3Com 2500 Switch User Manual

®
Part No. 801-00343-000
Published November 1996
Revision 02
LANPLEX® 2500 EXTENDED
SWITCHING USER GUIDE
3Com Corporation
■
5400 Bayfront Plaza
■
Santa Clara, California
■
95052-8145
© 3Com Corporation, 1996. All rights reserved. No part of this documentation may be reproduced in any form or by any means or used to make
any derivative work (such as translation, transformation, or adaptation) without permission from 3Com Corporation.
3Com Corporation reserves the right to revise this documentation and to make changes in content from time to time without obligation on the
part of 3Com Corporation to provide notification of such revision or change.
3Com Corporation provides this documentation without warranty of any kind, either implied or expressed, including, but not limited to, the
implied warranties of merchantability and fitness for a particular purpose. 3Com may make improvements or changes in the product(s) and/or
the program(s) described in this documentation at any time.
UNITED STATES GOVERNMENT LEGENDS:
If you are a United States government agency, then this documentation and the software described herein are provided to you subject to the
following restricted rights:
For units of the Department of Defense:
Restricted Rights Legend: Use, duplication or disclosure by the Government is subject to restrictions as set forth in subparagraph (c) (1) (ii) for
restricted Rights in Technical Data and Computer Software clause at 48 C.F.R. 52.227-7013. 3Com Corporation, 5400 Bayfront Plaza, Santa Clara,
California 95052-8145.
For civilian agencies:
Restricted Rights Legend: Use, reproduction or disclosure is subject to restrictions set forth in subparagraph (a) through (d) of the Commercial
Computer Software - Restricted Rights Clause at 48 C.F.R. 52.227-19 and the limitations set forth in 3Com’s standard commercial agreement for
the software. Unpublished rights reserved under the copyright laws of the United States.
3ComFacts, Ask3Com, CardFacts, NetFacts, and CardBoard are service marks of 3Com Corporation.
3Com, LANplex, Transcend, and NETBuilder II are registered trademarks of 3Com Corporation.
CompuServe is a registered trademark of CompuServe, Inc.
3Com registered trademarks are registered in the United States, and may or may not be registered in other countries.
Other brand and product names may be registered trademarks or trademarks of their respective holders.
Guide written, edited, and illustrated by Trish Crawford, Lynne Gelfand, Michael Jenness, Dave Sullivan, Patricia Johnson, Michael Taillon, Iain
Young, and Bonnie Jo Collins.
CONTENTS
ABOUT THIS GUIDE
Introduction 1
How to Use This Guide 1
Conventions 2
LANplex 2500 Documentation 3
Documentation Comments 5
PART I
1
GETTING STARTED
LANPLEX® EXTENDED SWITCHING FEATURES
About LANplex Extended Switching
Using Menus 1-2
Bridge Menu 1-3
IP Menu 1-4
IPX Menu 1-5
Appletalk Menu 1-6
1-1
PART II
VIRTUAL LAN TECHNOLOGY
2
VLANS ON THE LANPLEX® SYSTEM
About VLANs 2-1
Types of VLANs 2-1
Port Group VLANs 2-1
MAC Address Group VLANS 2-2
Application-Oriented VLANS 2-2
Protocol-Sensitive VLANS 2-2
LANplex Protocol-Sensitive VLAN Configuration
Protocol Suite 2-3
Switch Ports 2-4
Layer 3 Addressing Information 2-4
Default VLAN 2-5
2-3
Modifying the Default VLAN 2-5
How the LANplex® System Makes Flooding Decisions
VLAN Exception Flooding 2-6
Overlapped IP VLANs 2-7
Routing Between VLANs 2-8
VLAN Examples 2-10
Example 1 2-10
Example 2 2-11
PART III
3
ABOUT ROUTING PROTOCOLS
BRIDGING AND ROUTING IN THE LANPLEX® SYSTEM
What Is Routing? 3-1
LANplex in a Subnetworked Environment 3-2
Integrating Bridging and Routing 3-3
Bridging and Routing Models 3-4
Traditional Bridging and Routing Model 3-4
LANplex Bridging and Routing Model 3-6
4
2-5
ROUTING WITH IP TECHNOLOGY
IP Routing and the OSI Model 4-1
Elements of IP Routing 4-2
IP Addresses 4-2
Address Classes 4-3
Subnet Part of an IP Address 4-3
Router Interfaces 4-4
Routing Table 4-5
Static Routes 4-6
Dynamic Routes Using RIP 4-6
Default Route 4-7
Address Resolution Protocol (ARP) 4-7
IP Routing Transmission Errors 4-9
Routing with Classical IP over ATM 4-10
About Logical IP Subnets (LISs) 4-10
ATM ARP Servers 4-10
Forwarding to Nodes within an LIS 4-11
IP Routing References 4-11
5
ROUTING WITH IP MULTICAST
About IP Multicast Routing 5-1
IGMP 5-1
DVMRP 5-2
The MBONE 5-2
Multicast Routing
Algorithms 5-3
Flooding 5-3
Spanning Trees 5-3
Reverse Path Forwarding 5-4
Pruning 5-5
Multicast Interfaces 5-5
DVMRP Metric Value 5-5
Time-To-Live (TTL) Threshold 5-5
Rate Limit 5-6
Multicast Tunnels 5-6
6
ROUTING WITH IPX
IPX Routing in the NetWare® Environment 6-1
Internet Packet Exchange (IPX) 6-2
Routing Information Protocol (RIP) 6-3
Service Advertising Protocol (SAP) 6-3
How IPX Routing Works 6-4
IPX Packet Format 6-4
IPX Packet Delivery 6-6
Sending Node’s Responsibility 6-6
Router’s Responsibility 6-7
The Elements of
IPX Routing 6-8
Router Interfaces 6-8
Routing Tables 6-8
Generating Routing Table Information 6-9
Selecting the Best Route 6-10
Service Advertising Protocol 6-10
Internetwork Service Information 6-10
SAP Packet Structure 6-11
Server Information Table 6-13
Server Information Maintenance 6-14
7
ROUTING IN AN APPLETALK® ENVIRONMENT
About AppleTalk® 7-1
AppleTalk® Network Elements 7-1
AppleTalk® Networks 7-2
AppleTalk® Nodes 7-2
Named Entities 7-2
AppleTalk® Zones 7-3
Seed Routers 7-4
AppleTalk Protocols 7-4
Physical Connectivity 7-5
The Datagram Delivery Protocol (DDP)
End-to-End Services 7-6
Transport Layer Protocols 7-6
The Session Layer Protocols 7-9
Presentation Layer 7-10
About AARP 7-10
PART IV
8
7-6
ADMINISTERING EXTENDED SWITCHING FEATURES
ADMINISTERING VLANS
Displaying VLAN Information 8-1
Defining VLAN Information 8-3
Modifying VLAN Information 8-4
Removing VLAN Information 8-5
9
ADMINISTERING IP ROUTING
Administering interfaces 9-1
LIS Interfaces 9-2
Interface Characteristics 9-2
Displaying Interfaces 9-3
Defining an IP LIS Interface 9-4
Defining an IP VLAN Interface 9-6
Modifying an Interface 9-7
Removing an Interface 9-7
Adding an Advertisement Address 9-8
Removing an Advertisement Address 9-8
Adding a Permanent Virtual Circuit (PVC) 9-9
Removing a Permanent Virtual Circuit (PVC) 9-9
Administering Routes 9-9
Displaying the Routing Table 9-11
Defining a Static Route 9-11
Removing a Route 9-12
Flushing a Route 9-12
Setting the Default Route 9-12
Removing the Default Route 9-13
Administering the ARP Cache 9-13
Displaying the ARP Cache 9-14
Removing an ARP Cache Entry 9-14
Flushing the ARP Cache 9-15
Administering ATM ARP Servers 9-15
Displaying ATM ARP Servers 9-15
Defining an ATM ARP Server 9-16
Removing an ATM ARP Server 9-16
Displaying the ATM ARP Cache 9-17
Removing an ATM ARP Cache Entry 9-17
Flushing the ATM ARP Cache 9-18
Administering UDP Helper 9-18
Displaying UDP Helper Information 9-19
Defining a Port and an IP Forwarding Address 9-19
Removing a Port or an IP Forwarding Address 9-19
Setting the BOOTP Hop Count Limit 9-20
Setting the BOOTP Relay Threshold 9-20
Enabling and Disabling IP Routing 9-20
Enabling and Disabling ICMP Router Discovery 9-21
Setting the RIP Mode 9-21
Pinging an IP Station 9-22
Displaying IP Statistics 9-23
10
ADMINISTERING IP MULTICAST ROUTING
Enabling and Disabling DVMRP 10-2
Enabling and Disabling IGMP 10-2
Administering IP Multicast Interfaces 10-3
DVMRP Metric Value 10-3
Time To Live (TTL) Threshold 10-3
Rate Limit 10-4
Displaying Multicast Interfaces 10-4
Disabling Multicast Interfaces 10-5
Enabling Multicast Interfaces 10-5
Administering Multicast Tunnels 10-6
Displaying Multicast Tunnels 10-6
Defining a Multicast Tunnel 10-7
Removing a Multicast Tunnel 10-7
Displaying Routes 10-8
Displaying the Multicast Cache
11
10-9
ADMINISTERING IPX ROUTING
Administering Interfaces 11-2
Displaying IPX Interfaces 11-3
Defining an IPX Interface 11-3
Modifying an Interface 11-4
Removing an Interface 11-4
Administering Routes 11-5
Displaying the Routing Table 11-6
Defining a Static Route 11-6
Removing a Route 11-7
Flushing Routes 11-7
Administering Servers 11-8
Displaying the Server Table 11-9
Defining a Static Server 11-9
Removing a Server 11-10
Flushing Servers 11-10
Setting IPX Forwarding 11-11
Setting the RIP Mode 11-11
Setting the Enhanced RIP Mode 11-12
Setting the SAP Mode 11-13
Displaying Statistics 11-14
Displaying IPX Summary Statistics 11-14
Displaying IPX RIP Statistics 11-15
Displaying IPX SAP Statistics 11-16
Displaying IPX Forwarding Statistics 11-17
12
ADMINISTERING APPLETALK® ROUTING
Administering Interfaces 12-2
Displaying AppleTalk Interfaces 12-3
Defining an Interface 12-3
Removing an Interface 12-4
Administering Routes 12-5
Displaying the Routing Table 12-5
Flushing all Routes 12-6
Administering the AARP Cache 12-7
Displaying the AARP Cache 12-8
Removing an Entry in the Cache 12-9
Flushing All Cache Entries 12-9
Displaying the Zone Table 12-10
Configuring Forwarding 12-11
Configuring Checksum 12-12
Pinging an AppleTalk Node 12-12
Viewing Appletalk Statistics 12-13
Displaying DDP Statistics 12-13
Displaying RTMP Information 12-14
Displaying ZIP Information 12-15
Displaying NBP Information 12-17
PART V
13
REMOTE MONITORING (RMON) AND THE
LANPLEX® SYSTEM
REMOTE MONITORING (RMON) TECHNOLOGY
What Is RMON? 13-1
Benefits of RMON 13-2
LANplex RMON Implementation 13-2
3Com Transcend RMON Agents 13-3
Management Information Base (MIB) 13-4
MIB Objects 13-4
Alarms 13-6
Setting Alarm Thresholds 13-7
Example of an Alarm Threshold 13-7
RMON Hysteresis Mechanism 13-8
PART VI
A
APPENDIX
TECHNICAL SUPPORT
On-line Technical Services A-1
3Com Bulletin Board Service A-1
Access by Analog Modem A-1
Access by Digital Modem A-2
World Wide Web Site A-2
3ComForum on CompuServe® A-2
3ComFacts™ Automated Fax Service A-3
Support from Your Network Supplier A-3
Support from 3Com A-4
Returning Products for Repair
INDEX
A-4
ABOUT THIS GUIDE
Introduction
The LANplex® 2500 Extended Switching User Guide provides information
about the features included with the LANplex Extended Switching
software. These features include IP, IP Multicast, classical IP over ATM, IPX,
and AppleTalk routing, virtual LAN (VLAN) configuration, and remote
monitoring (RMON).
Use this guide with the LANplex® 2500 Administration Console User Guide
when you configure your LANplex 2500 system.
See the LANplex® 2500 Software Installation and Release Notes for
information about how to install Extended Switching software on your
LANplex system.
Audience description
This guide is intended for the system or network administrator who is
responsible for configuring, using, and managing the LANplex 2500 system. It
assumes a working knowledge of local area network (LAN) operations and a
familiarity with communications protocols used on interconnected LANs.
If the information in the release notes shipped with your product differs from
the information in this guide, follow the release notes.
How to Use This
Guide
The following table shows where to find specific information.
If you are looking for...
Turn to...
An overview of Extended Switching features
Chapter 1
Virtual LANs (VLANs) on the LANplex System
Chapter 2
General routing and routing models in the LANplex system
Chapter 3
IP routing strategies
Chapter 4
IP multicast routing and its protocols
Chapter 5
continued
2
ABOUT THIS GUIDE
Conventions
If you are looking for...
Turn to...
IPX routing and its protocols
Chapter 6
AppleTalk routing, network elements, and protocols
Chapter 7
How to administer VLANs
Chapter 8
How to administer IP routing
Chapter 9
How to administer IP mulitcast routing
Chapter 10
How to administer IPX routing
Chapter 11
How to administer AppleTalk routing
Chapter 12
Remote Monitoring (RMON)
Chapter 13
3Com Technical Support
Appendix A
Table 1 and Table 2 list conventions that are used throughout this guide.
Table 1 Notice Icons
Icon
Type
Description
Information Note Information notes call attention to important features or
instructions.
Caution
Cautions alert you to personal safety risk, system damage,
or loss of data.
Warning
Warnings alert you to the risk of severe personal injury.
LANplex 2500 Documentation
3
Table 2 Text Conventions
Convention
Description
“Enter”
“Enter” means type something, then press the [Return] or [Enter] key.
“Syntax” vs. “Command”
“Syntax” indicates that the general command syntax form is provided. You must
evaluate the syntax and supply the appropriate value; for example:
Set the date by using the following syntax:
mm/DD/yy hh:mm:ss xm
“Command” indicates that all variables in the command syntax form have been
supplied and you can enter the command as shown in text; for example:
To update the system software, enter the following command:
system software Update
This typeface indicates text that appears on your terminal screen; for example:
screen display
NetLogin:
This typeface indicates commands that you enter; for example:
commands
bridge port stpState
Italic
Italic is used to denote emphasis and buttons.
Keys
When specific keys are referred to in the text, they are called out by their labels, such
as “the Return key” or “the Escape key,” or they may be shown as [Return] or [Esc].
If two or more keys are to be pressed simultaneously, the keys are linked with a plus
sign (+), for example:
Press [Ctrl]+[Alt]+[Del].
LANplex 2500
Documentation
The following documents comprise the LANplex 2500 documentation set.
If you want to order a document that you do not have or order additional
documents, contact your sales representative for assistance.
■
LANplex® 2500 Unpacking Instructions
Describe how to unpack your LANplex system. It also provides you with
an inventory list of all the items shipped with your system. (Shipped
with system/Part No. 801-00353-00)
4
ABOUT THIS GUIDE
■
LANplex® 2500 Software Release Notes
Provide information about the software release, including new features and
bug fixes. It also provides information about any changes to the LANplex
system’s documentation. (Shipped with system)
■
LANplex® 2500 Getting Started
Describes all the procedures necessary for installing, cabling, powering up,
configuring management access to, and troubleshooting your LANplex system. (Shipped with system/Part No. 801-00355-000)
■
LANplex® 2500 Operation Guide
Provides information to help you understand system management and
administration, bridging, Fast Ethernet, ATM, and FDDI technology. It also
describes how these concepts are implemented in the LANplex system.
