delete a specific sequence number within a route map, enter no ip route-map followed by the route
map name, then sequence-number followed by the actual number. For example, the following command
deletes sequence 10 from the rip-to-isis route map:
-> no ip route-map rip-to-isis sequence-number 10
Note that in the above example, the rip-to-isis route map is not deleted. Only those statements associated
with sequence 10 are removed from the route map.
To delete a specific statement within a route map, enter no ip route-map followed by the route map name,
then sequence-number followed by the sequence number for the statement, then either match or set and
the match or set parameter and value. For example, the following command deletes only the match metric
8 statement from route map rip-to-isis sequence 10:
-> no ip route-map rip-to-isis sequence-number 10 match metric 8
Configuring Route Map Sequences
A route map may consist of one or more sequences of statements. The sequence number determines which
statements belong to which sequence and the order in which sequences for the same route map are
processed.
To add match and set statements to an existing route map sequence, specify the same route map name and
sequence number for each statement. For example, the following series of commands creates route map
rm_1 and configures match and set statements for the rm_1 sequence 10:
-> ip route-map rm_1 sequence-number 10 action permit
-> ip route-map rm_1 sequence-number 10 match metric 8
-> ip route-map rm_1 sequence-number 10 set metric 2
To configure a new sequence of statements for an existing route map, specify the same route map name
but use a different sequence number. For example, the following command creates a new sequence 20 for
the rm_1 route map:
-> ip route-map rm_1 sequence-number 20 action permit
-> ip route-map rm_1 sequence-number 20 match ipv4-interface to-finance
-> ip route-map rm_1 sequence-number 20 set metric 5
The resulting route map appears as follows:
-> show ip route-map rm_1
Route Map: rip-to-isis Sequence Number: 10 Action permit
match metric 8
set metric 2
Route Map: rip-to-isis Sequence Number: 20 Action permit
match ipv4 interface to-finance
set metric 5
Sequence 10 and sequence 20 are both linked to route map rm_1 and are processed in ascending order
according to their sequence number value. Note that there is an implied logical OR between sequences. As
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Configuring IS-IS
Configuring IS-IS
a result, if there is no match for the metric value in sequence 10, then the match interface statement in
sequence 20 is processed. However, if a route matches the metric value 8, then sequence 20 is not used.
The set statement for whichever sequence was matched is applied.
A route map sequence may contain multiple match statements. If these statements are of the same kind
(e.g., match metric 5, match metric 8, etc.) then a logical OR is implied between each like statement. If the
match statements specify different types of matches (e.g. match metric 8, match ip4 interface to-finance,
etc.), then a logical AND is implied between each statement. For example, the following route map
sequence will redistribute a route if its metric value is either 8 or 5:
-> ip route-map rm_1 sequence-number 10 action permit
-> ip route-map rm_1 sequence-number 10 match metric 5
-> ip route-map rm_1 sequence-number 10 match metric 8
The following route map sequence will redistribute a route if the route has a metric of 8 or 5 and if the
route was learned on the IPv4 interface to-finance:
->
->
->
->
ip
ip
ip
ip
route-map
route-map
route-map
route-map
rm_1
rm_1
rm_1
rm_1
sequence-number
sequence-number
sequence-number
sequence-number
10
10
10
10
action permit
match metric 5
match metric 8
match ipv4-interface to-finance
Configuring Access Lists
An IP access list provides a convenient way to add multiple IPv4 addresses to a route map. Using an
access list avoids having to enter a separate route map statement for each individual IP address. Instead, a
single statement is used that specifies the access list name. The route map is then applied to all the
addresses contained within the access list.
Configuring an IP access list involves two steps: creating the access list and adding IP addresses to the list.
To create an IP access list, use the ip access-list and specify a name to associate with the list. For example,
-> ip access-list ipaddr
To add addresses to an access list, use the ip access-list address command. For example, the following
commands add addresses to an existing access list:
-> ip access-list ipaddr address 16.24.2.1/16
Use the same access list name each time the above commands are used to add additional addresses to the
same access list. In addition, both commands provide the ability to configure if an address and/or its
matching subnet routes are permitted (the default) or denied redistribution. For example:
-> ip access-list ipaddr address 16.24.2.1/16 action deny redist-control allsubnets
For more information about configuring access list commands, see the “IP Commands” chapter in the
OmniSwitch CLI Reference Guide.
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Configuring IS-IS
Configuring IS-IS
Configuring Route Map Redistribution
The ip redist command is used to configure the redistribution of routes from a source protocol into the ISIS destination protocol. This command is used on the IS-IS router that will perform the redistribution.
A source protocol is a protocol from which the routes are learned. A destination protocol is the one into
which the routes are redistributed. Make sure that both protocols are loaded and enabled before configuring redistribution.
Redistribution applies criteria specified in a route map to routes received from the source protocol. Therefore, configuring redistribution requires an existing route map. For example, the following command
configures the redistribution of RIP routes into the IS-IS network using the rip-to-isis route map:
-> ip redist rip into isis route-map rip-to-isis
RIP routes received by the ISIS router interface are processed based on the contents of the rip-to-isis route
map. Routes that match criteria specified in this route map are either allowed or denied redistribution into
the ISIS network. The route map may also specify the modification of route information before the route is
redistributed. See “Using Route Maps” on page 3-24 for more information.
To remove a route map redistribution configuration, use the no form of the ip redist into isis route-map
command. For example:
-> no ip redist rip into isis route-map rip-to-isis
Use the show ip redist command to verify the redistribution configuration:
-> show ip redist
Source
Destination
Protocol
Protocol
Status
Route Map
------------+------------+---------+-------------------OSPF
ISIS
Enabled
ospf-to-isis
RIP
ISIS
Enabled
rip-to-isis
Configuring the Administrative Status of the Route Map Redistribution
The administrative status of a route map redistribution configuration is enabled by default. To change the
administrative status, use the status parameter with the ip redist into isis route-map command. For
example, the following command disables the redistribution administrative status for the specified route
map:
-> ip redist rip into isis route-map rip-to-isis status disable
The following command example enables the administrative status:
-> ip redist rip into isis route-map rip-to-isis status enable
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Configuring IS-IS
Route Map Redistribution Example
The following example configures the redistribution of RIP routes into an IS-IS network using a route map
(rip-to-isis) to filter specific routes:
-> ip route-map rip-to-isis sequence-number 10 action deny
-> ip route-map rip-to-isis sequence-number 10 match metric 5
-> ip route-map rip-to-isis sequence-number 20 action permit
-> ip route-map rip-to-isis sequence-number 20 match ipv4-interface intf_isis
-> ip route-map rip-to-isis sequence-number 20 set metric 60
-> ip route-map rip-to-isis sequence-number 30 action permit
-> ip route-map rip-to-isis sequence-number 30 set metric 8
-> ip redist rip into isis route-map rip-to-isis
The resulting rip-to-isis route map redistribution configuration does the following:
• Denies the redistribution of RIP routes with a metric value set to five.
• Redistributes into IS-IS all routes learned on the intf_isis interface and sets the metric for such routes
to 60.
Note. Wide metrics need to be enabled, if a metric of more than 64 is configured.
• Redistributes all other routes (those not processed by sequence 10 or 20) and sets the metric for such
routes to eight.
IS-IS allows redistributing Level-1 IS-IS routes into Level-2 IS-IS routes. This is termed as Level-1 to
Level-2 Leaking. This release also supports the prefix distribution from the level-2 IS-IS routes to level-1
IS-IS routes.
The following example configures the IS-IS Level-1 to Level-2 Leaking routes using a route map (is2is) to
filter specific routes.
To redistribute IS-IS Level-1 routes into IS-IS Level-2 routes, use the following route map sequence:
->
->
->
->
ip
ip
ip
ip
route-map is2is sequence-number
route-map is2is sequence-number
route-map is2is sequence-number
redist isis into isis route-map
1 action permit
1 match route-type level1
1 set level level2
is2is status enable
The resulting is2is route map redistribution configuration redistributes all Level-1 IS-IS routes into Level2 IS-IS routes.
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Configuring IS-IS
Configuring IS-IS
Configuring Router Capabilities
The following table lists various commands that can be useful in tailoring a router’s performance capabilities. All the listed parameters have defaults that are acceptable for running an IS-IS network.
ip isis overload
Sets the IS-IS router to operate in the overload state.
ip isis overload-on-boot
Configures the router to be in the overload state.
ip isis strict-adjacency-check
Enables or disables the adjacency check configuration.
To set the IS-IS router to operate in overload state, enter:
-> ip isis overload timeout 70
To configure the router to be in the overload state, enter:
-> ip isis overload-on-boot timeout 80
To enable the adjacency check configuration, enter:
-> ip isis strict-adjacency-check enable
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Configuring IS-IS
Configuring IS-IS
Configuring Redundant Switches in a Stack for Graceful Restart
By default, IS-IS graceful restart is disabled. When graceful restart is enabled, the router can either be a
helper or a restarting router. When graceful restart is enabled on the router, the helper mode is automatically enabled by default. To configure IS-IS graceful restart support on OmniSwitch 6850 Series switches,
use the ip isis graceful-restart command.
Note. In the current release, only the graceful restart helper mode is supported.
For example, to configure graceful restart on the router, enter:
-> ip isis graceful-restart
The helper mode can be disabled on the router with the ip isis graceful-restart helper command. For
example, to disable the helper support for neighboring routers, enter the following:
-> ip isis graceful-restart helper disable
To disable support for graceful restart, use the no form of the ip isis graceful-restart command by entering:
-> no ip isis graceful-restart
On OmniSwitch 6850 Series switches, continuous forwarding during a graceful restart depends on several
factors. If the secondary module has a different router MAC than the primary module, or if one or more
ports of a VLAN belonged to the primary module, spanning tree re-convergence might disrupt forwarding
state, even though IS-IS performs a graceful restart.
Note. Graceful restart is only supported on active ports (i.e., interfaces), which are on the secondary or
idle switches in a stack during a takeover. It is not supported on ports on a primary switch in a stack.
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IS-IS Application Example
Configuring IS-IS
IS-IS Application Example
This section will demonstrate how to set up a simple IS-IS network. It uses two routers, each with an area.
Each router is a L1-L2 capable router and can communicate with different areas. This section will demonstrate how to set it up by explaining the necessary commands for each router.
The following diagram is a simple IS-IS network. This network will be created using the steps explained
below.
VLAN 5
Interface 10.4.1.1
VLAN 5
Interface 10.4.1.2
level-1/2
level-1/2
Area
00.0002
Area
00.0001
Simple IS-IS Network
Step 1: Prepare the Routers
The first step is to create the VLANs on each router, add an IP interface to the VLAN, and assign a port to
the VLAN.
Note. The ports will be statically assigned to the router, as a VLAN must have a physical port assigned to
it for the router port to function. However, the router could be set up in such a way that mobile ports are
dynamically assigned to VLANs using VLAN rules. See the chapter titled “Defining VLAN Rules” in the
OmniSwitch 6800/6850/9000 Network Configuration Guide.
The commands to setup VLANs are shown below:
Router 1
-> vlan 5 name vlan-isis
-> ip interface vlan-isis address 10.4.1.1 mask 255.0.0.0 vlan 5
-> vlan 5 port default 1/10
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Configuring IS-IS
IS-IS Application Example
Router 2
-> vlan 5 name vlan-isis
-> ip interface vlan-isis address 10.4.1.2 mask 255.0.0.0 vlan 5
-> vlan 5 port default 1/10
Step 2: Enable IS-IS
The next step is to load and enable IS-IS on each router. The commands for this are shown below (the
commands are the same on each router):
-> ip load isis
-> ip isis status enable
Step 3: Create and Enable Area ID
Now the areas should be created and enabled. The commands for this are shown below:
Router 1
-> ip isis area-id 00.0001
This command created the area for Router 1.
Router 2
-> ip isis area-id 00.0002
This command created the area for Router 2.
Step 4: Configuring IS-IS Level Capability
The router must be configured with the IS-IS level capability, which decides whether the router will route
traffic within an area or between two or more areas.
Router 1
-> ip isis level-capability level-1/2
Router 2
-> ip isis level-capability level-1/2
Note. The default IS-IS level capability is Level-1/2.
Step 5: Create, Enable, and Assign Interfaces
Next, IS-IS interfaces must be enabled. The IS-IS interfaces should have the same IP address as the IP
router ports created above in “Step 1: Prepare the Routers” on page 3-32.
Router 1
-> ip isis interface vlan-isis
-> ip isis interface vlan-isis status enable
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Verifying IS-IS Configuration
Configuring IS-IS
Router 2
-> ip isis interface vlan-isis
-> ip isis interface vlan-isis status enable
Step 6: Examine the Network
After the network has been created, you can check various aspects of it using show commands:
• For IS-IS in general, use the show ip isis statistics command.
• For SPF details, use the show ip isis spf command.
• For summarization details, use the show ip isis summary-address command.
• To check for adjacencies formed with neighbors, use the show ip isis adjacency command.
• For routes, use the show ip isis routes command.
• For details of the interfaces, use the show ip isis interface command.
Verifying IS-IS Configuration
To verify information about adjacent routers, summary-address, SPF, or IS-IS in general, use the show
commands listed in the following table:
show ip isis adjacency
Displays information about IS-IS adjacent routers.
show ip isis database
Displays IS-IS LSP database information of the adjacent routers.
show ip isis hostname
Displays the database of IS-IS host names.
show ip isis routes
Displays the IS-IS route information known to the router.
show ip isis spf
Displays the IS-IS SPF calculation information.
show ip isis spf-log
Displays the IS-IS SPF log.
show ip isis statistics
Displays the IS-IS statistics information.
show ip isis status
Displays the IS-IS status.
show ip isis summary-address Displays the IS-IS summary address database.
show ip redist
Displays the IS-IS configured redistributions.
show ip isis interface
Displays the IS-IS interface information.
For more information about the commands output, see Chapter 3, “Configuring IS-IS” in the OmniSwitch
CLI Reference Guide.
page 3-34
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4
Configuring BGP
The Border Gateway Protocol (BGP) is an exterior routing protocol that guarantees the loop-free exchange
of routing information between autonomous systems. The Alcatel-Lucent implementation supports BGP
version 4 as defined in RFC 4271.
The Alcatel-Lucent implementation of BGP is designed for enterprise networks, specifically for border
routers handling a public network connection, such as the organization’s Internet Service Provider (ISP)
link. Up to 65,000 route table entries and next hop routes can be supported by BGP.
This chapter describes the configuration and use of BGP in IPv4 and IPv6 environments using the
Command Line Interface (CLI). The Alcatel-Lucent implementation of BGP-4 and Multiprotocol
Extensions to BGP-4 is based on several RFCs: 4271, 2439, 3392, 2385, 1997, 4456, 3065, 4273, 4760,
and 2545. CLI commands are used in the configuration examples in this chapter. For more details about
the syntax of these commands, see the OmniSwitch CLI Reference Guide.
Note. In this document, the BGP terms “peer” and “neighbor” are used interchangeably.
Note. This release allows you to configure and manage BGP in IPv4 and IPv6 environments via CLI,
WebView and SNMP interfaces.
In This Chapter
The topics and configuration procedures in this chapter include:
• Setting up global BGP parameters, such as a router’s Autonomous System (AS) number and default
local preference. See “Setting Global BGP Parameters” on page 4-20.
• Configuring a BGP peer and setting various parameters on that peer, such as timers, soft reconfigura-
tion, and policies. See “Configuring a BGP Peer” on page 4-26.
• Configuring route dampening parameters for the router. See “Controlling Route Flapping Through
Route Dampening” on page 4-36.
• Configuring route reflection using single and multiple route reflectors. See “Setting Up Route Reflec-
tion” on page 4-40.
• Configuring aggregate routes as well as values for aggregates, such as community strings and local
preference. See “Configuring Aggregate Routes” on page 4-32.
• Configuring BGP local networks. See “Configuring Local Routes (Networks)” on page 4-33.
• Configuring confederations. See “Creating a Confederation” on page 4-44.
• Using policies to control BGP routing. See “Routing Policies” on page 4-45.
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Configuring BGP
• Configuring redistribution using route maps. See “Configuring Redistribution” on page 4-53.
• Enabling IPv6 BGP Unicast. See “Enabling/Disabling IPv6 BGP Unicast” on page 4-68.
• Configuring an IPv6 BGP Peer. See “Configuring an IPv6 BGP Peer” on page 4-68.
• Configuring IPv6 BGP Networks. See “Configuring IPv6 BGP Networks” on page 4-73.
• Configuring IPv6 Redistribution. See “Configuring IPv6 Redistribution” on page 4-76.
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Configuring BGP
BGP Specifications
BGP Specifications
RFCs Supported
4271–A Border Gateway Protocol 4 (BGP-4)
2439–BGP Route Flap Damping
3392–Capabilities Advertisement with BGP-4
2385–Protection of BGP Sessions via the TCP MD5
Signature Option
1997–BGP Communities Attribute
4456–BGP Route Reflection: An Alternative to Full Mesh
Internal BGP (IBGP)
3065–Autonomous System Confederations for BGP
4273–Definitions of Managed Objects for BGP-4
4760–Multiprotocol Extensions for BGP-4
2545–Use of BGP-4 Multiprotocol Extensions for IPv6
Inter-Domain Routing
BGP Attributes Supported
Origin, AS Path, Next Hop (IPv4), MED, Local Preference, Atomic Aggregate, Aggregator (IPv4), Community,
Originator ID, Cluster List, Multiprotocol Reachable
NLRI (IPv6), Multiprotocol Unreachable NLRI (IPv6).
Maximum BGP Peers per Router
32
Maximum number of routes supported
65,000
Range for AS Numbers
1 to 65535
Range of Local Preference Values
0 to 4294967295
Range for Confederation IDs (not supported in IPv6)
0 to 65535
Range for MED Attribute
0 to 4294967295
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Quick Steps for Using BGP
Configuring BGP
Quick Steps for Using BGP
1 The BGP software is not loaded automatically when the router is booted. You must manually load the
software into memory by typing the following command:
-> ip load bgp
2 Assign an Autonomous System (AS) number to the local BGP speaker. By default the AS number is 1,
but you may want to change this number to fit your network requirements. For example:
-> ip bgp autonomous-system 100
3 Enable the BGP protocol by entering the following command:
-> ip bgp status enable
4 Create a BGP peer entry. The local BGP speaker should be able to reach this peer. The IP address you
assign the peer should be valid. For example:
-> ip bgp neighbor 198.45.16.145
5 Assign an AS number to the peer you just created. All peers require an AS number. The AS number
does not have to be the same as the AS number for the local BGP speaker. For example:
-> ip bgp neighbor 198.45.16.145 remote-as 200
6 By default a BGP peer is not active on the network until you enable it. Use the following commands to
enable the peer created in Step 4:
-> ip bgp neighbor 198.45.16.145 status enable
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Configuring BGP
BGP Overview
BGP Overview
BGP (Border Gateway Protocol) is a protocol for exchanging routing information between gateway hosts
in a network of autonomous systems. BGP is the most common protocol used between gateway hosts on
the Internet. The routing table exchanged between hosts contains a list of known routers, the addresses
they can reach, and attributes associated with the path. The OmniSwitch implementation supports BGP-4,
the latest version of BGP, as defined in RFC 1771.
BGP is a distance vector protocol, like the Routing Information Protocol (RIP). It does not require periodic refresh of its entire routing table, but messages are sent between BGP peers to ensure a connection is
active. A BGP speaker must retain the current routing table of its peers during the life of a connection.
Hosts using BGP communicate using the Transmission Control Protocol (TCP) on port 179. On connection start, BGP peers exchange complete copies of their routing tables, which can be quite large. However,
only changes are exchanged after startup, which makes long running BGP sessions more efficient than
shorter ones. BGP-4 lets administrators configure cost metrics based on policy statements.
BGP communicates with other BGP routers in the local AS using Internal BGP (IBGP).
BGP-4 makes it easy to use Classless Inter-Domain Routing (CIDR), which is a way to increase addresses
within the network beyond the current Internet Protocol address assignment scheme. BGP’s basic unit of
routing information is the BGP path, which is a route to a certain set of CIDR prefixes. Paths are tagged
with various path attributes, of which the most important are AS_PATH and NEXT_HOP.
One of BGP-4’s most important functions is loop detection at the autonomous system level, using the
AS_PATH attribute. The AS_PATH attribute is a list of ASs being used for data transport. The syntax
of this attribute is made more complex by its need to support path aggregation, when multiple paths are
collapsed into one to simplify further route advertisements. A simplified view of AS_PATH is that it is
the list of Autonomous Systems that a route goes through to reach its destination. Loops are detected
and avoided by checking for your own AS number in AS_PATHs received from neighboring
Autonomous Systems.
An OmniSwitch using BGP could be placed at the edge of an enterprise network to handle downstream
Internet traffic. However, a router using BGP should not be placed on the public Internet to handle
upstream traffic. The BGP implementation in an OmniSwitch can handle up to 32 peers, but ideally should
be configured with 2 peers. An example of such a configuration would be two (2) paths to the Internet, or
a dual-homed network.
ISP 2
AS 2
ISP 1
AS 1
OmniSwitch
Local Network
AS 1
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BGP Overview
Configuring BGP
BGP is intended for use in networks with multiple autonomous systems. It is not intended to be used as a
LAN routing protocol, such as RIP or Open Shortest Path First (OSPF). In addition, when BGP is used as
an internal routing protocol, it is best used in autonomous systems with multiple exit points as it includes
features that help routers decide among multiple exit paths.
BGP uses TCP as its transport protocol, eliminating the need for it to implement mechanisms for updating
fragmentation, retransmission, acknowledgment, and sequencing information.
Autonomous Systems (ASs)
Exterior routing protocols were created to control the expansion of routing tables and to provide a more
structured view of the Internet by segregating routing domains into separate administrations, called
Autonomous Systems (ASs). Each AS has its own routing policies and unique Interior Gateway Protocols
(IGP).
More specifically, an AS is a set of routers that has a single routing policy, runs under a single technical
administration, and that commonly utilizes a single IGP (though there could be several different IGPs
intermeshed to provide internal routing). To the rest of the networking world, an AS appears as a single
entity.
The diagram below demonstrates the relationship of BGP and ASs:
Internal
Gateway
Protocol
Internal
Gateway
Protocol
BGP
Autonomous System 100
Autonomous System 200
Each AS has a number assigned to it by an Internet Registry, much like an IP address. BGP is the standard
Exterior Gateway Protocol (EGP) used for exchanging information between ASs.
The main difference between routing within an AS (IGP) and routing outside of an AS (EGP) is that IGP
policies tend to be set due to traffic concerns and technical demands, while EGP policies are set more on
business relationships between corporate entities.
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Configuring BGP
BGP Overview
Internal vs. External BGP
Although BGP is an exterior gateway protocol, it can still be used inside an AS as a pipe to exchange BGP
updates. BGP connections inside an AS are referred to as Internal BGP (IBGP), while BGP connections
between routers in separate ASs are referred to as External BGP (EBGP).
ASs with more than one connection to the outside world are called multi-homed transit ASs, and can be
used to transit traffic by other ASs. Routers running IBGP are called transit routers when they carry the
transit traffic through an AS.
For example, the following diagram illustrates the use of IBGP in a multihomed AS:
AS 100
AS 200
Router D
Transit Traffic
Router A
External BGP
External BGP
Router B
Internal BGP
Router C
AS 300
In the above diagram, AS 100 and AS 200 can send and receive traffic via AS 300. AS 300 has become a
transit AS using IBGP between Router B and Router C.
Not all routers in an AS need to run BGP; in most cases, the internal routers use an IGP (such as RIP or
OSPF) to manage internal AS routing. This alleviates the number of routes the internal nontransit routers
must carry.
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BGP Overview
Configuring BGP
Communities
A community is a group of destinations that share some common property. A community is not restricted
to one network or one autonomous system.
Communities are used to simplify routing policies by identifying routes based on a logical property rather
than an IP prefix or an AS number. A BGP speaker can use this attribute in conjunction with other
attributes to control which routes to accept, prefer, and pass on to other BGP neighbors.
Communities are not limited by physical boundaries, and routers in a community can belong to different
ASs.
For example, a community attribute of “no export” could be added to a route, preventing it from being
exported, as shown:
Route A
(No Export)
Route B
AS 100
Route B
AS 200
AS 300
In the above example, Route A is not propagated to AS 100 because it belongs to a community that is not
to be exported by a speaker that learns it.
A route can have more than community attribute. A BGP speaker that sees multiple community attributes
in a route can act on one, several, or all of the attributes. Community attributes can be added or modified
by a speaker before being passed on to other peers.
Communities are discussed further in “Working with Communities” on page 4-43.
page 4-8
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Configuring BGP
BGP Overview
Route Reflectors
Route reflectors are useful if the internal BGP mesh becomes very large. A route reflector is a concentration router for other BGP peers in the local network, acting as a focal point for internal BGP sessions.
Multiple client BGP routers peer with the central route server (the reflector). The router reflectors then
peer with each other. Although BGP rules state that routes learned via one IBGP speaker cannot be advertised to another IBGP speaker, route reflection allows the router reflector servers to “reflect” routes,
thereby relaxing the IBGP standards.
Note. This feature, which is used to minimize the number of IBGP sessions in an AS is not supported in
the IPv6 BGP environment.
Since the router clients in this scenario only peer with the router reflector, the session load per router is
significantly reduced. Route Reflectors are discussed further in “Setting Up Route Reflection” on
page 4-40.
The following illustration demonstrates this concept:
AS 100 with Route Reflection
BGP Reflector 1
BGP Reflector 2
BGP Client 1
BGP Client 2
BGP Client 3
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BGP Client 4
BGP Client 5
BGP Client 6
December 2007
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BGP Overview
Configuring BGP
In the diagram above, Clients 1, 2, and 3 peer with Reflector 1, and Clients 4, 5, and 6 peer with Reflector
2. Reflector 1 and 2 peer with each other. This allows each BGP speaker to maintain only one BGP
session, rather than a possible seven sessions, as demonstrated below:
AS 100 without Route Reflection
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Configuring BGP
BGP Overview
BGP Confederations
Confederations are another way of dealing with large networks with many BGP speakers. Like route
reflectors, confederations are recommended when speakers are forced to handle large numbers of BGP
sessions at the same time.
Note. This feature is not supported in the IPv6 BGP environment.
Confederations are sub ASs within a larger AS. Inside each sub AS, all the rules of IBGP apply. Since
each sub AS has its own AS number, EBGP must be used to communicate between sub ASs. The
following example demonstrates a simple confederation set up:
EBGP
IBGP
AS 1001
AS 1002
AS 100
AS 100 is now a confederation consisting of AS 1001 and AS 1002. Even though EBGP is used to
communicate between AS 1001 and 1002, the entire confederation behaves as though it were using IBGP.
In other words, the sub AS attributes are preserved when crossing the sub AS boundaries.
Confederations are discussed further in “Creating a Confederation” on page 4-44.
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BGP Overview
Configuring BGP
Policies
Routing policies enable route classification for importing and exporting routes. The goal of routing
policies is to control traffic flow. Policies can be applied to egress and ingress traffic.
Note. Policies can be applied only to IPv4 routes and not to IPv6 prefixes.
Policies act as filters to either permit or deny specified routes that are being learned or advertised from a
peer. The following diagram demonstrates this concept:
Incoming policy
(deny AS 300)
Route 1
AS 200
Route 1
Route 2
AS 100
AS 300
Routes from AS 200 and AS 300 are being learned by AS 100. However, there is an incoming AS Path
policy at the edge of AS 100 that prevents routes that originate in AS 300 from being propagated throughout AS 100.
There are four main policy types:
• AS Path. This policy filters routes based on AS path lists. An AS path list notes all of the ASs the route
travels to reach its destination.
• Community Lists. Community list policies filter routes based on the community to which a route
belongs. Communities can affect route behavior based on the definition of the community.
• Prefix Lists. Prefix list policies filter routes based on a specific network address, or a range of network
addresses.
• Route Maps. Route map policies filter routes by amalgamating other policies into one policy. It is a
way of combining many different filter options into one policy.
Creating and assigning policies is discussed in “Routing Policies” on page 4-45.
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Configuring BGP
BGP Overview
Regular Expressions
Regular expressions are used to identify AS paths for purposes of making routing decisions. In this
context, an AS path is a list of one or more unsigned 16-bit AS numbers, in the range 1 through 65535.
An ordinary pattern match string looks like:
100 200
which matches any AS path containing the Autonomous System number 100 followed immediately by
200, anywhere within the AS path list. It would not match an AS path which was missing either number,
or where the numbers did not occur in the correct order, or where the numbers were not adjacent to one
another.
Special pattern matching characters (sometimes called metacharacters) add the ability to specify that part
of the pattern must match the beginning or end of the AS path list, or that some arbitrary number of AS
numbers should match, etc. The following table defines the metacharacters used in the BGP implementation.
Symbol
Description
^
Matches the beginning of the AS path list.
123
Matches the AS number 123.
.
Matches any single AS number.
?
Matches zero or one occurrence of the previous token, which must be an AS number,
a dot, an alternation, or a range.
+
Matches one or more occurrences of the previous token, which must be an AS number, a dot, an alternation, or a range.
*
Matches zero or more occurrences of the previous token, which must be an AS number, a dot, an alternation, or a range.
(
Begins an alternation sequence of AS numbers. It matches any AS number listed in
the alternation sequence.
|
Separates AS numbers in an alternation sequence.
)
Ends an alternation sequence of AS numbers.
[
Begin a range pair consisting of two AS numbers separated by a dash. It matches any
AS number within that inclusive range.
-
Separates the endpoints of a range.
]
Ends a range pair.
$
Matches the end of the AS path list.
,_
Commas, underscores (_), and spaces are ignored.
The regular expressions configured in the router are compared against an incoming AS path list one at a
time until a match is found, or until all patterns have been unsuccessfully matched. Unlike some implementations, which use a character-based pattern matching logic, the BGP implementation treats AS
numbers as single tokens, providing two benefits:
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BGP Overview
Configuring BGP
• It makes writing (and reading) policies much easier.
• It enables the router to begin using the policies more quickly after startup.
For example, to identify routes originating from internal autonomous systems, you would use the pattern:
[64512-65535]$
which means “match any AS number from 64512 to 65535 (inclusive) which occurs at the end of the AS
path.” To accomplish the same thing using character-based pattern matching, you would have to use the
following pattern:
(_6451[2-9]_|_645[2-9][0-9]_|_64[6-9][0-9][0-9]_|_65[0-9][0-9][0-9]_)$
Some examples of valid regular expressions are shown in the following table:
Example
100
^100
100$
^100 500$
100 . . 200
(100|200).+
[500-650]$
page 4-14
Description
Meaning:
Any route which passes through AS number 100.
Matches:
100 200 300
300 100 100
Doesn’t Match:
200 300
Meaning:
Any routes for which the next hop is AS number 100.
Matches:
100 200 100
Doesn’t Match:
50 100 200
Meaning:
Any route which originated from AS number 100 (AS numbers are
prepended to the AS path list as they are passed on, so the originating AS is always the last number in the list).
Matches:
100
200 200 100
Doesn’t Match:
100 200
Meaning:
A route with just two hops, 100 and 500.
Matches:
100 500
Doesn’t Match:
100 500 600
100 200 500
Meaning:
Any route with at least 4 hops, with 100 separated by any two hops
from 200.
Matches:
50 100 400 500 200 600
100 100 100 200
Doesn’t Match:
100 200
100 100 200
Meaning:
Any route which begins with 100 or 200, ends with an AS number
between 500 and 650 (inclusive), and is at least three hops in length.
The “.+” part matches at least one (but possibly more) AS numbers.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring BGP
^500
[100-199]*
500
(900|950)$
BGP Overview
Matches:
100 350 501
200 250 260 270 280 600
Doesn’t Match:
100 600
100 400 600 700
Meaning:
Only routes consisting of a single AS, 500.
Matches:
500
Doesn’t Match:
500 600
100 500 600
Meaning:
Any route which ends with any number of occurrences of AS numbers in the range 100 to 199, followed by 500, followed by either a
900 or 950.
Matches:
100 150 175 500 900
100 500 950
Doesn’t Match:
100 200 500 900
100 199 500
Some examples of invalid regular expressions are shown in the following table:
Error
Description
66543
Number is too large. AS numbers must be in the range 1 to 65535.
64,512
Possibly an error, if the user meant the number 64512. The comma gets interpreted as
a separator, thus the pattern is equivalent to the two AS numbers 64 and 512.
(100 200 | 300)
Alternation sequences must consist of single AS numbers separated by vertical bars,
enclosed by parentheses.
(100*|200)
No metacharacters other than vertical bars may be included within an alteration
sequence.
(100 |
(200|300))
Parthentheses may not be nested. This pattern is actually equivalent to (100|200|300).
100 ^ 200
The “^” metacharacter must occur first in the pattern, as it matches the beginning of
the AS path.
^500 $600
The “$” metacharacter must occur last in the pattern, as it matches the end of the AS
path.
^? 100
The repetition metacharacters (?,+,*) cannot be applied to the beginning of the line. If
it were legal, this pattern would be equivalent to the pattern: 100.
[1-(8|9)]*
A range cannot contain an alternation sequence.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 4-15
BGP Overview
Configuring BGP
The Route Selection Process
Several metrics are used to make BGP routing decisions. These metrics include the route’s local preference, the AS Path, and the Multi-Exit Discriminator (MED). These metrics are organized into a hierarchy
such that if a tie results, the next important criteria is used to break the tie until a decision is made for the
route path.
BGP selects the best path to an autonomous system from all known paths and propagates the selected path
to its neighbors. BGP uses the following criteria, in order, to select the best path. If routes are equal at a
given point in the selection process, then the next criterion is applied to break the tie.
1 The route with the highest local preference.
2 The route with the fewest autonomous systems listed in its AS Path.
3 The AS path origin. A route with an AS path origin of IGP (internal to the AS) is preferred. Next in
preference is a route with an AS path origin of EGP (external to the AS). Least preferred is an AS path that
is incomplete. In summary, the path origin preference is as follows: IGP < EGP < Incomplete.
4 The route with the lowest Multi-Exit Discriminator (MED). MEDs are by default compared between
routes that are received within the same AS. However, you can configure BGP to consider MED values
from external peers. This test is only applied if the local AS has two or more connections, or exits, to a
neighbor AS.
5 The route with a closer next hop (with respect to the internal routing distance).
6 The source of the route. A strictly interior route is preferred, next in preference is a strictly exterior
route, and third in preference is an exterior route learned from an interior session. In summary, the route
source preference is as follows: IGP < EBGP < IBGP.
7 Lowest BGP Router ID. The route whose next hop IP address is numerically lowest.
page 4-16
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring BGP
BGP Overview
Route Dampening
Route dampening is a mechanism for controlling route instability. If a route is enabled and disabled
frequently, it can cause an abundance of UPDATE and WITHDRAWN messages to expend speaker
resources. Route dampening categorizes a route as either behaved or ill behaved. A well behaved route
shows a high degree of stability over an extended period of time, while an ill behaved route shows a high
degree of instability over a short period of time. This instability is also known as flapping.
Route dampening can suppress (not advertise) an ill behaved route until it has achieved a certain degree of
stability. Route suppression is based on the number of times a route flaps over a period of time.
Note. This mechanism does not apply to IPv6 prefixes.
The following diagram illustrates this concept:
Route 1
Route 1
Route 2
(flapping)
Route 3
AS 100
Route 3
Routes 1, 2, and 3 are entering AS 100, but Route 2 (because it is flapping) has exceeded the dampening
threshold. It is therefore not propagated into the AS.
The dampening threshold and suppression time of a route is determined by various factors discussed in
“Controlling Route Flapping Through Route Dampening” on page 4-36.
CIDR Route Notation
Although CIDR is supported by the router, CIDR route notation is not supported on the CLI command
line. For example, in order to enter the route “198.16.10.0/24” you must input “198.16.10.0
255.255.255.0”. Some show commands, such as ip bgp policy prefix-list, do use CIDR notation to
indicate route prefixes.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 4-17
BGP Configuration Overview
Configuring BGP
BGP Configuration Overview
The following steps and points summarize configuring BGP. Not all of the following are necessary. For
the necessary steps to enable BGP on the OmniSwitch, see “Quick Steps for Using BGP” on page 4-4.
1 Load the BGP protocol. See “Starting BGP” on page 4-19.
2 Set up router-wide parameters, such as the router’s AS number, default local preference, and enable the
BGP protocol. See “Setting Global BGP Parameters” on page 4-20.
3 Configure peers on the router. These peers may be in the same AS as the router or in a different AS.
See “Configuring a BGP Peer” on page 4-26.
4 Configure peers that operate on remote routers. These peers may be in the same AS as the router or in a
different AS. See “Configuring a BGP Peer” on page 4-26.
5 Configure optional parameters. There are many optional features available in the Alcatel-Lucent
implementation of BGP-4. These features are described in later sections of this chapter. The following is a
list of BGP features you can configure on an OmniSwitch:
• Aggregate Routes. See “Configuring Aggregate Routes” on page 4-32.