(Shipped with system/Part No. 801-00344-000)
■
LANplex® 2500 Administration Console User Guide
Provides information about using the Administration Console to configure
and manage your LANplex system. (Shipped with system/Part No.
801-00322-000)
■
LANplex® 2500 Extended Switching User Guide (This book)
Describes® how the routing protocols, VLAN, and RMON are implemented
in the LANplex system and provides information about using the
Administration Console to configure and manage these features. (shipped
with the option package/Part No. 801-00343-000)
■
LANplex® 2500 Intelligent Switching Administration Console Command Quick
Reference card
Contains the Administration Console Intelligent Switching commands for
the LANplex system. (Shipped with the system/Part No. 801-000318-000)
■
LANplex® 2500 Extended Switching ADMINISTRATION CONSOLE Command Quick
Reference card
Contains the Administration Console Extended Switching commands for the
LANplex system. (Shipped with the option package/Part No. 801-00319-000)
Documentation Comments
■
5
Module Installation Guides
Provide an overview, installation instructions, LED status information, and
pin-out information for the particular option module. (Shipped with individual modules)
Documentation
Comments
Your suggestions are very important to us and will help make our
documentation more useful to you. Please email comments about this
document to 3Com at: sdtechpubs_comments@3Mail.3Com.com
Please include the following information when commenting:
Example:
■
Document title
■
Document part number (listed on back cover of document)
■
Page number (if appropriate)
LANplex® 2500 Operation Guide
Part No. 801-00344-000
Page 2-5 (chapter 2, page 5)
6
ABOUT THIS GUIDE
1
LANPLEX® EXTENDED SWITCHING
FEATURES
This chapter provides an overview of the Extended Switching software, and
describes the enhanced Administration Console menus.
About LANplex
Extended
Switching
The LANplex Extended Switching software replaces your existing LANplex
software and adds new functionality to your system. Extended Switching
software contains all the features of LANplex Intelligent Switching software,
in addition to:
■
Virtual LANs (VLANs)
■
Internet Protocol (IP) Routing (an enhanced version of IP from the standard
system software)
■
IP multicast routing
■
Classical IP routing over Asynchronous Transfer Mode (ATM)
■
Internet Packet Exchange (IPX) routing
■
AppleTalk® routing
■
Remote Monitoring (RMON)
For information on how to gain access to online help, to use scripts, and to
exit from the Administration Console, see the LANplex® 2500 Administration
Console User Guide.
See the LANplex® 2500 Software Installation and Release Notes for
information about how to install Extended Switching software on your
LANplex system.
1-2
CHAPTER 1: LANPLEX® EXTENDED SWITCHING FEATURES
Using Menus
When you gain access to the Administration Console, the top-level menu
appears. The Extended Switching software contains top-level menus and
additions to the Bridge and IP menu options not available with Intelligent
Switching software:
Option Descriptions
Menu options vary
by level of access
Menu options:
-------------------------------------------------------------------system - Administer system-level functions
ethernet- Administer Ethernet ports
fddi
- Administer FDDI resources
ATM
- Administer ATM resources
bridge - Administer bridging/VLANs
ip
- Administer IP
ipx
- Administer IPX
appletalk- Administer Appletalk
snmp
- Administer SNMP
analyzer- Administer Roving Analysis
script - Run a script of console commands
logout - Logout of the Administration Console
Type ? for help.
-------------------------------------------------------------------Select a menu option:
The following sections show the enhanced menus provided with Extended
Switching software. All other menu items appear in the LANplex® 2500
Administration Console User Guide.
The RMON feature is available through SNMP only. This feature is not
available through the Administration Console. See Chapter 13, Remote
Monitoring (RMON) Technology, for more information about this feature.
Using Menus
Bridge Menu
From the bridge menu, you can view information about and configure
Ethernet LANs, including VLANs. Figure 1-1 shows the bridge menu.
Top-Level Menu
system
ethernet
fddi
atm
➧ bridge
ip
ipx
appletalk
snmp
analyzer
script
logout
bridge menu
display
mode
ipFragmentation
ipxSnapTranslation
addressThreshold
agingTime
stpState
stpPriority
stpMaxAge
stpHelloTime
stpForwardDelay
stpGroupAddress
port
packetFilter
vlan
Figure 1-1 Bridge Menu Hierarchy
interface menu
summary
detail
define
modify
remove
1-3
1-4
CHAPTER 1: LANPLEX® EXTENDED SWITCHING FEATURES
IP Menu
From the ip menu, you can view information about and configure Internet
Protocol (IP) interfaces and routes as well as IP Multicast routing. You can
administer the Address Resolution Protocol (ARP), the Routing Information
Protocol (RIP), UDP Helper, IP Forwarding, and ping IP stations. You can also
define ATM ARP servers from the ip menu if you are running classical IP
over ATM. Figure 1-2 shows the ip menu. To define a new IP interface, for
example, enter ip at the top-level menu, interface at the ip menu, and then
define at the interface menu.
Top-Level Menu
system
ethernet
fddi
atm
bridge
➧ ip
ipx
appletalk
snmp
analyzer
script
logout
ip menu
➧ interface
➧ route
➧ arp
➧ atmArpServer
➧ multicast
➧ udpHelper
routing
icmpRouterDiscovery
rip
ping
statistics
interface menu
summary
detail
define
modify
remove
addAdvertisement
removeAdvertisement
addPvc
removePvc
route menu
display
static
remove
flush
default
noDefault
arp menu
display
remove
flush
atmArpServer
display
define
remove
arp
multicast
dvmrp
igmp
interfaces
tunnel
RouteDisplay
cacheDisplay
udpHelper menu
display
define
remove
hopCountLimit
threshold
Figure 1-2 IP Menu Hierarchy
Using Menus
IPX Menu
1-5
From the ipx menu, you can view information about and configure Internet
Packet Exchange (IPX) interfaces, routes, and servers. You can also
administer the Routing Information Protocol (RIP), Enhanced RIP mode,
Service Advertising Protocol (SAP), and statistics. Figure 1-3 shows the IPX
menu. For example, to define a new IPX interface, enter ipx at the top-level
menu, interface at the ipx menu, and then define at the interface menu.
Top-Level Menu
system
ethernet
fddi
atm
bridge
ip
➧ ipx
appletalk
snmp
analyzer
script
logout
ipx menu
➧ interface
➧ route
➧ server
forwarding
rip
enhanced
sap
➧ statistics
interface menu
display
define
modify
remove
route menu
display
static
remove
flush
server menu
display
static
remove
flush
statistics menu
summary
rip
sap
forwarding
Figure 1-3 IPX Menu Hierarchy
1-6
CHAPTER 1: LANPLEX® EXTENDED SWITCHING FEATURES
Appletalk Menu
From the appletalk menu, you can view information about and configure
Appletalk interfaces, routes, and zones. You can also administer the
Appletalk Address Resolution Protocol (AARP), AppleTalk forwarding, and
statistics. Figure 1-4 shows the Appletalk menu. For example, to define a
new AppleTalk interface, you would enter appletalk at the top-level menu,
interface at the AppleTalk menu, then define at the interface menu.
Top-Level Menu
system
ethernet
fddi
atm
bridge
ip
ipx
➧ appletalk
snmp
analyzer
script
logout
➧ interface
➧ route
➧ aarp
appletalk menu
interface menu
display
define
remove
zone
forwarding
checksum
ping
➧ statistics
route menu
display
flush
aarp menu
display
remove
flush
statistics menu
ddp
rtmp
zip
nbp
Figure 1-4 Appletalk Menu Hierarchy
VLANS ON THE
LANPLEX® SYSTEM
2
This chapter contains:
■
A description of Virtual LAN (VLAN) concepts and their operational aspects
in the LANplex® 2500 system
■
Examples of VLAN configurations
About VLANs
The VLAN concept in LAN technology helps minimize broadcast and
multicast traffic. It also makes end-station moves, adds, and changes easier
for the network administrator.
In the LANplex system, VLANs allow you to:
■
Create independent broadcast domains to optimize network performance
and create firewalls
■
Form flexible user groups independent of the users’ physical network
location
Types of VLANs
You can use several types of VLANs to group users. These types include:
■
Port group VLANs
■
MAC address group VLANs
■
Application-oriented VLANs
■
Protocol-sensitive VLANs
Port Group VLANs
Port group VLANs group together one or more switch ports. This simple
implementation of VLANs requires little configuration. All frames received
on a port are grouped together. For example, all frames received on a port
that is part of a port group are kept within that port group, regardless of
2-2
CHAPTER 2: VLANS ON THE LANPLEX® SYSTEM
the data contained in the frames. Port groups are useful when traffic
patterns are known to be directly associated with particular ports. They can
benefit the user by restricting traffic based on a set of simple rules.
MAC Address Group VLANS
VLANs allow a switch to make filtering decisions based on grouping MAC
addresses together. These MAC address groups can be configured so that
stations in the group can only communicate with each other or with
specific network resources. This solution is good for security. It allows the
VLAN association to move with the station. However,
MAC-address-grouped VLANs may require complex configuration in
comparison to other types of VLANs.
Port group and MAC address group VLANs are supported using the packet
filtering capabilities in the LANplex system. For information on port group
and MAC address group filtering, refer to your LANplex Operation Guide and
LANplex Administration Console User Guide.
Application-Oriented VLANS
Using the LANplex filtering capability, application-specific traffic such as
telnet traffic or FTP traffic can be filtered based on higher-layer information.
You create this application-oriented VLAN by configuring packet filters that
specify data and offsets of the data within received packets. For example, to
use a filter on a particular port for all telnet traffic, create a a filter that
discards all TCP traffic received on the telnet port.
IP multicast routing and autocast VLANs are additional VLAN features in the
LANplex that can be used to group IP multicast traffic for specific
applications. For more information on how the LANplex system manages IP
Multicast traffic, see Chapter 8.
Protocol-Sensitive VLANS
When the LANplex system receives data that has a broadcast, multicast, or
unknown destination address, it forwards the data to all ports. This process
is referred to as bridge flooding.
Protocol-sensitive VLANs group one or more switch ports together for a
specified network layer 3 protocol, such as IP or AppleTalk. These VLANs
make flooding decisions based on the network layer protocol of the frame.
In addition, for IP VLANs, you can also make flooding decisions based on
About VLANs
2-3
layer 3 subnet address information. Protocol-sensitive VLANs allow the
restriction of flood traffic for both routable and nonroutable protocols. They
have a relatively simple configuration comprising one or more protocols
and groups of switch ports. These protocol-sensitive VLANs operate
independent of each other. Additionally, the same switch port can belong
to multiple VLANs. For example, you can assign port 1 on a LANplex to
several IP subnet VLANs, plus one IPX VLAN, one AppleTalk VLAN, and one
NetBIOS VLAN. In a multiprotocol environment, protocol-sensitive VLANs
can be very effective for controlling broadcast and multicast flooding.
Two or more types of VLANs can coexist in the LANplex system. When
associating received data with a particular VLAN configuration in a multiple
VLAN configuration, port group, MAC address group, and
application-oriented VLANs always take precedence over protocol-sensitive
VLANs.
LANplex
Protocol-Sensitive
VLAN Configuration
The LANplex protocol-sensitive VLAN configuration includes three elements:
protocol suite, switch ports, layer 3 addressing information for IP VLANs.
Protocol Suite
The protocol suite describes which protocol entities can comprise a
protocol-sensitive VLAN. For example, LANplex VLANs support the IP
protocol suite, which is made up of the IP, ARP, and RARP protocols.
Table 2-1 lists the protocol suites that the LANplex supports, as well as the
protocol types included in each protocol suite.
Table 2-1 Supported Protocols for VLAN Configuration
Protocol Suite
Protocol Types
IP
IP, ARP, RARP (Ethertype, SNAP PID)
Novell® IPX
IPX (Ethertype, DSAP, SNAP PID)
AppleTalk®
DDP, AARP (Ethertype, SNAP PID)
Xerox® XNS
XNS IDP, XNS Address Translation, XNS Compatibility
(Ethertype, SNAP PID)
DECnet™
DEC MOP, DEC Phase IV, DEC LAT, DEC LAVC (Ethertype,
SNAP PID)
SNA
SNA Services over Ethernet (Ethertype)
Banyan VINES®
Banyan (Ethertype, DSAP, SNAP PID)
continued
2-4
CHAPTER 2: VLANS ON THE LANPLEX® SYSTEM
Table 2-1 Supported Protocols for VLAN Configuration (continued)
Protocol Suite
Protocol Types
X25
X.25 Layer 3 (Ethertype)
NetBIOS™
NetBIOS (DSAP)
Default
Default (all protocol types)
Switch Ports
A group of switch ports is any combination of switch ports on the LANplex
system. Included are switch ports created as ATM LAN Emulation Clients
(ATM LECs). VLANs do not support media implementations that do not run
over switch (bridge) ports, for example, ATM Logical IP Subnets (ATM LISs).
Layer 3 Addressing Information
For IP VLANs only, the LANplex system optionally supports configuring of
individual IP VLANs with network layer subnet addresses. With this
additional layer 3 information, you can create independent IP VLANs that
share the same switch ports for multiple IP VLANs. Data is flooded according
to both the protocol (IP) and the layer 3 information in the IP header to
distinguish among multiple IP VLANs on the same switch port. This
configuration is discussed later in the section “Overlapped IP VLANs.”
About VLANs
Default VLAN
2-5
When you start up the LANplex system, the system automatically creates a
VLAN interface called the default VLAN. Initially, the default VLAN includes
all of the switch ports in the system. In the LANplex system, the default
VLAN serves to define:
■
The flood domain for protocols not supported by any VLAN in the system
■
The flood domain for protocols supported by a VLAN in the system but
received on nonmember ports
Both cases represent exception flooding conditions that are described in
the following sections.
Modifying the Default VLAN
New switch ports can dynamically appear in the LANplex system if you
insert a daughter LAN card or create an ATM LEC. When a new switch port
that is not part of a default VLAN appears in the system at initialization, the
system software adds that switch port to the first default VLAN defined in
the system.
LANplex VLANs also allow you to modify the initial default VLAN to form two
or more subsets of switch ports. If you remove the default VLAN and no other
VLANs are defined for the system, no flooding of traffic can occur.
How the LANplex®
System Makes
Flooding Decisions
Protocol-sensitive VLANs directly affect how the LANplex system performs
flooding. Without protocol-sensitive VLANs, the flooding process is to
forward data to all switch ports in the system. With protocol-sensitive
VLANs, the flooding process follows this model:
■
As a frame is received that needs to be flooded, it is decoded to determine
its protocol type.
■
If a VLAN exists for that protocol in the LANplex system and the frame’s
source port is a member of the VLAN, the frame is flooded according to the
group of ports assigned to that VLAN.
■
If a VLAN exists for that protocol in the LANplex system but the frame’s
source port is not a member of the VLAN definition, then the frame is
flooded according to the default VLAN assigned to that port.
■
If the protocol type of the received frame has no VLAN defined for it in the
system, the frame is flooded to the Default VLAN for the receive port.
2-6
CHAPTER 2: VLANS ON THE LANPLEX® SYSTEM
This example shows how flooding decisions are made according to VLANs
set up by protocol (assuming an 18-port switch):
VLAN Exception
Flooding
Index
VLAN
Ports
1
Default
1 - 18
2
IP
1 - 12
3
IPX
11 - 16
Data received on... Is flooded on...
Because...
IP - port 1
VLAN 2
IP data received matches IP VLAN on the
source port.
IPX - port 11
VLAN 3
IPX data received matches IPX VLAN on the
source port.
XNS - port 1
VLAN 1
XNS data received matches no protocol
VLAN, so the Default VLAN is used.
If data arrives on a switch port for a certain protocol and VLANs for that
protocol are defined in the system but not on that switch port, the default
VLAN defines the flooding domain for that data. This case is called VLAN
exception flooding.
This example shows how the VLAN exception flooding decision is made
(assuming an 18-port switch):
Index
VLAN
Ports
1
Default
1 - 18
2
IP
1 - 10
About VLANs
Overlapped IP
VLANs
2-7
Data received on... Is flooded on...
Because...
XNS - port 1
VLAN 1
XNS data does not match any defined VLAN
in the system.
IP - port 2
VLAN 2
IP data received matches IP VLAN 2 for
source ports 1 - 10.
IP - port 12
VLAN 1
IP data received on source port 12 does not
match any defined source port for IP VLAN,
so the Default VLAN is used.
The LANplex system also gives you the ability to assign network layer
information to IP VLANs. This capability allows network administrators to
manage their VLANs by subnet. Flooding decisions are made by first
matching the incoming frame using the protocol (IP) and then matching it
with layer 3 subnet information. If received data is IP but does not match
any defined IP subnet VLAN, it is flooded within all IP VLANs using the
relevant switch port.
For example, two IP VLANs can be configured for ports 1-10 as follows:
IP VLAN 1 - Subnet 158.101.112.0, ports 1-10
IP VLAN 2 - Subnet 158.101.113.0, ports 1-10
This example shows how flooding decisions are made using overlapping IP
VLANs (assuming a 12-port switch):
Index
VLAN
Network
Address/Mask
Ports
1
Default
none
1 - 12
2
IP
158.103.122.0/
255.255.255.0
1-6
3
IP
158.103.123.0/
255.255.255.0
6 - 12
2-8
CHAPTER 2: VLANS ON THE LANPLEX® SYSTEM
Data received on... Is flooded on...
Because...
IP subnet
158.103.122.2
on port 6
VLAN 2
IP network layer matches layer 3 address for
VLAN 2.
IP subnet
158.103.123.2
on port 6
VLAN 3
IP network layer matches layer 3 address for
VLAN 3.
IP subnet
158.103.124.2
on port 6
VLAN 2 and
VLAN 3
IP network layer does not match any layer 3
address for IP VLANs.
IPX on port 6
VLAN 1
IPX frame does not match any defined VLAN.
As shown in this example, when the subnet address of an IP packet does
not match any subnet address of any defined IP VLAN in the system, it is
flooded to all of the IP VLANs that share the source switch port, in this case,
port 6.
Routing Between
VLANs
The only way for stations that are in two different VLANs to communicate is
to route between them. The LANplex system supports internal routing
among IP, IPX, and AppleTalk VLANs. If VLANs are configured for other
routable network layer protocols, they can communicate between them
only via an external router.
The LANplex routing model lets you configure routing protocol interfaces
based on a VLAN defined for that protocol. To assign a routing interface, you
must first create a VLAN for that protocol and then associate it with that
interface.
For example, to create an IP interface that can route through a VLAN:
1 Create an IP VLAN for a group of switch ports.
This IP VLAN does not need to contain layer 3 information unless you want
to further restrict flooding according to the layer 3 subnet address.
2 Configure an IP interface with a network address, subnet mask, broadcast
address, cost, and type (VLAN). Select an IP VLAN to “bind” to that IP
interface.
About VLANs
2-9
If layer 3 information is provided in the IP VLAN for which you are
configuring an IP interface, the subnet portion of both addresses must be
compatible.
For example:
IP VLAN subnet 157.103.54.0 with subnet mask of 255.255.255.0
IP host interface address 157.103.54.254 with subnet mask of
255.255.255.0
Layer 2 (bridging) communication is still possible within an IP VLAN (or
router interface) for the group of ports within that IP Interface’s IP VLAN. IP
data destined for a different IP subnet uses the IP routing interface to get to
that different subnet, even if the destination subnet is on a shared port.
2-10
CHAPTER 2: VLANS ON THE LANPLEX® SYSTEM
VLAN Examples
Example 1
Figure 2-1 is an example of a simple configuration that contains three
protocol-sensitive VLANs (2 IP and 1 IPX) that share a high-speed FDDI link.
The end-stations and servers are on 10Mbps ports with traffic segregated by
protocol. They are only aggregated over the high-speed FDDI link. See .
IP-1
IP-2
IPX-1
ERROR
LANplex 2500
Power
Run
IP-1
IP-2
IPX-1
FDDI
Processor
Power
Fan
ERROR
PCMCIA
Temp
Config
Inserted
IP-1
VLAN #1
LANplex 2500
Modem
IPX-1
VLAN #3
IP-2
VLAN #2
Power
Run
Processor
Power
Fan
PCMCIA
Temp
Config
Inserted
Terminal
IP-1
Server
Modem
Terminal
IPX-1
Server
IP-2
Server
Figure 2-1 Example of a Protocol-Sensitive VLAN Configuration
About VLANs
2-11
Example 2
Figure 2-2 is an example of a configuration that contains two different
protocol-sensitive VLANs (IP and IPX) with servers on separate high-speed
100BASE-T ports. The end-station clients share the same switch ports, yet
the IP and IPX traffic stays separate. See Figure 2-2.
.
= VLAN 1 (IP)
IP Server
VLAN #1
= VLAN 2 (IPX)
= VLAN 1 (IP) + VLAN 2 (IPX)
IPX
Fast Ethernet
100 BASEt
IPX
ERROR
LANplex 2500
Power
Run
Process
Power
Fan
PCMCIA
Temp
Config
Inserted
Modem
Terminal
IPX
IP
IP
IP
IPX Server
VLAN #2
IP Server
VLAN #1, #2, and #3
Figure 2-2 A VLAN Configuration with Servers on Separate 100BASE-T ports.
2-12
CHAPTER 2: VLANS ON THE LANPLEX® SYSTEM
BRIDGING AND ROUTING IN THE
LANPLEX® SYSTEM
3
This chapter shows how the LANplex® system operates in a subnetworked
routing environment and describes the LANplex routing methodology —
specifically, how the LANplex bridging and routing model compares with
traditional models.
What Is Routing?
Routing is the process of distributing packets over potentially dissimilar
networks. A router (also called a gateway) is the machine that accomplishes
this task. Routers are typically used to:
■
Connect enterprise networks together
■
Connect subnetworks (or client/server networks) to the enterprise network
Figure 3-1 shows where routers are typically used in a network.
The LANplex system performs routing that connects subnets to the
enterprise network, providing connectivity between devices within a
workgroup, department, or building.
3-2
CHAPTER 3: BRIDGING AND ROUTING IN THE LANPLEX® SYSTEM
Connecting
enterprise
networks
Connecting
subnets to the
enterprise
Router
FDDI Backbone
Sales
Router
Marketing
Router
Engineering
Router
Bridge
Bridge
Bridge
Bridge
Bridge
Figure 3-1 Traditional Architecture of a Routed Network
LANplex in a
Subnetworked
Environment
The LANplex system allows you to fit Ethernet switching capability into
highly subnetworked environments. When you put the LANplex system
into such a network, the system streamlines your network architecture
and easily switches traffic between and within subnets over Ethernet
and FDDI. See Figure 3-2.
Router
FDDI backbone
Sales
LANplex®
Engineering
LANplex®
Figure 3-2 Subnetted Architecture with LANplex® Switching Hubs
Marketing
What Is Routing?
Integrating
Bridging and
Routing
3-3
The LANplex system integrates bridging and routing. Multiple switch
ports can be assigned to each subnet. See Figure 3-3. Traffic between
ports assigned to the same subnet is switched transparently using
transparent bridging or Express switching (described in the LANplex®
2500 Operation Guide). Traffic traveling to different subnets is routed
using one of the supported routing protocols.
In the following descriptions of bridging and routing on the LANplex
system, the term MAC address refers to a physical hardware address.
The term network address refers to a logical address that applies to a
specific protocol.
Subnet 4
LANplex 2500
FDDI ports
Ethernet ports
Subnet 3
Subnet 1
Subnet 2
Figure 3-3 Multiple Ports per Subnets with the LANplex 2500 System
Because the LANplex model of bridging and routing allows several
segments to be connected to the same subnet, you can increase the
level of segmentation in your network without having to create new
subnets or assign network addresses. Instead, you can use additional
Ethernet ports to expand your existing subnets. This is in contrast to
more traditional forms of bridging and routing where, at most, one port
is connected to any subnet.
3-4
CHAPTER 3: BRIDGING AND ROUTING IN THE LANPLEX® SYSTEM
In the traditional model, if you want to increase the level of
segmentation in your network, you must create additional subnets and
assign new network addresses to your existing hosts.
Bridging and
Routing Models
Traditional Bridging
and Routing Model
The way routing is implemented in the LANplex system differs from
how bridging and routing usually coexist in a system.
■
Traditional Bridging and Routing Model — Traditionally, bridging and
routing are peer entities; either a packet is bridged or routed. Packets
belonging to recognized protocols are routed; all others are bridged.
■
LANplex Bridging and Routing Model — In the LANplex model, the
bridge and router operate hierarchically on the LANplex system, routing
over bridging. When a packet enters the system, the system first tries to
bridge the packet. If the packet’s destination network address is not on
the same subnet, then the system routes the packet.
The bridge or router determines whether a packet should be bridged or
routed based on the protocol to which the packet belongs. If the packet
belongs to a recognized protocol, the packet is routed. Otherwise, it is
bridged.
In the traditional bridging and routing model, a packet is bridged as
follows (see Figure 3-4):
1 The packet enters the bridge or router.
2 The bridge or router determines that the packet does not belong to a
recognized routing protocol, so the packet is passed to the bridge.
3 The bridge examines the destination MAC address and forwards the
packet to the port on which that address has been learned.
Bridging and Routing Models
Router
3-5
Bridge
3
2
Router vs. Bridge ?
1
Interfaces (ports)
Networks
Destination host
Transmitting host
Figure 3-4 Bridging in the Traditional Bridging and Routing Model
In the traditional bridging and routing model, a packet is routed as
follows (see Figure 3-5):
1 The packet enters the bridge or router.
2 The bridge or router determines that the packet belongs to a
recognized routing protocol, so the packet is passed to the router.
3 The router examines the destination network address and forwards the
packet to the interface (port) connected to the destination subnet.
Router
Bridge
3
2
Router vs. Bridge ?
1
Interfaces (ports)
Networks
Transmitting host
Destination host
Figure 3-5 Routing in the Traditional Bridging and Routing Model
3-6
CHAPTER 3: BRIDGING AND ROUTING IN THE LANPLEX® SYSTEM
LANplex Bridging
and Routing Model
The LANplex 2500 system uses the destination MAC address to
determine whether it will bridge or route a packet. Before a host system
sends a packet to another host, it compares its own network address to
the network address of the other host as follows:
■
If network addresses are on the same subnet, the packet is bridged
directly to the destination host’s address.
■
If network addresses are on different subnets, the packet must be
routed from one subnet to the other. In this case, the host transmits the
packet to the connecting router’s MAC address.
In the LANplex bridging/routing model, a packet is bridged as follows
(see Figure 3-6):
1 The packet enters the LANplex system.
2 The packet’s destination MAC address is examined by the bridging layer.
3 The destination MAC address does not correspond to the MAC address
of one of the system ports configured for routing. The bridging layer
selects a segment (port) based on the destination MAC address and
forwards the packet to that segment.
Router
Routing Layer
2
1
3
3
Router Interfaces
Bridge
2
Bridging Layer
1
1
2
3
Subnets
Transmitting Host
Destination Host
Figure 3-6 Bridging in the LANplex Bridging and Routing Model
Bridging and Routing Models
3-7
In the LANplex bridging and routing model, a packet is routed as follows
(see Figure 3-7):
1 The packet enters the LANplex system.
2 The packet’s destination address is examined by the bridging layer.
3 The destination address corresponds to the address of one of the system
ports configured for routing (as opposed to a learned end-station address).
The packet is passed to the router interface associated with the port on
which the packet was received.
4 The routing layer:
a Selects a destination interface based on the destination network
address.
b Determines the MAC address of the next hop (either the destination
host or another gateway).
c Passes the packet back to the bridging layer.
5 The bridging layer then selects a segment (port) based on the destination
MAC address and forwards the packet to that segment.
Router
4
Routing Layer
3
2
1
3
Router Interfaces
Bridge
5
2
Bridging Layer
1
1
2
3
Transmitting Host
Destination Host
Figure 3-7 Routing in the LANplex Bridging and Routing Model
Subnets
3-8
CHAPTER 3: BRIDGING AND ROUTING IN THE LANPLEX® SYSTEM
ROUTING WITH IP TECHNOLOGY
4
This chapter gives an overview of IP routing technology, specifically
defining:
IP Routing and
the OSI Model
■
What IP routing involves
■
What elements are necessary for IP routers to effectively transmit packets
■
How IP routing transmission errors are detected and resolved
■
Routing with classical IP over ATM
An IP router, unlike a bridge, operates at the network layer of the OSI
Reference Model. That is, it routes packets by examining the network layer
address (IP address). Bridges use the data-link layer MAC addresses to make
forwarding decisions. See Figure 4-1.
OSI Reference Model
Application Layer
Presentation Layer
Session Layer
Transport Layer
Network Layer
IP
RIP
ICMP
ARP
Data-link Layer
MAC
Physical Layer
Figure 4-1 OSI Reference Model and IP Routing
4-2
CHAPTER 4: ROUTING WITH IP TECHNOLOGY
When an IP router sends a packet, it does not know the complete path
to a destination — only the next hop. Each hop involves three steps:
■
The IP routing algorithm computes the next hop IP address, and next
router interface, using the routing table entries.
■
The Address Resolution Protocol (ARP) translates the next hop IP
address into a physical MAC address.
■
The router sends the packet over the network to the next hop.
These routing elements are described in more detail in the following
section.
Elements of IP
Routing
IP Addresses
IP routers use the following elements to transmit packets in a
subnetworking environment:
■
IP addresses
■
Router interfaces
■
Routing tables
■
Address Resolution Protocol (ARP)
IP addresses are 32-bit addresses composed of a network part (the
address of the network on which the host is located) and a host part
(the address of the host on that network). See Figure 4-2. IP addresses
differ from Ethernet and FDDI MAC addresses, which are unique
hardware-configured 48-bit addresses.
32 bits
IP Address
network
host
The boundary between
network and host parts
depends on the class of IP
Figure 4-2 IP Address: Network Part and Host Part
A central agency assigns the network part of the IP address, and the
network administrator assigns the host part. All devices connected to
the same network share the same IP address prefix (the network part of
the address).
Elements of IP Routing
4-3
Address Classes
The boundary of the network part and the host part depends on the
class that the central agency assigns to your network. The primary
classes of IP addresses are Class A, Class B, and Class C.
■
Class A addresses — have 8 bits for the network part and 24 bits for
the host part. Although only a few Class A networks can be created,
each can contain a very large number of hosts.
■
Class B addresses — have 16 bits for the network part and 16 bits for
the host part.
■
Class C addresses — have 24 bits for the network part and eight bits
for the host part. Each Class C network can contain only up to 254
hosts, but many such networks can be created.
The class of an IP address is designated in the high-order bits of the
network parts of the address.
Subnet Part of an IP Address
In some environments, the IP address contains a subnet part. Subnetting
allows a single Class A, B, or C network to be further subdivided
internally while still appearing as a single network to other networks.
The subnet part of the IP address is only visible to those hosts and
gateways on the subnet network.
When an IP address contains a subnet part, a subnet mask is used to
identify which bits are the subnet address and which are the host
address. A subnet mask is a 32-bit number that uses the same format
and representation as IP addresses. Each IP address bit corresponding to
a 1 in the subnet mask is in the network or subnet part of the address.
Each IP address bit corresponding to a 0 is in the host part of the IP
address. See Figure 4-3.