• Local networks, or routes. See “Configuring Local Routes (Networks)” on page 4-33.
• Route Dampening. See “Controlling Route Flapping Through Route Dampening” on page 4-36.
• Route Reflection. See “Setting Up Route Reflection” on page 4-40.
• Communities. See “Working with Communities” on page 4-43.
• Confederations. See “Creating a Confederation” on page 4-44.
• Policies to control BGP routing. See “Routing Policies” on page 4-45.
• Redistribution policies using route maps. See “Configuring Redistribution” on page 4-53.
page 4-18
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring BGP
Starting BGP
Starting BGP
Before BGP is operational on your router you must load it to running memory and then administratively
enable the protocol using the ip load bgp and ip bgp status commands. Follow these steps to start BGP.
1 Install advanced routing image file in the active boot directory.
2 Load the BGP image into running memory by issuing the following command:
-> ip load bgp
3 Administratively enable BGP by issuing the following command:
-> ip bgp status enable
Disabling BGP
You can administratively disable BGP by issuing the following command:
-> ip bgp status disable
Many BGP global commands require that you disable the protocol before changing parameters. The
following functions and commands require that you first disable BGP before issuing them:
Parameters Requiring that BGP first be disabled
Function
Command
Router’s AS number
ip bgp autonomous-system
Confederation identifier
ip bgp confederation identifier
Default local preference
ip bgp default local-preference
IGP synchronization
ip bgp synchronization
AS Path Comparison
ip bgp bestpath as-path ignore
MED comparison
ip bgp always-compare-med
Substitute missing MED value
ip bgp bestpath med missing-asworst
Equal-cost multi-path comparison
ip bgp maximum-paths
Route reflection
ip bgp client-to-client reflection
Cluster ID in route reflector group
ip bgp cluster-id
Fast External Fail Over
ip bgp fast-external-failover
Enable logging of peer changes
ip bgp log-neighbor-changes
Tag routes from OSPF
ip bgp confederation identifier
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 4-19
Setting Global BGP Parameters
Configuring BGP
Setting Global BGP Parameters
Many BGP parameters are applied on a router-wide basis. These parameters are referred to as global BGP
parameters. These values are taken by BGP peers in the router unless explicitly overridden by a BGP peer
command. This section describes how to enable or disable BGP global parameters.
Global BGP Defaults
Parameter Description
Command
Default Value/Comments
Router’s AS number
ip bgp autonomous-system
1
Confederation Number
ip bgp confederation identifier
No confederations configured
Default local preference
ip bgp default local-preference
100
IGP synchronization
ip bgp synchronization
Disabled
AS Path Comparison
ip bgp bestpath as-path ignore
Enabled
MED comparison on external
peers
ip bgp always-compare-med
Disabled
Substitute missing MED value
ip bgp bestpath med missing-asworst
Lowest (best) possible value
Equal-cost multi-path support
ip bgp maximum-paths
Disabled
Route reflection
ip bgp client-to-client reflection
Disabled
Cluster ID in route reflector group ip bgp cluster-id
0.0.0.0
Fast External Fail Over
ip bgp fast-external-failover
Disabled
Enable logging of peer changes
ip bgp log-neighbor-changes
Disabled
Route dampening
ip bgp dampening
Disabled
page 4-20
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring BGP
Setting Global BGP Parameters
Setting the Router AS Number
The router takes a single Autonomous System (AS) number. You can assign one and only one AS number
to a router using the ip bgp autonomous-system command. That same router may contain peers that
belong to a different AS than the AS you assign your router. In such a case these BGP peers with a different AS would be considered external BGP (EBGP) peers and the communication with those peers would
be EBGP.
The following command would assign an AS number of 14 to a router:
-> ip bgp autonomous-system 14
This command requires that you first disable the BGP protocol. If BGP were already enabled, you would
actually need to issue two commands to assign the router’s AS number to 14:
-> ip bgp status disable
-> ip bgp autonomous-system 14
Setting the Default Local Preference
A route’s local preference is an important attribute in the path selection process. In many cases it will be
the most important criteria in determining the selection of one route over another. A route obtains its local
preference in one of two ways:
• By taking the default local preference established globally in the router.
• By having this default local preference manipulated by another command. The BGP peer, aggregate
route, and network commands allow you to assign a local preference to a route. It is also possible to
manipulate the local preference of a route through BGP policy commands.
The local preference in the router is set by default to 100. If you want to change this value, use the
ip bgp default local-preference command. For example, if you wanted to change the default local preference for all routes to 200, you would issue the following command:
-> ip bgp default local-preference 200
This command requires that you first disable the BGP protocol. If BGP were already enabled, you would
actually need to issue two commands to change the default local preference to 200:
-> ip bgp status disable
-> ip bgp default local-preference 200
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 4-21
Setting Global BGP Parameters
Configuring BGP
Enabling AS Path Comparison
The AS path is a route attribute that shows the sequence of ASs through which a route has traveled. For
example if a path originated in AS 1, then went through AS 3, and reached its destination in AS 4, then the
AS path would be:
4 3 1
A shorter AS path is preferred over a longer AS path. The AS path is always advertised in BGP route
updates, however you can control whether BGP uses this attribute when comparing routes. The length of
the AS path may not always indicate the effectiveness for a given route. For example, if a route has an AS
path of:
1 3 4
using only T1 links, it might not be a faster path than a longer AS path of:
2 4 5 7
that uses only DS-3 links.
By default AS path comparison is enabled. You can disable it by specifying:
-> no ip bgp bestpath as-path ignore
This command requires that you first disable the BGP protocol. If BGP were already enabled, you would
actually need to issue two commands to turn off AS path comparison:
-> ip bgp status disable
-> no ip bgp bestpath as-path ignore
page 4-22
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring BGP
Setting Global BGP Parameters
Controlling the use of MED Values
The Multi Exit Discriminator, or MED, is used by border routers (i.e., BGP speakers with links to neighboring autonomous systems) to help choose between multiple entry and exit points for an autonomous
system. It is only relevant when an AS has more than one connection to a neighboring AS. If all other
factors are equal, the path with the lowest MED value takes preference over other paths to the neighbor
AS.
If received on external links, the MED may be propagated over internal links to other BGP speakers in the
same AS. However, the MED is never propagated to speakers in a neighboring AS. The MED attribute
indicates the weight of a particular exit point from an AS. Some exit points may be given a better MED
value because they lead to higher speed connections.
The Alcatel-Lucent implementation of BGP allows you to control MED values in the following ways:
• Compare MED values for external ASs
• Insert a MED value in routes that do not contain MEDs
The following two sections describe these MED control features.
Enabling MED Comparison for External Peers
By default, BGP only compares MEDs from peers within the same autonomous system when selecting
routes. However, you can configure BGP to compare MEDs values received from external peers, or other
autonomous systems. To enable MED comparison of external peers specify:
-> ip bgp always-compare-med
This command requires that you first disable the BGP protocol. If BGP were already enabled, you would
actually need to issue two commands to disable MED comparison:
-> ip bgp status disable
-> no ip bgp always-compare-med
Inserting Missing MED Values
A MED value may be missing in a route received from an external peer. Your can specify how a missing
MED in an external BGP path is to be treated for route selection purposes. The default behavior is to treat
missing MEDs as zero (best). The ip bgp bestpath med missing-as-worst command allows you to treat
missing MEDs as 232-1 (worst) for compatibility reasons.
To change the missing MED value from worst to best, enter the following command:
-> ip bgp bestpath med missing-as-worst
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page 4-23
Setting Global BGP Parameters
Configuring BGP
Synchronizing BGP and IGP Routes
The default behavior of BGP requires that it must be synchronized with the IGP before BGP may advertise transit routes to external ASs. It is important that your network is consistent about the routes it advertises, otherwise traffic can be lost.
The BGP rule is that a BGP router should not advertise to external neighbors destinations learned from
IBGP neighbors unless those destinations are also known via an IGP. This is known as synchronization. If
a router knows about a destination via an IGP, it is assumed that the route has already been propagated
inside the AS and internal reachability is ensured.
The consequence of injecting BGP routes inside an IGP is costly. Redistributing routes from BGP into the
IGP results in major overhead on the internal routers, and IGPs are really not designed to handle that many
routes.
The ip bgp synchronization command enables or disables BGP internal synchronization. Enabling this
command will force all routers (BGP and non-BGP) in an AS to learn all routes learned over external
BGP. Learning the external routes forces the routing tables for all routers in an AS to be synchronized and
ensure that all routes advertised within an AS are known to all routers (BGP and non-BGP). However,
since routes learned over external BGP can be numerous, enabling synchronization can place an extra
burden on non-BGP routers.
To enable synchronization, enter the following command:
-> ip bgp synchronization
The BGP speaker will now synchronize with the IGP. The default for synchronization is disabled.
To deactivate synchronization, enter the same command with the no keyword, as shown:
-> no ip bgp synchronization
page 4-24
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring BGP
Setting Global BGP Parameters
Displaying Global BGP Parameters
The following list shows the commands for viewing the various aspects of BGP set with the global BGP
commands:
show ip bgp
Displays the current global settings for the local BGP speaker.
show ip bgp statistics
Displays BGP global statistics, such as the route paths.
show ip bgp aggregate-address Displays aggregate configuration information.
show ip bgp dampening
Displays the current route dampening configuration settings.
show ip bgp dampening-stats
Displays route flapping statistics.
show ip bgp network
Displays information on the currently defined BGP networks.
show ip bgp path
Displays information, such as Next Hop and other BGP attributes, for
every path in the BGP routing table.
show ip bgp routes
Displays information on BGP routes known to the router. This information includes whether changes to the route are in progress, whether it is
part of an aggregate route, and whether it is dampened.
For more information about the output from these show commands, see the OmniSwitch CLI Reference
Guide.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 4-25
Configuring a BGP Peer
Configuring BGP
Configuring a BGP Peer
BGP supports two types of peers, or neighbors: internal and external. Internal sessions are run between
BGP speakers in the same autonomous system (AS). External sessions are run between BGP peers in
different autonomous systems. Internal neighbors may be located anywhere within the same autonomous
system while external neighbors are adjacent to each other and share a subnet. Internal neighbors usually
share a subnet.
BGP speakers can be organized into groups that share similar parameters, such as metrics, timers, and
route preferences. It is also possible to configure individual speakers with unique parameters.
An OmniSwitch is assigned an AS number. That same router may contain peers with different AS
numbers. The router may also contain information on peer routers residing in different physical routers.
However, the OmniSwitch will not dynamically learn about peers in other routers; you must explicitly
configure peers operating in other routers.
Note. In this document, the BGP terms “peer” and “neighbor” are used interchangeably to mean any BGP
entity known to the local router.
Peer Command Defaults
The following table lists the default values for many of the peer commands:
Parameter Description
Command
Default Value/
Comments
Configures the time interval for
updates between external BGP
peers.
ip bgp neighbor advertisement-interval
30
Enables or disables BGP peer
automatic restart.
ip bgp neighbor auto-restart
enabled
Configures this peer as a client to ip bgp neighbor route-reflector-client
the local route reflector.
disabled
The interval, in seconds,
between BGP retries to set up a
connection via the transport
protocol with another peer.
ip bgp neighbor conn-retry-interval
120
Enables or disables BGP peer
default origination.
ip bgp neighbor default-originate
disabled
Configures the tolerated hold
ip bgp neighbor timers
time interval, in seconds, for this
peer’s session.
90
Configures the timer interval
ip bgp neighbor timers
between KEEPALIVE messages
sent to this peer.
30
Configures the maximum number ip bgp neighbor maximum-prefix
of prefixes, or paths, the local
router can receive from this peer
in UPDATE messages.
5000
page 4-26
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December 2007
Configuring BGP
Parameter Description
Configuring a BGP Peer
Default Value/
Comments
Command
Enable or disables maximum pre- ip bgp neighbor maximum-prefix
fix warning for a peer.
warning-only
80 percent
Allows external peers to commu- ip bgp neighbor ebgp-multihop
nicate with each other even when
they are not directly connected.
disabled
Configures the BGP peer name.
peer IP address
ip bgp neighbor description
Sets the BGP peer to use next hop ip bgp neighbor next-hop-self
processing behavior.
disabled
Configures the local BGP
speaker to wait for this peer to
establish a connection.
ip bgp neighbor passive
disabled
Enables or disables the stripping
of private autonomous system
numbers from the AS path of
routes destined to this peer.
ip bgp neighbor remove-private-as
disabled
Enables or disables BGP peer
soft reconfiguration.
ip bgp neighbor soft-reconfiguration
enabled
Configures this peer as a member ip bgp confederation neighbor
of the same confederation as the
local BGP speaker.
disabled
Configures the local address from ip bgp neighbor update-source
which this peer will be contacted.
Not set until configured
Note. BGP peers are not dynamically learned. BGP peers must be explicitly configured on the router using
the ip bgp neighbor command.
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December 2007
page 4-27
Configuring a BGP Peer
Configuring BGP
Creating a Peer
1 Create the peer and assign it an address using the ip bgp neighbor command. For example to create a
peer with an address of 190.17.20.16 you would enter:
-> ip bgp neighbor 190.17.20.16
2 Assign an AS number to the peer using the ip bgp neighbor remote-as command. For example to
assign the peer created in Step 1 to AS number 100, you would enter:
-> ip bgp neighbor 190.17.20.16 remote-as 100
The AS number for a peer defaults to 1 if you do not configure an AS number through the
ip bgp neighbor remote-as command.
3 You can optionally assign this peer a descriptive name using the ip bgp neighbor description
command. Such a name may be helpful particularly in networks with connections to more than one ISP.
For example, you could name peers based on their connection to a given ISP. In the example above, you
could name the peer “FastISP” as follows:
-> ip bgp neighbor 190.17.20.16 description FastISP
4 Configure optional attributes for the peer. You can configure many attributes for a peer; these attributes
are listed in the table below along with the commands used to configure them.
Optional BGP Peer Parameters
Peer Parameter
Command
Interval between route advertisements
with external peers.
ip bgp neighbor advertisement-interval
Enables or disables BGP peer automatic
restart.
ip bgp neighbor auto-restart
The interval, in seconds, between BGP ip bgp neighbor conn-retry-interval
retries to set up a connection via the
transport protocol with another peer.
Enables or disables BGP peer default
origination.
ip bgp neighbor default-originate
Configures the tolerated hold time inter- ip bgp neighbor timers
val, in seconds, for messages to this peer
from other peers.
Configures the time interval between
ip bgp neighbor timers
KEEPALIVE messages sent by this peer.
Configures the maximum number of pre- ip bgp neighbor maximum-prefix
fixes, or paths, the local router can
receive from this peer in UPDATE messages.
Enable or disables maximum prefix
warning for a peer.
ip bgp neighbor maximum-prefix
warning-only
Configures the local address from which ip bgp neighbor update-source
this peer will be contacted.
page 4-28
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December 2007
Configuring BGP
Configuring a BGP Peer
Peer Parameter
Command
Allows external peers to communicate
with each other even when they are not
directly connected.
ip bgp neighbor ebgp-multihop
Sets the BGP peer to use next hop processing behavior.
ip bgp neighbor next-hop-self
Configures the local BGP speaker to wait ip bgp neighbor passive
for this peer to establish a connection.
Enables or disables the stripping of private autonomous system numbers from
the AS path of routes destined to this
peer.
ip bgp neighbor remove-private-as
Enables or disables BGP peer soft recon- ip bgp neighbor soft-reconfiguration
figuration.
5 After entering all commands to configure a peer you need to administratively enable the peer. The peer
will not begin advertising routes until you enable it. To enable the peer in the above step, enter the ip bgp
neighbor status command:
-> ip bgp neighbor 190.17.20.16 status enable
Restarting a Peer
Many BGP peer commands will automatically restart the peer once they are executed. By restarting the
peer, these parameters take effect as soon as the peer comes back up. However, there are some peer
commands (such as those configuring timer values) that do not reset the peer. If you want these parameters to take effect, then you must manually restart the BGP peer using the ip bgp neighbor clear. The
following command would restart the peer at address 190.17.20.16:
-> ip bgp neighbor 190.17.20.16 clear
The peer is not available to send or receive update or notification messages while it is restarting.
Use the ip bgp neighbor clear soft command to reset peer policy parameters.
Setting the Peer Auto Restart
When the auto restart is enabled, this peer will automatically attempt to restart a session with another peer
after a session with that peer terminates.
To enable the auto restart feature, enter the ip bgp neighbor auto-restart command with the peer IP
address, as shown:
-> ip bgp neighbor 190.17.20.16 auto-restart
To disable this feature, enter the following:
-> no ip bgp neighbor 190.17.20.16 auto-restart
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 4-29
Configuring a BGP Peer
Configuring BGP
Changing the Local Router Address for a Peer Session
By default, TCP connections to a peer's address are assigned to the closest interface based on reachability.
Any operational local interface can be assigned to the BGP peering session by explicitly forcing the TCP
connection to use the specified interface. The ip bgp neighbor update-source command sets the local
interface address or the name through which this BGP peer can be contacted.
For example, to configure a peer with an IP address of 120.5.4.6 to be contacted via 120.5.4.10, enter the
ip bgp neighbor update-source command as shown:
-> ip bgp neighbor 120.5.4.6 update-source 12.5.4.10
Alternatively, you can enter the name of the local IP interface, instead of the IP address as shown below:
-> ip bgp neighbor 120.5.4.6 update-source vlan-23
Clearing Statistics for a Peer
BGP tracks the number of messages sent to and received from other peers. It also breaks down messages
into UPDATE, NOTIFICATION, and TRANSITION categories. You can reset, or clear, the statistics for a
peer using the ip bgp peer stats-clear command. For example the following use of the ip bgp neighbor
stats-clear command would clear statistics for the peer at address 190.17.20.16:
-> ip bgp neighbor 190.17.20.16 stats-clear
The statistics that are cleared are shown in the show ip bgp neighbors statistics command. The following
is an example of output from this command:
-> show ip bgp neighbors statistics 190.17.20.16
Neighbor address
# of UP transitions
Time of last UP transition
# of DOWN transitions
Time of last DOWN transition
Last DOWN reason
# of msgs rcvd
# of Update msgs rcvd
# of prefixes rcvd
# of Route Refresh msgs rcvd
# of Notification msgs rcvd
Last rcvd Notification reason
Time last msg was rcvd
# of msgs sent
# of Update msgs sent
# of Route Refresh msgs sent
# of Notification msgs sent
Last sent Notification reason
Time last msg was sent
page 4-30
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
=
190.17.20.16,
0,
00h:00m:00s,
0,
00h:00m:00s,
none,
0,
0,
0,
0,
0,
none [none]
00h:00m:00s,
0,
0,
0
0,
none [none],
00h:00m:00s
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring BGP
Configuring a BGP Peer
Setting Peer Authentication
You can set which MD5 authentication key this router will use when contacting a peer. To set the MD5
authentication key, enter the peer IP address and key with the ip bgp neighbor md5 key command:
-> ip bgp neighbor 123.24.5.6 md5 key keyname
The peer with IP address 123.24.5.6 will be sent messages using “keyname” as the encryption password. If
this is not the password set on peer 123.24.5.6, then the local router will not be able to communicate with
this peer.
Setting the Peer Route Advertisement Interval
The route advertisement interval specifies the frequency at which routes external to the autonomous
system are advertised. These advertisements are also referred to as UPDATE messages. This interval
applies to advertisements to external peers.
To set the advertisement interval, enter the number of seconds in conjunction with the
ip bgp neighbor advertisement-interval command, as shown:
-> ip bgp neighbor 123.24.5.6 advertisement-interval 50
The interval is now set to 50 seconds. The default value is 30.
Configuring a BGP Peer with the Loopback0 Interface
Loopback0 is the name assigned to an IP interface to identify a consistent address for network management purposes. The Loopback0 interface is not bound to any VLAN, so it will always remain operationally active. This differs from other IP interfaces in that if there are no active ports in the VLAN, all IP
interface associated with that VLAN are not active. In addition, the Loopback0 interface provides a unique
IP address for the switch that is easily identifiable to network management applications.
It is possible to create BGP peers using the Loopback0 IP interface address of the peering router and binding the source (i.e., outgoing IP interface for the TCP connection) to its own configured Loopback0 interface. The Loopback0 IP interface address can be used for both Internal and External BGP peer sessions.
For EBGP sessions, if the External peer router is multiple hops away, the ebgp-multihop parameter may
need to be used.
The following example configures a BGP peering session using a Loopback0 IP interface address:
-> ip bgp neighbor 2.2.2.2 update-source Loopback0
See the OmniSwitch 6800/6850/9000 Network Configuration Guide for more information about configuring an IP Loopback0 interface.
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Configuring Aggregate Routes
Configuring BGP
Configuring Aggregate Routes
Aggregate routes are used to reduce the size of routing tables by combining the attributes of several different routes and allowing a single aggregate route to be advertised to peers.
You cannot aggregate an address (for example, 100.10.0.0) if you do not have at least one more-specific
route of the address (for example, 100.10.20.0) in the BGP routing table.
Aggregate routes do not need to be known to the local BGP speaker.
1 Indicate the address and mask for the aggregate route using the ip bgp aggregate-address command:
-> ip bgp aggregate-address 172.22.2.0 255.255.255.0
2 Optional. When an aggregate route is created BGP does not aggregate the AS paths of all routes
included in the aggregate. However, you may specify that a new AS path be created for the aggregate
route that includes the ASs traversed for all routes in the aggregate. To specify that the AS path also be
aggregated use the ip bgp aggregate-address as-set command. For example:
-> ip bgp aggregate-address 172.22.2.0 255.255.255.0 as-set
3 Optional. By default an aggregate route suppresses the advertisement of all more-specific routes within
the aggregate. This suppression of routes is the function of an aggregate route. However, you can disable
route summarization through the no ip bgp aggregate-address summary-only. For example:
-> no ip bgp aggregate-address 172.22.2.0 255.255.255.0 summary-only
4 Optional. You can manipulate several BGP attributes for routes included in this aggregate route. These
attributes and the corresponding commands used to manipulate them are shown in the table below:
Optional Aggregate Route Attribute Manipulation
BGP Attribute
Command
Community list for this aggregate route
ip bgp aggregate-address community
Local preference value for this aggregate. ip bgp aggregate-address local-preference
This value overrides the value set in the
ip bgp default-lpref command.
MED value for this aggregate route.
ip bgp aggregate-address metric
5 Once you have finished configuring values for this aggregate route, enable it using the
ip bgp aggregate-address status command. For example:
-> ip bgp aggregate-address 172.22.2.0 255.255.255.0 status enable
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Configuring BGP
Configuring Local Routes (Networks)
Configuring Local Routes (Networks)
A local BGP network is used to indicate to BGP that a network should originate from a specified router. A
network must be known to the local BGP speaker; it also must originate from the local BGP speaker.
Networks have some parameters that can be configured, such as local-preference, community, and
metric.
Adding the Network
To add a local network to a BGP speaker, use the IP address and mask of the local network in conjunction
with the ip bgp network command, as shown:
-> ip bgp network 172.20.2.0 255.255.255.0
In this example, network 172.20.2.0 with a mask of 255.255.255.0 is the local network for this BGP
speaker.
To remove the same network from the speaker, enter the same command with the no keyword, as shown:
-> no ip bgp network 172.20.2.0 255.255.255.0
The network would now no longer be associated as the local network for this BGP speaker.
Enabling the Network
Once the network has been added to the speaker, it must be enabled on the speaker. To do this, enter the IP
address and mask of the local network in conjunction with the ip bgp network status command, as
shown:
-> ip bgp network 172.20.2.0 255.255.255.0 status enable
In this example, network 172.20.2.0 with a mask of 255.255.255.0 has now been enabled.
To disable the same network, enter the following:
-> ip bgp network 172.20.2.0 255.255.255.0 status disable
The network would now be disabled, though not removed from the speaker.
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Configuring Local Routes (Networks)
Configuring BGP
Configuring Network Parameters
Once a local network is added to a speaker, you can configure three parameters that are attached to routes
generated by the ip bgp network command. These three attributes are the local preference, the community, and the route metric.
Local Preference
The local preference is a degree of preference to be given to a specific route when there are multiple routes
to the same destination. The higher the number, the higher the preference. For example, a route with a
local preference of 50 will be used before a route with a local preference of 30.
To set the local preference for the local network, enter the IP address and mask of the local network in
conjunction with the ip bgp network local-preference command and value, as shown:
-> ip bgp network 172.20.2.0 255.255.255.0 local-preference 600
The local preference for routes generated by the network is now 600. The default value is 0 (no network
local preference is set).
Community
Communities are a way of grouping BGP destination addresses that share some common property. Adding
the local network to a specific community indicates that the network shares a common set of properties
with the rest of the community.
To add a network to a community, enter the local network IP address and mask in conjunction with the ip
bgp network community command and name, as shown:
-> ip bgp network 172.20.2.0 255.255.255.0 community 100:200
Network 172.20.2.0, mask 255.255.255.0, is now in the 100:200 community. The default community is no
community.
To remove the local network from the community, enter the local network as above with the community
set to “none”, as shown:
-> ip bgp network 172.20.2.0 255.255.255.0 community none
The network is now no longer in any community.
Metric
A metric for a network is the Multi-Exit Discriminator (MED) value. This value is used when announcing
this network to internal peers; it indicates the best exit point from the AS, assuming there is more than one.
A lower value indicates a more preferred exit point. For example, a route with a MED of 10 is more likely
to be used than a route with an MED of 100.
To set the network metric value, enter the network IP address and mask in conjunction with the ip bgp
network metric command and value, as shown:
-> ip bgp network 172.20.2.0 255.255.255.0 metric 100
Network 172.20.2.0, mask 255.255.255.0, is now set with a metric of 100. The default metric is 0.
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Configuring BGP
Configuring Local Routes (Networks)
Viewing Network Settings
To view the network settings for all networks assigned to the speaker, enter the show ip bgp network
command, as shown:
-> show ip bgp network
A display similar to the following appears:
Network
Mask
Admin state Oper state
---------------+---------------+-----------+---------155.132.40.0
255.255.255.0
disabled
not_active
155.132.1.3
255.255.255.255 disabled
not_active
To display a specific network, enter the same command with the network IP address and mask, as shown:
-> show ip bgp network 172.20.2.0 255.255.255.0
A display similar to the following appears:
Network
Network
Network
Network
Network
Network
Network
address
mask
admin state
oper state
metric
local pref
community string
=
=
=
=
=
=
=
172.20.2.0,
255.255.255.0,
disabled,
not_active,
0,
0,
0:500 400:1 300:2
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page 4-35
Controlling Route Flapping Through Route Dampening
Configuring BGP
Controlling Route Flapping Through
Route Dampening
Route dampening minimizes the effect of flapping routes in a BGP network. Route flapping occurs when
route information is updated erratically, such as when a route is announced and withdrawn at a rapid rate.
Route flapping can cause problems in networks connected to the Internet, where route flapping will
involve the propagation of many routes. Route dampening suppresses flapping routes and designates them
as unreachable until they flap at a lower rate.
You can configure route dampening to adapt to the frequency and duration of a particular route that is
flapping. The more a route flaps during a period of time, the longer it will be suppressed.
Each time a route flaps (i.e., withdrawn from the routing table), its “instability metric” is increased by 1.
Once a route’s instability metric reaches the suppress value, it is suppressed and no longer advertised. The
instability metric may continue to increase even after the route is suppressed.
A route’s instability metric may be reduced. It is reduced once the route stops flapping for a given period
of time. This period of time is referred to as the half-life duration. If a suppressed route does not flap for a
given half-life duration, then its instability metric will be cut in half. As long as the route continues to be
stable, its instability metric will be reduced until it reaches the reuse value. Once below the reuse value, a
route will be re-advertised.
Example: Flapping Route Suppressed, then Unsuppressed
Consider, for example, a route that has started to flap. Once this route starts exhibiting erratic behavior,
BGP begins tracking the instability metric for the route. This particular route flaps more than 300 times,
surpassing the cutoff value of 300. BGP stops advertising the route; the route is now suppressed. The route
continues to flap and its instability metric reaches 1600.
Now the route stops flapping. In fact, it does not flap for 5 minutes, which is also the half-life duration
defined for BGP routes. The instability metric is reduced to 800. The route remains stable for another 5
minutes and the instability metric is reduced to 400. After another 5 minutes of stability, the route’s instability metric is reduced to 200, which is also the defined reuse value. Since the instability metric for the
route has dropped below the reuse value, BGP will begin re-advertising it again.
The following chart illustrates what happens to the described route in the above scenario:
1600
Half-life duration exceeded.
Instability metric halved.
Instability
metric
800
Instability metric cut in
half two more times.
600
400
Route Suppressed
200
5
10
Instability metric hits reuse
value. Route unsuppressed.
15
20
25
Time
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Configuring BGP
Controlling Route Flapping Through Route Dampening
Enabling Route Dampening
Route dampening is disabled by default. Route dampening must be enabled before it effects routes. To
enable route dampening on a BGP router, enter the ip bgp dampening command, as shown:
-> ip bgp dampening
To disable route dampening, enter the following:
-> no ip bgp dampening
Configuring Dampening Parameters
There are several factors in configuring route dampening. These factors work together to determine if a
route should be dampened, and for how long. The values all have defaults that are in place when dampening is enabled. It is possible to change these values, using the ip bgp dampening command with variables. The variables for these parameters must be entered together, in one command, in order. This is
demonstrated in the following sections.
• Setting the Reach Halflife. The reach halflife is the number of seconds a route can be reached, without
flapping, before the penalty number (of flaps) is reduced by half. See “Setting the Reach Halflife” on
page 4-37 for instructions on how this is done.
• Setting the Reuse Value. The reuse value determines if a route is advertised again. See “Setting the
Reuse Value” on page 4-38 for instructions on how this is done.
• Setting the Suppress Value. The suppress value is the number of route withdrawals required before the
route is suppressed. See “Setting the Suppress Value” on page 4-38 for instructions on how this is
done.
• Setting the Maximum Suppress Holdtime. The maximum holdtime is the number of seconds a route
stays suppressed. See “Setting the Maximum Suppress Holdtime” on page 4-38 for instructions on how
this is done.
Setting the Reach Halflife
The reach halflife value is the number of seconds that pass before a route is re-evaluated in terms of flapping. After the number of seconds set for halflife has passed, and a route has not flapped, then its total flap
count is reduced by half.
For example, if the reach halflife is set at 500 seconds, and a reachable route with a flap count of 300 does
not flap during this time, then its flap count is reduced to 150.
To change one variable to a number different than its default value, you must enter all of the variables
with the ip bgp dampening command in the correct order.
For example, to set the reach halflife value to 500, enter the halflife value and other variables with the
following command, as shown:
-> ip bgp dampening half-life 500 reuse 200 suppress 300 max-suppress-time 1800
In this example, the other variables have been set to their default values. The reach halflife is now set to
500. The default values for the reach halflife is 300.
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Controlling Route Flapping Through Route Dampening
Configuring BGP
Setting the Reuse Value
The dampening reuse value is used to determine if a route should be re-advertised. If the number of flaps
for a route falls below this number, then the route is re-advertised. For example, if the reuse value is set at
150, and a route with 250 flaps exceeds the reach halflife it would be re-advertised as its flap number
would now be 125.
To change one variable to a number different than its default value, you must enter all of the variables with
the ip bgp dampening command in the correct order.
For example, to set the reuse value to 500, enter the reuse value and other variables with the following
command, as shown:
-> ip bgp dampening half-life 300 reuse 500 suppress 300 max-suppress-time 1800
In this example, the other variables have been set to their default values. The reuse value is now set to 500.
The default value is 200.
Setting the Suppress Value
The dampening suppress value sets the number of times a route can flap before it is suppressed. A
suppressed route is not advertised. For example, if the cutoff value is set at 200, and a route flaps 201
times, it will be suppressed.
To change one variable to a number different than its default value, you must enter all of the variables with
the ip bgp dampening command in the correct order.
For example, to set the suppress value to 500, enter the suppress value and other variables with the following command, as shown:
-> ip bgp dampening half-life 300 reuse 200 suppress 500 max-suppress-time 1800
In this example, the other variables have been set to their default values. The suppress value is now set to
500. The default value is 300.
Setting the Maximum Suppress Holdtime
The maximum suppress holdtime is the number of seconds a route stays suppressed once it has crossed the
dampening cutoff flapping number. For example, if the maximum holdtime is set to 500, once a route is
suppressed the local BGP speaker would wait 500 seconds before advertising the route again.
To change one variable to a number different than its default value, you must enter all of the variables with
the ip bgp dampening command in the correct order.
For example, to set the maximum suppress holdtime value to 500, enter the maximum suppress holdtime
value and other variables with the following command, as shown:
-> ip bgp dampening half-life 300 reuse 200 suppress 300 max-suppress-time 500
In this example, the other variables have been set to their default values. The maximum suppress holdtime
is now set to 500 seconds. The default value is 1800 seconds.
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Configuring BGP
Controlling Route Flapping Through Route Dampening
Clearing the History
By clearing the dampening history, you are resetting all of the dampening information on all of the routes
back to zero, as if dampening had just been activated. Route flap counters are reset and any routes that
were suppressed due to route flapping violations are unsuppressed. Dampening information on the route
will start re-accumulating as soon as the command is entered and the statistics are cleared.
To clear the dampening history, enter the following command:
-> ip bgp dampening clear
Displaying Dampening Settings and Statistics
To display the current settings for route dampening, enter the following command:
-> show ip bgp dampening
A display similar to the following will appear:
Admin Status
Half life value (seconds)
Reuse value (seconds)
Suppress time (seconds)
Max suppress time (seconds)
=
=
=
=
=
disabled,
300,
200
300,
1800,
To display current route dampening statistics, enter the following command:
-> show ip bgp dampening-stats
A display similar to the following will appear:
Network
Mask
From
Flaps Duration
FOM
---------------+---------------+---------------+-----+-----------+----155.132.44.73
255.255.255.255 192.40.4.121
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page 4-39
Setting Up Route Reflection
Configuring BGP
Setting Up Route Reflection
BGP requires that all speakers in an autonomous system be fully meshed (i.e., each speaker must have a
peer connection to every other speaker in the AS) so that external routing information can be distributed to
all BGP speakers in an AS. However, fully meshed configurations are difficult to scale in large networks.
For this reason, BGP supports route reflection, a configuration in which one or more speakers—route
reflectors—handle intra-AS communication among all BGP speakers.
In a fully meshed BGP configuration, a BGP speaker that receives an external route must re-advertise the
route to all internal peers. In the illustration below, BGP speaker A receives a route from an external BGP
speaker and advertises it to both Speakers B and C in its autonomous system. Speakers B and C do not readvertise the route to each other so as to prevent a routing information loop.
AS 100
Speaker C
Route
External BGP
Speaker
Speaker A
Speaker B
Fully Meshed BGP Peers
In the above example, Speakers B and C do not re-advertise the external route they each received from
Speaker A. However, this fundamental routing rule is relaxed for BGP speakers that are route reflectors.
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Configuring BGP
Setting Up Route Reflection
This same configuration using a route reflector would not require that all BGP speakers be fully meshed.
One of the speakers is configured to be a route reflector for the group. In this case, the route reflector is
Speaker C. When the route reflector (Speaker C) receives route information from Speaker A it advertises
the information to Speaker B. This set up eliminates the peer connection between Speakers A and B.
AS 100
Route Reflector
Route
External BGP
Speaker
Client A
Client B
The internal peers of a route reflector are divided into two groups: client peers and non-client peers. The
route reflector sits between these two groups and reflects routes between them. The route reflector, its
clients, and non-clients are all in the same autonomous system.
The route reflector and its clients form a cluster. The client peers do not need to be fully meshed (and
therefore take full advantage of route reflection), but the non-client peers must be fully meshed. The
following illustration shows a route reflector, its clients within a cluster, and its non-client speakers
outside the cluster.
Non-Client
Non-Client
Cluster
External BGP
Speaker
Route
AS 100
Client
Client
Route Reflector, Clients, and Non-Clients
Note that the non-client BGP speakers are fully meshed with each other and that the client speakers in the
cluster do not communicate with the non-client speakers.
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page 4-41
Setting Up Route Reflection
Configuring BGP
When a route reflector receives a route it, selects the best path based on its policy decision criteria. The
internal peers to which the route reflector advertises depends on the source of the route. The table below
shows the rules the reflector follows when advertising path information:
Route Received From...
Route Advertised To...
External BGP Router
All Clients and Non-Clients
Non-Client Peer
All Clients
Client Peer
All Clients and Non-Clients
Configuring Route Reflection
1 Disable the BGP protocol by specifying:
-> ip bgp status disable
2 Specify this router as a route reflector, using the ip bgp client-to-client reflection command:
-> ip bgp client-to-client reflection
The route reflector will follow the standard rules for client route advertisement (i.e., routes from a client
are sent to all clients and non-clients, except the source client).