4-4
CHAPTER 4: ROUTING WITH IP TECHNOLOGY
Take the IP address
IP Address
Network
Subnet and Host
Apply the subnet mask
Subnet Mask
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 00 0 0 0 00 0
Result = subnet/host boundary
networ
Network
Subnet
subn
Host
Figure 4-3 How a Subnet Mask Is Applied to the IP Address
An example of an IP address that includes network, subnet, and host
parts is 158.101.230.52 with a subnet mask of 255.255.255.0. This address
is divided as follows:
■
158.101 is the network part
■
230 is the subnet part
■
52 is the host part
Router Interfaces
A router interface is the connection between the router and a subnet.
In traditional routing models, the interface is the same as the port, since
only one interface can exist per port. In the LANplex system’s IP routing
model, more than one port can be connected to the same subnet.
Each router interface has an IP address and a subnet mask. This address
defines both the number of the network to which the router interface is
attached and its host number on that network. A router interface’s IP
address serves two functions:
■
The IP address is used when sending IP packets to or from the router
itself.
■
The IP address defines the network and subnet numbers of the
segment connected to that interface. See Figure 4-4.
Elements of IP Routing
4-5
Network 2
Network 1
Interfaces
158.101.1.2
1
2
158.101.2.2
158.101.2.1
Router
Interface 1
IP Address
158.101.1.1
3
158.101.3.2
158.101.3.1
Interface
Network 3
Figure 4-4 Router Interfaces in the LANplex System
Routing Table
A routing table allows a router or host to determine how to send a
packet toward the packet’s ultimate destination. The routing table
contains an entry for every destination network, subnet, or host to
which the router or host is capable of forwarding packets. A router or
host uses the routing table when the destination IP address of the
packet it is sending is not on a network or subnet to which it is directly
connected. The routing table provides the IP address of a router that
can forward the packet toward its destination.
The routing table consists of the following elements:
■
Destination IP Address — the destination network, subnet, or host
■
Subnet Mask — the subnet mask corresponding to the destination IP
address
■
Metric — a measure of the “distance” to the destination. In the Routing
Information Protocol (RIP), the metric is the number of hops.
■
Gateway — the IP address of the next hop router (the IP address of the
interface through which the packet travels)
■
Interface — the interface number through which a packet must travel
to reach that router
Figure 4-5 shows the routing table of the router in Figure 4-4.
4-6
CHAPTER 4: ROUTING WITH IP TECHNOLOGY
Routing Table
Destination IP Address
Subnet Mask
Metric
Gateway
Interface
158.101.1.1
255.255.255.0
1
158.101.1.2
1
158.101.2.1
255.255.255.0
1
158.101.2.2
2
158.101.3.1
255.255.255.0
1
158.101.3.2
3
default route
255.255.255.0
1
158.101.1.2
1
Figure 4-5 Example of a Routing Table in the LANplex Routing Model
Routing table information is generated and updated in either of the
following ways:
■
Statically — You manually enter routes, which do not change until
you change them (that is, they will not time out).
■
Dynamically — The router uses a routing protocol, such as RIP, to
exchange information. Routes are recalculated at regular intervals.
Static Routes
A static route is one that you manually configure in the routing table.
Static routes are useful in environments where no routing protocol is
used or where you want to override some of the routes generated with
a routing protocol. Because static routes do not automatically change in
response to network topology changes, you should manually configure
only a small number of reasonably stable routes.
Dynamic Routes Using RIP
Automated methods of configuring routes help you keep up with a
changing network environment, allowing routes to be reconfigured
quickly and reliably. Interior Gateway Protocols (IGP), which operate
within networks, provide this automated method. The LANplex system
uses the Routing Information Protocol (RIP), one of the most widely
used IGPs, to configure its routing tables dynamically.
RIP operates in terms of active and passive devices. The active devices,
usually routers, broadcast their RIP messages to all devices in a network
or subnet; they update their own routing tables when they receive a RIP
message. The passive devices, usually hosts, listen for RIP messages and
update their routing tables; they do not send RIP messages.
Elements of IP Routing
4-7
An active router sends a RIP message every 30 seconds. This message
contains both the IP address and a metric (the distance to the
destination from that router) for each destination. In RIP, each router
that a packet must travel through to reach a destination equals one
hop.
Default Route
In addition to the routes to specific destinations, the routing table may
contain an entry called the default route. The router uses the default
route to forward packets that do not match any other routing table
entry. A default route is often used in place of routes to numerous
destinations all having the same gateway IP address and interface
number. The default route can be configured statically, or it can be
learned dynamically using RIP.
Address Resolution
Protocol (ARP)
ARP is a low-level protocol used to locate the MAC address corresponding to a given IP address. This protocol allows a host or router to make
its routing decisions using IP addresses while it uses MAC addresses to
forward packets from one hop to the next.
Once the host or router knows the IP address of the next hop to the
destination, the host or router must translate that IP address into a MAC
address before the packet can be sent. To do this translation, the host or
router first looks in its ARP cache, a table of IP addresses with their corresponding MAC addresses. Each device participating in IP routing
maintains an ARP cache. See Figure 4-6.
ARP Cache
IP Address
MAC Address
158.101.1.1
00308e3d0042
158.101.2.1
0080232b00ab
Figure 4-6 Example of an ARP Cache
If the IP address does not have a corresponding MAC address listed, the
host or router broadcasts an ARP request packet to all the devices on the
network. The ARP request contains information about the hardware and
4-8
CHAPTER 4: ROUTING WITH IP TECHNOLOGY
protocol. The two key elements of the ARP request are the target and
source addresses for both the hardware (MAC addresses) and the
protocol (IP addresses). See Figure 4-7.
ARP Request
00802322b00ad
Source hardware address
158.101.2.1
Source protocol address
?
Target hardware address
158.101.2.15
Target protocol address
Figure 4-7 Example of an ARP Request Packet
When the devices on the network receive this packet, they examine it,
and if their address is not the target protocol address, they discard the
packet. When a device receives the packet and confirms that its IP
address matches the target protocol address, this device places its MAC
address in the target hardware address field and sends the packet back
to the source hardware address. When the originating host or router
receives the ARP reply, it places the new MAC address in its ARP cache
next to the corresponding IP address. See Figure 4-8.
ARP Cache
IP Address
MAC Address
158.101.1.1
00308e3d0042
158.101.2.1
0080232b00ab
158.101.3.1
0134650f3000
Figure 4-8 Example of ARP Cache Updated with ARP Reply
Once the MAC address is known, the host or router can send the packet
directly to the next hop.
IP Routing Transmission Errors
IP Routing
Transmission
Errors
4-9
Because each router only knows about the next hop, it is not aware of
problems that might be further “down the road” toward the destination.
Destinations can be unreachable if:
■
Hardware is temporarily out of service
■
You inadvertently specified a nonexistent destination address
■
The router does not have a route to the destination network
To help routers and hosts know of problems in packet transmission, an
error-reporting mechanism called Internet Control Message Protocol
(ICMP) provides error reporting back to the source when routing
problems arise. ICMP allows you to determine whether a delivery
failure resulted from a local or a remote malfunction.
ICMP does the following:
■
Tests the reachability of nodes (ICMP Echo Request and ICMP Echo Reply)
A host or gateway sends an ICMP echo request to a specified
destination. If the destination receives the echo request, it sends an
ICMP echo reply back to the original sender. This process tests whether
the destination is reachable and responding and verifies that the major
pieces of the transport system work. The ping command is one
frequently used way to invoke this process.
■
Creates more efficient routing (ICMP Redirect)
Often the host route configuration specifies the minimal possible
routing information needed to communicate (for example, the address
of a single router). The host relies on routers to update its routing table.
In the process of routing packets, a router may detect a host not using
the best route. The router then sends the host an ICMP redirect,
requesting that the host use a different gateway when sending packets
to that destination. The next time the host sends a packet to that same
destination, it uses the new route.
■
Informs sources that a packet has exceeded its allocated time to exist
within the network (ICMP Time Exceeded)
4-10
CHAPTER 4: ROUTING WITH IP TECHNOLOGY
Routing with
Classical IP over
ATM
LANPlex Extended Switching software supports classical IP routing over ATM
ARP in an ATM network. Classical IP over ATM uses Logical IP Subnets (LISs)
to forward packets within the network environment.
See the LANplex® 2500 Operation Guide for detailed information about the
ATM protocol architecture. See the LANplex® 2500 Administration Console
User Guide for information about how to configure ATM ports.
About Logical IP
Subnets (LISs)
An LIS is a group of IP nodes that belong to the same subnet, and which are
directly connected to a single ATM network. When you add a node to a LIS
through the Administration Console IP interface menu, you define its IP
address, subnet mask, and the address an ATM ARP server that supports it.
ATM ARP Servers
An ATM ARP server maintains a table of IP addresses and their
corresponding ATM addresses and circuit information. To forward IP
packets over an ATM interface, the network node learns the ATM address for
the corresponding IP address from the ATM ARP server.
Each ATM ARP server supports a single LIS. You can associated two or more
LISs with the same ATM network, but each LIS operates independently of
other LISs on the network.
Several types of network nodes can function as ATM ARP servers:
■
Any LANplex system with revision 8.1.0 or later of Extended Switching
software
■
An ATM switch
■
A UNIX® workstation
The following sequence describes how the ATM ARP server learns and
stores information about the IP and ATM addresses of nodes in the network.
■
A node establishes a connection to the ATM ARP server
■
The ATM ARP server sends an inverse ATM ARP request to the node,
requesting its IP and ATM address
■
When the node returns this information, the ATM ARP server stores, or
caches, it in the ATM ARP server table.
IP Routing References
4-11
Forwarding to Nodes within an LIS
Nodes can forward packets directly to other nodes in the same LIS. To
forward a packet within the same LIS, the sending node requests a
translation from the destination IP address to the corresponding ATM
address from the ATM ARP server.
■
If the address is known to the server, the server returns a message with this
address
■
If the address is not known to the server, the server returns a message to
advise the sending node that the packet is discarded.
When the server returns a destination address, the sending node uses this
learned address to create a virtual circuit (VC) and to forward this and all
subsequent packets to the destination address. The sending node adds this
VC to its ATM ARP cache.
IP Routing
References
Comer, Douglas E. Internetworking with TCP/IP. Volume I: Principles, Protocols,
and Architecture. Englewood Cliffs, New Jersey: Prentice Hall, Inc., 1991.
Perlman, Radia. Interconnections: Bridges and Routers. Reading,
Massachusetts: Addison-Wesley Publishing Company, Inc., 1992.
Sterns, Richard. TCP/IP Illustrated. Volume 1: The Protocols. Reading,
Massachusetts: Addison-Wesley Professional Computing Services, 1992.
RFC 791. Internet Protocol Specification.
RFC 792. Internet Control Message Protocol Specification.
RFC 1009. Requirements for Internet Gateways.
RFC 1042. A Standard for the Transmission of IP Datagrams over IEEE 802
Networks.
RFC 1058. Routing Information Protocol.
RFC 1122. Requirements for Internet Hosts.
RFC 1577. Classical IP over ATM.
4-12
CHAPTER 4: ROUTING WITH IP TECHNOLOGY
ROUTING WITH IP MULTICAST
5
This chapter describes the IP multicast routing implementation on the
LANplex® system.
About IP
Multicast Routing
IP multicast routing is an extension of the Internet Protocol. Multicast
routing allows a router or switch to send packets to a specific group of
hosts without using broadcasts or multiple unicast transmissions. This group
can include members that reside on the local LAN, members that reside on
different sites within a private network, or members that are scattered
throughout the Internet. Mulitcast routing achieves this functionality
without loops or excess transmissions.
IP Multicast support within the LANplex system has two main components:
■
Internet Group Management Protocol (IGMP)
■
Distance Vector Multicast Routing Protocol (DVMRP)
This chapter describes these two protocols as well as the algorithms that
the LANplex system uses for multicast routing.
IGMP
The LANplex system is capable of dynamic multicast filtering based on the
Internet Group Management Protocol (IGMP). This protocol ensures that
multicast packets are flooded only to the appropriate ports within a routing
interface.
IGMP tracks end-station group membership within a multicast group.
Membership in a group is dynamic, and hosts are allowed to be a member
of more than one group at a time. Broadcast domains are maintained by
avoiding propagation of multicast broadcasts to the entire subnet by
confining them within the group (IGMP “snooping”).
5-2
CHAPTER 5: ROUTING WITH IP MULTICAST
DVMRP
The Distance Vector Multicast Routing Protocol (DVMRP) establishes
the multicast delivery path over a series of routing devices. DVMRP is a
simple distance vector routing protocol, similar to the IP Routing
Information Protocol (RIP). Multicast routers exchange distance vector
updates that contain lists of destinations as well as the distance in hops
to each destination. They maintain this information in a routing table.
DVMRP is the current routing protocol used on the Internet Multicast
Backbone (MBONE). Full support of DVMRP allows the LANplex system
to fully establish the delivery path without requiring a direct connection
to a multicast router.
The MBONE
The MBONE is an experimental “Multicast Backbone” network that exists
on the Internet. Users can test multicast applications and technology on
the MBONE without waiting for Internet multicast standards to be set.
You can gain access to the MBONE through any Internet service
provider.
The MBONE routers forward mulitcast packets over an interface or over
a multicast tunnel only if the Time-To-Live (TTL) value present in the
packet is larger than the tunnel’s threshold. (See the section “Multicast
Tunnels” on page 6 for more information about tunnels.)
LANplex 2500 systems at revisions earlier than 8.0 support up to 16 IP
multicast tunnels or routing interfaces when connected to the MBONE
network. LANplex 2500 systems at revision 8.0 or later can support up to
32 IP multicast tunnels or routing interfaces when connected to the
MBONE.
Multicast Routing Algorithms
Multicast Routing
Algorithms
Flooding
5-3
The LANplex system uses three algorithms that support multicast
routing:
■
Flooding
■
Spanning Trees
■
Reverse Path Forwarding
Several types of flooding algorithms exist, but they all share the same
general principles: a node in the network receives a packet that was
sent to a multicast destination. The node determines whether the
packet is an original that it has not seen before or a duplicate of a
packet that it has seen before. If the packet is an original, the node
forwards the packet on all interfaces except the incoming interface. If
the packet is a duplicate, the node discards it.
The flooding algorithm is useful in situations where the most important
requirement for the network is robustness. It does not depend on any
kind of routing tables. Destinations will receive packets as long as at
least one path to them exists and no errors occur during transmission.
Spanning Trees
The Spanning Tree algorithm detects loops and logically blocks
redundant paths in the network. The paths form a loopless graph, or
tree, spanning all the nodes in the network. A port in the blocking state
does not forward or receive data packets.
After the algorithm eliminates extra paths, the network configuration
stabilizes. When one or more of the paths in the stable topology fail, the
protocol automatically recognizes the changed configuration and
activates redundant links. This strategy ensures that all nodes remain
connected.
5-4
CHAPTER 5: ROUTING WITH IP MULTICAST
Figure 5-1 shows a simple network with five links.
A
1
B
3
2
C
4
D
6
E
5
Figure 5-1 Simple Network Implemented Without Using Spanning Tree
A spanning tree for this network consists of links 1, 2, 3, and 4. See
Figure 5-2.
A
1
3
B
2
C
4
D
6
E
5
Figure 5-2 Spanning Tree Algorithm Implemented to Block Redundant Paths
Reverse Path
Forwarding
Reverse path forwarding (RPF) is the multicast algorithm in use on the
MBONE network. RPF is designed to avoid duplicate paths on
multi-access links. It uses a routing table to compute a logical spanning
tree for each network source. The RPF algorithm has these basic steps:
1 When the system receives a multicast packet, the algorithm notes the
source network of the packet and the interface on the LANplex system
that received the packet.
2 If the interface belongs to the shortest path towards the source
network, then the system forwards the packet to all interfaces except
the interface on which the packet was received.
3 If the condition in Step 2 is false, the system drops the packet.
Multicast Interfaces
Pruning
5-5
Pruning is a method used in the RPF algorithm to forward packets to a
spanning tree only if group members exist in the tree. This method results
in fewer spanning trees, but it requires dynamic updates to the routing
table.
Nodes that are at the border of the network and have no point beyond
them in the RPF spanning tree are called leaf nodes. Leaf nodes all receive
the first multicast packet. If a group member is attached to the leaf node,
the node continues to accept packets. If no group member is attached to
the leaf node, the node sends back a “prune message” to the router that
sent the packet. The message tells the router to send no further packets to
this group. In the LANplex system, the Administration Console IP multicast
CacheDisplay includes information about when pruning will occur on the
spanning tree.
Multicast
Interfaces
Multicast interfaces on the LANplex system have several characteristics
which are described in this section:
DVMRP Metric Value
The DVMRP metric value determines the cost of a multicast interface. The
higher the cost, the slower the link. The default value is 1.
Time-To-Live (TTL)
Threshold
This TTL threshold determines whether the interface will forward multicast
packets to other switches and routers in the subnet. If the interface TTL is
greater than the packet TTL, then the interface does not forward the packet.
The default value is one 1, which means that the interface forwards most
packets.
5-6
CHAPTER 5: ROUTING WITH IP MULTICAST
Rate Limit
Multicast Tunnels
The rate limit determines how many multicast packets can travel over the
interface in kilobytes-per-second. The LANplex system drops multicast traffic
that travels faster than this rate. The default is set to 0, which implies no rate
limit is set. In all other instances, the lower the rate limit, the more limited
the traffic over the interface.
Multicast tunnels are logical connections between two multicast routers
through one or more unicast routers. The multicast router at the local
endpoint of the tunnel encapsulates multicast packets in a format that
unicast routers can interpret and forward. The multicast router at the
remote endpoint decapsulates the packets into their multicast format.
Tunnels are virtual links through the unicast IP network.
Multicast tunnels have characteristics similar to those of a multicast
interface: a DVMRP metric value, a TTL threshold, and a rate limit. When you
define a multicast tunnel, you also specify the destination address of the
remote multicast router that is the remote endpoint of the tunnel.
ROUTING WITH IPX
6
This chapter provides an overview of IPX routing, including:
IPX Routing in
the NetWare®
Environment
■
What part IPX plays in the NetWare environment
■
How IPX works
■
What elements are necessary for IPX routers to transmit packets effectively
The NetWare® network operating system was developed and introduced to
the market by Novell, Inc. in the early 1980s. Much of the NetWare
networking technology was derived from Xerox Network System (XNS) TM, a
networking system developed by Xerox Corporation.
The NetWare operating system is based on a client/server architecture
where clients request certain services from servers such as file access and
printer access. As a network operating system environment, the NetWare
operating system specifies the upper five layers of the OSI reference model.
It provides file and printer sharing and supports various applications such as
electronic mail and database access.
Figure 6-1 illustrates a simplified view of NetWare’s better-known protocols
and their relationship to the OSI reference model.
6-2
CHAPTER 6: ROUTING WITH IPX
Layers in the
OSI reference model
Application
NetWare
NetWare®
Control
Protocol
(NCP)
Appplications
Service
Advertising
Protocol
(SAP)
Routing
Information
Protocol
(RIP)
NetWare®
Shell
(Client)
Presentation
Session
NetBIOS™
Transport
SPX
Network
IPX
Data Link
Media Access Protocols
(Ethernet, FDDI)
Physical
Figure 6-1 NetWare Protocols and the OSI Reference Model
The LANplex system uses the following protocols for routing in a Netware
environment:
Internet Packet
Exchange (IPX)
■
Internet Packet Exchange (IPX)
■
Routing Information Protocol (RIP)
■
Service Advertisement Protocol (SAP)
IPX is the primary protocol used for routing in a netware environment. This
datagram, connectionless protocol does not require an acknowledgment for
each packet sent. Any packet acknowledgment, or connection control, must
be provided by protocols above IPX.
IPX defines internetwork and intranode addressing schemes. IPX
internetwork addressing is based on network numbers that are assigned to
each interface in an IPX network. IPX intranode addressing is in the form of
socket numbers. Since several processes are normally operating within a
node, socket numbers provide a type of mail slot so that each process can
distinguish itself to IPX.
IPX Routing in the NetWare® Environment
Routing
Information
Protocol (RIP)
6-3
RIP allows the exchange of routing information on a NetWare network. IPX
routers use RIP to dynamically create and maintain their routing tables.
RIP allows one router to exchange routing information with a neighboring
router. As a router becomes aware of any changes in the network layout,
it broadcasts this information to any neighboring routers. IPX routers also
send periodic RIP broadcast packets containing all routing information
known to the router. These broadcasts synchronize all routers on the
network and age those networks that might become inaccessible if a router
becomes disconnected from the network abnormally.
Service Advertising
Protocol (SAP)
SAP provides routers and servers that contain SAP agents with a means of
exchanging network service information.
Through SAP, servers advertise their services and addresses. Routers gather
this information and share it with other routers. This strategy allows routers
to dynamically create and maintain a database (server table) of network
service information. Clients on the network can determine what services are
available and obtain the network address of the nodes (servers) where they
can access those services. Clients require this information to initiate a
session with a file server.
SAP allows one router to exchange information with a neighboring SAP
agent. As a router’s SAP agent becomes aware of any change in the
network server layout, it immediately broadcasts this information to any
neighboring SAP agents. The router also periodically sends SAP broadcast
packets containing all server information known to the SAP agent. These
broadcasts synchronize all servers on the network and age those servers
that might become inaccessible because of any abnormal shut down of the
router or server.
6-4
CHAPTER 6: ROUTING WITH IPX
How IPX Routing
Works
IPX Packet Format
A router operates at the network layer of the OSI Reference Model. This
means that it receives its instructions to route packets from one segment to
another from a network-layer protocol. IPX, with the help of RIP, performs
these network layer tasks. These tasks include addressing, routing, and
switching information packets to move single packets from one location to
another. This section first describes the information included in an IPX
packet that helps it get delivered and then it describes the IPX packet
delivery process.
The IPX packet format consists of two parts: a 30-byte header and a data
portion. The network, node, and socket address for both the destination and
source are held within the packet’s IPX header.
Figure 6-2 shows the IPX packet format.
Checksum
(2 bytes)
Packet Length
(2 bytes)
Transport Control
(1 byte)
Packet Type
(1 byte)
Destination Network (4 bytes)
Destination Node
(6 bytes)
Destination Socket
(2 bytes)
Source Network
(4 bytes)
Source Node
(6 bytes)
Source Socket
(2 bytes)
Upper-layer Data
Figure 6-2 IPX Packet Format
How IPX Routing Works
6-5
The packet format consists of the following elements:
■
Checksum — The IPX packet begins with a 16-bit checksum field that is set
to 1s.
■
Packet Length — This 16-bit field contains the length, in bytes, of the
complete network packet. This field includes both the IPX header and the
data. The IPX length must be at least 30 bytes.
■
Transport Control — This 1-byte field indicates how many routers a packet
has passed through on its way to its destination. Packets are discarded
when this value reaches 16. A sending node always sets this field to 0 when
building an IPX packet.
■
Packet Type — This 1-byte field specifies the upper-layer protocol that will
receive the packet’s information.
■
Destination Network — This 4-byte field provides the destination node’s
network number. When a sending node sets this field to zero, the
destination node is assumed to be on the same local segment as the
sending node.
■
Destination Node — This 6-byte field contains the physical address of the
destination node.
■
Destination Socket — This 2-byte field contains the socket address of the
packet’s destination process.
■
Source Network — This 4-byte field provides the source node’s network
number. If a sending node sets this field to 0, it means the source’s local
network is unknown.
■
Source Node — This 6-byte field contains the physical address of the
source node. Broadcast addresses are not allowed.
■
Source Socket — This 2-byte field contains the socket address of the
process that transmitted the packet.
■
Upper-layer Data — The data field contains information for the upper-layer
processes.
6-6
CHAPTER 6: ROUTING WITH IPX
IPX Packet Delivery
On a NetWare network, the successful delivery of a packet depends both on
the proper addressing of the packet and on the internetwork configuration.
Packet addressing is handled in the packet’s Media Access Control (MAC)
protocol header and IPX header address fields.
To send a packet to another node, the sending node must know the
complete internetwork address including the network, node, and socket of
the destination node. Once the sending node has the destination node’s
address, it can proceed with addressing the packet. However, the way the
MAC header of that packet is addressed depends on whether the sending
and destination nodes are separated by a router. See Figure 6-3.
Sending Node
Router
Network = 000000AA
Node =
000000000001
Socket =
4003
Node
000000000020
Destination Node
Node
000000000021
Network = 000000BB
Node =
000000000003
Socket =
0451
MAC Header
Destination Node = 000000000020
Source Node =
000000000001
MAC Header
Destination Node = 000000000003
Source Node =
000000000021
IPX Header
Checksum =
Packet Length =
Tranport Control =
Packet Type =
IPX Header
Checksum =
Packet Length =
Tranport Control =
Packet Type =
Dest Network =
Dest Node =
Dest Socket =
FFFF
011E
00
11
000000BB
000000000003
0451
Source Network = 000000AA
Source Node =
000000000001
Source Socket = 4003
Data
Dest Network =
Dest Node =
Dest Socket =
FFFF
011E
01
11
000000BB
000000000003
0451
Source Network = 000000AA
Source Node =
000000000001
Source Socket = 4003
Data
Figure 6-3 IPX Packet Routing
Sending Node’s Responsibility
When a node needs to send information to another node with the same
network number, the sending node can simply address and send packets
directly to the destination node. However, if the sending and receiving
nodes have different network numbers, the sending node must find a
router on its own network segment that can forward packets to the
destination node’s network segment.
How IPX Routing Works
6-7
To find this router, the sending node broadcasts a RIP packet requesting the
best route to the destination node’s network number. The router residing on
the sending node’s segment with the shortest path to the destination
segment responds to the RIP request. The router’s response includes its
network and node address in the IPX header. If the sending node is a router
rather than a workstation, the router can get this information from its
internal routing tables and need not send a RIP request.
Once the sending node knows the router’s node address, it can send
packets to the destination node.
Router’s Responsibility
When a router receives an IPX packet, it handles the packet in one of two
ways:
■
If the packet is destined for a network number to which the router is
directly connected, the router performs the following tasks:
■
■
■
■
Places the destination node address from the IPX header in the
destination address field of the MAC header.
Places its own node address in the source address field of the MAC
header.
Increments the Transport Control field of the IPX header and transmits
the packet on the destination node segment.
If the packet is destined for a network number to which the router is not
directly connected, the router sends the packet to the next router along the
path to the destination node as follows:
■
■
■
The router looks up the node address (in the routing information table)
of the next router and places the address in the destination address field
of the packet’s MAC header. For more information on routing tables, see
the next section.
The router places its own node address in the source address field of the
packet’s MAC header.
The router increments the Transport Control field in the IPX header and
sends the packet to the next router.
6-8
CHAPTER 6: ROUTING WITH IPX
The Elements of
IPX Routing
IPX routers use the following elements to transmit packets over an
intranetwork:
■
Router interfaces
■
Routing tables
■
Service Advertising Protocol (SAP)
Router Interfaces
A router interface is the connection between the router and the network
number (address). In traditional routing models, the interface would be the
same as the port, because only one interface can exist per port.
In the LANplex system’s IPX routing, more than one port can be connected
to the network number. Therefore, the router interface is the relationship
between the ports and the network number (address) in your IPX network.
Each router interface has a network address. This address defines the
network number to which the router interface is attached. The router
interface’s IPX address serves two functions:
■
It is used when sending IPX packets to or from the router itself.
■
It defines the network number of the segment connected to that interface.
Routing Tables
A routing table holds information about all the network segments. It allows
a router to send a packet toward its ultimate destination using the best
possible route. The routing information table contains an entry for every
network number that the router currently knows exists. A router uses the
routing information table when the destination network number of the
packet it is sending is not on a network to which it is directly connected.
The routing information table provides the immediate address of a
forwarding router that can forward the packet toward its destination.
The routing table consists of the following elements:
■
Interface — Identifies the number of the router’s interface that will be used
to reach the specific network segment.
■
Address — Identifies the addresses for segments that the router currently
knows exists.
The Elements of IPX Routing
6-9
■
Hops to Network — Provides the number of routers that must be crossed
to reach the network segment.
■
Ticks to Network — Provides an estimate of the time necessary to reach
the destination segment.
■
Node — The node address of the router that can forward packets to each
segment. When set to all zeroes, the route is directly connected.
■
Aging Timer — The time since the network’s last update.
Figure 6-4 shows an example of a typical routing information table.
Routing Table
Interface Address
Hops
Ticks
Node
Age
1
1
1
1
00-00-00-00-00-00
0
2
45469f30
1
1
00-00-00-00-00-00
0
2
45469f33
2
3
08-00-17-04-33-45
40
Figure 6-4 Routing Table Example
Generating Routing Table Information
The routing information table is generated and updated as follows:
■
Statically — You manually enter routes. They do not change until you
change them (they do not time out).
■
Dynamically — The router uses RIP to exchange information with other
routers. Routes are recalculated at regular intervals.
Static Routes. A static route is one you manually configure in the routing
table. Static routes are useful in environments where no routing protocol is
used or where you want to override some of the routes generated with a
routing protocol. Because static routes do not automatically change in
response to network topology changes, you should manually configure only
a small number of reasonably stable routes.
Dynamic Routes Using RIP. Automated methods of learning routes help
you keep up with a changing network environment, allowing routes to be
reconfigured quickly and reliably. Interior Gateway Protocols (IGP), which
operate within intranetworks, provide this automated method. The LANplex
6-10
CHAPTER 6: ROUTING WITH IPX
system uses RIP (one of the most widely used IGPs), to dynamically build its
routing tables.
RIP operates in terms of active and passive devices. The active devices,
usually routers, broadcast their RIP messages to all devices in a network;
they update their own routing tables when they receive a RIP message. The
passive devices, usually hosts, listen for RIP messages and update their
routing tables; they do not send RIP messages.
An active router sends a RIP message every 60 seconds. This message
contains both the network number for each destination network and the
number of hops to reach it. In RIP, each router that a packet must travel
through to reach a destination equals one hop.
Selecting the Best Route
Large networks have multiple routes to a single network. The routers use
these criteria to select the best “route” to a network when choosing
between alternate routes:
Service Advertising
Protocol
■
Select the route that requires the lowest number of ticks.
■
If multiple routes exist with an equal number of ticks, select the route that
also has the lowest number of hops.
■
If multiple routes exist with both ticks and hops equal, choose any of the
routes as the “best” route.
The Service Advertising Protocol (SAP) allows servers (for example, file
servers, print servers, and gateway servers) to advertise their addresses and
services. Through the use of SAP, adding and removing services on an
internetwork becomes dynamic. As servers are booted up, they advertise
their services using SAP. When they are brought down, they use SAP to
indicate that their services are no longer available.
Internetwork Service Information
Using SAP, routers create and maintain a database of internetwork service
information. Clients on use this data to determine what services are
available on the network and to obtain the internetwork address of the
nodes (servers) where they can access desired services.
The Elements of IPX Routing
6-11
A workstation must first know a server’s network address before it can
initiate a session with a file server.
SAP Packet Structure
SAP uses IPX and the medium-access protocols for its transport. The packet
structure allows the following functions:
■
A workstation request for the name and address of the nearest server of a
certain type
■
A router request for the names and addresses of all the servers or of all the
servers of a certain type on the internetwork
■
A response to a workstation or a router request
■
Periodic broadcasts by servers and routers
■
Changed server information broadcasts
Figure 6-5 provides an overview of the SAP packet structure. Note that the
packet structure is encapsulated within the data area of IPX.