3 Indicate the client peers for this route reflector. For all internal peers (same AS as the router) that are to
be clients specify the ip bgp neighbor route-reflector-client command. For example, if you wanted the
peer at IP address 190.17.20.16 to become a client to the local BGP route-reflector, then you would specify the following command:
-> ip bgp neighbor 190.17.20.16 route-reflector-client
4 Repeat Step 3 for all internal peers that are to be clients of the route reflector.
Redundant Route Reflectors
A single BGP speaker will usually act as the reflector for a cluster of clients. In such a case, the cluster is
identified by the router ID of the reflector. It is possible to add redundancy to a cluster by configuring
more than one route reflector, eliminating the single point of failure. Redundant route reflectors must be
identified by a 4-byte cluster ID, which is specified in the ip bgp cluster-id command. All route reflectors
in the same cluster must be fully meshed and should have the exact same client and non-client peers.
Note. Using many redundant reflectors is not recommended as it places demands on the memory
required to store routes for all redundant reflectors’ peers.
To configure a redundant route reflector for this router, use the ip bgp cluster-id command. For example
to set up a redundant route reflector at 190.17.21.16, you would enter:
-> ip bgp cluster-id 190.17.21.16
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Configuring BGP
Working with Communities
Working with Communities
Distribution of routing information in BGP is typically based on IP address prefixes or on the value of the
AS_PATH attributes. To facilitate and simplify the control of routing information, destinations can be
grouped into communities and routing decisions can be applied based on these communities.
Communities are identified by using the numbering convention of the AS and the community number,
separated by a colon (for example, 200:500)
There are a few well known communities defined (in RFC 1997) that do not require the numbering
convention. Their community numbers are reserved and thus can be identified by name only. These are
listed below:
• no-export. Routes in this community are advertised within the AS but not beyond the local AS.
• no-advertise. Routes in this community are not advertised to any peer.
• no-export-subconfed. Routes in this community are not advertised to any external BGP peer.
Communities are added to routes using the policy commands, as described in “Routing Policies” on
page 4-45.
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Creating a Confederation
Configuring BGP
Creating a Confederation
A confederation is a grouping of ASs that together form a super AS. To BGP external peers, a confederation appears as another AS even though the confederation has multiple ASs within it. Within a confederation ASs can distinguish among one another and will advertise routes using EBGP.
1 Specify the confederation identifier for the local BGP router. This value is used to identify the confed-
eration affiliation of routes in advertisements. This value is essentially an AS number. To assign a confederation number to the router use the ip bgp confederation identifier command. For example, to assign a
confederation value of 2, you would enter:
-> ip bgp confederation-identifier 2
2 Indicate whether a peer belongs to the confederation configured on this router using the
ip bgp confederation neighbor command. For example to assign the peer at 190.17.20.16 to confederation 2, you would enter:
-> ip bgp confederation neighbor 190.17.20.16
3 Repeat Step 2 for all peers that need to be assigned to the confederation.
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Configuring BGP
Routing Policies
Routing Policies
BGP selects routes for subsequent advertisement by applying policies available in a pre-configured local
Policy Information database. This support of policy-based routing provides flexibility by applying policies based on the path (i.e. AS path list), community attributes (i.e. community lists), specific destinations
(i.e. prefix lists), etc.
You could also configure route maps to include all of the above in a single policy.
For BGP to do policy-based routing, each BGP peer needs to be tied to inbound and/or outbound policies
(direction based on whether routes are being learned or advertised). Each one of the above policies can be
assigned as an in-bound or out-bound policy for a peer.
First, you must create policies that match one of the specified criteria:
• AS Paths. An AS path list notes all of the ASs the route travels to reach its destination.
• Community List. Communities can affect route behavior based on the definition of the community.
• Prefix List. Prefix list policies filter routes based on a specific network address, or a range of network
addresses.
• Route Map. Route map policies filter routes by amalgamating other policies into one policy.
Then you must assign these policies to a peer. Policies can be assigned to affect routes learned from the
peer, routes being advertised to the peer, or both.
Creating a Policy
There are four different types of policies that can be created using the CLI, as described above. Each
policy has several steps that must be implemented for a complete policy to be constructed. Minimally, the
policy must be named, defined, and enabled.
The following sections describe the process of creating the four types of policies.
Creating an AS Path Policy
AS path policies must be assigned a name and a regular expression. Regular expressions are a set of
symbols and characters that represent an AS or part of an AS path. Regular expressions are fully described
in “Regular Expressions” on page 4-13.
To create an AS path policy:
1 Use the ip bgp policy aspath-list command, with a regular expression and a name, as shown:
-> ip bgp policy aspath-list aspathfilter “^100 200$”
This AS path policy is called aspathfilter. The policy looks for routes with an AS path with the next hop
AS 100, and originating from AS 200. Regular expressions must be enclosed by quotes.
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page 4-45
Routing Policies
Configuring BGP
2 Next, use the ip bgp policy aspath-list action command to set the policy action. The action of a policy
is whether the route filtered by the policy is permitted or denied. Denied routes are not propagated by the
BGP speaker, while permitted routes are. For example:
-> ip bgp policy aspath-list aspathfilter “^100 200$” action permit
The AS path policy aspathfilter now permits routes that match the regular expression ^100 200$. Regular
expressions must be enclosed by quotes.
3 Optionally, you can set the priority for routes filtered by the policy using the ip bgp policy aspath-list
priority command. Priority for policies indicates which policy should be applied first to routes. Routes
with a high priority number are applied first. To set the policy priority, enter the policy name with the
priority number, as shown:
-> ip bgp policy aspath-list aspathfilter “^100 200$” priority 10
The AS path policy aspathfilter now has a priority of 10. Regular expressions must be enclosed by
quotes.
Creating a Community List Policy
Community list policies must be assigned a name and a community number. Predetermined communities
are specified in RFC 1997.
To create a community policy:
1 Assign a name and community number to the policy using the ip bgp policy community-list
command, as shown:
-> ip bgp policy community-list commfilter 600:1
The policy name is commfilter and it looks for routes in the community 600:1.
2 Set the policy action using the ip bgp policy community-list action command. The policy action
either permits or denies routes that match the filter. Permitted routes are advertised, while denied routes
are not. For example:
-> ip bgp policy community-list commfilter 600:1 action permit
The commfilter policy now permits routes in community 600:1 to be advertised.
3 Set the policy match type using the ip bgp policy community-list match-type command. The match
type can be set to either exact or occur. An exact match only affects routes that are solely in the specified
community, while an occur match indicates that the community can be anywhere in the community list.
For example:
-> ip bgp policy community-list commfilter 600:1 match-type exact
Policy commfilter now looks for routes that only belong to the community 600:1.
4 Optionally, you can set the priority for routes filtered by the policy using the ip bgp policy
community-list priority command. Priority for policies indicates which policy should be applied first to
routes. Routes with a high priority number are applied first. To set the policy priority, enter the policy
name with the priority number, as shown:
-> ip bgp policy community-list commfilter 500:1 priority 3
Policy commfilter now has a priority of 3.
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Configuring BGP
Routing Policies
Creating a Prefix List Policy
Prefix policies filter routes based on network addresses and their masks. You can also set prefix upper and
lower limits to filter a range of network addresses.
To create a prefix list policy:
1 Name the policy and specify the IP network address and mask using the ip bgp policy prefix-list
command, as shown:
-> ip bgp policy prefix-list prefixfilter 12.0.0.0 255.0.0.0
Prefix policy prefixfilter now filters routes that match the network address 12.0.0.0 with a mask of
255.0.0.0.
2 Set the policy action using the ip bgp policy prefix-list action command. The policy action either
permits or denies routes that match the filter. Permitted routes are advertised, while denied routes are not.
For example:
-> ip bgp policy prefix-list prefixfilter 12.0.0.0 255.0.0.0 action deny
Prefix policy prefixfilter now denies routes that match the network address 12.0.0.0 with a mask of
255.0.0.0.
3 Optionally, you can set a lower prefix limit on the addresses specified in the policy using the ip bgp
policy prefix-list ge command. For example:
-> ip bgp policy prefix-list prefixfilter 14.0.0.0 255.0.0.0 ge 16
Prefix policy prefixfilter now denies routes after 14.0.0.0/16.
4 Optionally, you can set an upper prefix limit on the addresses specified in the policy using the ip bgp
policy prefix-list le command. For example:
-> ip bgp policy prefix-list prefixfilter 14.0.0.0 255.0.0.0 le 24
Prefix policy prefixfilter now denies routes between 14.0.0.0/16 and 14.0.0.0/24
Creating a Route Map Policy
Route map policies let you amalgamate the other policy types together, as well as add various other filters.
For example, you could have a route map policy that includes both an AS path policy and a community
policy.
To create a route map policy:
1 Name the route map policy and assign it a sequence number using the ip bgp policy route-map
command. The sequence number allows for multiple instances of a policy, and orders the route map policies so that a lower sequence number is applied first. For example:
-> ip bgp policy route-map mapfilter 1
Route map policy mapfilter is now ready.
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Routing Policies
Configuring BGP
2 Set the policy action using the ip bgp policy route-map action command. The policy action either
permits or denies routes that match the filter. Permitted routes are advertised, while denied routes are not.
For example:
-> ip bgp policy route-map mapfilter 1 action deny
Prefix policy mapfilter now denies routes that are filtered.
3 Add various conditions to the route map policy. It is possible to add an AS path policy, a community
policy, a prefix policy, as well as indicate other variables such as local preference and weight. The following table displays a list of the commands that can be used to construct a route map policy:
Route Map Options
Command
Assigns an AS path matching list to the
route map.
ip bgp policy route-map aspath-list
Configures the AS path prepend action to ip bgp policy route-map asprepend
be taken when a match is found.
Configures the action to be taken on the
community attribute when a match is
found.
ip bgp policy route-map community
Assigns a community matching list to the ip bgp policy route-map community-list
route map.
Configures the action to be taken for a
ip bgp policy route-map community-mode
community string when a match is found.
Configures the local preference value for ip bgp policy route-map lpref
the route map.
Configures the action to be taken when
setting local preference attribute for a
local matching route.
ip bgp policy route-map lpref-mode
Configures a matching community primi- ip bgp policy route-map match-community
tive for the route map.
Configures a matching mask primitive in ip bgp policy route-map match-mask
the route map.
Configures a matching prefix primitive in ip bgp policy route-map match-prefix
the route map.
Configures an AS path matching regular ip bgp policy route-map match-regexp
expression primitive in the route map.
Configures the Multi-Exit Discriminator ip bgp policy route-map med
(MED) value for a route map.
Configures the action to be taken when
setting the Multi-Exit Discriminator
(MED) attribute for a matching route.
ip bgp policy route-map med-mode
Configures the action to be taken on the
origin attribute when a match is found.
ip bgp policy route-map origin
Assigns a prefix matching list to the route ip bgp policy route-map prefix-list
map.
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Configuring BGP
Route Map Options
Routing Policies
Command
Configures a BGP weight value to be
ip bgp policy route-map weight
assigned to inbound routes when a match
is found.
Configures the value to strip from the
community attribute of the routes
matched by this route map instance
(sequence number).
ip bgp policy route-map community-strip
For example, to add AS path policy aspathfilter and community list policy commfilter to route map
policy mapfilter, enter the following:
-> ip bgp policy route-map mapfilter 1 aspath-list aspathfilter
-> ip bgp policy route-map mapfilter 1 community-list commfilter
Note. Conditions added to a route map policy must have already been created using their respective policy
commands. If you attempt to add non-existent policies to a route map policy, an error message is returned.
Each component of a route map policy must be added using a separate CLI command as shown above.
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Routing Policies
Configuring BGP
Assigning a Policy to a Peer
Once policies have been created using the commands described above, the policies can be applied to
routes learned from a specific peer, or route advertisements to a specific peer.
The following table shows the list of commands that allow you to assign a policy to a peer:
BGP Attribute
Command
Assigns an inbound AS path list filter to
a BGP peer.
ip bgp neighbor in-aspathlist
Assigns an inbound community list filter ip bgp neighbor in-communitylist
to a BGP peer.
Assigns an inbound prefix filter list to a
BGP peer.
ip bgp neighbor in-prefixlist
Assigns an outbound AS path filter list to ip bgp neighbor out-aspathlist
a BGP peer.
Assigns an outbound community filter
list to a BGP peer.
ip bgp neighbor out-communitylist
Assigns an outbound prefix filter list to a ip bgp neighbor out-prefixlist
BGP peer.
Assigns an inbound or outbound policy
map to a BGP peer.
ip bgp neighbor route-map
Invokes an inbound or outbound policy
re-configuration for a BGP peer.
ip bgp neighbor clear soft
Policies that should affect routes learned from a peer use the in- prefix, and policies that affect routes
being advertised to a peer use the out- prefix.
Assigning In and Out Bound AS Path Policies to a Peer
AS path policies filter routes based on matches made to a set AS list in the route. An AS list is a list of all
the ASs the route crosses until its destination. To filter routes learned from a peer by the AS list, enter the
peer’s IP address with the ip bgp neighbor in-aspathlist command as shown:
-> ip bgp neighbor 172.22.2.0 in-aspathlist aspathfilter
The AS path policy aspathfilter must be previously created using the ip bgp policy aspath-list command.
To attach the same policy on route advertisements to the peer, enter the peer IP address with the ip bgp
neighbor out-aspathlist command, as shown:
-> ip bgp neighbor 172.22.2.0 out-aspathlist aspathfilter
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Configuring BGP
Routing Policies
Assigning In and Out Bound Community List Policies to a Peer
Community list policies filter routes based on matches made to a list of communities of which the route is
a member. Communities group routes by attaching labels to them specifying a behavior (such as no
export).
To filter routes learned from a peer by the community list, enter the peer’s IP address with the ip bgp
neighbor in-communitylist command as shown:
-> ip bgp neighbor 172.22.2.0 in-communitylist commlistfilter
The community list policy commlistfilter must be previously created using the ip bgp policy
community-list command.
To assign the same policy to route advertisements to the peer, enter the peer IP address with the ip bgp
neighbor out-communitylist command, as shown:
-> ip bgp neighbor 172.22.2.0 out-communitylist commlistfilter
Assigning In and Out Bound Route Map Policies to a Peer
Route map policies filter routes combining routing criteria such as AS path, community, etc.
To filter routes learned from a peer by the route map, enter the peer’s IP address with the ip bgp neighbor
route-map command as shown:
-> ip bgp neighbor 172.22.2.0 route-map mapfilter in
The route map policy mapfilter must be previously created using the ip bgp policy route-map command.
To assign the same policy to route advertisements to the peer, enter the peer IP address with the ip bgp
neighbor route-map command, as shown:
-> ip bgp neighbor 172.22.2.0 route-map mapfilter out
Assigning In and Out Bound Prefix List Policies to a Peer
Prefix list policies filter routes based on a specific routing network, using an IP address or a series of IP
addresses.
To filter routes learned from a peer by the prefix list, enter the peer’s IP address with the ip bgp neighbor
in-prefixlist command as shown:
-> ip bgp neighbor 172.22.2.0 in-prefixlist prefixfilter
The route map policy prefixfilter must be previously created using the ip bgp policy prefix-list
command.
To assign the same policy to route advertisements to the peer, enter the peer IP address with the
ip bgp neighbor out-prefixlist command, as shown:
-> ip bgp neighbor 172.22.2.0 in-prefixlist prefixfilter
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Routing Policies
Configuring BGP
Reconfiguring Peer Policies
You can configure policies and assign these policies to a BGP peer, either to control in-bound routes or
out-bound routes advertisement. Additionally, it is possible to change or modify these peer policies, after
they are assigned to a peer.
Once the policies have been modified, they have to be re-applied to the peer. To re-apply the policies to
only the peer under consideration, you can use the in-reconfigure and the out-reconfigure commands.
To reconfigure a peer’s in policies, enter the peer’s IP address with the ip bgp neighbor clear soft
command as shown:
-> ip bgp neighbor 172.22.2.0 clear soft in
To reconfigure a peer’s out policies, enter the peer IP address with the ip bgp neighbor clear soft
command, as shown:
-> ip bgp neighbor 172.22.2.0 clear soft out
Displaying Policies
The following commands are used to display the various policies configured on a BGP router:
show ip bgp policy aspath-list
Displays information on policies based on AS path criteria.
show ip bgp policy community- Displays information on policies based on community list criteria.
list
show ip bgp policy prefix-list
Displays information on policies based on route prefix criteria.
show ip bgp policy route-map
Displays information on currently configured route maps.
For more information about the output from these show commands, see the OmniSwitch CLI Reference
Guide.
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Configuring BGP
Configuring Redistribution
Configuring Redistribution
It is possible to configure the BGP protocol to advertise routes learned from other routing protocols (external routes) into the BGP network. Such a process is referred to as route redistribution and is configured
using the ip redist command.
BGP redistribution uses route maps to control how external routes are learned and distributed. A route
map consists of one or more user-defined statements that can determine which routes are allowed or
denied access to the BGP network. In addition a route map may also contain statements that modify route
parameters before they are redistributed.
When a route map is created, it is given a name to identify the group of statements that it represents. This
name is required by the ip redist command. Therefore, configuring BGP route redistribution involves the
following steps:
1 Create a route map, as described in “Using Route Maps” on page 4-53.
2 Configure redistribution to apply a route map, as described in “Configuring Route Map Redistribution” on page 4-57.
Using Route Maps
A route map specifies the criteria that are used to control redistribution of routes between protocols. Such
criteria is defined by configuring route map statements. There are three different types of statements:
• Action. An action statement configures the route map name, sequence number, and whether or not
redistribution is permitted or denied based on route map criteria.
• Match. A match statement specifies criteria that a route must match. When a match occurs, then the
action statement is applied to the route.
• Set. A set statement is used to modify route information before the route is redistributed into the
receiving protocol. This statement is only applied if all the criteria of the route map is met and the
action permits redistribution.
The ip route-map command is used to configure route map statements and provides the following action,
match, and set parameters:
ip route-map action ...
ip route-map match ...
ip route-map set ...
permit
deny
ip-address
ip-nexthop
ipv6-address
ipv6-nexthop
tag
ipv4-interface
ipv6-interface
metric
route-type
metric
metric-type
tag
community
local-preference
level
ip-nexthop
ipv6-nexthop
Refer to the “IP Commands” chapter in the OmniSwitch CLI Reference Guide for more information about
the ip route-map command parameters and usage guidelines.
Once a route map is created, it is then applied using the ip redist command. See “Configuring Route Map
Redistribution” on page 4-57 for more information.
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Configuring Redistribution
Configuring BGP
Creating a Route Map
When a route map is created, it is given a name (up to 20 characters), a sequence number, and an action
(permit or deny). Specifying a sequence number is optional. If a value is not configured, then the number
50 is used by default.
To create a route map, use the ip route-map command with the action parameter. For example,
-> ip route-map ospf-to-bgp sequence-number 10 action permit
The above command creates the ospf-to-bgp route map, assigns a sequence number of 10 to the route
map, and specifies a permit action.
To optionally filter routes before redistribution, use the ip route-map command with a match parameter
to configure match criteria for incoming routes. For example,
-> ip route-map ospf-to-bgp sequence-number 10 match tag 8
The above command configures a match statement for the ospf-to-bgp route map to filter routes based on
their tag value. When this route map is applied, only OSPF routes with a tag value of eight are redistributed into the BGP network. All other routes with a different tag value are dropped.
Note. Configuring match statements is not required. However, if a route map does not contain any match
statements and the route map is applied using the ip redist command, the router redistributes all routes
into the network of the receiving protocol.
To modify route information before it is redistributed, use the ip route-map command with a set parameter. For example,
-> ip route-map ospf-to-bgp sequence-number 10 set tag 5
The above command configures a set statement for the ospf-to-bgp route map that changes the route tag
value to five. Because this statement is part of the ospf-to-bgp route map, it is only applied to routes that
have an existing tag value equal to eight.
The following is a summary of the commands used in the above examples:
-> ip route-map ospf-to-bgp sequence-number 10 action permit
-> ip route-map ospf-to-bgp sequence-number 10 match tag 8
-> ip route-map ospf-to-bgp sequence-number 10 set tag 5
To verify a route map configuration, use the show ip route-map command:
-> show ip route-map
Route Maps: configured: 1 max: 200
Route Map: ospf-to-bgp Sequence Number: 10 Action permit
match tag 8
set tag 5
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Configuring BGP
Configuring Redistribution
Deleting a Route Map
Use the no form of the ip route-map command to delete an entire route map, a route map sequence, or a
specific statement within a sequence.
To delete an entire route map, enter no ip route-map followed by the route map name. For example, the
following command deletes the entire route map named redistipv4:
-> no ip route-map redistipv4
To delete a specific sequence number within a route map, enter no ip route-map followed by the route
map name, then sequence-number followed by the actual number. For example, the following command
deletes sequence 10 from the redistipv4 route map:
-> no ip route-map redistipv4 sequence-number 10
Note that in the above example, the redistripv4 route map is not deleted. Only those statements associated
with sequence 10 are removed from the route map.
To delete a specific statement within a route map, enter no ip route-map followed by the route map name,
then sequence-number followed by the sequence number for the statement, then either match or set and
the match or set parameter and value. For example, the following command deletes only the match tag 8
statement from route map redistipv4 sequence 10:
-> no ip route-map redistipv4 sequence-number 10 match tag 8
Configuring Route Map Sequences
A route map may consist of one or more sequences of statements. The sequence number determines which
statements belong to which sequence and the order in which sequences for the same route map are
processed.
To add match and set statements to an existing route map sequence, specify the same route map name and
sequence number for each statement. For example, the following series of commands creates route map
rm_1 and configures match and set statements for the rm_1 sequence 10:
-> ip route-map rm_1 sequence-number 10 action permit
-> ip route-map rm_1 sequence-number 10 match tag 8
-> ip route-map rm_1 sequence-number 10 set metric 1
To configure a new sequence of statements for an existing route map, specify the same route map name
but use a different sequence number. For example, the following command creates a new sequence 20 for
the rm_1 route map:
-> ip route-map rm_1 sequence-number 20 action permit
-> ip route-map rm_1 sequence-number 20 match ipv4-interface to-finance
-> ip route-map rm_1 sequence-number 20 set metric 5
The resulting route map appears as follows:
-> show ip route-map rm_1
Route Map: rm_1 Sequence Number: 10 Action permit
match tag 8
set metric 1
Route Map: rm_1 Sequence Number: 20 Action permit
match ip4 interface to-finance
set metric 5
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Configuring Redistribution
Configuring BGP
Sequence 10 and sequence 20 are both linked to route map rm_1 and are processed in ascending order
according to their sequence number value. Note that there is an implied logical OR between sequences. As
a result, if there is no match for the tag value in sequence 10, then the match interface statement in
sequence 20 is processed. However, if a route matches the tag 8 value, then sequence 20 is not used. The
set statement for whichever sequence was matched is applied.
A route map sequence may contain multiple match statements. If these statements are of the same kind
(e.g., match tag 5, match tag 8, etc.) then a logical OR is implied between each like statement. If the match
statements specify different types of matches (e.g., match tag 5, match ip4 interface to-finance, etc.), then
a logical AND is implied between each statement. For example, the following route map sequence will
redistribute a route if its tag is either 8 or 5:
-> ip route-map rm_1 sequence-number 10 action permit
-> ip route-map rm_1 sequence-number 10 match tag 5
-> ip route-map rm_1 sequence-number 10 match tag 8
The following route map sequence will redistribute a route if the route has a tag of 8 or 5 and the route
was learned on the IPv4 interface to-finance:
->
->
->
->
ip
ip
ip
ip
route-map
route-map
route-map
route-map
rm_1
rm_1
rm_1
rm_1
sequence-number
sequence-number
sequence-number
sequence-number
10
10
10
10
action permit
match tag 5
match tag 8
match ipv4-interface to-finance
Configuring Access Lists
An IP access list provides a convenient way to add multiple IPv4 or IPv6 addresses to a route map. Using
an access list avoids having to enter a separate route map statement for each individual IP address. Instead,
a single statement is used that specifies the access list name. The route map is then applied to all the
addresses contained within the access list.
Configuring an IP access list involves two steps: creating the access list and adding IP addresses to the list.
To create an IP access list, use the ip access-list command (IPv4) or the ipv6 access-list command (IPv6)
and specify a name to associate with the list. For example:
-> ip access-list ipaddr
-> ipv6 access-list ip6addr
To add addresses to an access list, use the ip access-list address (IPv4) or the ipv6 access-list address
(IPv6) command. For example, the following commands add addresses to an existing access list:
-> ip access-list ipaddr address 16.24.2.1/16
-> ipv6 access-list ip6addr address 2001::1/64
Use the same access list name each time the above commands are used to add additional addresses to the
same access list. In addition, both commands provide the ability to configure if an address and/or its
matching subnet routes are permitted (the default) or denied redistribution. For example:
-> ip access-list ipaddr address 16.24.2.1/16 action deny redist-control allsubnets
-> ipv6 access-list ip6addr address 2001::1/64 action permit redist-control nosubnets
For more information about configuring access list commands, see the “IP Commands” chapter in the
OmniSwitch CLI Reference Guide.
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Configuring BGP
Configuring Redistribution
Configuring Route Map Redistribution
The ip redist command is used to configure the redistribution of routes from a source protocol into the
BGP destination protocol. This command is used on the BGP router that will perform the redistribution.
A source protocol is a protocol from which the routes are learned. A destination protocol is the one into
which the routes are redistributed. Make sure that both protocols are loaded and enabled before configuring redistribution.
Redistribution applies criteria specified in a route map to routes received from the source protocol. Therefore, configuring redistribution requires an existing route map. For example, the following command
configures the redistribution of OSPF routes into the BGP network using the ospf-to-bgp route map:
-> ip redist ospf into bgp route-map ospf-to-bgp
OSPF routes received by the router interface are processed based on the contents of the ospf-to-bgp route
map. Routes that match criteria specified in this route map are either allowed or denied redistribution into
the BGP network. The route map may also specify the modification of route information before the route
is redistributed. See “Using Route Maps” on page 4-53 for more information.
To remove a route map redistribution configuration, use the no form of the ip redist command. For example:
-> no ip redist ospf into bgp route-map ospf-to-bgp
Use the show ip redist command to verify the redistribution configuration:
-> show ip redist
Source
Destination
Protocol
Protocol
Status
Route Map
------------+------------+---------+-------------------LOCAL4
RIP
Enabled
rip_1
LOCAL4
OSPF
Enabled
ospf_2
LOCAL4
BGP
Enabled
bgp_3
RIP
OSPF
Enabled
ospf-to-bgp
Configuring the Administrative Status of the Route Map Redistribution
The administrative status of a route map redistribution configuration is enabled by default. To change the
administrative status, use the status parameter with the ip redist command. For example, the following
command disables the redistribution administrative status for the specified route map:
-> ip redist ospf into bgp route-map ospf-to-bgp status disable
The following command example enables the administrative status:
-> ip redist ospf into rip route-map ospf-to-bgp status enable
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Configuring Redistribution
Configuring BGP
Route Map Redistribution Example
The following example configures the redistribution of OSPF routes into a BGP network using a route
map (ospf-to-bgp) to filter specific routes:
-> ip route-map ospf-to-bgp sequence-number 10 action deny
-> ip route-map ospf-to-bgp sequence-number 10 match tag 5
-> ip route-map ospf-to-bgp sequence-number 10 match route-type external type2
-> ip route-map ospf-to-bgp sequence-number 20 action permit
-> ip route-map ospf-to-bgp sequence-number 20 match ipv4-interface intf_ospf
-> ip route-map ospf-to-bgp sequence-number 20 set metric 255
-> ip route-map ospf-to-bgp sequence-number 30 action permit
-> ip route-map ospf-to-bgp sequence-number 30 set tag 8
-> ip redist ospf into bgp route-map ospf-to-bgp
The resulting ospf-to-bgp route map redistribution configuration does the following:
• Denies the redistribution of Type 2 external BGP routes with a tag set to five.
• Redistributes into BGP all routes learned on the intf_ospf interface and sets the metric for such routes
to 255.
• Redistributes all other routes (those not processed by sequence 10 or 20) and sets the tag for such
routes to eight.
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Configuring BGP
Configuring Redistribution
Configuring Redundant CMMs for Graceful Restart
On OmniSwitch devices in a redundant CMM configuration, during a CMM takeover/failover, interdomain routing is disrupted. Alcatel-Lucent Operating System BGP needs to retain forwarding information, also help a peering router performing a BGP restart to support continuous forwarding for interdomain traffic flows by following the BGP graceful restart mechanism.
By default, BGP graceful restart is enabled. To configure BGP graceful restart support on OmniSwitch
switches, use the ip bgp graceful-restart command by entering ip bgp graceful-restart.
For example, to support BGP graceful restart, enter:
-> ip bgp graceful-restart
To configure the grace period (default is 90 seconds) for achieving a graceful BGP restart, use the ip bgp
graceful-restart restart-interval command, followed by the value in seconds.
For example, to configure a BGP graceful restart grace period as 300 seconds, enter:
-> ip bgp graceful-restart restart-interval 60
To disable support for graceful restart, use the no form of the ip bgp graceful-restart command by entering:
-> no ip bgp graceful-restart
For more information about graceful restart commands, see the “BGP Commands” chapter in the
OmniSwitch CLI Reference Guide.
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page 4-59
Application Example
Configuring BGP
Application Example
The following simple network using EBGP and IBGP will demonstrate some of the basic BGP setup
commands discussed previously:
AS 200
BGP Speaker 4
40.0.0.2/24
BGP Speaker 5
50.0.0.2/24
EBGP
BGP Speaker 1
40.0.0.1/24
10.0.0.1/24
20.0.0.1/24
AS 300
EBGP
IBGP
BGP Speaker 3
20.0.0.2/24
30.0.0.2/24
BGP Speaker 2
50.0.0.1/24
10.0.0.2/24
30.0.0.1/24
AS 100
In the above network, Speakers 1, 2, and 3 are part of AS 100 and are fully meshed. Speaker 4 is in AS
200 and Speaker 5 is in AS 300.
AS 100
BGP Speaker 1
Assign the speaker to AS 100:
-> ip bgp autonomous-system 100
Peer with the other speakers in AS 100 (for internal BGP, and to create a fully meshed BGP network):
-> ip bgp neighbor 20.0.0.2
-> ip bgp neighbor 20.0.0.2 remote-as 100
-> ip bgp neighbor 20.0.0.2 status enable
-> ip bgp neighbor 10.0.0.2
-> ip bgp neighbor 10.0.0.2 remote-as 100
-> ip bgp neighbor 10.0.0.2 status enable
Peer with the external speaker in AS 200 (for external BGP):
-> ip bgp neighbor 40.0.0.2
-> ip bgp neighbor 40.0.0.2 remote-as 200
-> ip bgp neighbor 40.0.0.2 status enable
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Configuring BGP
Application Example
Administratively enable BGP:
-> ip bgp status enable
BGP Speaker 2
Assign the speaker to AS 100:
-> ip bgp autonomous-system 100
Peer with the other speakers in AS 100 (for internal BGP, and to create a fully meshed BGP network):
-> ip bgp neighbor 30.0.0.2
-> ip bgp neighbor 30.0.0.2 remote-as 100
-> ip bgp neighbor 30.0.0.2 status enable
-> ip bgp neighbor 10.0.0.1
-> ip bgp neighbor 10.0.0.1 remote-as 100
-> ip bgp neighbor 10.0.0.1 status enable
Peer with the external speaker in AS 300 (for external BGP):
-> ip bgp neighbor 50.0.0.2
-> ip bgp neighbor 50.0.0.2 remote-as 300
-> ip bgp neighbor 50.0.0.2 status enable
Administratively enable BGP:
-> ip bgp status enable
BGP Speaker 3
Assign the speaker to AS 100:
-> ip bgp autonomous-system 100
Peer with the other speakers in AS 100 (for internal BGP, and to create a fully meshed BGP network):
-> ip bgp neighbor 30.0.0.1
-> ip bgp neighbor 30.0.0.1 remote-as 100
-> ip bgp neighbor 30.0.0.1 status enable
-> ip bgp neighbor 20.0.0.1
-> ip bgp neighbor 20.0.0.1 remote-as 100
-> ip bgp neighbor 20.0.0.1 status enable
Administratively enable BGP:
-> ip bgp status enable
AS 200
BGP Speaker 4
Assign the speaker to AS 200:
-> ip bgp as 200
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page 4-61
Application Example
Configuring BGP
Peer with the external speaker in AS 100 (for external BGP):
-> ip bgp neighbor 40.0.0.1
-> ip bgp neighbor 40.0.0.1 remote-as 100
-> ip bgp neighbor 40.0.0.1 status enable
Administratively enable BGP:
-> ip bgp status enable
AS 300
BGP Speaker 5
Assign the speaker to AS 300:
-> ip bgp autonomous-system 300
Peer with the external speaker in AS 100 (for external BGP):
-> ip bgp neighbor 50.0.0.1
-> ip bgp neighbor 50.0.0.1 remote-as 100
-> ip bgp neighbor 50.0.0.1 status enable
Administratively enable BGP:
-> ip bgp status enable
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Configuring BGP
Displaying BGP Settings and Statistics
Displaying BGP Settings and Statistics
Use the show commands listed in the following table to display information about the current BGP configuration and on BGP statistics:
show ip bgp
Displays the current global settings for the local BGP speaker.
show ip bgp statistics
Displays BGP global statistics, such as the route paths.
show ip bgp aggregate-address Displays aggregate configuration information.
show ip bgp dampening
Displays the current route dampening configuration settings.
show ip bgp dampening-stats
Displays route flapping statistics.
show ip bgp network
Displays information on the currently defined BGP networks.
show ip bgp path
Displays information, such as Next Hop and other BGP attributes, for
every path in the BGP routing table.
show ip bgp neighbors
Displays characteristics for BGP peers.
show ip bgp neighbors policy
Displays current inbound and outbound policies for all peers in the
router.
show ip bgp neighbors timer
Displays current and configured values for BGP timers, such as the hold
time, route advertisement, and connection retry.
show ip bgp neighbors statistics Displays statistics, such as number of messages sent and received, for
the peer.
show ip bgp policy aspath-list
Displays information on policies based on AS path criteria.
show ip bgp policy community- Displays information on policies based on community list criteria.
list
show ip bgp policy prefix-list
Displays information on policies based on route prefix criteria.
show ip bgp policy route-map
Displays information on currently configured route maps.
show ip redist
Displays the route map redistribution configuration.
show ip bgp routes
Displays information on BGP routes known to the router. This information includes whether changes to the route are in progress, whether it is
part of an aggregate route, and whether it is dampened.
For more information about the output from these show commands, see the OmniSwitch CLI Reference
Guide.
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page 4-63
BGP for IPv6 Overview
Configuring BGP
BGP for IPv6 Overview
IP version 6 (IPv6) is a new version of the Internet Protocol, designed as the successor to IP version 4
(IPv4), to overcome certain limitations in IPv4. IPv6 adds significant extra features that were not possible
with IPv4. These include automatic configuration of hosts, extensive multicasting capabilities, and built-in
security using authentication headers and encryption. Built-in support for QOS and path control are also
features found in IPv6.
IPv6 is a hierarchical 128-bit addressing scheme that consists of 8 fields, comprising 16 bits each. An IPv6
address is written as a hexadecimal value (0-F) in groups of four, separated by colons. IPv6 provides
3x10^38 addresses, which can help overcome the shortage of IP addresses needed for internet usage.
There are three types of IPv6 addresses: Unicast, Anycast, and Multicast. A Unicast address identifies a
single interface and a packet destined for a Unicast address is delivered to the interface identified by that
address. An Anycast address identifies a set of interfaces and a packet destined for an Anycast address is
delivered to the nearest interface identified by that Anycast address. A Multicast address identifies a set of
interfaces and a packet destined for a Multicast address is delivered to all the interfaces identified by that
Multicast address. There are no broadcast addresses in IPv6.
BGP uses Multiprotocol Extensions to support IPv6. The same procedures used for IPv4 prefixes can be
applied for IPv6 prefixes as well and the exchange of IPv4 prefixes will not be affected by this new
feature. However, there are some attributes that are specific to IPv4, such as AGGREGATOR,
NEXT_HOP and NLRI. Multiprotocol Extensions for BGP also supports backward compatibility for the
routers that do not support this feature. The OmniSwitch implementation supports Multiprotocol BGP as
defined in the following RFCs: 4271, 2439, 3392, 2385, 1997, 4456, 3065, 4273, 4760, and 2545.
Note. Multiprotocol extensions to BGP-4 is supported with its minimal or limited capability on OS6850
and OS9000 series switches in the current release.
To enable this implementation of BGP to support routing for multiple Network Layer protocols (e.g., IPv6,
etc.), the following capabilities are added:
• Associating a particular Network Layer protocol with the next hop information.
• Associating a particular Network Layer protocol with NLRI.
To support Multiprotocol BGP Extensions, two new non-transitive attributes are introduced, Multiprotocol Reachable NLRI (MP_REACH_NLRI) and Multiprotocol Unreachable NLRI
(MP_UNREACH_NLRI). MP_REACH_NLRI is utilized to carry the set of reachable destinations along
with the next hop information to be used for these destinations. The MP_UNREACH_NLRI attribute
carries the set of unreachable destinations.
Multiprotocol BGP extensions support the advertisement of IPv6 prefixes over the BGP sessions established between two BGP speakers using either of their IPv4 or IPv6 addresses. IPv6 prefixes can be redistributed into BGP using route maps. Similar to IPv4 networks, IPv6 networks should also be injected into
BGP for a BGP speaker to advertise the network to its peers. A BGP speaker can support up to approximately 5000 IPv6 prefixes.
Some features that are not supported in the current release of Multiprotocol BGP include:
• Route-Reflection capability.
• AS-Confederations capability.
• IPv6 route-flap dampening.
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Configuring BGP
BGP for IPv6 Overview
• IPv6 route aggregation.
• Policy-based route processing for IPv6 prefixes and peers.
• Routemap, prefix-list, community-list, and aspath-list policies.
• Graceful Restart capability for IPv6 prefixes.
• EBGP Multihop.
• Other multiprotocol capabilities for VPNs, MPLS label exchanges, etc.
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Quick Steps for Using BGP for IPv6
Configuring BGP
Quick Steps for Using BGP for IPv6
The following steps create an IPv4 BGP peer capable of exchanging IPv6 prefixes:
1 The BGP software is not loaded automatically when the router is booted. You must manually load the
software into memory by typing the following command:
-> ip load bgp
2 Assign an Autonomous System (AS) number to the local BGP speaker in this router. By default the AS
number is 1, but you may want to change this number to fit your network requirements. For example:
-> ip bgp autonomous-system 100
3 To enable unicast IPv6 updates for the BGP routing process, use the following command:
-> ipv6 bgp unicast
4 Create an IPv4 BGP peer entry. The local BGP speaker should be able to reach this peer. The IPv4
address you assign the peer should be valid. For example:
-> ip bgp neighbor 23.23.23.23
5 Assign an AS number to the IPv4 BGP peer you just created. All peers require an AS number. The AS
number does not have to be the same as the AS number for the local BGP speaker. For example:
-> ip bgp neighbor 23.23.23.23 remote-as 200
6 By default, the exchange of IPv4 unicast prefixes is enabled. To enable the exchange of IPv6 unicast
prefixes between IPv4 BGP peers, use the following command:
-> ip bgp neighbor 23.23.23.23 activate-ipv6
7 Configure the IPv6 next hop address for the IPv6 prefixes advertised to the IPv4 BGP peer using the
following command:
-> ip bgp neighbor 23.23.23.23 ipv6-nexthop 2001:100:3:4::1
Note. Optional. To reset the IPv6 next hop value, use an all-zero address. For example:
-> ip bgp neighbor 23.23.23.23 ipv6-nexthop::
For more information, refer to the OmniSwitch CLI Reference Guide.
8 By default, an IPv4 BGP peer is not active on the network until you enable it. Use the following
command to enable the IPv4 peer created in Step 4:
-> ip bgp neighbor 23.23.23.23 status enable
9 Administratively enable BGP using the following command:
-> ip bgp status enable
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Configuring BGP
Quick Steps for Using BGP for IPv6
The following steps create an IPv6 BGP peer capable of exchanging IPv6 prefixes:
1 Repeat steps 1 through 3 from the previous section to load the BGP software, assign an AS number to
the local BGP speaker, and enable unicast IPv6 updates for the BGP routing process, respectively.
2 Create an IPv6 BGP peer entry. The local BGP speaker should be able to reach this peer. The IPv6
address you assign the peer should be valid. For example:
-> ipv6 bgp neighbor 2001:100:3:4::1
3 Assign an AS number to the IPv6 BGP peer you just created. All peers require an AS number. The AS
number does not have to be the same as the AS number for the local BGP speaker. For example:
-> ipv6 bgp neighbor 2001:100:3:4::1 remote-as 10
4 To enable the exchange of IPv6 unicast prefixes between IPv6 BGP peers, use the following command:
-> ipv6 bgp neighbor 2001:100:3:4::1 activate-ipv6
5 By default, an IPv6 BGP peer is not active on the network until you enable it. Use the following
command to enable the IPv6 peer created in Step 2:
-> ipv6 bgp neighbor 2001:100:3:4::1 status enable
6 Administratively enable BGP using the following command:
-> ip bgp status enable
Note. In homogeneous IPv6 networks (i.e., in the absence of IPv4 interface configuration), the router's
router ID and the primary address must be explicitly configured prior to configuring the BGP protocol.
This is because the router ID is a unique 32-bit identifier and the primary address is a unique IPv4 address
that identifies the router. BGP uses the primary address in the AGGREGATOR attribute.
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page 4-67
Configuring BGP for IPv6
Configuring BGP
Configuring BGP for IPv6
This section describes the BGP for IPv6 configuration, which includes enabling and disabling IPv6 BGP
unicast, configuring IPv6 BGP peers, and configuring IPv6 BGP networks using Alcatel-Lucent’s
Command Line Interface (CLI) commands.
Enabling/Disabling IPv6 BGP Unicast
By default, BGP peers exchange only IPv4 unicast address prefixes. To exchange other address prefix
types, such as IPv6 prefixes, you need to enable IPv6 unicast advertisements.
To enable IPv6 unicast updates, use the ipv6 bgp unicast command, as shown:
-> ipv6 bgp unicast
In a homogenous IPv6 network, you need to first disable the IPv4 unicast updates, and then enable the
IPv6 unicast updates.
To disable IPv4 unicast updates, use the no form of the ip bgp unicast command, as shown:
-> no ip bgp unicast
Now, you can enable IPv6 unicast updates.
However, in IPv6 environments where the BGP speakers have established peering using their IPv4
addresses, IPv4 unicasting may not be disabled.
Configuring an IPv6 BGP Peer
A router configured to run the BGP routing protocol is called a BGP speaker. Unlike some other routing
protocols, BGP speakers do not automatically discover each other and begin exchanging information.
Instead, each BGP speaker must be explicitly configured with a set of BGP neighbors to exchange routing
information. BGP is connection-oriented and uses TCP to establish a reliable connection. An underlying
connection between two BGP speakers is established before any routing information is exchanged.
BGP supports two types of peers or neighbors, internal and external. Internal sessions run between BGP
speakers in the same autonomous system. External sessions run between BGP peers in different autonomous systems.
Every BGP speaker should be assigned to an AS. A BGP speaker can be configured as a peer within the
same or different AS.
You can configure BGP speakers to exchange IPv6 prefixes using either their IPv4 or IPv6 addresses. By
default, BGP speakers exchange only IPv4 unicast address prefixes. To exchange other address prefix
types, such as IPv6 prefixes, BGP speakers must be activated to advertise IPv6 BGP prefixes.
BGP peering can be established using either IPv4 or IPv6 addresses. However, in the absence of IPv4
interface configuration, it is mandatory to explicitly configure the router's router ID and assign a unique
IPv4 address as the router's primary address.
Note. In this document, the BGP terms “peer” and “neighbor” are used interchangeably to mean any BGP
entity known to the local router.
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Configuring BGP
Configuring BGP for IPv6
Configuring an IPv4 BGP Peer to Exchange IPv6 Prefixes
A BGP peer that is identified by its IPv4 address can be used to exchange IPv6 prefixes. However, to do
this both the peers should be enabled with IPv6 BGP unicast and should have interfaces that support IPv6
addresses. To configure an IPv4 BGP peer to exchange IPv6 prefixes, follow the steps mentioned below:
1 Create an IPv4 BGP peer with which the BGP speaker will establish peering using its IPv4 address
with the ip bgp neighbor command, as shown:
-> ip bgp neighbor 190.17.20.16
2 Assign an AS number to the IPv4 peer using the ip bgp neighbor remote-as command. For example,
to assign the peer created in Step 1 to AS number 200, you would enter:
-> ip bgp neighbor 190.17.20.16 remote-as 200
3 Enable IPv6 unicast capability for the IPv4 BGP peer using the ip bgp neighbor activate-ipv6
command, as shown:
-> ip bgp neighbor 190.17.20.16 activate-ipv6
4 Set the IPv6 next hop address for IPv6 prefixes advertised to the IPv4 BGP peer using the
ip bgp neighbor ipv6-nexthop command, as shown:
-> ip bgp neighbor 190.17.20.16 ipv6-nexthop 2001::1
5 Enable the BGP peer status using the ip bgp neighbor status command. For example, to enable the
status of the IPv4 BGP peer with an IPv4 address of 190.17.20.16, you would enter:
-> ip bgp neighbor 190.17.20.16 status enable
Configuring an IPv6 BGP Peer to Exchange IPv6 Prefixes
To configure an IPv6 BGP peer to exchange IPv6 prefixes, follow the steps mentioned below:
1 Create an IPv6 BGP peer with which the BGP speaker will establish peering using its IPv6 address
with the ipv6 bgp neighbor command, as shown:
-> ipv6 bgp neighbor 2001::1
2 Assign an AS number to the IPv6 peer using the ipv6 bgp neighbor remote-as command. For exam-
ple, to assign the peer created in Step 1 to AS number 10, you would enter:
-> ipv6 bgp neighbor 2001::1 remote-as 10
3 Enable IPv6 unicast capability for the IPv6 BGP peer using the ipv6 bgp neighbor activate-ipv6
command, as shown:
-> ipv6 bgp neighbor 2001::1 activate-ipv6
4 Enable the BGP peer status using the ipv6 bgp neighbor status command. For example, to enable the
status of the IPv6 BGP peer with an IPv6 address of 2001::1, you would enter:
-> ipv6 bgp neighbor 2001::1 status enable
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Configuring BGP for IPv6
Configuring BGP
Configuring an IPv6 BGP Peer Using Link-Local IPv6 Addresses to Exchange
IPv6 Prefixes
To configure an IPv6 BGP peer using its link-local IPv6 address to exchange IPv6 prefixes, follow the
steps mentioned below:
1 Create an IPv6 BGP peer with which the BGP speaker will establish peering using its link-local IPv6
address with the ipv6 bgp neighbor command, as shown:
-> ipv6 bgp neighbor fe80::2d0:95ff:fee2:6ed0
2 Assign an AS number to the IPv6 peer using the ipv6 bgp neighbor remote-as command. For exam-
ple, to assign the peer created in Step 1 to AS number 20, you would enter:
-> ipv6 bgp neighbor fe80::2d0:95ff:fee2:6ed0 remote-as 20
3 Configure the local IPv6 interface from which the BGP peer will be reachable using the
ipv6 bgp neighbor update-source command. For example, to configure Vlan2 as the IPv6 interface name
from which the BGP peer is connected, you would enter:
-> ipv6 bgp neighbor fe80::2d0:95ff:fee2:6ed0 update-source Vlan2
4 Enable IPv6 unicast capability to the IPv6 BGP peer using the ipv6 bgp neighbor activate-ipv6
command, as shown:
-> ipv6 bgp neighbor fe80::2d0:95ff:fee2:6ed0 activate-ipv6
5 Enable the BGP peer status using the ipv6 bgp neighbor status command. For example, to enable the
status of the BGP peer with a link-local IPv6 address of fe80::2d0:95ff:fee2:6ed0, you would enter,
-> ipv6 bgp neighbor fe80::2d0:95ff:fee2:6ed0 status enable
Configuring an IPv6 BGP peer to Exchange IPv4 Prefixes
A BGP peer that is identified by its IPv6 address can be used to exchange IPv4 prefixes. However, to do
this, both peers should be enabled with IPv4 BGP unicast and should have interfaces that support IPv4
addresses. To configure an IPv6 BGP peer to exchange IPv4 prefixes, follow the steps mentioned below:
1 Create an IPv6 BGP peer with which the BGP speaker will establish peering using its IPv6 address
with the ipv6 bgp neighbor command, as shown:
-> ipv6 bgp neighbor 2001::1
2 Assign an AS number to the IPv6 peer using the ipv6 bgp neighbor remote-as command. For exam-
ple, to assign the peer created in Step 1 to AS number 10, you would enter:
-> ipv6 bgp neighbor 2001::1 remote-as 10
3 Set the IPv4 next hop address for IPv4 prefixes advertised to the IPv6 BGP peer using the
ipv6 bgp neighbor ipv4-nexthop command, as shown:
-> ipv6 bgp neighbor 2001::1 ipv4-nexthop 190.17.20.1
4 Enable the BGP peer status using the ipv6 bgp neighbor status command, as shown:
-> ipv6 bgp neighbor 2001::1 status enable
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Configuring BGP
Configuring BGP for IPv6
Changing the Local Router Address for an IPv6 Peer Session
By default, TCP connections to an IPv6 peer's address are assigned to the closest interface based on reachability. Any operational local IPv6 interface can be assigned to the IPv6 BGP peering session by explicitly forcing the TCP connection to use the specified interface.
The ipv6 bgp neighbor update-source command sets the local IPv6 interface address or name through
which this BGP peer can be contacted.
For example, to configure a peer with an IPv6 address of 2004::1 to be contacted via the IPv6 interface
ipv6IntfVlan2, use the ipv6 bgp neighbor update-source command, as shown:
-> ipv6 bgp neighbor 2004::1 update-source ipv6IntfVlan2
Use the no form of the ipv6 bgp neighbor update-source command to prevent the peer with an IPv6
address of 2004::1 from contacting the speaker via the IPv6 interface ipv6IntfVlan2, as shown:
-> no ipv6 bgp neighbor 2004::1 update-source ipv6IntfVlan2
Note. Alternatively, you can configure a peer with a link-local address of fe80::2d0:95ff:fee2:6ed0, using
the ipv6 bgp neighbor update-source command, as shown below:
-> ipv6 bgp neighbor fe80::2d0:95ff:fee2:6ed0 update-source ipv6IntfVlan2
This command will establish a BGP peering session to establish neighborship.
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page 4-71
Configuring BGP for IPv6
Configuring BGP
Optional IPv6 BGP Peer Parameters
Peer Parameter
Command
The interval, in seconds, between BGP retries ipv6 bgp neighbor conn-retryto set up a connection via the transport protocol interval
with another peer.
Enables or disables a BGP speaker to send a
default route to its peer.
Default Value/
Comments
120 seconds
ipv6 bgp neighbor default-origi- Disabled
nate
Configures the KEEPALIVE message interval ipv6 bgp neighbor timers
and hold time interval (in seconds) with regards
to the specified BGP peer.
30 seconds
(keepalive)
90 seconds
(holdtime)
Configures the maximum number of prefixes
or paths the local router can receive from a
BGP peer in UPDATE messages.
ipv6 bgp neighbor maximumprefix
Configures the local IPv6 interface from which ipv6 bgp neighbor updatea BGP peer will be connected.
source
Configures router to advertise its peering
address as the next hop address for the specified neighbor.
page 4-72
5000
Not set until configured
ipv6 bgp neighbor next-hop-self Disabled
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Configuring BGP
Configuring BGP for IPv6
Configuring IPv6 BGP Networks
A local IPv6 BGP network is used to indicate to BGP that a network should originate from a specified
router. A network must be known to the local BGP speaker and must also originate from the local BGP
speaker.
Networks have certain parameters that can be configured, such as local-preference, community, metric,
etc. Note that the network specified must be known to the router, whether it is connected, static, or dynamically learned. This is not the case for an aggregate.
Adding a Network
To add a local network to a BGP speaker, use the IPv6 address and mask of the local network in conjunction with the ipv6 bgp network command, as shown:
-> ipv6 bgp network 2001::1/64
In this example, the network 2001::1/64 is the local IPv6 network for this BGP speaker.
To remove the same network from the BGP speaker, use the no form of the ipv6 bgp network command,
as shown:
-> no ipv6 bgp network 2001::1/64
The network will now no longer be associated as the local network for the BGP speaker.
Enabling a Network
Once the network has been added to the speaker, it must be enabled on the speaker. To do this, enter the
IPv6 address and mask of the local network in conjunction with the ipv6 bgp network status command,
as shown:
-> ipv6 bgp network 2001::1/64 status enable
In this example, the IPv6 network 2001::1/64 has now been enabled.
To disable the same network, enter the ipv6 bgp network status command, as shown:
-> ipv6 bgp network 2001::1/64 status disable
The network would now be disabled, though not removed from the speaker.
Configuring Network Parameters
Once a local IPv6 network is added to a speaker, you can configure three parameters that are attached to
routes generated by the ipv6 bgp network command. These three attributes are the local preference,
community, and route metric.
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page 4-73
Configuring BGP for IPv6
Configuring BGP
Local Preference
Local preference is an attribute that specifies the degree of preference to be given to a specific route when
there are multiple routes to the same destination. This attribute is propagated throughout the autonomous
system and is represented by a numeric value. The higher the number, the higher the preference. For
example, a route with two exits, one with a local preference of 50 and another with a local preference 30
will use the path which has the local preference of 50.
To set the local preference for the local network, enter the IPv6 address and mask of the local network in
conjunction with the ipv6 bgp network local-preference command and value, as shown:
-> ipv6 bgp network 2001::1/64 local-preference 600
The local preference for routes generated by the network is now 600. The default value is 0 (no network
local preference is set).
Community
Communities are a way of grouping BGP destination addresses that share some common property. Adding
the local network to a specific community indicates that the network shares a common set of properties
with the rest of the community.
To add a network to a community, enter the local network IPv6 address and mask in conjunction with the
ipv6 bgp network community command and name, as shown:
-> ipv6 bgp network 2001::1/64 community 100:200
Network 2001::1/64 is now in the 100:200 community. The default community is no community.
To remove the local network from the community, enter the local network as above with the community
set to “none”, as shown:
-> ipv6 bgp network 2001::1/64 community none
The network is now no longer in any community.
Metric
A metric for an IPv6 network is the Multi-Exit Discriminator (MED) value. This value is sent from routers of one AS to another to indicate the path that the remote AS can use to send data to the local AS
assuming there is more than one. A lower value indicates a more preferred exit point. For example, a route
with a MED of 10 is more likely to be used than a route with an MED of 100.
To set the network metric value, enter the network IPv6 address and mask in conjunction with the ipv6
bgp network metric command and value, as shown:
-> ipv6 bgp network 2001::1/64 metric 100
The IPv6 network 2001::1/64 is now set with a metric of 100. The default metric is 0.
page 4-74
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Configuring BGP
Configuring BGP for IPv6
Viewing Network Settings
To view the network settings for all IPv6 networks assigned to the speaker, enter the show ipv6 bgp
network command, as shown:
-> show ipv6 bgp network
A display similar to the following appears:
Network
Admin state Oper state
----------------------+-----------+-----------2525:500:600::/64
enabled
active
To display a specific IPv6 network, enter the same command with the network IPv6 address and mask, as
shown:
-> show ipv6 bgp network 2525:500:600::/64.
A display similar to the following appears:
Network
Network
Network
Network
Network
Network
address
admin state
oper state
metric
local preference
community string
=
=
=
=
=
=
2525:500:600::/64,
enabled,
active,
0,
0,
<none>
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page 4-75
Configuring IPv6 Redistribution
Configuring BGP
Configuring IPv6 Redistribution
It is possible to learn and advertise IPv6 routes between different routing protocols. Such a process is
referred to as route redistribution and is configured using the ipv6 redist command.
IPv6 redistribution uses route maps to control how external routes are learned and distributed. A route map
consists of one or more user-defined statements that can determine which routes are allowed or denied
access to the network. In addition, a route map may also contain statements that modify route parameters
before they are redistributed.
When a route map is created, it is given a name to identify the group of statements that it represents. This
name is required by the ipv6 redist command. Therefore, configuring IPv6 BGP route redistribution
involves the following steps:
1 Create a route map, as described in “Using Route Maps for IPv6 Redistribution” on page 4-76.
2 Configure IPv6 redistribution to apply a route map, as described in “Configuring IPv6 Route Map
Redistribution” on page 4-76.
Using Route Maps for IPv6 Redistribution
A route map specifies the criteria that are used to control redistribution of routes between protocols. Route
maps that are used for redistributing both IPv4 and IPv6 routes are created in the same way. Refer to
“Using Route Maps” on page 4-53 for more information.
Configuring IPv6 Route Map Redistribution
Once a route map is created, it is then applied using the ipv6 redist command. The ipv6 redist command
is used to configure the redistribution of routes from a source protocol into the IPv6 BGP destination
protocol. This command is used on the IPv6 BGP router that will perform the redistribution.
A source protocol is a protocol from which the routes are learned. A destination protocol is the one into
which the routes are redistributed. Make sure that both protocols are loaded and enabled before configuring redistribution.
Redistribution applies criteria specified in a route map to routes received from the source protocol. Therefore, configuring redistribution requires an existing route map. For example, the following command
configures the redistribution of OSPFv3 routes into the IPv6 BGP network using the ospf-to-bgp route
map:
-> ipv6 redist ospf into bgp route-map ospf-to-bgp
OSPFv3 routes received by the router interface are processed based on the contents of the ospf-to-bgp
route map. Routes that match criteria specified in this route map are either allowed or denied redistribution into the IPv6 BGP network. The route map may also specify the modification of route information
before the route is redistributed. See “Using Route Maps” on page 4-53 for more information.
To remove a route map redistribution configuration, use the no form of the ipv6 redist command. For
example:
-> no ipv6 redist ospf into bgp route-map ospf-to-bgp
page 4-76
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December 2007
Configuring BGP
Configuring IPv6 Redistribution
Use the show ipv6 redist command to verify the redistribution configuration:
-> show ipv6 redist
Source
Destination
Protocol
Protocol
Status
Route Map
------------+------------+---------+-------------------localIPv6
BGP
Enabled
ipv6rm
OSPFv3
RIPng
Enabled
ospf-to-rip
Configuring the Administrative Status of the Route Map Redistribution
The administrative status of a route map redistribution configuration is enabled by default. To change the
administrative status, use the status parameter with the ipv6 redist command. For example, the following
command disables the redistribution administrative status for the specified route map:
-> ipv6 redist ospf into bgp route-map ospf-to-bgp status disable
The following command example enables the administrative status:
-> ipv6 redist ospf into bgp route-map ospf-to-bgp status enable
Route Map Redistribution Example
The following example configures the redistribution of OSPFv3 routes into an IPv6 BGP network using a
route map (ospf-to-bgp) to filter specific routes:
-> ip route-map ospf-to-bgp sequence-number 10 action deny
-> ip route-map ospf-to-bgp sequence-number 10 match tag 5
-> ip route-map ospf-to-bgp sequence-number 10 match route-type external type2
-> ip route-map ospf-to-bgp sequence-number 20 action permit
-> ip route-map ospf-to-bgp sequence-number 20 match ipv6-interface intf_ospf
-> ip route-map ospf-to-bgp sequence-number 20 set metric 255
-> ip route-map ospf-to-bgp sequence-number 30 action permit
-> ip route-map ospf-to-bgp sequence-number 30 set tag 8
-> ipv6 redist ospf into bgp route-map ospf-to-bgp
The resulting ospf-to-bgp route map redistribution configuration does the following:
• Denies the redistribution of Type 2 external OSPFv3 routes with a tag set to five.
• Redistributes into IPv6 BGP all routes learned on the intf_ospf interface and sets the metric for such
routes to 255.
• Redistributes into IPv6 BGP all other routes (those not processed by sequence 10 or 20) and sets the
tag for such routes to eight.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 4-77
IPv6 BGP Application Example
Configuring BGP
IPv6 BGP Application Example
The following simple network using EBGP and IBGP will demonstrate some of the basic BGP setup
commands discussed previously:
AS 200
BGP Speaker 5
30.0.0.1/24
BGP Speaker 4
20.0.0.1/24
2001:ABCD:B02:1::1/64
AS 300
EBGP
EBGP
IBGP
BGP Speaker 1
10.0.0.1/24
20.0.0.2/24
2001:DB8:C17:1::1/64
2001:DB8:C18:1::1/64
2001:ABCD:B02:1::2/64
BGP Speaker 3
2001:DB8:C18:1::2/64
2001:DB8:C19:1::2/64
BGP Speaker 2
10.0.0.2/24
30.0.0.2/24
2001:DB8:C17:1::2/64
2001:DB8:C19:1::1/64
AS 100
In the above network, Speakers 1, 2, and 3 are part of AS 100 and are fully meshed. Speaker 4 is in AS
200. Speaker 3 is part of a homogenous IPv6 network domain (i.e. pure IPv6 network), internal to AS 100.
Speaker 5 in AS 300 is not aware of IPv6 capabilities.
AS 100
BGP Speaker 1
Assign the speaker to AS 100:
-> ip bgp autonomous-system 100
Enable IPv6 BGP unicast:
-> ipv6 bgp unicast
Peer with the other speakers in AS 100 (for internal BGP, and to create a fully meshed BGP network):
-> ip interface Link_To_Speaker2 vlan 2
-> ip interface Link_To_Speaker2 address 10.0.0.1/24
-> ipv6 interface Link_To_Speaker2 vlan 2
-> ipv6 address 2001:DB8:C17:1::1/64 Link_To_Speaker2
->
->
->
->
->
page 4-78
ipv6
ipv6
ipv6
ipv6
ipv6
bgp
bgp
bgp
bgp
bgp
neighbor
neighbor
neighbor
neighbor
neighbor
2001:DB8:C17:1::2
2001:DB8:C17:1::2
2001:DB8:C17:1::2
2001:DB8:C17:1::2
2001:DB8:C17:1::2
remote-as 100
activate-ipv6
ipv4-nexthop 10.0.0.1
status enable
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring BGP
->
->
->
->
->
->
ipv6
ipv6
ipv6
ipv6
ipv6
ipv6
IPv6 BGP Application Example
interface Link_To_Speaker3 vlan 3
address 2001:DB8:C18:1::1/64 Link_To_Speaker3
bgp neighbor 2001:DB8:C18:1::2
bgp neighbor 2001:DB8:C18:1::2 remote-as 100
bgp neighbor 2001:DB8:C18:1::2 activate-ipv6
bgp neighbor 2001:DB8:C18:1::2 status enable
Peer with the external speaker in AS 200 using its IPv4 address and an IPv6 forwarding interface (for IPv6
traffic):
-> ip interface Link_To_AS200 vlan 4
-> ip interface Link_To_AS200 address 20.0.0.2/24
-> ipv6 interface Link_to_AS200 vlan 4
-> ipv6 address 2001:ABCD:B02:1::2/64 Link_to_AS200
->
->
->
->
->
ip
ip
ip
ip
ip
bgp
bgp
bgp
bgp
bgp
neighbor
neighbor
neighbor
neighbor
neighbor
20.0.0.1
20.0.0.1
20.0.0.1
20.0.0.1
20.0.0.1
remote-as 200
activate-ipv6
ipv6-nexthop 2001:ABCD:B02:1::2
status enable
Administratively enable BGP:
-> ip bgp status enable
BGP Speaker 2
Assign the speaker to AS 100:
-> ip bgp autonomous-system 100
Enable IPv6 BGP unicast:
-> ipv6 bgp unicast
Peer with the other speakers in AS 100 (for internal BGP, and to create a fully meshed BGP network):
-> ip interface Link_To_Speaker1 vlan 2
-> ip interface Link_To_Speaker1 address 10.0.0.2/24
-> ipv6 interface Link_To_Speaker1 vlan 2
-> ipv6 address 2001:DB8:C17:1::2/64 Link_To_Speaker1
->
->
->
->
->
ipv6
ipv6
ipv6
ipv6
ipv6
bgp
bgp
bgp
bgp
bgp
neighbor
neighbor
neighbor
neighbor
neighbor
2001:DB8:C17:1::1
2001:DB8:C17:1::1
2001:DB8:C17:1::1
2001:DB8:C17:1::1
2001:DB8:C17:1::1
remote-as 100
activate-ipv6
ipv4-nexthop 10.0.0.2
status enable
-> ipv6 interface Link_To_Speaker3 vlan 3
-> ipv6 address 2001:DB8:C19:1::1/64 Link_To_Speaker3
->
->
->
->
ipv6
ipv6
ipv6
ipv6
bgp
bgp
bgp
bgp
neighbor
neighbor
neighbor
neighbor
2001:DB8:C19:1::2
2001:DB8:C19:1::2 remote-as 100
2001:DB8:C19:1::2 activate-ipv6
2001:DB8:C19:1::2 status enable
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December 2007
page 4-79
IPv6 BGP Application Example
Configuring BGP
Peer with the external speaker in AS 300 using IPv4 address:
-> ip interface Link_To_AS300 vlan 4
-> ip interface Link_To_AS300 address 30.0.0.2/24
-> ip bgp neighbor 30.0.0.1
-> ip bgp neighbor 30.0.0.1 remote-as 300
-> ip bgp neighbor 30.0.0.1 status enable
Administratively enable BGP:
-> ip bgp status enable
BGP Speaker 3
Assign the speaker to AS 100:
-> ip bgp autonomous-system 100
Administratively disable IPv4 unicast, as this speaker is part of a homogeneous IPv6 domain:
-> no ip bgp unicast
Explicitly configure the router ID and the primary address of the speaker:
-> ip router router-id 10.0.0.3
-> ip router primary-address 10.0.0.3
Peer with the other speakers in AS 100 (for internal BGP, and to create a fully meshed BGP network):
-> ipv6 interface Link_To_Speaker1 vlan 2
-> ipv6 address 2001:DB8:C18:1::2/64 Link_To_Speaker1
-> ipv6 interface Link_To_Speaker2 vlan 3
-> ipv6 address 2001:DB8:C19:1::2/64 Link_To_Speaker2
->
->
->
->
ipv6
ipv6
ipv6
ipv6
bgp
bgp
bgp
bgp
neighbor
neighbor
neighbor
neighbor
address
address
address
address
2001:DB8:C18:1::1
2001:DB8:C18:1::1 remote-as 100
2001:DB8:C18:1::1 activate-ipv6
2001:DB8:C18:1::1 status enable
->
->
->
->
ipv6
ipv6
ipv6
ipv6
bgp
bgp
bgp
bgp
neighbor
neighbor
neighbor
neighbor
address
address
address
address
2001:DB8:C19:1::1
2001:DB8:C19:1::1 remote-as 100
2001:DB8:C19:1::1 activate-ipv6
2001:DB8:C19:1::1 status enable
Administratively enable BGP:
-> ip bgp status enable
AS 200
BGP Speaker 4
Assign the speaker to AS 200:
-> ip bgp autonomous-system 200
Enable IPv6 BGP unicast:
-> ipv6 bgp unicast
page 4-80
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December 2007
Configuring BGP
IPv6 BGP Application Example
Peer with the external speaker in AS 100 using its IPv4 address and an IPv6 forwarding interface (for IPv6
traffic):
-> ip interface Link_To_AS100 vlan 2
-> ip interface Link_To_AS100 address 20.0.0.1/24
-> ipv6 interface Link_to_AS100 vlan 2
-> ipv6 address 2001:ABCD:B02:1::1/64 Link_to_AS100
->
->
->
->
->
ip
ip
ip
ip
ip
bgp
bgp
bgp
bgp
bgp
neighbor
neighbor
neighbor
neighbor
neighbor
20.0.0.2
20.0.0.2
20.0.0.2
20.0.0.2
20.0.0.2
remote-as 100
activate-ipv6
ipv6-nexthop 2001:ABCD:B02:1::1
status enable
Administratively enable BGP:
-> ip bgp status enable
AS 300
BGP Speaker 5
Assign the speaker to AS 300:
-> ip bgp autonomous-system 300
Peer with the external speaker in AS 100 using its IPv4 address:
-> ip interface Link_To_AS100 vlan 2
-> ip interface Link_To_AS100 address 30.0.0.1/24
-> ip bgp neighbor 30.0.0.2
-> ip bgp neighbor 30.0.0.2 remote-as 100
-> ip bgp neighbor 30.0.0.2 status enable
Administratively enable BGP:
-> ip bgp status enable
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December 2007
page 4-81
Displaying IPv6 BGP Settings and Statistics
Configuring BGP
Displaying IPv6 BGP Settings and Statistics
Use the show commands listed in the following table to display information about the current IPv6 BGP
configuration and on IPv6 BGP statistics:
show ipv6 bgp network
Displays the status of all the IPv6 BGP networks or a specific IPv6 BGP
network.
show ipv6 bgp path
Displays the known IPv6 BGP paths for all the routes or a specific route.
show ipv6 bgp routes
Displays the known IPv6 BGP routes.
show ipv6 bgp neighbors
Displays the configured IPv6 BGP peers.
show ipv6 bgp neighbors
timers
Displays the timers for configured IPv6 BGP peers.
show ipv6 bgp neighbors
statistics
Displays the neighbor statistics of the configured IPv6 BGP peers.
show ip bgp
Displays the current global settings for the local BGP speaker.
show ip bgp neighbors
Displays the configured IPv4 BGP peers.
For more information about the output from these show commands, see the OmniSwitch CLI Reference
Guide.
page 4-82
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December 2007
5
Configuring Multicast
Address Boundaries
Multicast boundaries confine scoped multicast addresses to a particular domain. Confining scoped
addresses helps to ensure that multicast traffic passed within a multicast domain does not conflict with
multicast users outside the domain.
In This Chapter
This chapter describes the basic components of scoped multicast boundaries and how to configure them
through the Command Line Interface (CLI). CLI commands are used in the configuration examples; for
more details about the syntax of commands, see the OmniSwitch CLI Reference Guide.
Configuration procedures described in this chapter include:
• Configuring multicast address boundaries—see page 5-7.
• Verifying the multicast address boundary configuration—see page 5-8.
For information about additional multicast routing commands, see the “Multicast Routing Commands”
chapter in the OmniSwitch CLI Reference Guide.5
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 5-1
Multicast Boundary Specifications
Configuring Multicast Address Boundaries
Multicast Boundary Specifications
RFCs Supported
2365—Administratively Scoped IP Multicast
2932—IPv4 Multicast Routing MIB
Maximum Multicast Flows per Network 400 (with hardware routing; see note below)
Interface (NI) Module
Valid Scoped Address Range
239.0.0.0 to 239.255.255.255
Note. If software routing is used, the number of total flows supported is variable, depending on the
number of flows and the number of routes per flow.
Quick Steps for Configuring Multicast Address
Boundaries
Using Existing IP Interfaces
1 Before attempting to configure a multicast address boundary, be sure that you have manually loaded
the multicast protocol software for your network (e.g., PIM-SM or DVMRP). Otherwise, you will receive
an error stating that “the specified application is not loaded.” To manually load multicast protocol software, use the ip load command. For example:
-> ip load pim
2 Configure a multicast address boundary for a VLAN interface using the ip mroute-boundary
command. Information must include the interface IP address, followed by the multicast boundary address
and the corresponding subnet mask. For example:
-> ip mroute-boundary vlan-3 239.120.0.0 255.255.0.0
On New IP Interface
1 Be sure that you have loaded one of the dynamic routing features (e.g., PIM-SM). Otherwise, you will
receive an error stating that “the specified application is not loaded.” To load a dynamic routing feature,
use the ip load command. For example:
-> ip load pim
2 Create a new IP interface on an existing VLAN by specifying a valid IP address. For example:
-> ip interface vlan-2 address 178.14.1.43 vlan 3
Note. The ip interface command is not supported in Release 5.3.1. For this release use the vlan router ip
command instead. See the OmniSwitch CLI Reference Guide for more information.
The VLAN must already be created on the switch. For information about creating VLANs, see the
“Configuring VLANs” chapter in the OmniSwitch 6800/6850/9000 Network Configuration Guide.
page 5-2
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December 2007
Configuring Multicast Address Boundaries
Quick Steps for Configuring Multicast Address Boundaries
3 Configure a multicast address boundary on the IP interface. Information must include the IP address
assigned at step 2, as well as a scoped multicast address and the corresponding subnet mask.
For example:
-> ip mroute-boundary vlan-2 239.120.0.0 255.255.0.0
Note. Optional. To verify the multicast boundary configuration, enter the show ip mroute-boundary
command. The display is similar to the one shown here:
-> show ip mroute-boundary
Interface Name Interface Address Boundary Address
--------------+-----------------+------------------vlan-2
178.14.1.43
239.120.0.0/16
For more information about this display, see the “Multicast Routing Commands” chapter in the
OmniSwitch CLI Reference Guide.
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December 2007
page 5-3
Multicast Address Boundaries Overview
Configuring Multicast Address Boundaries
Multicast Address Boundaries Overview
Multicast Addresses and the IANA
The Internet Assigned Numbers Authority (IANA) regulates unique parameters for different types of
network protocols. For example, the IANA regulates addresses for IP, DVMRP, PIM, PIM-SSM, etc., and
also provides a range of administratively scoped multicast addresses. For more information, refer to the
section below.
Administratively Scoped Multicast Addresses
Multicast addresses 239.0.0.0 through 239.255.255.255 have been reserved by the IANA as administratively scoped addresses for use in private multicast domains. These addresses cannot be used for any other
protocol or network function. Because they are regulated by the IANA, these addresses can theoretically
be used by network administrators without conflicting with networks outside of their multicast domains.
However, to ensure that the addresses used in a private multicast domain do not conflict with other
domains (e.g., within the company network or out on the Internet), multicast address boundaries must be
configured.