IPX Packet Format
IPX Header (30 bytes)
Packet Type = 4
Socket = 452h
Data
Server Entry Structure
SAP Packet Structure
Operation
Server Entry (1)
Service Type
(2 bytes)
(2 bytes)
Server Name
(48 bytes)
(64 bytes)
Network Address
(4 bytes)
Node Address
(6 bytes)
Socket Address
(2 bytes)
Hops to Server
(2 bytes)
.
.
.
Server Entry (n)
(n <= 7)
Figure 6-5 SAP Packet Structure
(64 bytes)
6-12
CHAPTER 6: ROUTING WITH IPX
A SAP packet consists of the following fields:
■
Operation — This field indicates the type of operation the SAP packet
performs. It can be set to one of the following values:
1=Request
2=Response
3=Get Nearest Server Request
4=Get Nearest Server Response
■
Server Entry — Each 64-byte server entry includes information about a
particular server. It consists of the following fields:
■
Service Type — This 2-byte field identifies the type of service the server
provides.
Although IPX routers use SAP, routers typically do not act as servers and
require no Service Type assignment.
■
■
■
■
■
Server Name — This field contains the 48-byte character string name
that is assigned to a server. The server name, in combination with the
service type, uniquely identifies a server on an internetwork.
Network Address — This 4-byte field contains the server’s network
address.
Node Address — This 6-byte field contains the server’s node address.
Socket Address — This 2-byte field contains the socket number that
the server uses to receive service requests.
Hops to Server — This 2-byte field indicates the number of
intermediate networks that must be passed through to reach the server
associated with this field entry. Each time the packet passes through an
intermediate network, the field is incremented by 1.
By using SAP, servers can advertise their services and addresses. The
information that these servers broadcast is not directly used by clients;
rather it is collected by a SAP agent within each router on the server’s
segment. The SAP agents store this information in a server information
table. If the agents reside within a server, the information is also stored in
their server’s bindery. The clients can then contact the nearest router or file
server SAP agent for server information.
The Elements of IPX Routing
6-13
The SAP broadcasts that servers and routers send are local and, therefore,
only received by SAP agents on their connected segments. However, SAP
agents periodically broadcast their server information so that all SAP agents
on the internetwork have information about all servers that are active on
the internetwork.
Server Information Table
A server information table holds information about all the servers on the
internetwork. SAP agents use this table to store information received in SAP
broadcasts. Figure 6-6 shows an example of a typical server information
table.
Server Table
Interface Name
Type
Network
Node
1
LPX1102
4
45469f33
1
LPX1103
4
2
LPX2001
4
Socket
Hops
Age
00-00-00-00-00-01 451
2
102
45469f44
00-00-00-00-00-01 451
5
65
45470001
00-00-00-00-00-01 451
4
33
Figure 6-6 Server Information Table
The server information table provides the following information:
■
Interface — Indicates from which interface the information was received
■
Server Name — The name of the server
■
Server Type — Indicates the type of service provided
■
Network Address — The address of the network on which the server
resides
■
Node Address — The node of the server
■
Socket Address — The socket number on which the server will receive
service requests
■
Hops to Server — The number of intermediate networks that must be
passed through to reach the server associated with this entry
■
Age of Server — The time since the last update for that server
The server information table is either statically or dynamically generated
and updated.
6-14
CHAPTER 6: ROUTING WITH IPX
Static Servers. A static server is one you manually configure in the server
information table. Static servers are useful in environments where no
routing protocol is used or where you want to override some of the servers
generated with a routing/server protocol. Because static servers do not
automatically change in response to network topology changes, you
should manually configure only a small number of relatively stable servers.
Dynamic Routes Using SAP. An automated method of adding and
removing services helps you keep up with a changing network
environment, allowing servers to advertise their services and addresses
quickly and reliably. SAP provides this automated method.
As servers are booted up, they advertise their services using SAP. When
servers are brought down, they use SAP to indicate that their services are
no longer available.
The information that these servers broadcast is not directly used by clients;
rather it is collected by a SAP agent within each router on the server’s
segment. The SAP agents store this information in the server information
table. Clients can then use the table to contact the nearest router or file
server SAP agent for server information.
Server Information Maintenance
When a router’s SAP agent receives a SAP broadcast response indicating a
change in the internetwork server configuration, the agent must update its
server information table and inform other SAP agents of these changes.
Examples of such a change are when a server is disconnected or becomes
accessible through a better route.
To relay this changed information to the rest of the internetwork, the SAP
agent immediately sends a broadcast to all of its directly connected
segments except the segment from which the information was received.
This broadcast packet contains information regarding the server change.
The change information is also reflected in all future periodic broadcasts.
SAP Aging. Router SAP agents implement an aging mechanism to handle
conditions that cause a SAP agent to go down suddenly without sending a
DOWN broadcast. Examples of such changes are a hardware failure, power
interruptions, and power surges. A SAP agent maintains a timer for each
entry in its server information tables that keeps track of how much time has
The Elements of IPX Routing
6-15
elapsed since information was received concerning a particular table entry.
Since this information is either new or changed, the SAP agent that receives
this information immediately passes it on, and the change is quickly learned
throughout the internetwork.
SAP Request Handling. When a SAP agent receives a general request, it
sends the sending source a SAP response packet containing information
about all servers of any type known to the receiving SAP agent. This
response includes the same information sent out in a periodic broadcast.
When the request is specific, the SAP agent sends a SAP response directly to
the requesting node. This response contains all known information
regarding all servers of the requested type.
6-16
CHAPTER 6: ROUTING WITH IPX
ROUTING IN AN APPLETALK®
ENVIRONMENT
7
This chapter provides an overview of AppleTalk® routing, and includes these
topics:
■
AppleTalk Network Elements
■
AppleTalk Protocols
■
About AARP
About AppleTalk®
AppleTalk is a suite of protocols defined by Apple Computer, Inc., for
connecting computers, peripherals devices, and other equipment on a
network. AppleTalk protocols support most of the functions offered by the
Open Standards Interconnect (OSI) reference model.
The AppleTalk protocols work together to provide file sharing and printer
sharing, as well as applications like electronic mail and database access. All
Macintosh® computers have AppleTalk connectivity options built into
them, making it the de facto standard for Apple® computer networks.
AppleTalk®
Network
Elements
An AppleTalk network consists of different nodes in groups of networks in
an AppleTalk internet. These nodes can include workstations, routers, and
printers, or services for other computers, called clients.
This section describes the elements of an AppleTalk internet:
■
AppleTalk networks
■
AppleTalk nodes
■
AppleTalk zones
■
Seed routers
7-2
CHAPTER 7: ROUTING IN AN APPLETALK® ENVIRONMENT
AppleTalk®
Networks
A network in an AppleTalk internet is a cable segment attached to a router.
Each network is identified by a network number or range of network
numbers. The network administrator assigns these numbers from a range of
valid network numbers.
Two AppleTalk network numbering systems are currently in use:
nonextended (Phase 1) and extended (Phase 2). 3Com routers support
extended network numbers. While the LANplex system will not translate
Phase 1 packets to Phase 2 packets, it will route packets to a Phase 1
network. The LANplex system anticipates that a gateway exists between
the two networks to translate the packets.
An extended network can span a range of logical networks. Network
numbers in an extended network consist of a range, such as 15 through 20.
This numbering scheme allows for as many as 16,580,608 nodes, although
the actual cables will not support this many nodes.
AppleTalk® Nodes
A node in a AppleTalk network is any addressable device, including
workstations, printers, and routers. Nodes are physically attached to a
network. Each AppleTalk node is identified by a unique AppleTalk address
that each node selects at initialization. The address consists of the node’s
network number and a unique node number.
Named Entities
When a device on the network provides a service for other users, the
network administrator can give the device a name. The name appears on
the Chooser menu of the Macintosh with an associated icon. For example,
the Chooser of the Macintosh can include a printer icon. When you select
the printer icon, several printer names can appear in a list, such as Laser1, or
Laser 2. The Name Binding Protocol (NBP), described later in this chapter,
translates these device names into AppleTalk addresses.
AppleTalk® Network Elements
AppleTalk® Zones
7-3
An AppleTalk zone is a logical collection of nodes on an AppleTalk internet.
A zone can include all nodes in a single network or a collection of nodes in
different networks. You assign a unique name to each zone to identify it in
the internet. Figure 7-1 illustrates the relationship between physical
AppleTalk networks and logical AppleTalk zones.
Network 8-8
Network 20-40
Router
Router
Network 47-47
Zone: Administration
Zone: Accounting
Router
Zone: Marketing
Figure 7-1 AppleTalk Networks and AppleTalk Zones
Figure 7-1 shows an AppleTalk internet with three networks: 47-47, 20-40,
and 8-8. Three AppleTalk zones span the networks in this internet:
Administration, Accounting, and Marketing. Network 20-40 includes two
nodes in the Administration zone and five nodes in the Accounting zone.
Network 47-47 includes a node from the Accounting zone as well as the
Marketing nodes. Network 8-8 consists of nodes in the Administration zone
only.
Creating zones within a network reduces the amount of searching a router
has to do to find a resource on the network. For example, you may want to
gain access to a printer on the network. Instead of searching the whole
network when you want to print a file to a certain printer, the router
searches for it within a particular zone. You gain access to the printer more
7-4
CHAPTER 7: ROUTING IN AN APPLETALK® ENVIRONMENT
quickly within the zone because the zone includes fewer devices than the
entire internet does.
Seed Routers
A seed router initializes the internet with AppleTalk configuration
information, including network numbers and zone names. The seed router
broadcasts this information so that nonseed routers can learn it. You can
designate a seed router through the Administration Console.
A nonseed router listens for a seed router and then takes the configuration
information from the first seed router it detects. After a nonseed router
obtains the configuration information, it can participate in the network as if
it were a seed router as well.
AppleTalk
Protocols
AppleTalk protocols work together to ensure the seamless flow of
information throughout the AppleTalk internet. Figure 7-2 shows a
simplified view of AppleTalk protocols and their relationship to the OSI
reference model. Together, these protocols provide the following services:
■
Physical Connectivity
■
End-to-End Services
■
Reliable Data Delivery
AppleTalk Protocols
7-5
OSI Reference Model
Application
AppleTalk®
Filing
Protocol (AFP)
PostScript®
Presentation
Session
Transport
AppleTalk
Data Stream
Protocol (ADSP)
Zone Information
Protocol (ZIP)
Routing Table
Maintenance
Protocol (RTMP)
Network
AppleTalk Echo
Protocol (AEP)
AppleTalk
Session
Protocol (ASP)
Printer Access
Protocoo (PAP)
AppleTalk
Transaction
Protocol (ATP)
Name Binding
Protocol (NBP)
Datagram Delivery Protocol (DDP)
Link
TokenTalk®
Link Access
Protocol
EtherTalk®
Link Access
Protocol
LocalTalk®
Link Access
Protocol
Physical
Token Ring
Hardware
Ethernet
Hardware
LocalTalk®
Hardware
Figure 7-2 AppleTalk Protocols and the OSI Reference Model
The AppleTalk six-layer protocol suite is not fully compliant with the OSI
seven-layer reference model. However, AppleTalk provides many of the
functions and services provided by OSI. Note that AppleTalk has no specific
protocols for the application layer, since the lower levels provide printer and
file service.
Physical
Connectivity
The physical layer of the OSI protocol stack defines the network hardware.
You can use standard network hardware, such as that defined for Ethernet
and Token Ring networks, with AppleTalk. Apple has also defined its own
network hardware, called LocalTalk, which uses a synchronous RS-422A bus
for communications.
The data link layer provides the interface between the network hardware
and the upper layers of the protocol stack. The AppleTalk data link layer
includes three link access protocols (LAPs): TokenTalk LAP (TLAP), Ethernet
LAP (ELAP), and LocalTalk Link Access Protocol (LLAP).
The AppleTalk Address Resolution Protocol (AARP), which translates
hardware addresses to AppleTalk addresses, also exists at the datalink layer
7-6
CHAPTER 7: ROUTING IN AN APPLETALK® ENVIRONMENT
because it is closely related to the Ethernet and token ring LAPs. This
protocol is usually included in the definition of each LAP, so it does not
appear in the reference model. See the section “About AARP” later in this
chapter for more information about this protocol.
The Datagram
Delivery Protocol
(DDP)
The network layer accepts data from the layers above it and divides the data
into packets that can be sent over the network through the layers below it.
The Datagram Delivery Protocol (DDP) transfers data in packets called
datagrams.
Datagram delivery is the basis for building other AppleTalk services, such as
electronic mail. The DDP allows AppleTalk to run as a process-to-process,
best-effort delivery system in which the processes running in the nodes of
interconnected networks can exchange packets with each other.
End-to-End Services
The transport layer and the session layer provide end-to-end services in the
AppleTalk network. These services ensure that routers transmit data
accurately between one another. Each layer includes four protocols that
work together to support these services. This section describes these
protocols and provides more detail for those that you can view using the
LANplex Administration Console.
Transport Layer Protocols
An AppleTalk internet has four transport layer protocols:
■
Routing Table Maintenance Protocol (RTMP)
■
AppleTalk Echo Protocol (AEP)
■
AppleTalk Transaction Protocol (ATP)
■
Name Binding Protocol (NBP)
Routing Table Maintenance Protocol (RTMP). The protocol maintains
information about AppleTalk addresses and connections between different
networks. It specifies that each router 1) learns about new routes from the
other routers and 2) deletes routes after a certain period if the local router
no longer broadcasts the route to the network.
AppleTalk Protocols
7-7
Each router builds a routing table that is the basis of dynamic routing
operations in an AppleTalk internet. Every 10 seconds, each router sends an
RTMP data packet to the network. Routers use the information that they
receive in the RTMP broadcasts to build their routing tables. Each entry in
the routing table contains these items:
■
The network range
■
The distance in hops to the destination network
■
The interface number of the destination network
■
The state of each port (good, suspect, bad, really bad)
The router uses these items to determine the best path along which to
forward a data packet to its destination on the network. The routing table
contains an entry for each network that a datagram can reach within 15
hops of the router. The table is aged at set intervals as follows:
1 After a period of time, the RTMP changes the status of an entry from good
to suspect.
2 After an additional period of time, the RTMP changes the status of an entry
from suspect to bad.
3 After an additional period of time, the RTMP changes the status of an entry
from bad to really bad.
4 Finally, the router removes from the table the entry of a nonresponding
router with a really bad status.
The data in the routing table is cross-referenced to the Zone Information
Table (ZIT). This table maps networks into zones. The section on the session
layer protocols includes information about the ZIT.
Figure 7-3 illustrates a simple AppleTalk network and Table 7-1 shows the
corresponding routing table.
7-8
CHAPTER 7: ROUTING IN AN APPLETALK® ENVIRONMENT
Network 5-5
Router 802
Network 64-64
Router 801
Router 36
Network 18-20
Interface 2
Router 200
Router 24
Interface 1
Interface 3
Network 12-12
Network 103-103
Figure 7-3 A Simple AppleTalk Network
Table 7-1 The Routing Table for Router 24 in Figure 7-3
Network Range
Distance
Interface
State
5-5
1
2
Good
12-12
3
3
Good
18-20
2
3
Good
103-103
0
1
Good
64-64
1
3
Good
You can view the AppleTalk routing tables in your network through the
Administration Console.
AppleTalk Echo Protocol (AEP). AppleTalk nodes use the AEP to send
datagrams to other nodes in the network. It causes the destination node to
return, or echo, the datagram to the sending node. This protocol can
determine whether a node is accessible before any sessions are started,
and it can enable users to estimate the round-trip delay time between two
nodes.
AppleTalk Protocols
7-9
AppleTalk Transaction Protocol (ATP). This protocol, along with the
AppleTalk Data Stream Protocol (ADSP), ensures that DDP packets are
delivered to a destination without any losses or corruption.
Name Binding Protocol (NBP). This protocol translates alphanumeric
entity names to AppleTalk addresses. It maintains a table that references the
addresses of nodes and named entities that reside in that node. Because
each node maintains its own list of named entities, the names directory
within an AppleTalk network is not centralized. It is a distributed database of
all nodes on the internet.
The Session Layer Protocols
An AppleTalk internet has four session-layer protocols:
■
Zone Information Protocol (ZIP)
■
AppleTalk Data Stream Protocol (ADSP)
■
AppleTalk Session Layer Protocol (ASP)
■
Printer Access Protocol (PAP)
The Zone Information Protocol (ZIP). ZIP works with RTMP to maintain a
table that maps network numbers to network zones for the entire AppleTalk
internet. Network zones are the logical groupings of AppleTalk networks. As
we have seen it, the table created by ZIP is called the Zone Information
Table (ZIT). The Administration Console allows you to view the zone
information table by network number or network zone.
ZIP creates a zone information table in each router. Each entry in the ZIT is a
“tuple,” or pair, that includes a network number and a network zone name.
When an NBP packet arrives at the router, it includes the zone name which
the router compares with entries in the zone table. The router then matches
the network number from the matching ZIT tuple to the one in the RTMP
table to find the interface where it can route the packets.
7-10
CHAPTER 7: ROUTING IN AN APPLETALK® ENVIRONMENT
AppleTalk Data Stream Protocol (ADSP). The ADSP works with the ATP to
ensure reliable data transmission. Unlike ATP, however, ADSP provides
full-duplex byte-stream delivery. This means that two nodes can
communicate simultaneously. ASDP also includes flow control, so that a
fast sender does not overwhelm a slow receiver.
AppleTalk Session Protocol (ASP). The ASP passes commands between a
workstation and a server once a connection is made between the two. ASP
ensures that the commands are delivered in the same order as they were
sent and returns the results of these commands to the workstation.
Printer Access Protocol (PAP). The PAP maintains communications
between a workstation and a printer or print service. The PAP functions
include setting up and maintaining a connection, transferring the data, and
tearing down the connection on completion of the job. Like other protocols
at the session layer, PAP relies on NBP to find the addresses of named
entities. PAP also depends on ATP for sending data.
Presentation Layer
About AARP
The presentation layer maintains information about files, formats, and
translations between formats. An AppleTalk internet has two protocols at
the presentation layer: the AppleTalk Filing Protocol (AFP) and PostScript®.
AFP provides remote access to files on the network. PostScript is a paged
description language used by many printers.
The AppleTalk Address Resolution Protocol (AARP) maps the hardware
address of an AppleTalk node to an AppleTalk protocol address. It does this
mapping for both extended and nonextended networks.
When a node on the network initializes, it randomly selects an AppleTalk
address for itself. At the same time, it sends out ten AARP probe packets.
The probe packets determine whether any other nodes on the network are
using the address it has chosen. If a node on the network is already using
that address, the node randomly selects another address and sends out
another probe packet.
About AARP
7-11
The AARP maintains an Address Mapping Table (AMT) with the most
recently used hardware addresses and their corresponding AARP addresses.
If an address is not in this table, AARP sends a request to the protocol
address and adds the hardware address to the table when the destination
node replies. You can view this table, called the AARP cache, through the
LANplex Administration Console.
7-12
CHAPTER 7: ROUTING IN AN APPLETALK® ENVIRONMENT
ADMINISTERING VLANS
8
This chapter describes how to display information about VLANs and how to
configure VLANs.
Through the Administration Console, you can:
Displaying VLAN
Information
Top-Level Menu
system
ethernet
fddi
display
atm
mode
➧ bridge
ipFragmentation
ip
ipxSnapTranslation
ipx
addressThreshold
appletalk agingTime
snmp
stpState
analyzer stpPriority
➧ summary
script
stpMaxAge
logout
stpHelloTIme ➧ detail
stpForwardDelay define
stpGroupAddress modify
remove
port
packetFilter
➧ vlan
■
Display summary or detailed information on VLANs
■
Define or modify a VLAN definition
■
Delete a VLAN definition
You can display a summary of VLAN information or a detailed report. When
you display a summary, you receive information about the protocols and
ports assigned to each VLAN plus the layer 3 addresses used to manage
flood domains for overlapping IP subnets. The detailed VLAN report includes
the summary information plus additional utilization statistics.
From the top level of the Administration Console, enter:
bridge vlan summary
or
bridge vlan detail
The VLAN information is displayed in the format you specified.
Example of a summary display for several VLANs:
Select menu option (bridge/vlan): summary
Index Protocol
1
default
2
IP
3
IPX
4
IP
Identifier
0
2
3
4
Ports
1-17
1, 5-7
8-10
7, 12-15
8-2
CHAPTER 8: ADMINISTERING VLANS
Index
1
2
3
4
Name
none
eastgroup
westgroup
northgroup
Layer 3
158.101.111.16
none
158.101.112.14
255.255.255.0
255.255.255.0
Example of a detailed display for the VLANs:
Select menu option (bridge/vlan): detail
Index Protocol
1
default
2
IP
3
IPX
4
IP
Index
1
2
3
4
Identifier
0
2
3
4
Name
none
eastgroup
westgroup
northgroup
index inPackets
1
342
2
125
3
345
4
876
inBytes
3676
7654
7554
8651
Ports
1-17
1, 5-7
8-10
7, 12-15
Layer 3
158.101.111.16
none
158.101.112.14
outPackets
322
118
289
765
255.255.255.0
255.255.255.0
outBytes
2987
6897
7431
7969
Table 8-1 describes these statistics.
Table 8-1 Fields for VLAN Information
Field
Description
Index
A system-assigned index used for identifying a particular VLAN
Protocol
The protocol suite of the VLAN
Identifier
A unique, user-defined (4-byte) integer for use by global
management operations
Ports
The numbers of the ports assigned to the VLAN
Name
A 16-byte character string intended to identify the members of the
VLAN
Layer 3
Optional parameters consisting of IP subnet and mask used to set
up flood domains for overlapping IP VLAN subnets
continued
Defining VLAN Information
8-3
Table 8-1 Fields for VLAN Information (continued)
Field
Description
inPackets
Number of flooded broadcast and multicast packets that were
received on the VLAN
inBytes
Number of flooded broadcast and multicast bytes that were
received on the VLAN
outPackets
Number of flooded broadcast and multicast packets transmitted
over the VLAN
outBytes
Number of flooded broadcast and multicast bytes transmitted over
the VLAN
Defining VLAN
Information
Top-Level Menu
system
ethernet
fddi
display
atm
mode
➧ bridge
ipFragmentation
ip
ipxSnapTranslation
ipx
addressThreshold
appletalk agingTime
snmp
stpState
analyzer
stpPriority
summary
script
stpMaxAge
detail
logout
stpHelloTIme ➧ define
stpForwardDelay modify
stpGroupAddress remove
port
packetFilter
➧ vlan
Follow these steps to create a VLAN definition:
1 From the top level of the Administration Console, enter:
bridge vlan define
2 Enter the appropriate protocol suite: (IP, IPX, AppleTalk, XNS,
DECnet, SNA, Banyan, X.25, NetBIOS, NetBEUI, default)
3 Enter the VLAN interface identifier.
4 Enter the VLAN name, enclosed in quotation marks.
5 Enter the number(s) of the port(s) or all to assign all ports to the VLAN.
You are prompted to enter the number(s) of the port(s) that can be
assigned to the VLAN.
If you did not choose the IP protocol suite for this VLAN, you have
completed the steps for defining the VLAN.
If you selected the IP protocol suite, follow these steps:
1 Enter defined to use layer 3 subnet addressing and continue with steps 2
and 3, OR enter undefined to not use layer 3 addressing.
2 Enter the IP subnet address.
3 Enter the subnet mask.
8-4
CHAPTER 8: ADMINISTERING VLANS
Example:
Select menu option (bridge/vlan): define
Enter Protocol Suite
(IP,IPX,AppleTalk,XNS,DECnet,SNA,Banyan,X.25,NetBIOS,NeBEUI,
default): IP
Enter VLAN Identifier: 1
Enter VLAN Name: “SD Marketing”
Ports 1=FDDI, 2-17=Ethernet
Enter port(s)
(1-17|all): 1-5
Layer 3 Address (undefined, defined): defined
Enter IP Subnet Address: 158.111.122.0
Enter subnet mask [255.255.0.0] 255.255.255.0
The maximum number of VLANs you can define on a single bridge is 32.
Modifying VLAN
Information
Top-Level Menu
system
ethernet
fddi
display
atm
mode
➧ bridge ipFragmentation
ip
ipxSnapTranslation
ipx
addressThreshold
appletalk agingTime
snmp
stpState
analyzer stpPriority
summary
script
stpMaxAge
detail
logout
stpHelloTIme
stpForwardDelay define
stpGroupAddress ➧ modify
remove
port
packetFilter
➧ vlan
To modify VLAN information:
1 From the top level of the Administration Console, enter:
bridge vlan modify
You are prompted to reenter the information that defines the VLAN. Press
the Return or Enter key to accept any value that appears in brackets [ ].
2 Enter the number of the VLAN interface index.
3 Enter the protocol suite for that VLAN: (IP, IPX, AppleTalk, XNS,
DECnet, SNA, Banyan, X.25, NetBIOS, NetBEUI, default).
4 Enter the VLAN identifier.
5 Enter the VLAN name.
6 Enter the number(s) of the port(s) or all.
7 If you have selected the IP protocol suite and want to use the Layer 3
address information, enter defined for layer 3 addressing. Enter
undefined if you do not want layer 3 addressing.
Removing VLAN Information
Example:
Select menu option (bridge/vlan): modify
Select VLAN interface [1-2]: 2
Protocol Suite (IP,IPX,AppleTalk,XNS,DECnet,SNA,
Banyan,X.25,NetBIOS,NetBEUI,default) [AppleTalk]: IP
VLAN Identifier [1]: 2
VLAN Name [Sales]:
Ports 1=FDDI, 2-17=Ethernet
Enter port(s)
(1-17|all) [1-5]:
Layer 3 Address (undefined,defined) [undefined]:
Removing VLAN
Information
Top-Level Menu
system
ethernet
fddi
display
atm
mode
➧ bridge
ipFragmentation
ip
ipxSnapTranslation
ipx
addressThreshold
appletalk agingTime
snmp
stpState
analyzer
stpPriority
summary
script
stpMaxAge
detail
logout
stpHelloTIme
define
stpForwardDelay
modify
stpGroupAddress
➧ remove
port
packetFilter
➧ vlan
Follow these steps to remove a VLAN definition:
1 From the top level of the Administration Console, enter:
bridge vlan remove
2 Enter the indexes for the VLANs you want to remove.
Example:
Select menu option (bridge/vlan): remove
Select VLAN index(es) (1-2|all): 1
8-5
8-6
CHAPTER 8: ADMINISTERING VLANS
ADMINISTERING IP ROUTING
9
This chapter describes how to set up your LANplex® system to use the
Internet Protocol (IP). For more information about how IP works, see Part III
of this guide.
You can display or configure the following IP characteristics on your
LANplex system:
Administering
interfaces
■
IP interfaces
■
Routes
■
Address Resolution Protocol (ARP) cache
■
UDP Helper
■
ATM ARP Server (for LANplex systems with ATM modules)
■
IP Routing
■
ICMP Router Discovery
■
Routing Information Protocol (RIP)
■
Ping
■
IP statistics
You can define two types of IP interfaces through LANplex Extended
Switching software: IP VLAN interfaces and IP LIS interfaces. This section
describes these interfaces and how to administer them.
An IP VLAN interface defines the relationship between an IP Virtual LAN
(VLAN) and the subnets in the IP network. Every IP VLAN interface has one
IP VLAN associated with it. Each Ethernet or FDDI switching module has one
interface defined for each subnet directly connected to it. You must first
define a VLAN, as described in Chapter 8, Administering VLANs, before you
define an associated IP VLAN interface.
9-2
CHAPTER 9: ADMINISTERING IP ROUTING
LIS Interfaces
A logical IP subnet (LIS) interface supports logical IP over ATM. You define
LIS interfaces for the ports on ATM modules only. See the Chapter 11 of the
LANplex® 2500 Operation Guide for more information about the ATM
protocol. See the LANplex® 2500 Administration Console User Guide for
information about how to configure ATM ports.
Interface
Characteristics
Each IP interface has the following information associated with it:
■
IP Address — This address, which is specific to your network, should be
chosen from the range of addresses assigned to your organization by the
central agency. This address defines both the number of the network to
which the interface is attached and the interface’s host number on that
network.
■
Subnet Mask — A subnet mask is a 32-bit number that uses the same
format and representation as IP addresses. The subnet mask determines
which bits in the IP address are interpreted as the network number, the
subnet number, and the host number. Each IP address bit corresponding to
a 1 in the subnet mask is in the network/subnet part of the address. Each IP
address bit corresponding to a 0 is in the host part of the IP address.
■
Advertisement Address — The switching module uses this IP address
when it advertises routes to other stations on the same subnet. In particular,
the system uses this address for sending RIP updates. By default the
switching module uses a directed advertisement (all 1s in the host field).
■
Cost — This number, between 1 and 15, is used when calculating route
metrics. Unless your network has special requirements, assign a cost of 1 to
all interfaces.
■
Type — The IP interface is one of these types:
■
VLAN, which supports routing between two VLANs
■
LIS, which supports classical IP over ATM
■
State — This status of the IP interface indicates whether the interface is
available for communications.
■
VLAN Interface — When you select VLAN as the interface type, the
Administration Console prompts you for the VLAN index number. The VLAN
index number indicates which bridge ports are associated with the IP
interface. When the LANplex Administration Console menu prompts you for
Administering interfaces
9-3
this option, the system displays a list of available VLAN indexes and the
bridge ports associated with them.
■
LIS Interface — When you select LIS as the interface type, the
Administration Console prompts you for LIS interface information. The
information you enter depends on whether you define permanent virtual
circuits (PVCs), switched virtual circuits (SVCs), or both on the LIS interface.
See the LANplex® 2500 Operation Guide for more information on PVCs and
SVCs.
If you define SVCs, you need to enter an ATM ARP server address. This server
maintains the IP-to-ATM address translation table. You can enter the
maximum number of SVCs allowed on this interface. The minimum holding
time determines the least amount of time an SVC connection remains open.
The inactivity timer determines how long the connection can remain open
with no activity after the minimum holding time has expired. You also need
to enter the ATM port number for this interface.
If you define only PVCs on the interface, you need to enter only the PVC
numbers and the ATM port number. The other prompts do not appear
because you do not enter an ATM ARP server address. If you define both
SVCs and PVCs, enter all LIS interface information.
Displaying
Interfaces
Top-Level Menu
system
ethernet ➧ interface
route ➧ summary
fddi
arp
atm
➧ detail
bridge atmArpServer
define
multicast modify
➧ ip
udpHelper remove
ipx
appletalk routing addAdvertisement
icmpRouterDiscovery
snmp
removeAdvertisement
analyzer rip
addPVC
ping
script
removePVC
logout statistics
You can display both summary and detailed information about all IP
interfaces configured for the system. The detail display contains all the
summary information as well as information about the advertisement
address, PVCs, and VLANs.
To display IP interface information, enter one of the following command
strings from the Administration Console top-level menu:
ip interface summary
OR
ip interface detail
9-4
CHAPTER 9: ADMINISTERING IP ROUTING
Example summary display:
IP routing is enabled, RIP is active,
ICMP discovery is disabled.