Source-Specific Multicast Addresses
Multicast addresses 232.0.0.0 through 232.255.255.255 have been reserved by the Internet Assigned
Numbers Authority (IANA) as source-specific multicast (SSM) destination addresses. Addresses within
this range are reserved for use by source-specific applications and protocols (e.g., PIM-SSM) and cannot
be used for any other functions or protocols.
page 5-4
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December 2007
Configuring Multicast Address Boundaries
Multicast Address Boundaries Overview
Multicast Address Boundaries
Without multicast address boundaries, multicast traffic conflicts can occur between domains. For example, a multicast packet addressed to 239.140.120.10 from a device in one domain could “leak” into another
domain. If the other domain contains a device attempting to send a separate multicast packet with the same
address, a conflict may occur. A boundary is used to eliminate these conflicts by confining multicast traffic on an IP interface. When a boundary is set, multicast packets with a destination address within the
specified boundary will not be forwarded on the interface.
The figure below provides an example of a multicast address boundary configured on an interface.
Multicast Domain 1
239.140.120.x
Multicast Traffic
VLAN 2
Router
Port
172.22.2.44
Multicast Address Boundary
239.140.120.0/24
Simple Multicast Address Boundary Example
An IP interface is configured on VLAN 2, with the IP address 172.22.2.44. The IP interface is also
referred to as the router interface; the IP address serves as the identifier for the interface.
In this example, the multicast address boundary has been defined as 239.140.120.0. The mask value of
255.255.255.0 is shown in Classless Inter-Domain Routing (CIDR) prefix format as /24. This specifies
that no multicast traffic addressed to multicast addresses 239.140.120.0 through 239.140.120.255 will be
forwarded on interface 172.22.2.44.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 5-5
Multicast Address Boundaries Overview
Configuring Multicast Address Boundaries
Concurrent Multicast Addresses
Because multicast boundaries confine scoped multicast addresses to a particular domain, multicast
addresses can be used concurrently in more than one region in the network. In other words, scoped multicast addresses can be reused throughout the network. This allows network administrators to conserve
limited multicast address space. The figure below shows multicast addresses 239.140.120.0 through
239.140.120.255 being used by both Multicast Domain 1 and Multicast Domain 2.
Multicast Domain 1
Multicast Domain 2
VLAN 2
Router
Port
172.22.2.10
239.140.120.x
Multicast Traffic
Multicast Address Boundary
239.140.120.0/24
VLAN 3
Router
Port
178.14.1.43
239.140.120.x
Multicast Traffic
Multicast Address Boundary
239.140.120.0/24
Concurrent Multicast Addresses Example
Although the same block of multicast addresses—239.140.120.0 through 239.140.120.255—is being used
in two different domains at once, multicast traffic from one domain cannot conflict with multicast traffic in
the other domain because they are effectively confined by boundaries on their corresponding interfaces. In
this case, the boundary 239.140.120.0/24 has been configured on interfaces 172.22.2.120 and 178.14.1.43.
page 5-6
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring Multicast Address Boundaries
Configuring Multicast Address Boundaries
Configuring Multicast Address Boundaries
Because multicast address boundaries are part of the Advanced Routing software, the advanced routing
image must be present in an OmniSwitch, before you can begin configuring the feature. In addition, the
multicast routing protocol (e.g., PIM-SM or DVMRP) for your network must first be loaded to memory
via the ip load command.
Basic Multicast Address Boundary Configuration
Configuring a multicast address boundary prevents multicast traffic that is addressed to a particular
address or range of addresses from being forwarded on an interface. Boundaries may be configured in
more than one region in the network.
The basic command for creating a multicast address boundary is:
ip mroute-boundary
The next section describes how to use this command.
Creating a Multicast Address Boundary
To create a multicast address boundary on an interface, enter the ip mroute-boundary command, with the
interface IP address, the boundary address, and the corresponding mask. For example:
-> ip mroute-boundary vlan-2 239.120.0.0 255.255.0.0
The interface IP address must be a valid IP interface that has been assigned to an existing VLAN. For
information about creating VLANs and assigning IP interfaces, see the
“Configuring VLANs” chapter in the OmniSwitch 6800/6850/9000 Network Configuration Guide.
The boundary address must be an administratively-scoped multicast address from 239.0.0.0 to
239.255.255.255.
Deleting a Multicast Address Boundary
To delete a multicast address boundary from an interface, enter the no ip mroute-boundary command,
with the interface IP address, the boundary address, and the corresponding mask. For example:
-> no ip mroute-boundary vlan-2 239.120.0.0 255.255.0.0
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 5-7
Verifying the Multicast Address Boundary Configuration
Configuring Multicast Address Boundaries
Verifying the Multicast Address Boundary
Configuration
A summary of the show commands used for verifying the multicast address boundary configuration is
given here:
show ip mroute-boundary
Displays scoped multicast address boundaries for the switch’s router
interfaces.
For more information about the displays that result from these commands, see the OmniSwitch CLI
Reference Guide.
Application Example for Configuring Multicast
Address Boundaries
This section illustrates multicast address boundary configuration for a simple multicast network. The
network consists of a core switch with a backbone connection to the Internet. The core switch is given a
boundary of 239.0.0.0/8. This is the broadest boundary, keeping all multicast traffic addressed to 239.0.0.0
through 239.255.255.255 from leaving the company network.
The core switch is connected to two wiring closet switches. The wiring closet switches serve the Human
Resources and Training network domains. A boundary of 239.188.0.0/16 is created for both the Human
Resources and Training domains. No multicast traffic within the range of 239.188.0.0 through
239.188.255.255 is permitted to leave either domain. This allows multicast addresses within the range to
be used simultaneously in both domains without conflict.
Note. For a diagram showing this sample network with the multicast address boundaries described above,
refer to page 5-11.
1 Verify that either PIM or DVMRP is loaded on the switch. Refer to the “Configuring PIM” or “Config-
uring DVMRP” chapters in the OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide for
more information.
2 Create a VLAN on the core switch. For example:
-> vlan 2
3 Next, create a IP interface on the VLAN. The IP interface serves as the interface identifier on which the
boundary will be created. To create a IP interface, use the ip interface command. For example:
-> ip interface vlan-2 address 178.10.1.1 vlan 2
Note. The ip interface command is not supported in Release 5.3.1. For this release use the vlan router ip
command instead. See the OmniSwitch CLI Reference Guide for more information.
page 5-8
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December 2007
Configuring Multicast Address Boundaries
Application Example for Configuring Multicast Address Boundaries
4 You are now ready to create a boundary on the core switch’s router interface. For this example, the
broadest possible boundary, 239.0.0.0, will be configured on the interface. This boundary will keep all
traffic addressed to multicast addresses 239.0.0.0 through 239.255.255.255 from being forwarded on the
interface. To assign the boundary, use the ip mroute-boundary command. For example:
-> ip mroute-boundary vlan-2 239.0.0.0 255.0.0.0
Note that the command includes the interface IP address (178.10.1.1), along with the multicast address
boundary (239.0.0.0) and the corresponding subnet mask (255.0.0.0).
5 Verify your changes using the show ip mroute-boundary command:
-> show ip mroute-boundary
Interface Name Interface Address Boundary Address
--------------+-----------------+------------------vlan-2
178.10.1.1
239.0.0.0/8
The correct multicast address boundary of 239.0.0.0 is shown on VLAN 2. (VLAN 2 is displayed in the
table because it contains the IP interface on which the boundary was configured. In this case, that IP interface is 178.10.1.1.) In addition, the subnet mask has been translated into the CIDR prefix length of /8.
The figure below illustrates the multicast address boundary as currently configured.
Internet
VLAN 2
Router
Port
178.10.1.1
239.x.x.x
Multicast Traffic
Core Switch
239.0.0.0/8
Network with a Single Multicast Address Boundary
All multicast traffic ranging from 239.0.0.0 through 239.255.255.255 is blocked and cannot be forwarded
from switch’s 178.10.1.1 router interface. As shown by the arrow, multicast traffic addressed to 239.x.x.x
cannot leave the domain.
6 Next, create a VLAN on the wiring closet switch used for Human Resources. For example:
-> vlan 3
VLAN 3 is now used to define the Human Resources network domain.
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December 2007
page 5-9
Application Example for Configuring Multicast Address Boundaries
Configuring Multicast Address Boundaries
7 Create an IP interface on VLAN 3. For example:
-> ip interface vlan-3 address 178.20.1.1 vlan 3
Note. The ip interface command is not supported in Release 5.3.1. For this release use the vlan router ip
command instead. See the OmniSwitch CLI Reference Guide for more information.
8 Assign a boundary on the switch’s router interface. For this example, the interface is given the bound-
ary 239.188.0.0/16. This boundary will keep all traffic addressed to multicast addresses 239.188.0.0
through 239.188.255.255 from being forwarded on the interface:
-> ip mroute-boundary vlan-3 239.188.0.0 255.255.0.0
The command syntax includes the interface IP address (178.20.1.1), along with the multicast address
boundary (239.188.0.0) and the corresponding subnet mask (255.255.0.0).
9 Create a VLAN on the separate wiring closet switch used for Training. For example:
-> vlan 4
VLAN 4 is now used to define the Training network domain.
10 Create an IP interface on VLAN 4. For example:
-> ip interface vlan-4 address 178.30.1.1 vlan 4
Note. The ip interface command is not supported in Release 5.3.1. For this release use the vlan router ip
command instead. See the OmniSwitch CLI Reference Guide for more information.
11 Assign a boundary on the Training router interface. The interface is given the same boundary as
Human Resources (i.e., 239.188.0.0/16).
-> ip mroute-boundary vlan-4 239.188.0.0 255.255.0.0
Because there is a boundary configured at each domain, multicast users in Human Resources can forward
239.188.x.x multicast traffic without conflicting with users in Training who are forwarding traffic with the
same addresses. By allowing addresses to be used concurrently in more than one department, network
administrators can conserve limited scoped multicast address space.
page 5-10
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December 2007
Configuring Multicast Address Boundaries
Application Example for Configuring Multicast Address Boundaries
The figure below illustrates all configured multicast address boundaries for this network.
Internet
VLAN 2
Router
Port
178.10.1.1
239.x.x.x
Multicast Traffic
Core Switch
Training
Human Resources
239.188.x.x
Multicast Traffic
VLAN 3
Router
Port
178.20.1.1
VLAN 4
Router
Port
178.30.1.1
239.188.0.0/16
239.188.x.x
Multicast Traffic
239.188.0.0/16
239.0.0.0/8
Network with Multiple Multicast Addresses Boundaries
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 5-11
Application Example for Configuring Multicast Address Boundaries
page 5-12
Configuring Multicast Address Boundaries
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
6
Configuring DVMRP
This chapter includes descriptions for Distance Vector Multicast Routing Protocol (DVMRP). DVMRP is
a dense-mode multicast routing protocol. DVMRP—which is essentially a “broadcast and prune” routing
protocol—is designed to assist routers in propagating IP multicast traffic through a network.
In This Chapter
This chapter describes the basic components of DVMRP and how to configure them through the
Command Line Interface (CLI). CLI commands are used in the configuration examples; for more details
about the syntax of commands, see the OmniSwitch CLI Reference Guide.
Configuration procedures described in this chapter include:
• Loading DVMRP into memory—see page 6-10.
• Enabling DVMRP—see page 6-12.
• Neighbor communications—see page 6-13.
• Routes—see page 6-14.
• Pruning—see page 6-15.
• Grafting—see page 6-17.
• Tunnels—see page 6-17.
• Verifying the DVMRP configuration—see page 6-18.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 6-1
DVMRP Specifications
Configuring DVMRP
DVMRP Specifications
RFCs Supported
2667—IP Tunnel MIB
IETF Internet-Drafts Supported
Distance-Vector Multicast Routing Protocol MIB
draft-ietf-idmr-dvmrp-v3-11.txt
DVMRP Version Supported
DVMRPv3.255
DVMRP Attributes Supported
Reverse Path Multicasting, Neighbor Discovery, Multicast
Source Location, Route Report Messages, Distance
metrics, Dependent Downstream Routers, Poison Reverse,
Pruning, Grafting, DVMRP Tunnels
DVMRP Timers Supported
Flash update interval, Graft retransmissions, Neighbor
probe interval, Neighbor timeout, Prune lifetime, Prune
retransmission, Route report interval, Route hold-down,
Route expiration timeout
Range for Interface Distance Metrics
1 to 31
Range for Tunnel TTL Value
0 to 255
Multicast Protocols per Interface
1 (e.g., you cannot enable both PIM-SM and DVMRP on
the same IP interface)
DVMRP Defaults
The following table lists the defaults for DVMRP configuration:
Parameter Description
Command
Default Value/Comments
DVMRP load status
ip load dvmrp
Unloaded
DVMRP status
ip dvmrp status
Disabled
DVMRP interface status
ip dvmrp interface
Disabled
Flash update interval
ip dvmrp flash-interval
5 seconds
Graft retransmission timeout
ip dvmrp graft-timeout
5 seconds
Neighbor probe interval time
ip dvmrp neighbor-interval
10 seconds
Neighbor timeout
ip dvmrp neighbor-timeout
35 seconds
Prune lifetime
ip dvmrp prune-lifetime
7200 seconds
Prune retransmission timeout
ip dvmrp prune-timeout
30 seconds
Route report interval
ip dvmrp report-interval
60 seconds
Route hold-down time
ip dvmrp route-holddown
120 seconds
Route expiration timeout
ip dvmrp route-timeout
140 seconds
Interface distance metric
ip dvmrp interface metric
1
DVMRP tunnel status
ip dvmrp tunnel
Disabled
DVMRP tunnel TTL value
ip dvmrp tunnel ttl
255
Subordinate neighbor status
ip dvmrp subord-default
true
page 6-2
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December 2007
Configuring DVMRP
Quick Steps for Configuring DVMRP
Quick Steps for Configuring DVMRP
Note. DVMRP requires that IP Multicast Switching (IPMS) is enabled. IPMS is automatically enabled
when a multicast routing protocol (either PIM-SM or DVMRP) is enabled globally and on an interface
and when the operational status of the interface is up. However, if you wish to manually enable IPMS on
the switch, use the ip multicast status command.
1 Manually load DVMRP into memory by entering the following command:
-> ip load dvmrp
2 Create a router port (i.e., interface) on an existing VLAN by specifying a valid IP address. To do this,
use the ip interface command. For example:
-> ip interface vlan-2 address 178.14.1.43 vlan 2
Note. The ip interface command is not supported in Release 5.3.1. For this release use the vlan router ip
command instead. See the OmniSwitch CLI Reference Guide for more information.
3 Enable the DVMRP protocol on the interface via the ip dvmrp interface command. For example:
-> ip dvmrp interface vlan-2
4 Globally enable the DVMRP protocol by entering the following command:
-> ip dvmrp status enable
5 Save your changes to the Working directory’s boot.cfg file by entering the following command:
-> write memory
Once loaded and enabled, DVMRP is typically ready to use because its default values are appropriate for
the majority of installations.
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page 6-3
Quick Steps for Configuring DVMRP
Configuring DVMRP
Note. Optional. To verify DVMRP interface status, enter the show ip dvmrp interface command. The
display is similar to the one shown here:
Address
Vlan
Metric Admin-Status Oper-Status
-----------------+------+--------+-------------+------------178.14.1.43
44
1
Enabled
Enabled
To verify the global DVMRP status, enter the show ip dvmrp command:
DVMRP Admin Status
Flash Interval
Graft Timeout
Neighbor Interval
Neighbor Timeout
Prune Lifetime
Prune Timeout
Report Interval
Route Holddown
Route Timeout
Subord Default
=
=
=
=
=
=
=
=
=
=
=
enabled,
5,
5,
10,
35,
7200,
30,
60,
120,
140,
true,
Number of Routes
= 20,
Number of Reachable Routes = 18
For more information about these displays, see the “DVMRP Commands” chapter in the OmniSwitch CLI
Reference Guide.
page 6-4
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Configuring DVMRP
DVMRP Overview
DVMRP Overview
Distance Vector Multicast Routing Protocol (DVMRP) Version 3 is a multicast routing protocol that
enables routers to efficiently propagate IP multicast traffic through a network. Multicast traffic consists of
a data stream that originates from a single source and is sent to hosts that have subscribed to that stream.
Live video broadcasts, video conferencing, corporate communications, distance learning, and distribution
of software, stock quotes, and news services are examples of multicast traffic. Multicast traffic is distinguished from unicast traffic and broadcast traffic as follows:
• Unicast traffic is addressed to a single host.
• Broadcast traffic is transmitted to all hosts.
• Multicast traffic is transmitted to a subset of hosts (the hosts that have subscribed to the multicast data
stream).
DVMRP is a distributed multicast routing protocol that dynamically generates per-source delivery trees
based upon routing exchanges, using a technique called Reverse Path Multicasting. When a multicast
source begins to transmit, the multicast data is flooded down the delivery tree to all points in the network.
DVMRP then prunes (i.e., removes branches from) the delivery tree where the traffic is unwanted.
Pruning continues to occur as group membership changes or routers determine that no group members are
present. This restricts the delivery trees to the minimum branches necessary to reach all group members,
thus optimizing router performance. New branches can also be added to the delivery trees dynamically as
new members join the multicast group. The addition of new branches is referred to as grafting.
Reverse Path Multicasting
DVMRP uses Internet Group Management Protocol (IGMP) messages to exchange the routing information needed to build per-source multicast delivery trees. Once built, packets follow a multicast delivery
tree from the source to all members of the multicast group. Packets are replicated only at necessary
branches in the delivery tree. The trees are calculated and updated dynamically to track the membership of
individual groups.
When a packet arrives on an interface, the reverse path back to the source of the packet is determined by
examining a DVMRP routing table of known source networks. If the packet arrived on an upstream interface that would be used to transmit packets back to the source, it is forwarded to the appropriate list of
downstream interfaces. Otherwise, it is not on the optimal delivery tree and is discarded. In this way duplicate packets can be filtered when loops exist in the network topology.
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December 2007
page 6-5
DVMRP Overview
Configuring DVMRP
Neighbor Discovery
DVMRP routers must maintain a database of DVMRP adjacencies with other DVMRP routers. A DVMRP
router must be aware of its DVMRP neighbors on each interface. To gather this information, DVMRP
routers use a neighbor discovery mechanism and periodically multicast DVMRP Probe messages to the
All-DVMRP-Routers group address (224.0.0.4). Each Probe message includes a Neighbor List of DVMRP
routers known to the transmitting router.
When a DVMRP router (let’s call it “router B”) receives a Probe (let’s say from “router A”), it adds the IP
address of router A to its own internal list of DVMRP neighbors on that interface. It then sends a Probe of
its own with the IP address of router A included in the Probe’s Neighbor List. When a DVMRP router
receives a Probe with its own IP address included in the Neighbor List, the router knows that a two-way
adjacency has been successfully formed between itself and the neighbor that sent the Probe.
Probes effectively serve three main purposes:
• Probes provide a mechanism for DVMRP routers to locate each other as described above.
• Probes provide a way for DVMRP routers to determine each others’ capabilities. This is deduced from
the major and minor version numbers in the Probe packet and directly from the capability flags in the
Probe packet.
• Probes provide a keep-alive function in order to quickly detect neighbor loss.
A DVMRP router sends periodic Route Report messages to its DVMRP neighbors (by default, every 60
seconds). A Route Report message contains the sender’s current routing table, which contains entries that
advertise a source network (with a mask) and a hop-count that is used as the routing metric.This routing
information is used to build source distribution trees and to perform multicast forwarding. The DVMRP
neighbor that advertises the route with the lowest metric will be used for forwarding. (In case of a tie, the
DVMRP neighbor with the lowest IP address will be used.)
In DVMRPv3, a router will not accept a Route Report from another DVMRP router until it has established adjacency with that neighboring router.
Note. Older versions of DVMRP use Route Report messages to perform neighbor discovery rather than
the Probe messages used in DVMRP Version 3.
page 6-6
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Configuring DVMRP
DVMRP Overview
Multicast Source Location, Route Report Messages, and Metrics
When an IP multicast packet is received by a router running DVMRP, it first looks up the source network
in the DVMRP routing table. The interface that provides the best route back to the source of the packet is
called the upstream interface. If the packet arrived on that upstream interface, then it is a candidate for
forwarding to one or more downstream interfaces. If the packet did not arrive on that anticipated upstream
interface, then it is discarded. This check is known as a reverse path forwarding check and is performed
by all DVMRP routers.
Note. Under normal, stable DVMRP operation, packets would not arrive on the wrong interface because
the upstream router would not forward the packet unless the downstream router poison-reversed the route
in the first place (as explained below). However, there are cases—such as immediately after a network
topology change—when DVMRP routing has not yet converged across all routers where this can occur. It
can also occur when loops exist in the network topology.
In order to ensure that all DVMRP routers have a consistent view of the path back to a source, routing
tables are propagated by all DVMRP routers in Route Report messages. Each router transmits a Route
Report message at specified intervals. The Route Report message advertises the network numbers and
masks of those interfaces to which the router is directly connected. It also relays the routes received from
neighboring routers.
DVMRP requires an interface metric (i.e., a hop count) to be configured on all physical and tunnel interfaces. When a route is received from a neighboring router via a Route Report message, the metric of the
interface over which the packet was received is added to the metric of the route being advertised. This
adjusted metric is used when comparing metrics to determine the most efficient upstream interface.
Dependent Downstream Routers and Poison Reverse
In addition to providing a consistent view of source networks, the exchange of routes in DVMRP Route
Report messages provides one other important feature. DVMRP uses the route exchange as a mechanism
for upstream routers to determine if any downstream routers depend on them for forwarding packets from
particular source networks.
DVMRP accomplishes this by using a technique called poison reverse. If a downstream router selects an
upstream router as the best next hop to a particular source network, it indicates this by echoing back the
route on the upstream interface with a metric equal to the original metric plus infinity. (DVMRP uses a
metric of 32 as infinity.) When the upstream router receives the report and sees a metric that lies between
infinity and twice infinity (that is, between 32 and 64), it adds the downstream router from which it
received the report to a list of dependent routers for this source network.
The list of dependent routers per source network built by the poison reverse technique provides the foundation necessary to determine when it is appropriate to prune back the IP source-specific multicast trees.
Note. Poison reverse is used differently in DVMRP than in most unicast distance vector routing protocols
(such as RIP), which use poison reverse to advertise that a particular route is unreachable.
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December 2007
page 6-7
DVMRP Overview
Configuring DVMRP
Pruning Multicast Traffic Delivery
Initially, all interfaces with downstream-dependent neighbors are included in the downstream interface list
and multicast traffic is flooded down the truncated broadcast tree to all possible receivers. This allows the
downstream routers to be aware of traffic destined for a particular Source, Group (S, G) pair. The downstream routers then have the option to send prunes (and subsequent grafts) for this (S, G) pair as requirements change.
A DVMRP router will remove an interface from its forwarding list that has no group members associated
with an IP multicast packet. If a router removes all of its downstream interfaces, it notifies the upstream
router that it no longer wants traffic destined for that particular (S, G) pair. This is accomplished by sending a DVMRP Prune message upstream to the router expected to forward packets from that particular
source.
A downstream router will inform an upstream router that it depends on the upstream router to receive
packets from particular source networks by using the poison reverse technique during the exchange of
Route Report messages. This method allows the upstream router to build a list of downstream routers on
each interface that are dependent upon it for packets from a particular source. If the upstream router
receives Prune messages from each one of the dependent downstream routers on an interface, then the
upstream router can in turn remove this interface from its downstream interface list. If the upstream router
is able to remove all of its downstream interfaces in this manner, it can then send a DVMRP Prune
message to its upstream router. This continues until all unneeded branches are removed. Refer to
“Pruning” on page 6-15 for more specific information on pruning.
Grafting Branches Back onto the Multicast Delivery Tree
A pruned branch will be automatically reattached to the multicast delivery tree when the prune times out.
However, the graft mechanism provides a quicker method to reattach a pruned branch than waiting for the
prune to time out. Without the graft mechanism, the join latency for new hosts in the group might be unacceptably great, because the prunes in the upstream routers would have to time out before multicast traffic
could again begin to flow to the pruned branches. Depending on the number of routers along the pruned
branch and the timeout values in use, several minutes might elapse before the host could begin to receive
multicast traffic. By using a graft mechanism, DVMRP reduces the join latency to a few milliseconds.
The graft mechanism is made reliable through the use of Graft-Ack (Graft Acknowledgment) messages. A
Graft-Ack message is returned by the upstream router in response to a Graft message. If the Graft-Ack
message is not received, the downstream router will resend the Graft message. This prevents the loss of a
Graft message due to congestion.
The ip dvmrp graft-timeout command enables you to set the Graft message retransmission value. This
value defines the duration of time that the router will wait before retransmitting a Graft message if it has
not received a Graft-Ack message. Refer to “Grafting” on page 6-17 for more information.
page 6-8
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Configuring DVMRP
DVMRP Overview
DVMRP Tunnels
Because not all IP routers support native multicast routing, DVMRP includes direct support for tunneling
IP multicast packets through routers. Tunnel interfaces are used when routers incapable of supporting
multicast traffic exist between DVMRP neighbors. In tunnel interfaces, IP multicast packets are encapsulated in unicast IP packets and addressed directly to the routers that do not support native multicast routing. DVMRP protocol messages (such as Route Reports, Probes for neighbor discovery, etc.) and
multicast traffic are sent between tunnel endpoints using unicast, rather than multicast, packets.
Multicast data is encapsulated using a standard IP-IP encapsulation method. The unicast IP addresses of
the tunnel endpoints are used as the source and destination IP addresses in the outer IP header. The inner
IP header remains unchanged from the original multicast packet.
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page 6-9
Configuring DVMRP
Configuring DVMRP
Configuring DVMRP
Before configuring DVMRP, consider the following:
• The advanced routing image must be present in the switch’s current running directory (i.e., Working or
Certified) before DVMRP can be enabled or configured.
• DVMRP requires that IP Multicast Switching (IPMS) is enabled. IPMS is automatically enabled when
a multicast routing protocol (either PIM-SM or DVMRP) is enabled globally and on an interface and
when the operational status of the interface is up. However, if you wish to manually enable IPMS on
the switch, use the ip multicast status command.
• You can configure DVMRP parameters when the protocol is not running as long as DVMRP is loaded
into memory (see “Loading DVMRP into Memory” below).
• The DVMRP parameters will not take effect until the protocol is enabled globally and on specific IP
interfaces.
Enabling DVMRP on the Switch
By default, the DVMRP protocol is disabled on the switch. Before running DVMRP, you must enable the
protocol by completing the following steps:
• Loading DVMRP into memory
• Enabling DVMRP on desired IP interfaces
• Enabling DVMRP globally on the switch
Note. Once loaded and enabled, DVMRP is typically ready to use because its factory default values are
appropriate for the majority of installations. Note, however, if neighbors in the DVMRP domain have
difficulty handling large initial bursts of traffic, it is recommended that the subordinate neighbor status is
changed to false. For more information on the subordinate neighbor status, refer to the ip dvmrp suborddefault command in the OmniSwitch CLI Reference Guide.
For information on completing these steps, refer to the sections below.
Loading DVMRP into Memory
You must load DVMRP into memory before you can begin configuring the protocol on the switch. If
DVMRP is not loaded and you enter a configuration command, the following message displays:
ERROR: The specified application is not loaded
To dynamically load DVMRP into memory, enter the following command:
-> ip load dvmrp
page 6-10
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Configuring DVMRP
Configuring DVMRP
Enabling DVMRP on a Specific Interface
Note. It does not matter whether DVMRP is first enabled globally or on specific interfaces. However,
DVMRP will not run on an interface until it is enabled both globally and on the interface.
DVMRP must be enabled on an interface before any other interface-specific DVMRP command can be
executed (e.g, the ip dvmrp interface metric command). An interface can be any IP router port that has
been assigned to an existing VLAN. For information on assigning a router port to a VLAN, refer to the
“Configuring VLANs” chapter in the OmniSwitch 6800/6850/9000 Network Configuration Guide.
To enable DVMRP on a specific interface, use the ip dvmrp interface command. The interface identifier
used in the command syntax is the valid IP address of an existing VLAN router port. For example:
-> ip dvmrp interface vlan-2
Note. Only one multicast routing protocol is supported per interface. This means that you cannot enable
both PIM-SM and DVMRP on the same interface.
Disabling DVMRP on a Specific Interface
To disable DVMRP on a specific IP interface, use the no ip dvmrp interface command. Be sure to
include the interface IP address. For example:
-> no ip dvmrp interface vlan-2
Specifying a Distance Metric on a Specific Interface
The ip dvmrp interface metric command enables you to specify the distance metric for an interface. The
default interface distance metric value is 1. DVMRP uses the metric value to determine the most costeffective way of passing data. The higher an interface’s metric value, the higher the cost of passing data
over that interface. DVMRP will transmit data over the interface with the lowest available metric. Note
that, just as in RIP, the metric of an incoming route advertisement is automatically incremented by the
metric of the incoming interface (typically one hop). You can assign an interface any distance metric from
1 to 31.
To assign a distance metric to a specific interface, use the ip dvmrp interface metric command. The
command syntax must include the IP address for the VLAN router port (i.e., interface), as well as a
distance metric value. For example:
-> ip dvmrp interface vlan-2
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page 6-11
Configuring DVMRP
Configuring DVMRP
Viewing DVMRP Status and Parameters for a Specific Interface
To view current DVMRP interfaces, including their operational status and assigned metrics, use the
show ip dvmrp interface command. For example:
-> show ip dvmrp interface
Interface Name Vlan
Metric
Admin-Status
Oper-Status
--------------+------+--------+-------------+-------------vlan-2
2
1
Enabled
Enabled
Current assigned metric
is shown as 1.
The interface is
operationally down
because there are no
ports operationally
up in VLAN 2.
The corresponding
interface is configured
for DVMRP (i.e., it is
DVMRP-enabled).
Note. The show ip dvmrp interface command displays information for all multicast-capable interfaces
(i.e. even interfaces where DVMRP might not be configured).
Globally Enabling DVMRP on the Switch
To globally enable DVMRP on the switch, enter the following command:
-> ip dvmrp status enable
Globally Disabling DVMRP
The following command will globally disable DVMRP on the switch:
-> ip dvmrp status disable
Checking the Current Global DVMRP Status
To view current global DVMRP enable/disable status, as well as additional global DVMRP settings, use
the show ip dvmrp command. For example:
-> show ip dvmrp
DVMRP Admin Status
Flash Interval
Graft Timeout
Neighbor Interval
Neighbor Timeout
Prune Lifetime
Prune Timeout
Report Interval
Route Holddown
Route Timeout
Subord Default
=
=
=
=
=
=
=
=
=
=
=
enabled,
5,
5,
10,
35,
7200,
30,
60,
120,
140,
true,
Current global DVMRP status
is shown as enabled.
Number of Routes
= 20,
Number of Reachable Routes = 18
page 6-12
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December 2007
Configuring DVMRP
Configuring DVMRP
Automatic Loading and Enabling of DVMRP Following a System Boot
If any DVMRP command is saved to the boot.cfg file in the post-boot running directory, DVMRP will be
loaded into memory automatically. The post-boot running directory refers to the directory the switch will
use as its running directory following the next system boot (i.e., Working or Certified). If the command
syntax ip dvmrp status enable is saved to the boot.cfg file in the post-boot running directory, DVMRP
will be automatically loaded into memory and globally enabled following the next system boot. For
detailed information on the Working and Certified directories and how they are used during system boot,
see the “CMM Directory Management” chapter in the OmniSwitch 6800/6850/9000 Switch Management
Guide.
Neighbor Communications
Probe messages are sent out periodically on all the DVMRP interfaces. However, only on the non-tunnel
interfaces are they sent out to the multicast group address 224.0.0.4.
Note. Older versions of DVMRP use Route Report messages to perform neighbor discovery rather than
the Probe messages used in DVMRP Version 3.
The ip dvmrp neighbor-interval command enables you to configure the interval, in seconds, at which
Probe messages are transmitted. For example, to configure the Probe interval to ten seconds, enter the
following command:
-> ip dvmrp neighbor-interval 10
The ip dvmrp neighbor-timeout command enables you to configure the number of seconds that the
DVMRP router will wait for activity from a neighboring DVMRP router before assuming the neighbor is
down. For example, to configure the neighbor timeout period to 35 seconds, enter the following command:
-> ip dvmrp neighbor-timeout 35
When the neighbor timeout expires and it is assumed that the neighbor is down, the following occurs:
• All routes learned from the neighbor are immediately placed in hold down.
• If the neighbor is considered to be the designated forwarder for any of the routes it is advertising, a
new designated forwarder for each source network is selected.
• If the neighbor is upstream, any cache entries based upon this upstream neighbor are flushed.
• Any outstanding grafts awaiting acknowledgments from this neighbor are flushed.
• All downstream dependencies received from this neighbor are removed.
The ip dvmrp neighbor-interval should be set to 10 seconds and the ip dvmrp neighbor-timeout should
be set to 35 seconds. This allows fairly early detection of a lost neighbor yet provides tolerance for busy
multicast routers. Both of these values must be coordinated between all DVMRP routers on a physical
network segment.
Note. Current global DVMRP parameter values—including the ip dvmrp neighbor-interval value and
the ip dvmrp neighbor-timeout value—can be viewed via the show ip dvmrp command. The DVMRP
neighbor table can be viewed via the show ip dvmrp neighbor command.
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page 6-13
Configuring DVMRP
Configuring DVMRP
Routes
In DVMRP, source network routing information is exchanged in the same basic manner as it is in RIP.
That is to say, periodic Route Report messages are sent between DVMRP neighbors (by default, every 60
seconds). A Route Report contains the sender’s current routing table. The routing table contains entries
that advertise a source network (with a mask) and a hop-count that is used as the routing metric. (The key
difference between the way routing information is exchanged in DVMRP and in RIP is that DVMRP
routes are advertised with a subnet mask, which makes DVMRP effectively a classless protocol.)
The routing information stored in a DVMRP routing table is separate from the unicast routing table and is
used to build source distribution trees and to perform multicast forwarding (that is, Reverse Path Forwarding checks).
The ip dvmrp report-interval command enables you to specify the number of seconds between transmission of Route Report messages. For example, the following command specifies that a Route Report
message be sent every 60 seconds:
-> ip dvmrp report-interval 60
The ip dvmrp flash-interval command enables you to specify the number of seconds between transmission of Routing Table Change messages. Routing Table Change messages are sent between transmissions
of the complete routing tables contained in Route Report messages. For this reason, the Flash Interval
value must be lower than the Route Report interval. For example:
-> ip dvmrp flash-interval 5
The ip dvmrp route-timeout command enables you to specify the route expiration timeout value. The
route expiration timeout value determines the number of seconds before a route to an inactive network is
aged out. For example, the following command specifies that the route to an inactive network age out in
140 seconds:
-> ip dvmrp route-timeout 140
The ip dvmrp route-holddown command enables you to specify the number of seconds that DVMRP
routes are kept in a hold-down state. A hold-down state refers to the period of time that a route to an inactive network continues to be advertised as unreachable. When a route is deleted (because it expires, the
neighbor it was learned from goes down, etc.) a router may be able to reach the source network described
by the route through an alternate gateway. However, in the presence of complex topologies, often the alternate gateway may only be echoing back the same route learned via a different path. If this occurs, the route
will continue to be propagated long after it is no longer valid.
In order to prevent this, it is common in distance vector protocols to continue to advertise a route that has
been deleted with a metric of infinity for one or more report intervals. This is a hold-down. While it is in
hold-down, a route must only be advertised with an infinity metric. The hold down period is usually two
report intervals.
For example, the following command specifies that the route to an inactive network continue to be advertised for 120 seconds:
-> ip dvmrp route-holddown 120
Note. Current global DVMRP parameter values—including the ip dvmrp report-interval, ip dvmrp
flash-interval, ip dvmrp route-timeout, and ip dvmrp route-holddown values—can be viewed via the
show ip dvmrp command. The DVMRP routes that are being advertised to other routers can be viewed
via the show ip dvmrp route command.
page 6-14
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring DVMRP
Configuring DVMRP
Pruning
DVMRP uses a flood-and-prune mechanism that starts by delivering multicast traffic to all routers in the
network. This means that, initially, traffic is flooded down a multicast delivery tree. DVMRP routers then
prune this flow where the traffic is unwanted. Routers that have no use for the traffic send DVMRP Prune
messages up the delivery tree to stop the flow of unwanted multicast traffic, thus pruning the unwanted
branches of the tree. After pruning, a source distribution tree for that specific source exists.
However, the source distribution tree that results from DVMRP pruning reverts back to the original delivery tree when the prunes time out. When a prune times out, traffic is again flooded down the branch.
The ip dvmrp prune-lifetime command sets the period of time that a prune will be in effect — essentially, the prune’s lifetime. When the prune-lifetime period expires, the interface is joined back onto the
multicast delivery tree. (If unwanted multicast traffic continues to arrive at the interface, the prune mechanism is reinitiated and the cycle continues.) For example, the following command sets a prune’s lifetime to
7200 seconds:
-> ip dvmrp prune-lifetime 7200
Refer to “More About Prunes” below for further information on the ip dvmrp prune-lifetime command
and how it affects the lifetime of prunes sent and, in some cases, received.
The ip dvmrp prune-timeout command sets the Prune packet retransmission interval. This is the duration of time that the router will wait before retransmitting a Prune message if it continues to receive
unwanted multicast traffic. For example, the following command sets the Prune packet retransmission
interval to forty seconds:
-> ip dvmrp prune-timeout 40
Note. Current global DVMRP parameter values—including the ip dvmrp prune-lifetime value and the
ip dvmrp prune-timeout value—can be viewed via the show ip dvmrp command. Current DVMRP
prunes can be viewed via the show ip dvmrp prune command.
More About Prunes
Prune-Lifetime Values in Sent Prune Packets
The value of ip dvmrp prune-lifetime is set to 7200 seconds (two hours) by default. On leaf routers (that
is, routers that have no further downstream dependent routers), the value of ip dvmrp prune-lifetime is
inserted into prune packets sent upstream as their lifetime value.
However, when a branch router (that is, a router that does have further downstream dependent routers)
sends a prune upstream, the prune-lifetime value inserted into the prune packet is the smallest of the
following values:
• the value of ip dvmrp prune-lifetime on the sending device
• the amount of lifetime that remains for each individual prune on the router’s timer queue that was
received for the pruned group. (When a prune is queued on the router’s timer queue, its lifetime value
decrements until the prune expires.)
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December 2007
page 6-15
Configuring DVMRP
Configuring DVMRP
As an example, let’s say that the following situation exists on a branch router: ip dvmrp prune-lifetime is
set to 7200 seconds and three prunes for the pruned group exist on the router’s timer queue. These three
prunes have remaining lifetimes of 7000 seconds, 5000 seconds, and 4500 seconds. When the branch
router sends a prune upstream for this group, a prune-lifetime value of 4500 seconds will be inserted into
the prune packet.
Prune-Lifetime Expiration Value
You can view the prunes that have been sent via the show ip dvmrp prune command. (However, note
that this command does not display received prunes.) The expiration time displayed by the show ip dvmrp
prune command is the earliest time that the router expects multicast traffic for the pruned group to start
arriving. If the expiration time displays as expired, the prune has expired but no further multicast traffic
has been received. The expiration value may be reset if multicast traffic is received and another prune was
sent because no stations downstream want the traffic.
Received Prunes
When prune packets are received, a timer is set up on the receiving device that halts traffic sent to the
pruned group on the neighbor that originated the prune. The timer value used is the prune-lifetime value
found in the received prune packet. The setting of ip dvmrp prune-lifetime on the device that received
the prune is not normally taken into consideration in this situation.
However, there are times when the setting of ip dvmrp prune-lifetime can affect the timeout value used
for received prunes. This occurs if the setting of ip dvmrp prune-lifetime is modified after prunes have
been received. If the new prune-lifetime value is less than the period of time a received prune has been on
the router's timer queue, the router will treat the prune as if it just expired. This means that multicast traffic may flow to the neighbor even though the neighbor does not expect the prune to have expired.
Even in cases where modification of the ip dvmrp prune-lifetime setting does not cause the received
prunes to expire earlier than specified by their internal prune-lifetime value, such modification will still
cause the prune-lifetime value of received prunes to be adjusted to the new value. This means that received
prunes may expire sooner or later than the neighbor expects.
Once the lifetime value of received prunes on the router’s timer queue have been modified per the new
setting of ip dvmrp prune-lifetime, all future incoming prunes will experience normal timer operation
and the prune-lifetime value in the received prune packet will be used without modification. Outgoing
prunes will use the new value of ip dvmrp prune-lifetime.
For the reasons explained, the value of ip dvmrp prune-lifetime should only be modified with caution.
page 6-16
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring DVMRP
Configuring DVMRP
Grafting
A pruned branch will be automatically reattached to the multicast delivery tree when the prune times out.
However, the graft mechanism provides a quicker method to reattach a pruned branch than waiting for the
prune to time out. As traffic is forwarded, routers that do not want multicast traffic send Prune messages to
signal the upstream router to stop sending the traffic. If new IGMP membership requests are later received
by the downstream router, the router can send Graft messages to the upstream router and wait for
acknowledgment (a Graft Ack).
The ip dvmrp graft-timeout command enables you to set the Graft message retransmission value. This
value defines the duration of time that the router will wait before retransmitting a Graft message if it has
not received a Graft-Ack message acknowledging that a previously transmitted Graft message was
received. For example, enter the following to set the Graft message retransmission value to 5 seconds:
-> ip dvmrp graft-timeout 5
Note. Current global DVMRP parameter values, including the ip dvmrp graft-timeout value, can be
viewed via the show ip dvmrp command.
Tunnels
DVMRP networks may use DVMRP tunnels to interconnect two multicast-enabled networks across nonmulticast networks. In a DVMRP tunnel, IP multicast packets are encapsulated in unicast IP packets so
that the multicast traffic can traverse a non-multicast network.
The ip dvmrp tunnel command enables you to add or delete a DVMRP tunnel between a specified local
interface name and remote address. Any packets sent through the tunnel will be encapsulated in an outer
IP header. For example, the following command would create a tunnel between local name vlan-2 and
remote address 172.22.2.120:
-> ip dvmrp tunnel vlan-2 172.22.2.120
The local tunnel address must match an existing IP interface on a router that has been configured for
DVMRP. The tunnel’s remote address must be the IP address of the remote DVMRP router to which the
tunnel is connected.
Important. The tunnel will be operational only when the DVMRP interface is also operational. To enable
DVMRP on an interface, use the ip dvmrp interface. For more information, refer to “Enabling DVMRP
on a Specific Interface” on page 6-11.
The ip dvmrp tunnel ttl command sets the tunnel’s Time-To-Live (TTL) value. For example:
-> ip dvmrp tunnel vlan-2 172.22.2.120 ttl 255
Note. Current DVMRP tunnels, including the tunnels’ operational (OPER) status and TTL values, can be
viewed via the show ip dvmrp tunnel command. The status of the DVMRP interface can be viewed via
the show ip dvmrp interface command.
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page 6-17
Verifying the DVMRP Configuration
Configuring DVMRP
Verifying the DVMRP Configuration
A summary of the show commands used for verifying the DVMRP configuration is given here:
show ip dvmrp
Displays global DVMRP parameters such as admin status, flash interval
value, graft timeout value, neighbor interval value, subordinate neighbor
status, number of routes, number of routes reachable, etc.
show ip dvmrp interface
Displays the DVMRP interface table, which lists all multicast-capable
interfaces.
show ip dvmrp neighbor
Displays the DVMRP neighbor table, which lists adjacent DVMRP
routers.
show ip dvmrp nexthop
Displays the DVMRP next hop entries table. The next hop entries table
lists which VLANs will receive traffic forwarded from a designated
multicast source. The table also lists whether a VLAN is considered a
DVMRP branch or leaf for the multicast traffic (i.e., its hop type).
show ip dvmrp prune
Displays the prune table. Each entry in the prune table lists a pruned
branch of the multicast delivery tree and includes the time interval
remaining before the current prune state expires.
show ip dvmrp route
Displays the DVMRP routes that are being advertised to other routers in
Route Report messages.
show ip dvmrp tunnel
Displays DVMRP tunnels. This command lists DVMRP tunnel interfaces, including both active and inactive tunnels.
For more information about the displays that result from these commands, see the OmniSwitch CLI
Reference Guide.
page 6-18
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7
Configuring PIM
Protocol-Independent Multicast (PIM) is an IP multicast routing protocol that uses routing information
provided by unicast routing protocols such as RIP and OSPF. PIM is “protocol-independent” because it
does not rely on any particular unicast routing protocol. PIM-Sparse Mode (PIM-SM) contrasts with floodand-prune dense mode multicast protocols, such as DVMRP and PIM-Dense Mode (PIM-DM) in that
multicast forwarding in PIM-SM is initiated only via specific requests, referred to as Join messages. PIMDM packets are transmitted on the same socket as PIM-SM packets, as both use the same protocol and
message format. Unlike PIM-SM, in PIM-DM there are no periodic joins transmitted, only explicitly triggered prunes and grafts. Unlike PIM-SM, there is no Rendezvous Point (RP) in PIM-DM. This release
allows you to implement PIM in both the IPv4 and the IPv6 environments.
Source-Specific Multicast (PIM-SSM). The current implementation of PIM includes support for SourceSpecific Multicast (PIM-SSM). For more information on PIM-SSM support, refer to “PIM-SSM Support”
on page 7-31.
In This Chapter
This chapter describes the basic components of PIM and how to configure them through the Command
Line Interface (CLI). CLI commands are used in the configuration examples; for more details about the
syntax of commands, see the OmniSwitch CLI Reference Guide.
Configuration procedures described in this chapter include the following:
• Enabling PIM on the switch—see page 7-18.
• Enabling PIM on a specific interface—see page 7-20.
• Enabling PIM mode on the switch—see page 7-21.
• Mapping an IP multicast group to a PIM mode—see page 7-22.
• Configuring Candidate Rendezvous Points (C-RPs)—see page 7-24.
• Candidate Bootstrap Routers (C-BSRs)—see page 7-25.
• Configuring Keepalive period—see page 7-28.
• Configuring Notification period—see page 7-29.
• Verifying PIM configuration—see page 7-32.
• Enabling IPv6 PIM on a specific interface—see page 7-35.
• Enabling IPv6 PIM mode on the switch—see page 7-35.
• Mapping an IPv6 multicast group to a PIM mode—see page 7-36.
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page 7-1
In This Chapter
Configuring PIM
• Configuring Candidate Rendezvous Points (C-RPs) in IPv6 PIM—see page 7-38.
• Configuring Candidate Bootstrap Routers (C-BSRs) in IPv6 PIM—see page 7-39.
• Configuring RP-switchover for IPv6 PIM—see page 7-41.
• Verifying IPv6 PIM configuration—see page 7-43.
For detailed information about PIM commands, see the “PIM Commands” chapter in the OmniSwitch CLI
Reference Guide.
page 7-2
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Configuring PIM
PIM Specifications
PIM Specifications
RFCs Supported
2362—Protocol Independent Multicast-Sparse Mode
(PIM-SM) Protocol Specification
2934—Protocol Independent Multicast MIB for Ipv4
2932—Ipv4 Multicast Routing MIB
3973—Protocol Independent Multicast-Dense Mode
(PIM-DM)
3376—Internet Group Management Protocol
4601—Protocol Independent Multicast-Sparse Mode
(PIM-SM)
Internet Drafts Supported
draft-ietf-pim-sm-v2-new-05.txt—Protocol Independent
Multicast – Sparse Mode PIM-SM
draft-ietf-pim-mib-v2-00.txt—Protocol Independent
Multicast MIB includes support for PIM-DM
draft-ietf-pim-sm-bsr-02.txt—Bootstrap Router (BSR)
Mechanism for PIM Sparse Mode
draft-ietf-pim-mib-v2-10.txt—Protocol Independent Multicast MIB
draft-ietf-mboned-ip-mcast--mib-02.txt—IP Multicast
MIB
draft-ietf-pim-sm-bsr-10.txt—Bootstrap Router (BSR)
Mechanism for PIM
draft-ietf-pim-bsr-mib-02.txt—PIM Bootstrap Router
MIB
PIM-SM Version Supported
PIM-SMv2
PIM Attributes Supported
Shared trees (also referred to as RP trees), Designated
Routers (DRs), Bootstrap Routers (BSRs), Candidate
Bootstrap Routers (C-BSRs), Rendezvous Points (RPs)
(applicable only for PIM-SM), Candidate Rendezvous
Points (C-RPs)
PIM Timers Supported
C-RP expiry, C-RP holdtime, C-RP advertisement,
Join/Prune, Probe, Register suppression, Hello, Expiry,
Assert, Neighbor liveness
Maximum Rendezvous Point (RP)
routers allowed in a PIM-SM domain
100 (default value is 32)
Maximum Bootstrap Routers (BSRs)
allowed in a PIM domain
1
Multicast Protocols per Interface
1 (e.g., you cannot enable both PIM and DVMRP on the
same IP interface)
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page 7-3
PIM Defaults
Configuring PIM
PIM Defaults
The following table lists the defaults for PIM configuration:
Parameter Description
Command
Default Value/Comments
PIM status
ip load pim
Disabled
PIM load status - sparse mode
ip pim sparse status
Disabled
PIM load status - dense mode
ip pim dense status
Disabled
Priority
ip pim ssm group
Disabled
Priority
ip pim dense group
Disabled
C-BSR mask length
ip pim cbsr
30 bits
Priority
ip pim cbsr
64
Static RP configuration
ip pim static-rp
Disabled
Priority
ip pim candidate-rp
192
C-RP advertisements
ip pim candidate-rp
60 seconds
RP threshold
ip pim rp-threshold
1
Keepalive timer
ip pim keepalive-period
210 seconds
Maximum RP routers allowed
ip pim max-rps
32
Probe timer
ip pim probe-time
5 seconds
Register checksum value
ip pim register checksum
header
Register suppression timer
ip pim register-suppress-timeout
60 seconds
Source, group data timeout
ip pim keepalive-period
210 seconds
Switchover to Shortest Path Tree
(SPT)
ip pim spt status
Enabled
Successive state refresh interval
ip pim state-refresh-interval
60 seconds
State refresh message limit
ip pim state-refresh-limit
0
State refresh ttl
ip pim state-refresh-ttl
16
Hello interval
ip pim interface
30 seconds
Triggered hello
ip pim interface
5 seconds
Join/Prune interval
ip pim interface
60 seconds
Hello holdtime
ip pim interface
105 seconds
Join/Prune holdtime
ip pim interface
210 seconds
Prune delay
ip pim interface
500 milliseconds
Override interval
ip pim interface
2500 milliseconds
Designated Router Priority
ip pim interface
1
Prune limit interval
ip pim interface
60 seconds
Graft retry interval
ip pim interface
3 seconds
Stub
ip pim interface
Disabled
page 7-4
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Configuring PIM
Parameter Description
PIM Defaults
Command
Default Value/Comments
Neighbor loss notification interval ip pim neighbor-loss-notificationperiod
0 seconds
Invalid register notification interval
ip pim invalid-register-notificationperiod
65535 seconds
RP mapping notification interval
ip pim rp-mapping-notificationperiod
65535 seconds
Invalid joinprune notification
interval
ip pim invalid-joinprune-notification- 65535 seconds
period
Interface election notification
interval
ip pim interface-election-notification- 65535 seconds
period
PIM-SM status
ipv6 pim sparse status
Disabled
PIM-DM status
ipv6 pim dense status
Disabled
Priority
ipv6 pim ssm group
Disabled
Priority
ipv6 pim dense group
Disabled
Candidate-BSR
ipv6 pim cbsr
64 bits
Hash mask length
ipv6 pim cbsr
126
Static RP configuration
ipv6 pim static-rp
Disabled
Priority
ipv6 pim candidate-rp
192
C-RP advertisements
ipv6 pim candidate-rp
60 seconds
RP
ipv6 pim rp-switchover
Enabled
Switchover to Shortest Path Tree
(SPT)
ipv6 pim spt status
Enabled
Hello interval
ipv6 pim interface
30 seconds
Triggered hello
ipv6 pim interface
5 seconds
Join Prune interval
ipv6 pim interface
60 seconds
Hello holdtime
ipv6 pim interface
105 seconds
Join Prune holdtime
ipv6 pim interface
210 seconds
Prune delay
ipv6 pim interface
500 milliseconds
Override interval
ipv6 pim interface
2500 milliseconds
Designated Router Priority
ipv6 pim interface
1
Prune limit interval
ipv6 pim interface
60 seconds
Graft retry interval
ipv6 pim interface
3 seconds
Stub
ipv6 pim interface
Disabled
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December 2007
page 7-5
Quick Steps for Configuring PIM-DM
Configuring PIM
Quick Steps for Configuring PIM-DM
.
Note PIM requires that IP Multicast Switching (IPMS) is enabled. IPMS is automatically enabled when
a multicast routing protocol (either PIM or DVMRP) is enabled globally and on an interface and when the
operational status of the interface is up. However, if you wish to manually enable IPMS on the switch, use
the ip multicast status command.
1 Manually load PIM into memory by entering the following command:
-> ip load pim
2 Create a router port (i.e., interface) on an existing VLAN by specifying a valid IP address. To do this,
use the ip interface command. For example:
-> ip interface vlan-2 address 178.14.1.43 vlan 2
Note. The ip interface command is not supported in Release 5.3.1. For this release, use the vlan router ip
command instead. See the OmniSwitch CLI Reference Guide for more information.
3 Enable PIM on the interface using the ip pim interface command. For example:
-> ip pim interface vlan-2
Note. The interface on which the PIM is enabled must be an already configured IP interface on the switch.
4 Map the PIM-Dense Mode (DM) protocol for a multicast group via the ip pim dense group command.
For example:
-> ip pim dense group 224.0.0.0/4
5 Globally enable the PIM protocol by entering the following command. By default, PIM protocol status
is disabled.
-> ip pim sparse status enable
-> ip pim dense status enable
page 7-6
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Configuring PIM
Quick Steps for Configuring PIM-DM
6 Save your changes to the Working directory’s boot.cfg file by entering the following command:
-> write memory
Note. Optional. To verify PIM interface status, enter the show ip pim interface command. The display is
similar to the one shown here:
-> show ip pim interface
Total 1 Interfaces
Interface Name
IP Address
Designated
Hello
J/P
Oper
Router
Interval Interval Status
--------------------+---------------+---------------+--------+--------+-------tesvl
50.1.1.1
50.1.1.1
100
10
disabled
To verify global PIM status, enter the show ip pim sparse or show ip pim dense command. The display
for sparse mode is similar to the one shown here:
-> show ip pim sparse
Status
Keepalive Period
Max RPs
Probe Time
Register Checksum
Register Suppress Timeout
RP Threshold
SPT Status
= enabled,
= 210,
= 32,
= 5,
= header,
= 60,
= 1,
= enabled,
The display for dense mode is similar to the one shown here:
-> show ip pim dense
Status
Source Lifetime
State Refresh Interval
State Refresh Limit Interval
State Refresh TTL
=
=
=
=
=
enabled,
210,
60,
0,
16
(additional table output not shown)
For more information about these displays, see the “PIM Commands” chapter in the OmniSwitch CLI
Reference Guide.
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page 7-7
PIM Overview
Configuring PIM
PIM Overview
Protocol-Independent Multicast (PIM) is an IP multicast routing protocol that uses routing information
provided by unicast routing protocols such as RIP and OSPF. Note that PIM is not dependent on any
particular unicast routing protocol.
Downstream routers must explicitly join PIM distribution trees in order to receive multicast streams on
behalf of receivers or other downstream PIM routers. This paradigm of receiver-initiated forwarding
makes PIM ideal for network environments where receiver groups are thinly populated and bandwidth
conservation is a concern, such as in wide area networks (WANs).
Note. OmniSwitch 6800/6850/9000 switches support PIM-DM and PIM-SMv2 are not compatible with
PIM-SMv1.
PIM-Sparse Mode (PIM-SM)
Sparse mode PIM (PIM-SM) contrasts with flood-and-prune dense mode multicast protocols, such as
DVMRP and PIM-Dense Mode (PIM-DM) in that multicast forwarding in PIM is initiated only via
specific requests, referred to as Join messages.
The following sections provide basic descriptions for key components used when configuring a PIM-SM
network. These components include the following:
• Rendezvous Points (RPs) and Candidate Rendezvous Points (C-RPs)
• Bootstrap Routers (BSRs) and Candidate Bootstrap Routers (C-BSRs)
• Designated Routers (DRs)
• Shared Trees, also referred to as Rendezvous Point Trees (RPTs)
• Avoiding Register Encapsulation
Rendezvous Points (RPs)
In PIM-SM, shared distribution trees are rooted at a common forwarding router termed a Rendezvous
Point (RP). The RP unencapsulates Register messages and forwards multicast packets natively down
established distribution trees to receivers. The resulting topology is referred to as the RP Tree (RPT).
For an illustrated example of an RPT and the RP’s role in a simple PIM-SM environment, refer to “Shared
(or RP) Trees” on page 7-9.
Candidate Rendezvous Points (C-RPs)
A Candidate Rendezvous Point (C-RP) is a PIM-enabled router that sends periodic C-RP advertisements
to the Bootstrap Router (BSR). When a BSR receives a C-RP advertisement, the BSR may include the CRP in its RP-set. For more information on the BSR and RP-set, refer to page 7-9.
page 7-8
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Configuring PIM
PIM Overview
Bootstrap Routers (BSRs)
The role of a Bootstrap Router (BSR) is to keep routers in the network up to date on reachable C-RPs. The
BSR’s list of reachable C-RPs is also referred to as an RP set. There is only one BSR per PIM domain.
This allows all PIM routers in the PIM domain to view the same RP set.
A C-RP periodically sends out messages, known as C-RP advertisements. When a BSR receives one of
these advertisements, the associated C-RP is considered reachable (if it has a valid route). The BSR then
periodically sends its RP set to neighboring routers in the form of a Bootstrap message.
Note. For information on viewing the current RP set, see page 7-27.
BSRs are elected from the Candidate Bootstrap Routers (C-BSRs) in the PIM domain. For information on
C-BSRs, refer to the section below.
Candidate Bootstrap Routers (C-BSRs)
A Candidate Bootstrap Router (C-BSR) is a PIM-enabled router that is eligible for BSR status. To become
a BSR, a C-BSR must become elected. A C-BSR sends Bootstrap messages to all neighboring routers. The
messages include its IP address—which is used as an identifier—and its priority level. The C-BSR with
the highest priority level is elected as the BSR by its neighboring routers. If two or more C-BSRs have the
same priority value, the C-BSR with the highest IP address is elected as the BSR.
For information on configuring C-BSRs, including C-BSR priority levels, refer to “Candidate Bootstrap
Routers (C-BSRs)” on page 7-25.
Designated Routers (DRs)
There is only one Designated Router (DR) used per LAN. When a DR receives multicast data from the
source, the DR encapsulates the data packets into the Register messages, which are in turn sent to the RP.
Downstream PIM routers express interest in receiving multicast streams on behalf of a host via explicit
Join/Prune messages originating from the DR and directed to the RP.
The DR for a LAN is selected by an election process. This election process takes into account the DR
priority of each PIM neighbor on the LAN. If multiple neighbors share the same DR priority, the neighbor
with the highest IP address is elected. The ip pim interface command is used to specify the DR priority
on a specific PIM-enabled interface. Note that the DR priority is taken into account only if all of the PIM
neighbors on the LAN are using the DR priority option in their Hello packets.
For an illustrated example of the DR’s role in a simple PIM environment, refer to “Shared (or RP) Trees”
on page 7-9.
Shared (or RP) Trees
Shared distribution trees are also referred to as RP trees (or RPTs) because the routers in the distribution
tree share a common Rendezvous Point (RP). The following diagrams illustrate a simple RP tree in a
PIM-SM domain.
In this example, a multicast receiver (Receiver 1) uses IGMP to express interest in receiving multicast
traffic destined for a particular multicast group. After getting the IGMP Join request, the receiver’s Designated Router (DR) then passes on the request, in the form of a PIM Join message, to the RP.
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page 7-9
PIM Overview
Configuring PIM
Note. The Join message is known as a (*,G) join because it joins group G for all sources to that group.
Sender 1
Receiver Designated
Router (DR)
RP Router
Legend
IGMP Join from Receiver
Receiver 1
PIM Join Message from DR
Note. Depending on the network configuration, multiple routers may exist between the receiver’s DR and
the RP router. In this case, the (*, G) Join message travels hop-by-hop toward the RP. In each router along
the way, the multicast tree state for group G is instantiated. These Join messages converge on the RP to
form a distribution tree for group G that is rooted at the RP.
page 7-10
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Configuring PIM
PIM Overview
Sender 1 sends multicast data to its Designated Router (DR). The source DR then unicast-encapsulates the
data into PIM-SM Register messages and sends them on to the RP.
Sender 1
Source Designated
Router (DR)
Receiver Designated
Router (DR)
RP Router
Legend
Native Multicast Data
Encapsulated Data
Receiver 1
Receiver PIM Join Message
Once the distribution tree for group G is learned at the RP, the encapsulated data being sent from the
source DR are now unencapsulated at the RP and forwarded natively to the Receiver.
Sender 1
Source Designated
Router (DR)
Receiver Designated
Router (DR)
RP Router
Legend
Native Multicast Data
Receiver 1
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
Encapsulated Data
December 2007
page 7-11
PIM Overview
Configuring PIM
Avoiding Register Encapsulation
Switching to a Shortest Path Tree (SPT) topology allows PIM routers to avoid Register encapsulation of
data packets that occurs in an RPT. Register encapsulation is inefficient for the following reasons:
• The encapsulation and unencapsulation of Register messages tax router resources. Hardware routing
does not support encapsulation and unencapsulation.
• Register encapsulation may require that data travel unnecessarily over long distances. For example,
data may have to travel “out of their way” to the RP before turning back down the shared tree in order
to reach a receiver.
For some applications, this increased latency is undesirable. There are two methods for avoiding register
encapsulation: RP initiation of (S, G) source-specific Join messages, and switchover to a Shortest Path
Tree (SPT). For more information, refer to the sections below.
PIM-Dense Mode (PIM-DM)
PIM-DM is a multicast routing protocol that defines a multicast routing algorithm for multicast groups
densely distributed across a network. PIM-DM uses the underlying unicast routing information base to
flood multicast datagrams to all multicast routers. Prune messages are used to prevent future messages
from propagating to routers with no group membership information. It employs the same packet formats as
PIM-SM.
PIM-DM assumes that when a multicast source starts sending, all downstream systems receive multicast
datagrams. Multicast datagrams are initially flooded to all network areas. PIM-DM utilizes Reverse Path
Forwarding to prevent looping of multicast datagrams while flooding. If some areas of the network do not
have group members, PIM-DM will prune off the forwarding branch by instantiating the prune state.
PIM-DM differs from PIM-SM in two essential ways:
• There are no periodic joins transmitted, only explicitly triggered prunes and grafts.
• There is no Rendezvous Point (RP). This is particularly important in networks that cannot tolerate a
single point of failure.
Note. A PIM router cannot differentiate a PIM-DM neighbor and a PIM-SM neighbor based on Hello
messages, and PIM-DM is not intended to interact directly with a PIM-SM router.
page 7-12
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring PIM
PIM Overview
RP Initiation of (S, G) Source-Specific Join Message
When the data rate at the Rendezvous Point (RP) exceeds the configured RP threshold value, the RP will
initiate a (S, G) source-specific Join message toward the source.
Legend
Encapsulated Data Exceeding RP Threshold
Sender
Source-Specific Join
Native Traffic
DR
!
RP
DR
Source-Specific Join
Receiver
Note. To configure the RP threshold value, use the ip pim rp-threshold command.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 7-13
PIM Overview
Configuring PIM
When the Sender’s DR receives the (S,G) Join, it sends data natively as well. When these data packets
arrive natively at the RP, the RP will be receiving two copies of each of these packets—one natively and
one encapsulated. The RP drops the register-encapsulated packets and forwards only the native packets.
Legend
Register-Encapsulated Traffic
Sender
Native Traffic
DR
DR
RP
The RP receives both native and
encapsulated data. It drops the
encapsulated data and forwards only
the native packets.
Receiver
A register-stop packet is sent back to the sender’s DR to prevent the DR from unnecessarily encapsulating
the packets. Once the register-encapsulated packets are discontinued, the packets flow natively from the
sender to the RP—along the source-specific tree to the RP and, from there, along the shared tree to all
receivers.
Legend
Sender
Register-Stop
Native Traffic
The Sender’s DR stops sending registerencapsulated packets once it receives
the Register-Stop packet. The DR now
sends only native traffic.
DR
Register-Stop Packet
RP
DR
Receiver
Because packets are still forwarded along the shared tree from the RP to all of the receivers, this does not
constitute a true Shortest Path Tree (SPT). For many receivers, the route via the RP may involve a significant detour when compared with the shortest path from the source to the receivers.
page 7-14
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring PIM
PIM Overview
SPT Switchover
The last hop Designated Router (DR) initiates the switchover to a true Shortest Path Tree (SPT) once the
DR receives the first multicast data packet. This method does not use any preconfigured thresholds, such
as RP threshold (as described above). Instead, the switchover is initiated automatically, as long as the SPT
status is enabled on the switch.
Important. SPT status must be enabled for SPT switchover to occur. SPT status is enabled by default. If
the SPT status is disabled, the SPT switchover will not occur. The SPT status is configured via the
ip pim spt status command. To view the current SPT status, use the show ip pim sparse command.
Upon receiving the first multicast data packet, the last hop DR issues a (S, G) source-specific Join
message toward the source.
Legend
Multicast Traffic
Sender
Source-Specific Join
DR
Source-Specific Join
SPT switchover is enabled at the
last hop DR; the switchover is
initiated upon receiving the first
multicast data packet.
RP
DR
Receiver
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 7-15
PIM Overview
Configuring PIM
Once the Sender’s DR receives the (S,G) Join message, the DR sends the multicast packets natively along
the Shortest Path Tree. At this point, Router X (the router shown between the Sender’s DR and the
Receiver’s DR) will be receiving two copies of the multicast data—one from the SPT and one from the
RPT. This router drops the packets arriving via the RP tree and forwards only those packets arriving via
the SPT.
Sender
Traffic is received on this router
from both the SPT and RPT.
DR
Router X
DR
RP
Receiver
An (S, G, RPT) Prune message is sent toward the RP. As a result, traffic destined for this group from this
particular source will no longer be forwarded along the RPT. The RP will still receive traffic from the
Source. If there are no other routers wishing to receive data from the source, the RP will send an
(S, G) Prune message toward the source to stop this unrequested traffic.
Legend
Multicast Traffic
Sender
(S, G, RPT) Prune
DR
Router X
(S, G, RPT)
Prune Message
RP
SPT switchover is enabled at the
last hop DR; the switchover is
initiated upon receiving the first
multicast data packet.
DR
Receiver
page 7-16
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring PIM
PIM Overview
The Receiver is now receiving multicast traffic along the Shortest Path Tree between the Receiver and the
Source.
Sender
DR
RP
DR
Receiver
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 7-17
Configuring PIM
Configuring PIM
Configuring PIM
Enabling PIM on the Switch
By default, PIM protocol is disabled on a switch. Before running PIM, you must enable the protocol by
completing the following steps:
• Verifying the software
• Loading PIM into memory
• Enabling PIM on desired IP interfaces
• Enabling PIM globally on the switch
Note. These steps are common for enabling PIM in the IPv4 as well as IPv6 environments.
For information on completing these steps, refer to the sections below.
Verifying the Software
Before you can begin configuring PIM, the advanced routing image must be present in an OmniSwitch’s
current running directory (i.e., Working or Certified).
To identify the current running directory (also referred to as running configuration), use the
show running-directory command. For example:
-> show running-directory
CONFIGURATION STATUS
Running CMM
:
CMM Mode
:
Current CMM Slot
:
Running configuration
:
Certify/Restore Status
:
SYNCHRONIZATION STATUS
Running Configuration
:
NIs Reload On Takeover
PRIMARY,
MONO CMM,
A,
WORKING,
CERTIFY NEEDED
SYNCHRONIZED,
: NONE
(additional table output not shown)
To view the software contents of the current running directory using the ls command. A display similar to
the following will display on OmniSwitch 6800 or 6850 switches. If you are currently in the root flash, be
sure to include the current running directory in the command line. In this example, the current running
directory is the Working directory.
page 7-18
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring PIM
Configuring PIM
-> ls working
Listing Directory /flash/working:
drw
drw
-rw
-rw
-rw
-rw
-rw
-rw
2048
2048
164
662998
2791518
296839
698267
876163
Jan
Jan
Jan
Jan
Jan
Jan
Jan
Jan
1
1
1
1
1
1
1
1
04:37
05:58
04:32
04:36
04:36
04:36
04:37
04:37
./
../
boot.cfg
Kadvrout.img
Kbase.img
Kdiag.img
Keni.img
Kos.img
The Kadvrout.img file is present
in the current running configuration
(in this case, Working).
(additional table output not shown)
Note. The output on OmniSwitch 9000 switches is similar.
Loading PIM into Memory
You must load PIM into memory before you can begin configuring the protocol on the switch. If PIM is
not loaded and you enter a configuration command, the following message displays:
ERROR: The specified application is not loaded
To dynamically load PIM into memory, enter the following command:
-> ip load pim
Enabling IPMS
PIM requires that IP Multicast Switching (IPMS) be enabled. IPMS is automatically enabled when a
multicast routing protocol (either PIM or DVMRP) is enabled globally and on an interface and the operational status of the interface is up. If you wish to manually enable IPMS on the switch, use the
ip multicast status command.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 7-19
Configuring PIM
Configuring PIM
Checking the Current IPMS Status
To view the current status of IPMS on the switch, use the show ip multicast command.
For example:
-> show ip multicast
Status:
Enabled
Querying:
Disabled
Proxying:
Disabled
Spoofing:
Disabled
Zapping:
Disabled
Querier Forwarding:
Disabled
Version:
2
Robustness:
2
Query Interval (seconds):
125
Query Response Interval (tenths of seconds): 100
Last Member Query Interval(tenths of seconds):10
Unsolicited Report Interval(seconds):
1
Router Timeout (seconds):
90
Source Timeout (seconds):
30
Enabling PIM on a Specific Interface
PIM must be enabled on an interface using the ip pim interface command. An interface can be any IP
router port that has been assigned to an existing VLAN. For information on assigning a router port to a
VLAN, refer to the “Configuring VLANs” chapter in the OmniSwitch 6800/6850/9000 Network Configuration Guide.
To enable PIM on a specific interface, use the ip pim interface command. By default, PIM is disabled on
an interface. The interface identifier used in the command syntax is the valid interface name of an existing
VLAN router port. For example:
-> ip pim interface vlan-2
Note. Only one multicast routing protocol is supported per interface. This means that you cannot enable
both DVMRP and PIM on the same interface. Only one of the three protocols is allowed per interface.
Disabling PIM on a Specific Interface
To disable PIM on a specific IP interface, use the no ip pim interface command. Be sure to include the
name of the interface. For example:
-> no ip pim interface vlan-2
page 7-20
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring PIM
Configuring PIM
Viewing PIM Status and Parameters for a Specific Interface
To view the current PIM interface information—which includes IP addresses for PIM-enabled interfaces,
Hello and Join/Prune intervals, and current operational status—use the show ip pim interface command.
For example:
-> show ip pim interface
Total 1 Interfaces
Interface Name
IP Address
Designated
Hello
J/P
Oper
Router
Interval Interval Status
--------------------+---------------+---------------+--------+--------+------tesvl
50.1.1.1
50.1.1.1
100
10
disabled
The IP address of the Designated
Router for the interface is displayed.
The Interface Name used to identify
the PIM enabled interface is listed in
the PIM interface table.
Enabling PIM Mode on the Switch
To globally enable PIM-Sparse Mode on the switch, use the ip pim sparse status command. Enter the
command syntax as shown below:
-> ip pim sparse status enable
To globally enable PIM-Dense Mode on the switch, use the ip pim dense status command. Enter the
command syntax as shown below:
-> ip pim dense status enable
Disabling PIM Mode on the Switch
To globally disable PIM-Sparse Mode on the switch, use the ip pim sparse status command. Enter the
command syntax as shown below:
-> ip pim sparse status disable
To globally disable PIM-Dense Mode on the switch, use the ip pim dense status command. Enter the
command syntax as shown below:
-> ip pim dense status disable
Checking the Current Global PIM Status
To view current global PIM enable/disable status, as well as additional global PIM settings, use the show
ip pim sparse or show ip pim dense command. For example:
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 7-21
Configuring PIM
Configuring PIM
-> show ip pim sparse
Status
Keepalive Period
Max RPs
Probe Time
Register Checksum
Register Suppress Timeout
RP Threshold
SPT Status
=
=
=
=
=
=
=
-> show ip pim dense
Status
Source Lifetime
State Refresh Interval
State Refresh Limit Interval
State Refresh TTL
enabled,
210,
32,
5,
header,
60,
1,
= enabled,
=
=
=
=
enabled,
210,
60,
0,
= 16
Mapping an IP Multicast Group to a PIM Mode
PIM mode is an attribute of the IP multicast group mapping and cannnot be configured on an interface
basis. The Dense mode or Source-Specific Multicast mode can be configured only on a multicast group
basis.
Mapping an IP Multicast Group to PIM-DM
To statically map an IP multicast group(s) to PIM-Dense mode (DM), you can use the ip pim dense group
command. For example:
-> ip pim dense group 224.0.0.0/4 priority 50
This command entry maps all multicast groups 224.0.0.0/4 to PIM-Dense mode and specifies the priority
value to be used for the entry as 50. This priority specifies the preference value to be used for this static
configuration and provides fine control over which configuration is overridden by this static configuration. Values may range from 0 to 128. If the priority option has been defined, a value of 65535 can be used
to unset the priority.
You can also specify whether or not this static configuration overrides the dynamically learned group
mapping information for the specified group using the override parameter. As specifying the priority
value obsoletes the override option, you can use either the priority or override parameter only. By
default, the priority option is not set, and the override option is set to false.
Use the no form of this command to remove a static configuration of a dense mode group mapping.
-> no ip pim dense group 224.0.0.0/4
Mapping an IP Multicast Group to PIM-SSM
To statically map an IP multicast group(s) to PIM-Source-Specific Multicast mode (SSM), you can use the
ip pim ssm group command. For example:
-> ip pim ssm group 224.0.0.0/4 priority 50
This command entry maps all multicast groups 224.0.0.0/4 to PIM-SSM mode and specifies the priority
value to be used for the entry as 50. This priority specifies the preference value to be used for this static
configuration and provides fine control over which configuration is overridden by this static configuration. Values may range from 0 to 128. If the priority option has been defined, a value of 65535 can be used
to unset the priority.
page 7-22
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring PIM
Configuring PIM
You can also specify whether or not this static configuration overrides the dynamically learned group
mapping information for the specified group using the override parameter. As specifying the priority
value obsoletes the override option, you can use either the priority or override parameter only. By
default, the priority option is not set, and the override option is set to false.
Use the no form of this command to remove a static configuration of a SSM mode group mapping.
-> no ip pim ssm group 224.0.0.0/4
PIM-Source-Specific Multicast (SSM) mode for the default SSM address range (232.0.0.0 through
232.255.255.255) reserved by the Internet Assigned Numbers Authority is not enabled automatically and
must be configured manually to support SSM. You can also map additional multicast address ranges for
the SSM group. However, the multicast groups in the reserved address range can be mapped only to the
SSM mode.
Verifying Group Mapping
To view PIM-Dense Mode Group Mappings
Displays the static configuration of multicast group mappings for PIM-Dense Mode (DM).
-> show ip pim dense group
Group Address/Pref Length
Mode Override Precedence Status
---------------------------+-----+--------+----------+-------224.0.0.0/4
dm
false
none
enabled
To view PIM-Source-Specific Multicast Mode Group Mappings
Displays the static configuration of multicast group mappings for PIM-Source-Specific Multicast (SSM)
mode.
-> show ip pim ssm group
Group Address/Pref Length
Mode Override Precedence Status
---------------------------+-----+--------+----------+-------224.0.0.0/4
ssm
false
none
enabled
Automatic Loading and Enabling of PIM following a System
Boot
If any PIM command is saved to the boot.cfg file in the post-boot running directory, PIM will be loaded
into memory automatically. The post-boot running directory refers to the directory the switch will use as
its running directory following the next system boot (i.e., Working or Certified). If the command syntax ip
pim sparse status enable or ip pim dense status enable is saved to the boot.cfg file in the post-boot
running directory, PIM will be automatically loaded into memory and globally enabled following the next
system boot. For detailed information on the Working and Certified directories and how they are used
during system boot, see the “CMM Directory Management” chapter in the OmniSwitch 6800/6850/9000
Switch Management Guide.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 7-23
Configuring PIM
Configuring PIM
PIM Bootstrap and RP Discovery
Before configuring PIM-SM parameters, please consider the following important guidelines.
For correct operation, every PIM-SM router within a PIM-SM domain must be able to map a particular
multicast group address to the same Rendezvous Point (RP). Otherwise, some receivers in the domain will
not receive some groups. Two mechanisms are supported for multicast group address mapping:
• Bootstrap Router (BSR) Mechanism
• Static RP Configuration
The chosen multicast group address mapping mechanism should be used consistently throughout PIM-SM
domain. Any RP address configured or learned must be a domain-wide reachable address.
Configuring a C-RP
Note. If you attempt to configure an interface that is not PIM enabled as a C-RP, you will receive the
following error message:
ERROR: PIM is not enabled on this Interface
For information on enabling PIM on an interface, refer to page 7-20.
To configure the local router as the Candidate-Rendezvous Point (C-RP) for a specified IP multicast
group(s), use the ip pim candidate-rp command. For example:
-> ip pim candidate-rp 50.1.1.1 224.16.1.1/32 priority 100 interval 100
This configures the switch to advertise the address 50.1.1.1 as the C-RP for the multicast group 224.16.1.1
with a mask of 255.255.255.255, priority level for this entry to be 100, and the interval at which the C-RP
advertisements are sent to the Bootstrap Router as 100.
Use the no form of this command to remove the association of the device as a C-RP for a particular multicast group.
-> no ip pim candidate-rp 50.1.1.1 224.16.1.1/32
If a C-RP address is defined on the switch and no explicit entries are defined, then the switch will advertise itself as a C-RP for all multicast groups (i.e., 224.0.0.0 with a mask of 240.0.0.0). If no C-RP address
is defined, the switch will not advertise itself as a C-RP for any groups. Only one RP address is supported
per switch. If multiple candidate-RP entries are defined, they must use the same rp-address.
The C-RP priority is used by a Designated Router in determining the RP for a particular group. The priority level may range from 0 to 192. The lower the numerical value, the higher the priority. The default
priority level for a C-RP is 0 (highest). If two or more C-RPs have the same priority value and the same
hash value, the C-RP with the highest IP address is selected by the DR.
Verifying C-RP Configuration
Check C-RP address, priority level, and explicit multicast group information using the show ip pim candidate-rp command, as follows:
-> show ip pim candidate-rp
RP Address
Group Address
Priority Interval Status
------------------+---------------+---------+---------+-------172.21.63.11
224.0.0.0/4
192
60
enabled
page 7-24
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring PIM
Configuring PIM
The group address is listed as 224.0.0.0. The class D group mask (255.255.255.255) has been translated
into the Classless Inter-Domain Routing (CIDR) prefix length of /4. The C-RP is listed as 172.21.63.11.
The status is enabled.
Specifying the Maximum Number of RPs
You can specify the maximum number of RPs allowed in a PIM-SM domain. (The switch’s default value
is 32.)
Important. PIM must be globally disabled on the switch before changing the maximum number of
RPs. To disable PIM, use the ip pim sparse status command. See page 7-21 for more information.
The maximum number of allowed RPs can range from 1 to 100. To specify a maximum number of
RPs, use the ip pim max-rps command. For example:
-> ip pim max-rps 12
Note. This command is used with both IPv4 and IPv6 PIM-SM. PIM-SM must be disabled before changing max-rps value.
Verifying Maximum-RP Configuration
Check the maximum number of RPs using the show ip pim sparse command. For example:
-> show ip pim sparse
Status
Keepalive Period
Max RPs
Probe Time
Register Checksum
Register Suppress Timeout
RP Threshold
SPT Status
=
=
=
=
=
=
=
enabled,
210,
32,
5,
header,
60,
1,
= enabled,
For more information about these displays, see the “PIM Commands” chapter in the OmniSwitch CLI
Reference Guide.
Candidate Bootstrap Routers (C-BSRs)
A Candidate Bootstrap Router (C-BSR) is a PIM-SM-enabled router that is eligible for Bootstrap Router
(BSR) status. To become a BSR, a C-BSR must be elected. A C-BSR sends Bootstrap messages to all
neighboring routers. The messages include its IP address—which is used as an identifier—and its priority
level. The C-BSR with the highest priority level is elected as the BSR by its neighboring routers. If there
are multiple C-BSRs with the same highest priority, the C-BSR with the highest IP address will become
the BSR.
For information on configuring a C-BSR, refer to “Configuring a C-BSR” below.
Configuring a C-BSR
You can use the ip pim cbsr command to configure the local router as the candidate-BSR for PIM
domain. For example:
-> ip pim cbsr 50.1.1.1 priority 100 mask-length 4
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 7-25
Configuring PIM
Configuring PIM
This command specifies the router to use its local address 50.1.1.1 for advertising it as the candidate-BSR
for that domain, the priority value of the local router as a C-BSR to be 100, and the mask-length that is
advertised in the bootstrap messages as 4. The value of the priority is considered for the selection of CBSR for PIM domain. The higher the value, the higher the priority.
Use the no form of this command to remove the local routers’ candidacy as the BSR. For example:
-> no ip pim cbsr 50.1.1.1
Verifying the C-BSR Configuration
Note. Check the C-BSR and information about priority and mask-length using the show ip pim cbsr
command as follows:
-> show ip pim cbsr
CBSR Address
Status
CBSR Priority
Hash Mask Length
Elected BSR
Timer
=
=
=
=
=
214.0.0.7,
enabled,
0,
30,
False,
= 00h:00m:00s
For more information about these displays, see the “PIM Commands” chapter in the OmniSwitch CLI
Reference Guide.
Bootstrap Routers (BSRs)
As described in the “PIM Overview” section, the role of a Bootstrap Router (BSR) is to keep routers in the
network “up to date” on reachable Candidate Rendezvous Points (C-RPs). BSRs are elected from a set of
Candidate Bootstrap Routers (C-BSRs). Refer to page 7-9 for more information on C-BSRs.
Reminder. For correct operation, all PIM-SM routers within a PIM-SM domain must be able to map a
particular multicast group address to the same Rendezvous Point (RP). PIM-SM provides two methods for
group-to-RP mapping. One method is the Bootstrap Router mechanism, which also involves C-RP advertisements, as described in this section; the other method is static RP configuration. Note that, if static RP
configuration is enabled, the Bootstrap mechanism and C-RP advertisements are automatically disabled.
For more information on static RP status and configuration, refer to “Configuring Static RP Groups”
below.
A C-RP periodically sends out messages, known as C-RP advertisements. When a BSR receives one of
these advertisements, the associated C-RP is considered reachable (if a valid route to the network exists).
The BSR then periodically sends an updated list of reachable C-RPs to all neighboring routers in the form
of a Bootstrap message.
page 7-26
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring PIM
Configuring PIM
Note. The list of reachable C-RPs is also referred to as an RP set. To view the current RP set, use the
show ip pim group-map command. For example:
-> show ip pim group-map
Origin
Group Address/Pref Length
RP Address
Mode Precedence
---------+---------------------------+-------------+-----+----------BSR
224.0.0.0/4
172.21.63.11 asm
192
BSR
224.0.0.0/4
214.0.0.7
asm
192
Static
232.0.0.0/8
ssm
For more information about these displays, see the “PIM Commands” chapter in the OmniSwitch CLI
Reference Guide.
Note. There is only one BSR per PIM-SM domain. This allows all PIM-SM routers in PIM-SM domain to
view the same list of reachable C-RPs.
Configuring Static RP Groups
A static RP group is used in the group-to-RP mapping algorithm. To specify a static RP group, use the
ip pim static-rp command. Be sure to enter a multicast group address, a corresponding group mask, and a
32-bit IP address for the static RP in the command line. For example:
-> ip pim static-rp 224.0.0.0/4 10.1.1.1 priority 10
This command entry maps all multicast groups 224.0.0.0/4 to the static RP 10.1.1.1 and specifies the
priority value to be used for the static RP configuration as 10. This priority value provides fine control
over which configuration is overridden by this static configuration. If the priority option has been defined,
a value of 65535 can be used to unset the priority.
You can also specify this static RP configuration to override the dynamically learned RP information for
the specified group using the override parameter. As specifying the priority value obsoletes the override
option, you can use either the priority or override parameter only.
Use the no form of this command to delete a static RP configuration.
-> no ip pim static-rp 224.0.0.0/4 10.1.1.1
PIM-Source-Specific Multicast (SSM) mode for the default SSM address range (232.0.0.0 through
232.255.255.255) reserved by the Internet Assigned Numbers Authority is not enabled automatically and
must be configured manually to support SSM. You can also map additional multicast address ranges for
the SSM group. However, the multicast groups in the reserved address range can be mapped only to the
SSM mode.
Note. If static RP status is specified, the method for group-to-RP mapping provided by the Bootstrap
mechanism and C-RP advertisements is automatically disabled. For more information on this alternate
method of group-to-RP mapping, refer to page 7-26.
Verifying Static-RP Configuration
To view current Static RP Configuration settings, use the show ip pim static-rp command. For example:
-> show ip pim static-rp
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December 2007
page 7-27
Configuring PIM
Configuring PIM
Group Address/Pref Length
RP Address
Mode Override Precedence Status
---------------------------+-------------+-----+--------+----------+-------224.0.0.0/4
172.21.63.11 asm
false
none
enabled
Group-to-RP Mapping
Using one of the mechanisms described in the sections above, a PIM-SM router receives one or more
possible group-range-to-RP mappings. Each mapping specifies a range of multicast groups (expressed as a
group and mask), as well as the RP to which such groups should be mapped. Each mapping may also have
an associated priority. It is possible to receive multiple mappings—all of which might match the same
multicast group. This is the common case with the BSR mechanism. The algorithm for performing the
group-to-RP mapping is as follows:
1 Perform longest match on group-range to obtain a list of RPs.
2 From this list of matching RPs, find the one with the highest priority. Eliminate any RPs from the list
that have lower priorities.
3 If only one RP remains in the list, use that RP.
4 If multiple RPs are in the list, use the PIM-SM hash function defined in the RFC to choose one. The RP
with the highest resulting hash value is then chosen as the RP. If more than one RP has the same highest
hash value, then the RP with the highest IP address is chosen.
This algorithm is invoked by a DR when it needs to determine an RP for a given group, such as when
receiving a packet or an IGMP membership indication.
Configuring Keepalive Period
You can specify the duration for the Keepalive Timer using the ip pim keepalive-period command. This is
the period during which the PIM router will maintain (S,G) state in the absence of explicit (S,G) local
membership of (S,G) Join messages received to maintain it. For example,
-> ip pim keepalive-period 500
The above example configures the keepalive period as 500 seconds. The default value is 210.
This timer is called the Keepalive period and Source Lifetime period in PIM-SM specification and PIMDM specification, respectively.
Note. The value configured by the above command is common for PIM in the IPv4 as well as IPv6 environments.
Verifying Keepalive Period
To view the configured keepalive period, use the show ip pim sparse command. For example:
-> show ipv6 pim sparse
Status
Keepalive Period
Max RPs
Probe Time
Register Suppress Timeout
page 7-28
=
=
=
=
=
enabled,
210,
32,
5,
60,
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December 2007
Configuring PIM
RP Switchover
SPT Status
Configuring PIM
= enabled,
= enabled,
You can also use the show ip pim dense, show ipv6 pim sparse, and show ipv6 pim dense commands to
view the configured keepalive period.
Configuring Notification Period
The switch can be configured for a minimum time interval that must elapse between various notifications,
such as neighbor loss notification, invalid register notification, invalid joinprune notification, RP mapping
notification, and interface election notification. For example:
To set the time that must elapse between PIM neighbor loss notifications originated by the router, enter ip
pim neighbor-loss-notification-period followed by the time in seconds. For example, to set the time
period of 10 seconds, enter:
-> ip pim neighbor-loss-notification-period 10
To set the time that must elapse between PIM invalid register notifications originated by the router, enter
ip pim invalid-register-notification-period followed by the time in seconds. For example, to set the time
period of 100 seconds, enter:
-> ip pim invalid-register-notification-period 100
To set the time that must elapse between PIM invalid joinprune notifications originated by the router,
enter ip pim invalid-joinprune-notification-period followed by the time.For example, to set the time
period of 100 seconds, enter:
-> ip pim invalid-joinprune-notification-period 100
To set the time that must elapse between PIM RP mapping notifications originated by the route, enter ip
pim rp-mapping-notification-period followed by the time in seconds.For example, to set the time period
of 100 seconds, enter:
-> ip pim rp-mapping-notification-period 100
To set the time that must elapse between PIM interface election notifications originated by the router,
enter ip pim interface-election-notification-period followed by the time in seconds. For example, to set
the time period of 100 seconds, enter:
-> ip pim interface-election-notification-period 100
Note. The values configured by the above commands are common for PIM in the IPv4 as well as IPv6
environments.
Verifying the Notification Period
To view the configured notification period, use the show ip pim notifications command. For example:
-> show ip pim notifications
Neighbor Loss Notifications
Period
= 0
Count
= 0
Invalid Register Notifications
Period
= 65535
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December 2007
page 7-29
Configuring PIM
Configuring PIM
Msgs Rcvd
= 0
Origin
= None
Group
= None
RP
= None
Invalid Join Prune Notifications
Period
= 65535
Msgs Rcvd
= 0
Origin
= None
Group
= None
RP
= None
RP Mapping Notifications
Period
= 65535
Count
= 0
Interface Election Notifications
Period
= 65535
Count
= 0
page 7-30
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December 2007
Configuring PIM
PIM-SSM Support
PIM-SSM Support
Protocol-Independent Multicast Source-Specific Multicast (PIM-SSM) is a highly-efficient extension of
PIM. SSM, using an explicit channel subscription model, allows receivers to receive multicast traffic
directly from the source; an RP tree model is not used. In other words, a Shortest Path Tree (SPT) between
the receiver and the source is created without the use of a Rendezvous Point (RP).
By default, PIM software supports Source-Specific Multicast. No additional user configuration is required.
PIM-SSM is automatically enabled and operational as long as PIM is loaded (see page 7-6) and IGMPv3
source-specific joins are received within the SSM address range.
For detailed information on PIM-SSM and Source-Specific Multicast, refer to the IETF Internet Drafts
draft-ietf-pim-sm-v2-new-05.txt and draft-ietf-ssm-arch-04.txt, as well as RFC 3569, “An Overview of
Source-Specific Multicast (SSM).”
Note. For networks using IGMP proxy, be sure that the IGMP proxy version is set to Version 3.
Otherwise, PIM-SSM will not function. For information on configuring the IGMP version, refer to the ip
multicast version command.
Source-Specific Multicast Addresses
The multicast address range from 232.0.0.0 through 232.255.255.255 have been reserved by the Internet
Assigned Numbers Authority (IANA) as Source-Specific Multicast (SSM) destination addresses. The
PIM-Source-Specific Multicast (SSM) mode for the default SSM address range is not enabled automatically and needs to be configured manually to support SSM. Addresses within this range are reserved for
use by source-specific applications and protocols (e.g., PIM-SSM). These addresses cannot be used for
any other functions or protocols. However, you can also map additional multicast address ranges for the
SSM group.
PIM-SSM Specifications
RFCs Supported
3569—An Overview of Source-Specific Multicast (SSM)
Internet Drafts Supported
draft-ietf-pim-sm-v2-new-05.txt—Protocol Independent
Multicast – Sparse Mode (PIM-SM)
draft-ietf-ssm-arch-04.txt—An Overview of SourceSpecific Multicast (SSM)
Valid SSM Address Range
232.0.0.0 to 232.255.255.255
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page 7-31
Verifying PIM Configuration
Configuring PIM
Verifying PIM Configuration
A summary of the show commands used for verifying PIM configuration is given here:
show ip pim sparse
Displays the status of the various global parameters for PIM-Sparse
Mode.
show ip pim dense
Displays the status of the various global parameters for PIM-Dense
Mode.
show ip pim ssm group
Displays the static configuration of multicast group mappings for PIMSource-Specific Multicast (SSM) mode.
show ip pim dense group
Displays the static configuration of multicast group mappings for PIMDense Mode (DM).
show ip pim neighbor
Displays a list of active PIM neighbors.
show ip pim candidate-rp
Displays the IP multicast groups for which the local router advertises
itself as a Candidate-RP.
show ip pim group-map
Displays the PIM group mapping table.
show ip pim interface
Displays detailed PIM settings for a specific interface. In general, it displays PIM settings for all the interfaces if no argument is specified.
show ip pim groute
Displays all (*,G) states that the IPv4 PIM has.
show ip pim sgroute
Displays all (S,G) states that the IPv4 PIM has.
show ip pim notifications
Displays the configuration of the configured notification periods as well
as information on the events triggering the notifications.
show ip mroute
Displays multicast routing information for IP datagrams sent by particular sources to the IP multicast groups known to this router.
show ip pim static-rp
Displays the PIM Static RP table, which includes group address/mask,
the static Rendezvous Point (RP) address, and the current status of Static
RP configuration (i.e., enabled or disabled).
show ip pim bsr
Displays information about the elected BSR.
show ip pim cbsr
Displays the Candidate-BSR information that is used in the Bootstrap
messages.
For more information about the displays that result from these commands, see the OmniSwitch CLI
Command Reference Guide.
page 7-32
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Configuring PIM
PIM for IPv6 Overview
PIM for IPv6 Overview
IP version 6 (IPv6) is a new version of the Internet Protocol, designed as the successor to IP version 4
(IPv4), to overcome certain limitations in IPv4. IPv6 adds significant extra features that were not possible
with IPv4. These include automatic configuration of hosts, extensive multicasting capabilities, and built-in
security using authentication headers and encryption. Built-in support for QOS and path control are also
features found in IPv6.
IPv6 is a hierarchical 128-bit addressing scheme that consists of 8 fields, composed of 16 bits each. An
IPv6 address is written as a hexadecimal value (0-F) in groups of four, separated by colons. IPv6 provides
3x10^38 addresses, which can help overcome the shortage of IP addresses needed for Internet usage.
There are three types of IPv6 addresses: Unicast, Anycast, and Multicast. A Unicast address identifies a
single interface, and a packet destined for a Unicast address is delivered to the interface identified by that
address. An Anycast address identifies a set of interfaces, and a packet destined for an Anycast address is
delivered to the nearest interface identified by that Anycast address. A Multicast address identifies a set of
interfaces, and a packet destined for a Multicast address is delivered to all the interfaces identified by that
Multicast address. There are no broadcast addresses in IPv6.
The current release also provides support for PIM to be configured in IPv6 environments using IPv6
multicast addresses. In the IPv6 addressing scheme, multicast addresses begin with the prefix ff00::/8.
Similar to IPv6 unicast addresses, IPv6 multicast addresses also have different scopes depending on their
prefix, though the range of possible scopes is different.
Multicast Listener Discovery (MLD) is the protocol used by an IPv6 router to discover the nodes that
request multicast packets on its directly attached links and the multicast addresses that are of interest to
those neighboring nodes. MLD is derived from version 2 of IPv4's Internet Group Management Protocol,
IGMPv2. MLD uses ICMPv6 message types, rather than IGMP message types.
Note. IPv6 PIM is supported on OS6850 and OS9000 series switches in the current release.
Quick Steps for Configuring IPv6 PIM-DM
Note. PIM requires that IP Multicast Switching (IPMS) is enabled. IPMS is automatically enabled when a
multicast routing protocol (either PIM or DVMRP) is enabled globally and on an interface and when the
operational status of the interface is up. However, if you wish to manually enable IPMS on the switch, use
the ip multicast status command.
1 Manually load PIM into memory by entering the following command:
-> ip load pim
2 Create a router port (i.e., interface) on an existing VLAN by specifying a valid IPv6 address. To do
this, use the ipv6 interface command. For example:
-> ipv6 interface vlan 1
3 Enable PIM on the IPv6 interface using the ipv6 pim interface command. For example:
-> ipv6 pim interface vlan-1
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page 7-33
Quick Steps for Configuring IPv6 PIM-DM
Configuring PIM
Note. The IPv6 interface on which the PIM is enabled must be an already configured IPv6 interface on the
switch
4 Map the IPv6 PIM-Dense Mode (DM) protocol for a multicast group via the ipv6 pim dense group
command. For example:
-> ipv6 pim dense group ff0e::1234/128
5 Globally enable the IPv6 PIM protocol by entering the following command. By default, PIM protocol
status is disabled.
-> ipv6 pim sparse status enable
-> ipv6 pim dense status enable
6 Save your changes to the Working directory’s boot.cfg file by entering the following command:
-> write memory
Note. Optional. To verify IPv6 PIM interface status, enter the show ipv6 pim interface command. The
display is similar to the one shown here:
-> show ipv6 pim interface
Interface Name
Designated
Hello
Join/Prune Oper
Router
Interval Interval
Status
--------------------+--------------------------+--------+----------+--------vlan-5
fe80::2d0:95ff:feac:a537
30
60
enabled
vlan-30
fe80::2d0:95ff:feac:a537
30
60
disabled
vlan-40
fe80::2d0:95ff:fee2:6eec
30
60
enabled
To verify global IPv6 PIM status, enter the show ipv6 pim sparse or show ipv6 pim dense command.
The display for sparse mode is similar to the one shown here:
-> show ipv6 pim sparse
Status
Keepalive Period
Max RPs
Probe Time
Register Suppress Timeout
RP Switchover
SPT Status
=
=
=
=
=
=
=
enabled,
210,
32,
5,
60,
enabled,
enabled,
The display for dense mode is similar to the one shown here:
-> show IPv6 pim dense
Status
Source Lifetime
State Refresh Interval
State Refresh Limit Interval
State Refresh TTL
=
=
=
=
=
enabled,
210,
60,
0,
16
(additional table output not shown)
For more information about these displays, see the “PIM Commands” chapter in the OmniSwitch CLI
Reference Guide.
page 7-34
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Configuring PIM
Configuring IPv6 PIM
Configuring IPv6 PIM
This section describes PIM for IPv6 configuration, which includes enabling/disabling IPv6 PIM on a
specific interface, Enabling/disabling IPv6 PIM mode on the Switch, IPv6 PIM Bootstrap and RP Discovery, Configuring a C-RP for IPv6 PIM, Configuring Candidate Bootstrap Routers (C-BSRs) for IPv6 PIM,
Configuring Static RP Groups for IPv6 PIM, and Configuring RP-switchover for IPv6 PIM using AlcatelLucent’s Command Line Interface (CLI) commands.
Enabling IPv6 PIM on a Specific Interface
IPv6 PIM must be enabled on an interface using the ipv6 pim interface command. An interface can be
any IPv6 router port that has been assigned to an existing VLAN.
To enable PIM on a specific IPv6 interface, use the ipv6 pim interface command. By default, IPv6 PIM is
disabled on an interface. The interface identifier used in the command syntax is the valid interface name of
an existing VLAN router port. For example:
-> ipv6 pim interface vlan-2
Note. Only one multicast routing protocol is supported per IPv6 interface. This means that you cannot
enable both DVMRP and PIM on the same interface. Only one of the three protocols is allowed per interface.
Disabling IPv6 PIM on a Specific Interface
To disable PIM on a specific IPv6 interface, use the no ipv6 pim interface command. Be sure to include
the name of the interface. For example:
-> no ipv6 pim interface vlan-2
Viewing IPv6 PIM Status and Parameters for a Specific Interface
To view the current IPv6 PIM interface information—which includes IPv6 addresses for PIM-enabled
interfaces, Hello and Join/Prune intervals, and current operational status—use the show ipv6 pim interface command. For example:
-> show ipv6 pim interface
Interface Name
Designated
Hello
Join/Prune Oper
Router
Interval Interval
Status
--------------------+--------------------------+--------+----------+--------vlan-5
fe80::2d0:95ff:feac:a537
30
60
enabled
vlan-30
fe80::2d0:95ff:feac:a537
30
60
disabled
vlan-40
fe80::2d0:95ff:fee2:6eec
30
60
enabled
Enabling IPv6 PIM Mode on the Switch
To globally enable IPv6 PIM-Sparse Mode on the switch, use the ipv6 pim sparse status command. Enter
the command syntax as shown below:
-> ipv6 pim sparse status enable
To globally enable IPv6 PIM-Dense Mode on the switch, use the ipv6 pim dense status command. Enter
the command syntax as shown below:
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page 7-35
Configuring IPv6 PIM
Configuring PIM
-> ipv6 pim dense status enable
Disabling IPv6 PIM Mode on the Switch
To globally disable IPv6 PIM-Sparse Mode on the switch, use the ipv6 pim sparse status command.
Enter the command syntax as shown below:
-> ipv6 pim sparse status disable
To globally disable IPv6 PIM-Dense Mode on the switch, use the ipv6 pim dense status command. Enter
the command syntax as shown below:
-> ipv6 pim dense status disable
Checking the Current Global IPv6 PIM Status
To view the current global IPv6 PIM enable/disable status, as well as additional global IPv6 PIM settings,
use the show ipv6 pim command. For example:
-> show ipv6 pim sparse
Status
Keepalive Period
Max RPs
Probe Time
Register Suppress Timeout
RP Switchover
SPT Status
=
=
=
=
=
=
-> show ipv6 pim dense
Status
Source Lifetime
State Refresh Interval
State Refresh Limit Interval
State Refresh TTL
enabled,
210,
32,
5,
60,
enabled,
= enabled,
=
=
=
=
enabled,
210,
60,
0,
= 16
Mapping an IPv6 Multicast Group to a PIM mode
PIM mode is an attribute of the IPv6 multicast group mapping and cannnot be configured on an interface
basis. The Dense mode or Source-Specific Multicast mode can be configured only on a IPv6 multicast
group basis.
Mapping an IPv6 Multicast Group to PIM-DM
To statically map an IPv6 multicast group(s) to PIM Dense Mode (DM), you can use the ipv6 pim dense
group command. For example:
-> ipv6 pim dense group ff0e::1234/128 priority 50
This command entry maps all multicast groups ff0e::1234/128 to PIM Dense Mode and specifies the
priority value to be used for the entry as 50. This priority specifies the preference value to be used for this
static configuration and provides fine control over which configuration is overridden by this static configuration. Values may range from 0 to 128. If the priority option has been defined, a value of 65535 can be
used to un-set the priority
You can also specify whether or not this static configuration overrides the dynamically learned group
mapping information for the specified group using the override parameter. As specifying the priority
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Configuring PIM
Configuring IPv6 PIM
value obsoletes the override option, you can use either the priority or override parameter only. By
default, the priority option is not set, and the override option is set to false.
Use the no form of this command to remove a static configuration of a dense mode group mapping.
-> no ipv6 pim dense group ff0e::1234/128
Mapping an IPv6 Multicast Group to PIM-SSM
To statically map an IPv6 multicast group(s) to PIM-Source-Specific Multicast mode (SSM), you can use
the ipv6 pim ssm group command. For example:
-> ipv6 pim ssm group ff30::1234:abcd/128 priority 50
This command entry maps all multicast groups ff30::1234:abcd/128 to PIM-SSM mode and specifies
the priority value to be used for the entry as 50. This priority specifies the preference value to be used for
this static configuration and provides fine control over which configuration is overridden by this static
configuration. Values may range from 0 to 128. If the priority option has been defined, a value of 65535
can be used to un-set the priority.
You can also specify this static configuration to override the dynamically learned group mapping information for the specified group using the override parameter. As specifying the priority value obsoletes the
override option, you can use either the priority or override parameter only. By default, the priority
option is not set, and the override option is set to false.
Use the no form of this command to remove a static configuration of a SSM mode group mapping.
-> no ipv6 pim ssm group ff30::1234:abcd/128
The IPv6 PIM-Source-Specific Multicast (SSM) mode for the default SSM address range (FF3x::/32)
reserved by the Internet Assigned Numbers Authority is not enabled automatically and must be configured manually to support SSM. You can also map additional IPv6 multicast address ranges for the SSM
group using this command. However, the IPv6 multicast groups in the reserved address range can be
mapped only to the SSM mode.
Verifying Group Mapping
To view IPv6 PIM-Dense Mode Group Mappings
Displays the static configuration of IPv6 multicast group mappings for PIM-Dense Mode (DM).
-> show ipv6 pim dense group
Group Address/Pref Length
Mode Override Precedence Status
---------------------------+-----+--------+----------+-------ff00::/8
dm
false
none
enabled
ff34::/32
dm
false
none
enabled
To view PIM-Source-Specific Multicast Mode Group Mappings
To view the static configuration of IPv6 multicast group mappings for PIM-Source-Specific Multicast
(SSM) mode, enter:
-> show ipv6 pim ssm group
Group Address/Pref Length
Mode Override Precedence Status
---------------------------+-----+--------+----------+-------ff00::/8
ssm
false
none
enabled
ff34::/32
ssm
false
none
enabled
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page 7-37
Configuring IPv6 PIM
Configuring PIM
IPv6 PIM Bootstrap and RP Discovery
Before configuring IPv6 PIM-SM parameters, please consider the following important guidelines.
For correct operation, every IPv6 PIM-SM router within an IPv6 PIM-SM domain must be able to map a
particular multicast group address to the same Rendezvous Point (RP). Otherwise, some receivers in the
domain will not receive some groups. Two mechanisms are supported for multicast group address
mapping:
• Bootstrap Router (BSR) Mechanism
• Static RP Configuration
The chosen multicast group address mapping mechanism should be used consistently throughout the IPv6
PIM-SM domain. Any RP address configured or learned must be a domain-wide reachable address.
Configuring a C-RP for IPv6 PIM
To configure the local router as the Candidate-Rendezvous Point (C-RP) for a specified IPv6 multicast
group(s), use the ipv6 pim candidate-rp command. For example:
-> ipv6 pim candidate-rp 2000::1 ff0e::1234/128 priority 100 interval 100
This specifies the switch to advertise the address 2000::1 as the C-RP for the multicast group ff0e::1234
with a prefix length of 128, priority level for this entry to be 100, and the interval at which the C-RP
advertisements are sent to the bootstrap router as 100.
Use the no form of this command to remove the association of the device as a C-RP for a particular multicast group.
-> no ipv6 pim candidate-rp 2000::1 ff0e::1234/128
If a C-RP address is defined on the switch and no explicit entries are defined, then the switch will advertise itself as a C-RP for all multicast groups (i.e., ff0e::1234 with a prefix length of 128). If no C-RP
address is defined, the switch will not advertise itself as a C-RP for any groups. Only one RP address is
supported per switch. If multiple candidate-RP entries are defined, they must use the same rp-address.
The C-RP priority is used by a Designated Router in determining the RP for a particular group. The priority level may range from 0 to 192. The lower the numerical value, the higher the priority. The default
priority level for a C-RP is 0 (highest). If two or more C-RPs have the same priority value and the same
hash value, the C-RP with the highest IPv6 address is selected by the DR.
Verifying the Changes
Note. Check the maximum number of RPs using the show ipv6 pim sparse command. For example:
-> show ipv6 pim sparse
Status
Keepalive Period
Max RPs
Probe Time
Register Suppress Timeout
RP Switchover
SPT Status
=
=
=
=
=
=
enabled,
210,
32,
5,
60,
enabled,
= enabled,
Check C-RP address, priority level, and explicit multicast group information using the show ipv6 pim
candidate-rp command:
page 7-38
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Configuring PIM
Configuring IPv6 PIM
-> show ipv6 pim candidate-rp
RP Address
Group Address
Priority Interval Status
------------------+---------------+---------+---------+-------3000::11
FF00::/8
192
60
enabled
The group address is listed as FF00::/8. The C-RP is listed as 3000::11. The status is enabled.
For more information about these displays, see the “PIM Commands” chapter in the OmniSwitch CLI
Reference Guide.
Configuring Candidate Bootstrap Routers (C-BSRs) for IPv6 PIM
You can use the ipv6 pim cbsr command to configure the local router as the candidate-BSR for the IPv6
PIM domain. For example:
-> ipv6 pim cbsr 2000::1 priority 100 mask-length 4
This command specifies the router to use its local address 2000::1 for advertising it as the candidate-BSR
for that domain, the priority value of the local router as a C-BSR to be 100, and the mask-length that is
advertised in the bootstrap messages as 4. The value of the priority is considered for the selection of CBSR for the IPv6 PIM domain. The higher the value, the higher the priority.
Use the no form of this command to remove the local routers' candidacy as the BSR. For example:
-> no ipv6 pim cbsr 2000::1
Verifying the C-BSR Configuration
Note. Check C-BSR and information about priority and mask-length using the show ipv6 pim cbsr
command, as follows:
-> show ipv6 pim cbsr
CBSR Address
Status
CBSR Priority
Hash Mask Length
Elected BSR
Timer
= 3000::7,
= enabled,
= 0,
= 126,
= False,
= 00h:00m:00s
For more information about these displays, see the “PIM Commands” chapter in the OmniSwitch CLI
Reference Guide.
Bootstrap Routers (BSRs)
As described in the “PIM Overview” section, the role of a Bootstrap Router (BSR) is to keep routers in the
network “up to date” on reachable Candidate Rendezvous Points (C-RPs). BSRs are elected from a set of
Candidate Bootstrap Routers (C-BSRs). Refer to page 7-9 for more information on C-BSRs.
Reminder. For correct operation, all IPv6 PIM-SM routers within an IPv6 PIM-SM domain must be able
to map a particular multicast group address to the same Rendezvous Point (RP). PIM-SM provides two
methods for group-to-RP mapping. One method is the Bootstrap Router mechanism, which also involves
C-RP advertisements, as described in this section; the other method is static RP configuration. Note that, if
static RP configuration is enabled, the Bootstrap mechanism and C-RP advertisements are automatically
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Configuring IPv6 PIM
Configuring PIM
disabled. For more information on static RP status and configuration, refer to “Configuring Static RP
Groups” below.
A C-RP periodically sends out messages, known as C-RP advertisements. When a BSR receives one of
these advertisements, the associated C-RP is considered reachable (if a valid route to the network exists).
The BSR then periodically sends an updated list of reachable C-RPs to all neighboring routers in the form
of a Bootstrap message.
Note. The list of reachable C-RPs is also referred to as an RP set. To view the current RP set, use the
show ipv6 pim group-map command. For example:
-> show ipv6 pim group-map
Origin
Group Address/Pref Length
RP Address
Mode Precedence
---------+---------------------------+-------------+-----+----------BSR
ff00::/8
3000::11
asm
192
BSR
ff00::/8
4000::7
asm
192
SSM
ff33::/32
ssm
For more information about these displays, see the “PIM Commands” chapter in the OmniSwitch CLI
Reference Guide.
Note. There is only one BSR per IPv6 PIM-SM domain. This allows all IPv6 PIM-SM routers in the IPv6
PIM-SM domain to view the same list of reachable C-RPs.
Configuring Static RP Groups for IPv6 PIM
A static RP group is used in the group-to-RP mapping algorithm. To specify a static RP group, use the
ipv6 pim static-rp command. Be sure to enter a multicast group address, a corresponding group mask, and
a 128-bit IPv6 address for the static RP in the command line. For example:
-> ipv6 pim static-rp ff0e::1234/128 2000::1 priority 10
This command entry maps all multicast groups ff0e::1234/128 to the static RP 2000::1 and specifies the
priority value to be used for the static RP configuration as 10. This priority value provides fine control
over which configuration is overridden by this static configuration. If the priority option has been defined,
a value of 65535 can be used to unset the priority
You can also specify whether or not this static RP configuration to override the dynamically learned RP
information for the specified group using the override parameter. As specifying the priority value obsoletes the override option, you can use either the priority or override parameter only.
Use the no form of this command to delete a static RP configuration.
-> no ipv6 pim static-rp ff0e::1234/128 2000::1
The IPv6 PIM-Source-Specific Multicast (SSM) mode for the default SSM address range (FF3x::/32)
reserved by the Internet Assigned Numbers Authority is not enabled automatically and must be configured manually to support SSM. You can also map additional IPv6 multicast address ranges for the SSM
group. However, the IPv6 multicast groups in the reserved address range can be mapped only to the SSM
mode.
page 7-40
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring PIM
Configuring IPv6 PIM
Note. If static RP status is specified, the method for group-to-RP mapping provided by the Bootstrap
mechanism and C-RP advertisements is automatically disabled. For more information on this alternate
method of group-to-RP mapping, refer to page 7-26.
To view current Static RP Configuration settings, use the show ipv6 pim static-rp command.
Group-to-RP Mapping
Using one of the mechanisms described in the sections above, an IPv6 PIM-SM router receives one or
more possible group-range-to-RP mappings. Each mapping specifies a range of IPv6 multicast groups
(expressed as a group and mask), as well as the RP to which such groups should be mapped. Each
mapping may also have an associated priority. It is possible to receive multiple mappings—all of which
might match the same multicast group. This is the common case with the BSR mechanism. The algorithm
for performing the group-to-RP mapping is as follows:
1 Perform longest match on group-range to obtain a list of RPs.
2 From this list of matching RPs, find the one with the highest priority. Eliminate any RPs from the list
that have lower priorities.
3 If only one RP remains in the list, use that RP.
4 If multiple RPs are in the list, use the PIM-SM hash function defined in the RFC to choose one. The
RP with the highest resulting hash value is then chosen as the RP. If more than one RP has the same highest hash value, then the RP with the highest IPv6 address is chosen.
This algorithm is invoked by a DR when it needs to determine an RP for a given group, such as when
receiving a packet or an IGMP membership indication.
Configuring RP-Switchover for IPv6 PIM
You can configure an RP to attempt switching to native forwarding upon receiving the first register-encapsulated packet from the source DR in the IPv6 PIM domain. For example:
-> ipv6 pim rp-switchover enable
The above command enables the RP to switch to native forwarding.
-> ipv6 pim rp-switchover disable
The above command disables the RP from switching to native forwarding.
By default, this capability is enabled. You cannot specify a pre-configured threshold, such as the RP
threshold, as you would do for IPv4 PIM.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 7-41
IPv6 PIM-SSM Support
Configuring PIM
Verifying RP-Switchover
To view the status of the RP-switchover capability, use the show ipv6 pim sparse command.
-> show ipv6 pim sparse
Status
Keepalive Period
Max RPs
Probe Time
Register Suppress Timeout
RP Switchover
SPT Status
=
=
=
=
=
=
enabled,
210,
32,
5,
60,
enabled,
= enabled
IPv6 PIM-SSM Support
IPv6 Protocol-Independent Multicast Source-Specific Multicast (IPv6 PIM-SSM) is a highly efficient
extension of IPv6 PIM. SSM, using an explicit channel subscription model, allows receivers to receive
multicast traffic directly from the source; an RP tree model is not used. In other words, a Shortest Path
Tree (SPT) between the receiver and the source is created without the use of a Rendezvous Point (RP).
By default, IPv6 PIM software supports Source-Specific Multicast. No additional user configuration is
required. IPv6 PIM-SSM is automatically enabled and operational as long as IPv6 PIM is loaded (see page
7-6) and IGMPv3 source-specific joins are received within the SSM address range.
Source-Specific Multicast Addresses
The multicast addresses range FF3x::/32 that has been reserved by the Internet Assigned Numbers Authority (IANA) as Source-Specific Multicast (SSM) destination addresses is not enabled automatically and
must be configured manually to support SSM. Addresses within this range are reserved for use by sourcespecific applications and protocols (e.g., IPv6 PIM-SSM) and cannot be used for any other functions or
protocols. However, you can also map additional multicast address ranges for the SSM group.
PIM-SSM Specifications
RFCs Supported
3306—An Overview of Source-Specific Multicast (SSM)
Valid SSM Address Range
FF3x::/32
page 7-42
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Configuring PIM
Verifying IPv6 PIM Configuration
Verifying IPv6 PIM Configuration
A summary of the show commands used for verifying PIM configuration is given here:
show ipv6 pim sparse
Displays the status of the various global parameters for the IPv6 PIMSparse Mode.
show ipv6 pim dense
Displays the status of the various global parameters for the IPv6 PIMDense Mode.
show ipv6 pim ssm group
Displays the static configuration of IPv6 multicast group mappings for
PIM-Source-Specific Multicast (SSM).
show ipv6 pim dense group
Displays the static configuration of IPv6 multicast group mappings for
PIM-Dense Mode (DM).
show ipv6 pim neighbor
Displays a list of active IPv6 PIM neighbors.
show ipv6 pim candidate-rp
Displays the IPv6 multicast groups for which the local router advertises
itself as a Candidate-RP.
show ipv6 pim group-map
Displays the IPv6 PIM group mapping table.
show ipv6 pim interface
Displays detailed IPv6 PIM settings for a specific interface. In general,
it displays IPv6 PIM settings for all the interfaces if no argument is
specified.
show ipv6 pim groute
Displays all (*,G) states that IPv6 PIM has.
show ipv6 pim sgroute
Displays all (S,G) states that IPv6 PIM has.
show ip pim notifications
Displays the configuration of the configured notification periods as well
as information on the events triggering the notifications.
show ipv6 mroute
Displays multicast routing information for IPv6 datagrams sent by particular sources to the IPv6 multicast groups known to this router.
show ipv6 pim static-rp
Displays the IPv6 PIM Static RP table, which includes IPv6 multicast
group address/prefix length, the static Rendezvous Point (RP) address,
and the current status of the static RP configuration (i.e., enabled or disabled).
show ipv6 pim bsr
Displays information about the elected IPv6 BSR.
show ipv6 pim cbsr
Displays the IPv6 Candidate-BSR information that is used in the Bootstrap messages.
For more information about the displays that result from these commands, see the OmniSwitch CLI
Command Reference Guide.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page 7-43
Verifying IPv6 PIM Configuration
Configuring PIM
page 7-44
December 2007
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
A Software License and
Copyright Statements
This appendix contains Alcatel-Lucent and third-party software vendor license and copyright statements.
Alcatel-Lucent License Agreement
ALCATEL-LUCENT SOFTWARE LICENSE AGREEMENT
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but only a limited right to use revocable in accordance with the terms of this License Agreement.
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December 2007
page -1
Alcatel-Lucent License Agreement
3. Confidentiality. Alcatel-Lucent considers the Licensed Files to contain valuable trade secrets of Alcatel-Lucent, the unauthorized disclosure of which could cause irreparable harm to Alcatel-Lucent. Except as
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loss or damages resulting from any claims, demands, or actions arising out of or relating to this License
Agreement shall not exceed the license fee paid to Alcatel-Lucent for the Licensed Materials. IN NO
EVENT SHALL ALCATEL-LUCENT BE LIABLE FOR ANY INDIRECT, INCIDENTAL, CONSEQUENTIAL, SPECIAL, OR EXEMPLARY DAMAGES OR LOST PROFITS, EVEN IF ALCATELLUCENT HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO
NOT ALLOW THE LIMITATION OR EXCLUSION OF LIABILITY FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO THE ABOVE LIMITATION OR EXCLUSION TO INCIDENTAL OR
CONSEQUENTIAL DAMAGES MAY NOT APPLY TO LICENSEE.
7. Export Control. This product is subject to the jurisdiction of the United States. Licensee may not
export or reexport the Licensed Files, without complying with all United States export laws and regulations, including but not limited to (i) obtaining prior authorization from the U.S. Department of Commerce
if a validated export license is required, and (ii) obtaining “written assurances” from licensees, if required.
8. Support and Maintenance. Except as may be provided in a separate agreement between AlcatelLucent and Licensee, if any, Alcatel-Lucent is under no obligation to maintain or support the copies of the
Licensed Files made and distributed hereunder and Alcatel-Lucent has no obligation to furnish Licensee
with any further assistance, documentation or information of any nature or kind.
9. Term. This License Agreement is effective upon Licensee opening this package and shall continue until
terminated. Licensee may terminate this License Agreement at any time by returning the Licensed Materials and all copies thereof and extracts therefrom to Alcatel-Lucent and certifying to Alcatel-Lucent in writing that all Licensed Materials and all copies thereof and extracts therefrom have been returned or erased
by the memory of Licensee’s computer or made non-readable. Alcatel-Lucent may terminate this License
Agreement upon the breach by Licensee of any term hereof. Upon such termination by Alcatel-Lucent,
Licensee agrees to return to Alcatel-Lucent or destroy the Licensed Materials and all copies and portions
thereof.
page -2
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Alcatel-Lucent License Agreement
10. Governing Law. This License Agreement shall be construed and governed in accordance with the
laws of the State of California.
11. Severability. Should any term of this License Agreement be declared void or unenforceable by any
court of competent jurisdiction, such declaration shall have no effect on the remaining terms herein.
12. No Waiver. The failure of either party to enforce any rights granted hereunder or to take action against
the other party in the event of any breach hereunder shall not be deemed a waiver by that party as to
subsequent enforcement of rights or subsequent actions in the event of future breaches.
13. Notes to United States Government Users. Software and documentation are provided with restricted
rights. Use, duplication or disclosure by the government is subject to (i) restrictions set forth in GSA ADP
Schedule Contract with Alcatel-Lucent’s reseller(s), or (ii) restrictions set forth in subparagraph (c) (1)
and (2) of 48 CFR 52.227-19, as applicable.
14.Third Party Materials. Licensee is notified that the Licensed Files contain third party software and
materials licensed to Alcatel-Lucent by certain third party licensors. Some third party licensors (e.g., Wind
River and their licensors with respect to the Run-Time Module) are third part beneficiaries to this License
Agreement with full rights of enforcement. Please refer to the section entitled “Third Party Licenses and
Notices” on page A-4 for the third party license and notice terms.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page -3
Third Party Licenses and Notices
Third Party Licenses and Notices
The licenses and notices related only to such third party software are set forth below:
A. Booting and Debugging Non-Proprietary Software
A small, separate software portion aggregated with the core software in this product and primarily used for
initial booting and debugging constitutes non-proprietary software, some of which may be obtained in
source code format from Alcatel-Lucent for a limited period of time. Alcatel-Lucent will provide a
machine-readable copy of the applicable non-proprietary software to any requester for a cost of copying,
shipping and handling. This offer will expire 3 years from the date of the first shipment of this product.
B. The OpenLDAP Public License: Version 2.4, 8 December 2000
Redistribution and use of this software and associated documentation (“Software”), with or without modification, are permitted provided that the following conditions are met:
1 Redistributions of source code must retain copyright statements and notices.
2 Redistributions in binary form must reproduce applicable copyright statements and notices, this list of
conditions, and the following disclaimer in the documentation and/or other materials provided with the
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THIS SOFTWARE IS PROVIDED BY THE OPENLDAP FOUNDATION AND CONTRIBUTORS “AS
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OpenLDAP is a trademark of the OpenLDAP Foundation.
Copyright 1999-2000 The OpenLDAP Foundation, Redwood City,
California, USA. All Rights Reserved. Permission to copy and
distributed verbatim copies of this document is granted.
page -4
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Third Party Licenses and Notices
C. Linux
Linux is written and distributed under the GNU General Public License which means that its source code
is freely-distributed and available to the general public.
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OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
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Third Party Licenses and Notices
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page -6
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
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Third Party Licenses and Notices
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Third Party Licenses and Notices
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written in the body of this License.
9 The Free Software Foundation may publish revised and/or new versions of the General Public License
from time to time. Such new versions will be similar in spirit to the present version, but may differ in
detail to address new problems or concerns.
Each version is given a distinguishing version number. If the Program specifies a version number of this
License which applies to it and “any later version”, you have the option of following the terms and conditions either of that version or of any later version published by the Free Software Foundation. If the
Program does not specify a version number of this License, you may choose any version ever published by
the Free Software Foundation.
10 If you wish to incorporate parts of the Program into other free programs whose distribution conditions
are different, write to the author to ask for permission. For software which is copyrighted by the Free Software Foundation, write to the Free Software Foundation; we sometimes make exceptions for this. Our
decision will be guided by the two goals of preserving the free status of all derivatives of our free software and of promoting the sharing and reuse of software generally.
NO WARRANTY
11 BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR
THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
PROVIDE THE PROGRAM “AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO
THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE
PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
REPAIR OR CORRECTION.
12 IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT
LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES
SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE
WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN
ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
END OF TERMS AND CONDITIONS.
page -8
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Third Party Licenses and Notices
Appendix: How to Apply These Terms to Your New Programs
If you develop a new program, and you want it to be of the greatest possible use to the public, the best way
to achieve this is to make it free software which everyone can redistribute and change under these terms.
To do so, attach the following notices to the program. It is safest to attach them to the start of each source
file to most effectively convey the exclusion of warranty; and each file should have at least the “copyright” line and a pointer to where the full notice is found.
<one line to give the program’s name and a brief idea of what it does.> Copyright (C)
19yy <name of author>
This program is free software; you can redistribute it and/or modify it under the terms of
the GNU General Public License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License along with this
program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge,
MA 02139, USA.
Also add information on how to contact you by electronic and paper mail.
If the program is interactive, make it output a short notice like this when it starts in an interactive mode:
Gnomovision version 69, Copyright (C) 19yy name of author Gnomovision comes with
ABSOLUTELY NO WARRANTY; for details type ‘show w’. This is free software,
and you are welcome to redistribute it under certain conditions; type ‘show c’ for details.
The hypothetical commands ‘show w’ and ‘show c’ should show the appropriate parts of the General
Public License. Of course, the commands you use may be called something other than ‘show w’ and
‘show c’; they could even be mouse-clicks or menu items--whatever suits your program.
You should also get your employer (if you work as a programmer) or your school, if any, to sign a “copyright disclaimer” for the program, if necessary. Here is a sample; alter the names:
Yoyodyne, Inc., hereby disclaims all copyright interest in the program ‘Gnomovision’
(which makes passes at compilers) written by James Hacker.
<signature of Ty Coon>, 1 April 1989
Ty Coon, President of Vice
This General Public License does not permit incorporating your program into proprietary programs. If
your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Library General Public License
instead of this License.
URLWatch:
For notice when this page changes, fill in your email address.
Maintained by: Webmaster, Linux Online Inc.
Last modified: 09-Aug-2000 02:03AM.
Views since 16-Aug-2000: 177203.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page -9
Third Party Licenses and Notices
Material copyright Linux Online Inc.
Design and compilation copyright (c)1994-2002 Linux Online Inc.
Linux is a registered trademark of Linus Torvalds
Tux the Penguin, featured in our logo, was created by Larry Ewing
Consult our privacy statement
URLWatch provided by URLWatch Services.
All rights reserved.
E. University of California
Provided with this product is certain TCP input and Telnet client software developed by the University of
California, Berkeley.
F. Carnegie-Mellon University
Provided with this product is certain BOOTP Relay software developed by Carnegie-Mellon University.
G. Random.c
PR 30872 B Kesner created May 5 2000
PR 30872 B Kesner June 16 2000 moved batch_entropy_process to own task iWhirlpool to make code
more efficient
random.c -- A strong random number generator
Version 1.89, last modified 19-Sep-99
Copyright Theodore Ts’o, 1994, 1995, 1996, 1997, 1998, 1999. All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided
that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice, and the entire permission notice
in its entirety, including the disclaimer of warranties.
2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
following disclaimer in the documentation and/or other materials provided with the distribution.
3. The name of the author may not be used to endorse or promote products derived from this software
without specific prior written permission. ALTERNATIVELY, this product may be distributed under the
terms of the GNU Public License, in which case the provisions of the GPL are required INSTEAD OF the
above restrictions. (This clause is necessary due to a potential bad interaction between the GPL and the
restrictions contained in a BSD-style copyright.)
THIS SOFTWARE IS PROVIDED “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF WHICH ARE HEREBY DISCLAIMED. IN
NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF NOT
ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
page -10
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Third Party Licenses and Notices
H. Apptitude, Inc.
Provided with this product is certain network monitoring software (“MeterWorks/RMON”) licensed from
Apptitude, Inc., whose copyright notice is as follows: Copyright (C) 1997-1999 by Apptitude, Inc. All
Rights Reserved. Licensee is notified that Apptitude, Inc. (formerly, Technically Elite, Inc.), a California
corporation with principal offices at 6330 San Ignacio Avenue, San Jose, California, is a third party beneficiary to the Software License Agreement. The provisions of the Software License Agreement as applied
to MeterWorks/RMON are made expressly for the benefit of Apptitude, Inc., and are enforceable by
Apptitude, Inc. in addition to Alcatel-Lucent. IN NO EVENT SHALL APPTITUDE, INC. OR ITS
SUPPLIERS BE LIABLE FOR ANY DAMAGES, INCLUDING COSTS OF PROCUREMENT OF
SUBSTITUTE PRODUCTS OR SERVICES, LOST PROFITS, OR ANY SPECIAL, INDIRECT,
CONSEQUENTIAL OR INCIDENTAL DAMAGES, HOWEVER CAUSED AND ON ANY THEORY
OF LIABILITY, ARISING IN ANY WAY OUT OF THIS AGREEMENT.
I. Agranat
Provided with this product is certain web server software (“EMWEB PRODUCT”) licensed from Agranat
Systems, Inc. (“Agranat”). Agranat has granted to Alcatel-Lucent certain warranties of performance,
which warranties [or portion thereof] Alcatel-Lucent now extends to Licensee. IN NO EVENT,
HOWEVER, SHALL AGRANAT BE LIABLE TO LICENSEE FOR ANY INDIRECT, SPECIAL, OR
CONSEQUENTIAL DAMAGES OF LICENSEE OR A THIRD PARTY AGAINST LICENSEE ARISING OUT OF, OR IN CONNECTION WITH, THIS DISTRIBUTION OF EMWEB PRODUCT TO
LICENSEE. In case of any termination of the Software License Agreement between Alcatel-Lucent and
Licensee, Licensee shall immediately return the EMWEB Product and any back-up copy to AlcatelLucent, and will certify to Alcatel-Lucent in writing that all EMWEB Product components and any copies
of the software have been returned or erased by the memory of Licensee’s computer or made non-readable.
J. RSA Security Inc.
Provided with this product is certain security software (“RSA Software”) licensed from RSA Security Inc.
RSA SECURITY INC. PROVIDES RSA SOFTWARE “AS IS” WITHOUT ANY WARRANTY WHATSOEVER. RSA SECURITY INC. DISCLAIMS ALL WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO ANY MATTER WHATSOEVER INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT OF
THIRD PARTY RIGHTS.
K. Sun Microsystems, Inc.
This product contains Coronado ASIC, which includes a component derived from designs licensed from
Sun Microsystems, Inc.
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page -11
Third Party Licenses and Notices
L. Wind River Systems, Inc.
Provided with this product is certain software (“Run-Time Module”) licensed from Wind River Systems,
Inc. Licensee is prohibited from: (i) copying the Run-Time Module, except for archive purposes consistent with Licensee’s archive procedures; (ii) transferring the Run-Time Module to a third party apart from
the product; (iii) modifying, decompiling, disassembling, reverse engineering or otherwise attempting to
derive the source code of the Run-Time Module; (iv) exporting the Run-Time Module or underlying technology in contravention of applicable U.S. and foreign export laws and regulations; and (v) using the RunTime Module other than in connection with operation of the product. In addition, please be advised that:
(i) the Run-Time Module is licensed, not sold and that Alcatel-Lucent and its licensors retain ownership of
all copies of the Run-Time Module; (ii) WIND RIVER DISCLAIMS ALL IMPLIED WARRANTIES,
INCLUDING WITHOUT LIMITATION THE IMPLIED WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE, (iii) The SOFTWARE LICENSE AGREEMENT
EXCLUDES LIABILITY FOR ANY SPECIAL, INDIRECT, PUNITIVE, INCIDENTAL AND CONSEQUENTIAL DAMAGES; and (iv) any further distribution of the Run-Time Module shall be subject to the
same restrictions set forth herein. With respect to the Run-Time Module, Wind River and its licensors are
third party beneficiaries of the License Agreement and the provisions related to the Run-Time Module are
made expressly for the benefit of, and are enforceable by, Wind River and its licensors.
M.Network Time Protocol Version 4
The following copyright notice applies to all files collectively called the Network Time Protocol Version 4
Distribution. Unless specifically declared otherwise in an individual file, this notice applies as if the text
was explicitly included in the file.
***********************************************************************
*
*
* Copyright (c) David L. Mills 1992-2003
*
*
*
* Permission to use, copy, modify, and distribute this software and
*
* its documentation for any purpose and without fee is hereby
*
* granted, provided that the above copyright notice appears in all
*
* copies and that both the copyright notice and this permission
*
* notice appear in supporting documentation, and that the name
*
* University of Delaware not be used in advertising or publicity
*
* pertaining to distribution of the software without specific,
*
* written prior permission. The University of Delaware makes no
*
* representations about the suitability this software for any
*
* purpose. It is provided "as is" without express or implied
*
* warranty.
*
*
*
*************************************************************************
page -12
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Index
A
aggregate routes
BGP 4-32
application examples
BGP 4-4, 4-60
BGP IPv6 4-66
DVMRP 6-3
IS-IS 3-5, 3-32
multicast address boundaries 5-2, 5-8
OSPF 1-4, 1-34, 2-4, 2-25
area border routers 1-8, 1-9, 2-9, 2-10
areas 1-8, 2-9
assigning interfaces 1-20
backbones 1-8
creating 1-17, 2-15
deleting 1-18, 2-16
NSSAs 1-11
ranges 1-19
route metrics 1-19, 2-16
specifying type 1-17, 2-15
status 1-18, 2-15
stub 1-10, 2-11
summarization 1-18
Totally Stubby 1-11
AS 4-6
AS boundary routers 1-9, 2-10
AS path policies
assigning to peers 4-50
creating 4-45
authentication 1-21
MD5 encryption 1-21
simple 1-21
autonomous systems
see AS
global parameters 4-20
internal vs. external 4-7
MED values 4-23
overview 4-5
policies 4-12, 4-45
regular expressions 4-13
restarting a peer 4-29
route dampening 4-17, 4-36
route notation 4-17
route reflection 4-9, 4-40
route selection 4-16
setting the AS number 4-21
setting the default local preference
specifications 4-3
synchronizing 4-24
verify information about 4-63
BGP IPv6
application examples 4-66
configuring 4-68
configuring a peer 4-68
networks 4-73
overview 4-64
Bootstrap Router
see BSR
Border Gateway Protocol
see BGP
BSR 7-9, 7-26, 7-39
4-21
C
Candidate Bootstrap Router
see C-BSR
Candidate Rendezvous Point
see C-RP router
C-BSR 7-9, 7-39
communities 4-43
community list policies
assigning to peers 4-51
creating 4-46
concurrent multicast addresses
confederations
creating 4-44
C-RP router 7-8, 7-24
5-6
B
D
backbone routers 1-9
BGP 4-1
aggregate route 4-32
application examples 4-4, 4-60
clearing peer statistics 4-30
communities 4-8, 4-43
confederations 4-11, 4-44
configuration overview 4-18
configuring 4-18
configuring a peer 4-26
disabling 4-19
displaying 4-25
enabling path comparison 4-22
flapping 4-36
defaults
DVMRP 6-2
OSPF 1-3, 2-3
PIM 7-4
Designated Routerssee DR
Distance Vector Multicast Routing Protocol
see DVMRP
DR 7-9
DVMRP 6-1
application examples 6-3
automatic loading and enabling 6-13
configuring 6-10
defaults 6-2
dependent downstream routers 6-7
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
Index-1
enabling 6-10
graft acknowledgment messages 6-8
graft messages 6-8
grafting 6-8, 6-17
hop count 6-7
IGMP 6-5
interface metric 6-7
loading 6-10
metrics 6-7
multicast source location 6-7
neighbor communications 6-13
neighbor discovery 6-6
overview 6-5
poison reverse 6-7
probe messages 6-6
prune messages 6-8
pruning 6-8, 6-15
reverse path forwarding check 6-7
reverse path multicasting 6-5
route report messages 6-6, 6-7, 6-14
routes 6-14
specifications 6-2
tunnels 6-9, 6-17
verifying the configuration 6-17
dynamic routing
DVMRP 6-1
multicast address boundaries 5-1
E
EBGP 4-7
exterior gateway protocol
BGP 4-6
External BGP
see EBGP
I
IBGP 4-7
IGMP
DVMRP 6-5
interior gateway protocol
BGP 4-6
Internal BGP
see IBGP
internal routers 1-9, 2-10
ip bgp aggregate-address as-set command 4-32
ip bgp aggregate-address command 4-32
ip bgp aggregate-address status command 4-32
ip bgp aggregate-address summary-only command 4-32
ip bgp autonomous-system command 4-21
ip bgp bestpath med missing-as-worst command 4-23
ip bgp client-to-client reflection command 4-42
ip bgp cluster-id command 4-42
ip bgp confederation identifier command 4-44
ip bgp confederation neighbor command 4-44
ip bgp dampening command 4-37
ip bgp default local-preference command 4-21
ip bgp graceful-restart command 4-59
ip bgp graceful-restart restart-interval command 4-59
page -2
ip bgp neighbor advertisement-interval command 4-31
ip bgp neighbor auto-restart command 4-29
ip bgp neighbor clear command 4-29
ip bgp neighbor clear soft command 4-29
ip bgp neighbor command 4-28
ip bgp neighbor description command 4-28
ip bgp neighbor in-aspathlist command 4-50
ip bgp neighbor in-communitylist command 4-51
ip bgp neighbor in-prefixlist command 4-51
ip bgp neighbor md5 key command 4-31
ip bgp neighbor out-aspathlist command 4-50
ip bgp neighbor out-communitylist command 4-51
ip bgp neighbor out-prefixlist command 4-51
ip bgp neighbor remote-as command 4-28
ip bgp neighbor route-map command 4-51
ip bgp neighbor route-reflector-client command 4-42
ip bgp neighbor stats-clear command 4-30
ip bgp neighbor update-source command 4-30
ip bgp network command 4-33
ip bgp network community command 4-34
ip bgp network local-preference command 4-34
ip bgp network metric command 4-34
ip bgp network status command 4-33
ip bgp policy aspath-list action command 4-46
ip bgp policy aspath-list command 4-45, 4-50
ip bgp policy aspath-list priority command 4-46
ip bgp policy community-list action command 4-46
ip bgp policy community-list command 4-46
ip bgp policy community-list match-type command 4-46
ip bgp policy community-list priority command 4-46
ip bgp policy prefix-list action command 4-47
ip bgp policy prefix-list command 4-47
ip bgp policy prefix-list ge command 4-47
ip bgp policy prefix-list le command 4-47
ip bgp policy route-map action command 4-48
ip bgp policy route-map command 4-47
ip bgp status command 4-19
ip bgp synchronization command 4-24
ip bgp unicast command 4-68
ip dvmrp flash-interval command 6-14
ip dvmrp graft-timeout command 6-8
ip dvmrp interface command 6-11
ip dvmrp interface metric command 6-11
ip dvmrp neighbor-interval command 6-13
ip dvmrp neighbor-timeout command 6-13
ip dvmrp prune-lifetime command 6-15
ip dvmrp prune-timeout command 6-15
ip dvmrp report-interval command 6-14
ip dvmrp route-holddown command 6-14
ip dvmrp route-timeout command 6-14
ip dvmrp status command 6-12
ip dvmrp subord-default command 6-10
ip dvrmp tunnel command 6-17
ip interface command 6-3
ip load bgp command 4-19
ip load dvmrp command 6-10
ip load ospf command 1-16, 2-14, 3-15
ip mroute-boundary command 5-2, 5-7
ip multicast status command 6-3, 7-19, 7-33
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
ip ospf area command 1-17, 2-15, 3-16
ip ospf area summary command 1-18
ip ospf area type command 1-17, 2-15
ip ospf exit-overflow-interval command 1-30
ip ospf extlsdb-limit command 1-30
ip ospf host command 1-30, 2-24
ip ospf interface area command 1-20
ip ospf interface auth-key command 1-21
ip ospf interface auth-type command 1-21, 3-19, 3-20
ip ospf interface command 1-20, 2-16, 3-16
ip ospf interface cost command 1-22, 3-22
ip ospf interface dead-interval command 1-22, 3-22
ip ospf interface hello-interval command 1-22, 2-17, 3-22
ip ospf interface md5 key command 1-21
ip ospf interface poll-interval command 1-22
ip ospf interface priority command 1-22
ip ospf interface retrans-interval 1-22, 2-17
ip ospf interface status command 1-21
ip ospf interface transit-delay command 1-22
ip ospf mtu-checking command 1-30, 2-24
ip ospf restart-support command 1-32, 1-33
ip ospf route-tag command 1-30, 2-24
ip ospf spf-timer command 1-30, 3-30
ip ospf status command 1-16
ip ospf virtual-link command 1-23
ip pim dense group command 7-6
ip pim dense status command 7-21
ip pim dense status command 7-35
ip pim interface command 7-6
ip pim max-rps command 7-25
ip pim sparse status command 7-21, 7-35
IPv6
redistribution 4-76
ipv6 bgp neighbor activate-ipv6 command 4-69
ipv6 bgp neighbor command 4-69
ipv6 bgp neighbor remote-as command 4-69
ipv6 bgp neighbor status command 4-69
ipv6 bgp network community command 4-74
ipv6 bgp network local-preference command 4-74
ipv6 bgp network metric command 4-74
ipv6 bgp unicast command 4-68
ipv6 interface command 7-33
IPv6 PIM
C-BSR 7-39
interface 7-35
MLD 7-33
overview 7-33
unicast address 7-33
ipv6 pim dense group command 7-34
ipv6 pim interface command 7-33
ipv6 pim static-rp command 7-40
IPv6 PIM-SSM 7-42
ipv6 redist command 4-76
IPv6 Source-Specific Multicast (SSM)
see PIM-SSM
IS-IS
activating 3-15
application examples 3-5, 3-32
classification of routers 3-11
configuring 3-14
enabling 3-15
filters 3-24
global authentication 3-20
interface authentication 3-21
interior gateway protocols 3-8
level authentication 3-21
link-state protocol 3-8
MD5 authentication 3-20
packet types 3-10
simple authentication 3-19
specifications 3-2
M
multicast address boundaries 5-1, 5-5
application examples 5-2, 5-8
configuring 5-7
creating 5-7
deleting 5-7
overview 5-4
specifications 5-2
multicast routing
boundaries 5-1
DVMRP 6-1
N
networks
BGP IPv6 4-73
metric 4-34, 4-74
Not-So-Stubby-Areas
see NSSAs
NSAP address 3-8
O
Open Shortest Path First
see OSPF
OSPF 1-1, 2-1
activating 1-16, 2-14
application examples 1-4, 1-34, 2-4, 2-25
area border routers 1-8, 2-9
areas 1-8, 2-9
backbones 1-8
classification of routers 1-9, 2-10
configuring 1-15, 2-13
configuring routers 1-30, 2-24
defaults 1-3, 2-3
ECMP routing 1-12, 2-12
enabling 1-16
filters 1-23
graceful restart on stacks 1-13
graceful restart on switches 1-14
interfaces 1-20, 2-16
interior gateway protocols 1-7, 2-8
link-state protocol 1-7, 2-8
loading software 1-16, 2-14
MD5 encryption 1-21
modifying interfaces 1-22, 2-17
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page -3
NBMA routing 1-12
overview 1-7, 2-8
preparing the network 1-16, 2-14
redistribution policies 1-23
routers 1-9, 2-10
simple authentication 1-21
specifications 1-2, 2-2
stub areas 1-10, 2-11
verify configuration 1-39, 2-30, 3-34
virtual links 1-9, 1-22, 2-10, 2-17
OSPF filters 1-23, 3-24
OSPF interfaces 1-20, 2-16
assigning to areas 1-20
authentication 1-21
creating 1-20, 3-16
enabling 1-21
modifying 1-22, 2-17
OSPF redistribution policies 1-23
deleting 1-26, 1-28, 2-20, 2-23, 3-26, 3-28, 4-55, 4-57,
4-76
P
peer
clearing statistics 4-30
configuring 4-26
configuring IPv6 4-68
defaults 4-26
restarting 4-29
PIM 7-1
BSR 7-9, 7-26, 7-39
C-BSR 7-9
configuring 7-18
C-RP for ipv6 7-38
C-RP router 7-8, 7-24
defaults 7-4
DR 7-9
enabling 7-18
enabling on a specific interface
join messages 7-1
keepalive period 7-28
notification period 7-29
overview 7-8
register encapsulation 7-12
specifications 7-3
verifying software 7-18
PIM-SM
RP router 7-8
RP trees 7-9
shared trees 7-9
PIM-SSM 7-1, 7-31
PIM-SSM Support
see PIM-SSM
policies
AS paths 4-45
assigning to peers 4-50
community lists 4-45
creating 4-45
displaying 4-52
page -4
7-20
prefix lists 4-45
reconfiguring 4-52
route maps 4-45
routing 4-45
prefix list policies
assigning to peers 4-51
creating 4-47
R
Rendezvous Point
see RP router
reverse path multicasting 6-5
route dampening 4-36
clearing 4-39
configuring 4-37
displaying 4-39
enabling 4-37
example 4-36
flapping 4-36
route map policies
assigning to peers 4-51
creating 4-47
route reflection 4-40
configuring 4-42
redundant route reflectors 4-42
routers
area border routers 1-9, 2-10
AS boundary routers 1-9, 2-10
backbone routers 1-9
configuring OSPF 1-30, 2-24
internal routers 1-9, 2-10
routing
DVMRP 6-1
multicast address boundaries 5-1
RP router 7-8
S
scoped multicast addresses 5-4
show ip bgp aggregate-address command 4-63
show ip bgp command 4-63
show ip bgp dampening command 4-63
show ip bgp dampening-stats command 4-63
show ip bgp neighbors command 4-63
show ip bgp neighbors policy command 4-63
show ip bgp neighbors statistics command 4-30
show ip bgp neighbors timer command 4-63
show ip bgp network command 4-35
show ip bgp path command 4-63
show ip bgp policy aspath-list command 4-63
show ip bgp policy community-list command 4-63
show ip bgp policy prefix-list command 4-63
show ip bgp policy route-map command 4-63
show ip bgp routes command 4-63
show ip bgp statistics command 4-63
show ip dvmrp command 6-12
show ip dvmrp interface command 6-12
show ip dvrmp prune command 6-16
show ip mroute-boundary command 5-3, 5-8
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
show ip ospf area stub command 1-18, 2-16
show ip ospf interface command 1-20, 2-16
show ip pim group-map command 7-27
show ip pim sparse command 7-21
show ip redist command 4-63
show ipv6 bgp neighbors command 4-82
show ipv6 bgp neighbors timers command 4-82
show ipv6 bgp network command 4-75
show ipv6 bgp path command 4-82
show ipv6 bgp routes command 4-82
show ipv6 pim dense command 7-34
show ipv6 redist command 4-77
Source-Specific Multicast (SSM)
see PIM-SSM
source-specific multicast addresses 5-4
specifications
BGP 4-3
DVMRP 6-2
IS-IS 3-2
multicast address boundaries 5-2
OSPF 1-2, 2-2
PIM 7-3
V
Verify
DVMRP Configuration
virtual links 1-9, 2-10
creating 1-23
deleting 1-23, 2-18
modifying 1-23, 2-18
6-18
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007
page -5
page -6
OmniSwitch 6800/6850/9000 Advanced Routing Configuration Guide
December 2007