Index Type
IP address
Subnet mask
1 VLAN
158.101.1.1
255.255.255.0
Index Type
IP address
Subnet mask
2 LIS
158.101.112.1
Cost
1
Cost
255.255.255.0
1
State VLAN Index
Down
2
State Port
Up
1
Example detail display:
IP forwarding is enabled, RIP is active,
ICMP discovery is disabled.
Index
1
Type
VLAN
IP address
158.101.1.1
Subnet mask
255.255.255.0
Cost
1
State VLAN index
Down
2
Index
2
Type
LIS
IP address
158.101.112.1
Subnet mask
255.255.255.0
Cost
1
State Port
Up
1
4 Advertisement Addresses:
158.101.112.200 158.101.112.203 158.101.112.204 158.101.112.205
atmArpServer
47-0000-00-000000-0000-0000-00cc-080001200054-ff
maxSvcCount
0
inactivityTime
1200
minHoldingTime
60
1PVC:
1/32
Defining an IP LIS
Interface
Top-Level Menu
system
ethernet➧ interface
route summary
fddi
arp
detail
atm
➧ define
bridge atmArpServer
multicast modify
➧ ip
udpHelperremove
ipx
appletalk routing addAdvertisement
removeAdvertisement
snmp icmpRouterDiscovery
addPVC
analyzer rip
ping
removePVC
script
statistics
logout
When you define an IP LIS interface, you specify several general IP interface
characteristics and IP LIS characteristics.
Before you define an IP LIS interface with SVCs, be sure you have defined an
ATM ARP server as described in the section “Administering ATM ARP Servers”
later in this chapter. If the LIS interface has only PVCs, you do not need to
define an ATM ARP server.
To define an IP interface:
1 From the top level of the Administration Console, enter:
ip interface define
Administering interfaces
9-5
The Console prompts you for the interface’s parameters. To use the value in
brackets, press [Return] at the prompt.
2 Enter the IP address of the interface.
3 Enter the subnet mask of the network to which the interface is to be
connected.
4 Enter the cost value of the interface.
5 Enter the type of IP interface: LIS.
6 Enter the advertisement addresses for this interface. You can enter up to 32
advertisement addresses for each interface. (The maximum number on the
LANplex system is 64.)
7 Enter the LIS information:
■
■
For a LIS interface with SVCs, enter the ATM ARP server address, the
maximum SVC count, the inactivity timer, the minimum holding time,
and the ATM port associated with the interface. (You can also accept the
defaults for these values.)
For a LIS interface with only PVCs, enter the ATM port and the PVCs
associated with the interface. You can enter up to 51 PVCs for each
interface. (The maximum number on the LANplex system is 64.)
LIS interface example with both PVCs and SVCs:
Enter IP address: 158.101.1.1
Enter subnet mask [255.255.0.0]: 255.255.255.0
Enter cost [1]:
Enter interface type (vlan,lis) [lis]:
Enter advertisement address(es) []: 158.101.112.1
Enter ATM arp server address
[00-0000-00-000000-0000-0000-0000-000000000000-00]: 47-0000-00-000000-000
00000-00cc -000000000001-ff
Accept completed ATM address (yes,no) [yes]:
Enter max. SVC count (0=no max.0) [0]:
Enter inactivity time (0=infinite, 10-10000) seconds [1200]:
Enter min. holding time (0-10000) seconds [60]:
Select ATM port [1]:
Enter PVC(s) (VPI/VCI)[]: 1/32,1/200,1/3330
9-6
CHAPTER 9: ADMINISTERING IP ROUTING
Defining an IP
VLAN Interface
When you define an IP VLAN interface, you specify several interface
characteristics, as well as the index of the VLAN associated with the
interface.
You must first define a VLAN, as described in Chapter 8, Administering VLANs,
before you define an associated IP VLAN interface.
Top-Level Menu
system
ethernet
➧ interface
fddi
summary
route
atm
detail
arp
bridge
➧ define
atmArpServer
➧ ip
multicast modify
ipx
udpHelperremove
appletalk routing addAdvertisement
snmp icmpRouterDiscovery
removeAdvertisement
analyzer rip
addPVC
script ping
removePVC
logout statistics
To define an IP VLAN interface:
1 From the top level of the Administration Console, enter:
ip interface define
The Console prompts you for the interface’s parameters. To use the value in
brackets, press [Return] at the prompt.
2 Enter the IP address of the interface.
3 Enter the subnet mask of the network to which the interface is to be
connected.
4 Enter the cost value of the interface.
5 Enter the type of IP interface: VLAN.
6 Enter the advertisement address for this interface.
7 Enter the index of the VLAN associated with the interface.
Example:
Enter IP address: 158.101.1.1
Enter subnet mask [255.255.0.0]: 255.255.255.0
Enter cost [1]:
Enter interface type (vlan, lis) [vlan]:
Enter advertisement address(es) [158.101.1.255]:
IP VLANs:
Index
Ports
3
1-8
4
9-12
Select VLAN index: 3
If you physically change the configuration of your system after defining IP
interfaces, the ports designated for those interfaces might no longer be valid
and you might want to reconfigure your interfaces.
Administering interfaces
Modifying an
Interface
9-7
You might want to change the configuration of an interface you have
already defined.
You can add one or more advertisement addresses or PVCs to an interface
through the addAdvertisement and addPVC commands as well as through
the IP interface modify command. If you add or change an advertisement
address or PVC through the modify command, you must re-enter all
addresses or PVCs associated with the interface, not just the one you want to
add or change.
Top-Level Menu
system
ethernet➧ interface
summary
fddi
route
detail
atm
arp
1
define
bridge atmArpServer
➧
modify
➧ ip
multicast
ipx
udpHelper remove
appletalk routing addAdvertisement
removeAdvertisement
snmp
icmpRouterDiscovery
addPvc
analyzer rip
removePvc
script
ping
logout statistics
To modify an IP interface:
From the top level of the Administration Console, enter:
ip interface modify
You are prompted for the interface parameters. Press [Return] at the
prompts for the parameters you do not want to modify.
2 Modify the existing interface parameters by entering a new value at the
prompt.
Removing an
Interface
Top-Level Menu
system
ethernet➧ interface
summary
fddi
route
detail
atm
arp
define
bridge atmArpServer
modify
➧ ip
multicast
➧ remove
ipx
udpHelper
appletalk routing addAdvertisement
removeAdvertisement
snmp
icmpRouterDiscovery
addPvc
analyzer rip
script
ping removePvc
logout statistics
You might want to remove an interface if you no longer route on the ports
associated with the interface.
To remove an IP interface definition:
1 From the top level of the Administration Console, enter:
ip interface remove
2 Enter the index numbers of the interfaces you want to remove.
If you have defined one or more PVCs on the interface, the Administration
Console displays a message indicating that the PVCs will be removed with
the interface. The following is an example of a prompt for interface 2, which
has one PVC associated with it:
1 PVC associated with the interface index 2. Do you wish
to continue (yes/no) [yes]:
Accept the default (yes) if you want to delete the interface.
9-8
CHAPTER 9: ADMINISTERING IP ROUTING
Adding an
Advertisement
Address
This command adds an advertisement address to the advertisement
address list associated with the interface.
To add an advertisement address:
Top-Level Menu
system
ethernet➧ interface
summary
fddi
route
detail
atm
arp
define
bridge atmArpServer
modify
multicast
➧ ip
remove
udpHelper
ipx
➧ addAdvertisement
appletalk routing
removeAdvertisement
icmpRouterDiscovery
snmp
addPvc
analyzer rip
removePvc
ping
script
logout statistics
1 From the top level of the Administration Console, enter:
ip interface addAdvertisement
2 Enter the interface index number.
3 Enter the advertisement address, separated by commas.
Example:
Select interface index [1]: 1
Enter advertisement address: 158.101.255.1, 158.111.1.1
Removing an
Advertisement
Address
Top-Level Menu
system
ethernet
fddi ➧ interface
route
summary
atm
detail
bridge arp
atmArpServer
define
➧ ip
multicast modify
ipx
appletalk udpHelperremove
routing addAdvertisement
snmp
➧ removeAdvertisement
analyzer icmpRouterDiscovery
rip
addPvc
script
removePvc
logout ping
statistics
This command removes an advertisement address from the advertisement
address list associated with the interface.
To remove an advertisement address:
1 From the top level of the Administration Console, enter:
ip interface removeAdvertisement
2 Enter the index interface number and the advertisement address you want
to remove.
Administering Routes
Adding a Permanent
Virtual Circuit (PVC)
9-9
This command adds a PVC to an LIS interface.
To add a PVC:
Top-Level Menu
system
ethernet
fddi ➧ interface
route
summary
atm
detail
bridge arp
atmArpSErver
define
➧ ip
multicast modify
ipx
appletalk udpHelperremove
routing addAdvertisement
snmp
removeAdvertisement
analyzer icmpRouterDiscovery
rip
➧ addPvc
script
removePvc
logout ping
statistics
1 From the top level of the Administration Console, enter:
ip interface addPvc
2 Enter the index interface number that you want to associate with the PVC.
3 Enter the Virtual Path Interface (VPI) and the Virtual Circuit Interface (VCI)
pairs in this format: VPI/VCI. Separate additional entries with a comma.
Example:
Select interface index [1]: 1
Enter [VPI/VCI]: 2/20
Removing a
Permanent Virtual
Circuit (PVC)
This command removes one or more PVCs associated with an LIS interface.
To remove a PVC, from the top level of the Administration Console, enter:
ip interface removePVC
Top-Level Menu
system
ethernet
fddi ➧ interface
summary
route
atm
detail
bridge arp
multicast define
➧ ip
modify
atmArpServer
ipx
remove
appletalk udpHelperaddAdvertisement
routing
snmp
removeAdvertisement
analyzer icmpRouterDiscovery
addPvc
rip
script
➧ removePvc
logout ping
statistics
Enter the index number of the interface you want to remove and the
VPI/VCI pair that you want to remove.
Administering
Routes
Each system maintains a table of routes to other IP networks, subnets, and
hosts. You can make static entries in this table using the Administration
Console or configure the system to use RIP to exchange routing information
automatically.
Each routing table entry contains the following information:
■
Destination IP Address and Subnet Mask — These elements define the
address of the destination network, subnet, or host. A route matches an IP
address if the bits in the IP address that correspond to the bits set in the
route subnet mask match the route destination address. If the system finds
9-10
CHAPTER 9: ADMINISTERING IP ROUTING
more than one routing table entry matching an address, it uses the most
specific route, which is the route with the most bits set in its subnet mask.
For example, the route to a subnet within a destination network is more
specific than the route to the destination network.
■
Routing Metric — This metric specifies the number of networks or subnets
through which a packet must pass to reach its destination. This metric is
included in RIP updates to allow routers to compare routing information
received from different sources.
■
Gateway IP Address — This address tells the router how to forward
packets whose destination addresses match the route’s IP address and
subnet mask. The system forwards such packets to the indicated gateway.
■
Status — For each interface, the route provides the status information in
Table 9-1.
Table 9-1 Interface Status Information
Status
Description
Direct
Route goes to a directly connected network
Static
Route was statically configured
Learned
Route was learned using indicated protocol
Timing out
Route was learned but is partially timed out
Timed out
Route has timed out and is no longer valid
In addition to the routes to specific destinations, the routing table can
contain an additional entry called the default route. The system uses the
default route to forward packets that do not match any other routing table
entry. You might want to use a default route in place of routes to numerous
destinations that all have the same gateway IP address.
Administering Routes
Displaying the
Routing Table
Top-Level Menu
system
ethernet interface ➧ display
➧ route
fddi
static
arp
atm
atmArpServer remove
bridge
flush
multicast
➧ ip
default
udpHelper
ipx
noDefault
appletalk routing
icmpRouterDiscovery
snmp
analyzer rip
ping
script
statistics
logout
9-11
You can display a switching module’s routing table to determine which
routes are configured and whether the routes are operational.
To display the contents of the routing table, enter the following command
string from the top level of the Administration Console:
ip route display
The example shows routes for the LANplex 2500 system. The display
indicates the configuration of RIP. The default route appears as Default
Route.
IP routing is enabled, RIP is active, ICMP router discovery is
disabled.
Destination
158.101.4.0
158.101.3.0
158.101.2.0
158.101.1.0
Default Route
Defining a Static
Route
Subnet mask
Metric
255.255.255.0
2
255.255.255.0
2
255.255.255.
1
255.255.255.0
1
-5
Gateway
158.101.2.8
158.101.1.2
--158.101.1.2
Status
Static
Learned(RIP)
Direct
Direct
Learned (RIP)
Before you can define static routes, you must define at least one IP
interface. Static routes remain in the table until you remove them or the
corresponding interface. Static routes take precedence over dynamically
learned routes to the same destination.
Static routes are not included in periodic RIP updates sent by the system.
To define a static route:
Top-Level Menu
system
ethernet interface
fddi
➧ route
display
atm
arp
➧ static
bridge
atmArpServer remove
➧ ip
multicast
flush
ipx
udpHelper default
appletalk routing
noDefault
snmp
icmpRouterDiscovery
analyzer rip
script
ping
logout
statistics
1 From the top level of the Administration Console, enter:
ip route static
You are prompted for the route’s parameters. To use the value in brackets,
press [Return] at the prompt.
2 Enter the destination IP address of the route.
3 Enter the subnet mask of the route.
4 Enter the gateway IP address of the route.
9-12
CHAPTER 9: ADMINISTERING IP ROUTING
Example:
Enter destination IP address: 158.101.4.0
Enter subnet mask [255.255.0.0]: 255.255.255.0
Enter gateway IP address: 158.101.2.8
Removing a Route
Top-Level Menu
system
ethernet interface
display
➧ route
fddi
static
atm
arp
bridge
atmArpServer➧ remove
multicast
flush
➧ ip
udpHelper
default
ipx
noDefault
appletalk routing
icmpRouterDiscovery
snmp
analyzer rip
ping
script
statistics
logout
Flushing a Route
Top-Level Menu
system
interface
ethernet
display
➧ route
fddi
static
arp
atm
atmArpServer remove
bridge
multicast ➧ flush
➧ ip
udpHelper default
ipx
routing
noDefault
appletalk
icmpRouterDiscovery
snmp
rip
analyzer
ping
script
statistics
logout
Setting the Default
Route
To remove a route:
1 From the top level of the Administration Console, enter:
ip route remove
2 Enter the destination IP address of the route.
3 Enter the subnet mask of the route.
The route is immediately deleted from the routing table.
Flushing deletes all learned routes from the routing table.
To flush all learned routes, from the top level of the Administration Console,
enter:
ip route flush
All learned routes are immediately deleted from the routing table.
If you define a default route, the system uses it to forward packets that do
not match any other routing table entry. A system can learn a default route
using RIP, or you can configure a default route statically.
If a system’s routing table does not contain a default route — either
statically configured or learned using RIP — then it cannot forward a packet
that does not match any other routing table entry. If this occurs, then the
module drops the packet and sends an ICMP “destination unreachable”
message to the host that sent the packet.
Administering the ARP Cache
Top-Level Menu
system
ethernet interface
display
fddi
➧ route
static
atm
arp
remove
bridge
atmArpServer
flush
➧ ip
multicast
ipx
udpHelper ➧ default
noDefault
appletalk routing
snmp
icmpRouterDiscovery
analyzer rip
script
ping
logout
statistics
Removing the
Default Route
Top-Level Menu
system
ethernet
interface
fddi
➧ route
display
atm
static
arp
bridge
remove
multicast
➧ ip
atmArpServer flush
ipx
udpHelper default
appletalk
routing
➧ noDefault
snmp
icmpRouterDiscovery
analyzer
rip
script
ping
logout
statistics
Administering
the ARP Cache
9-13
To statically configure the default route:
1 From the top level of the Administration Console, enter:
ip route default
2 Enter the gateway IP address of the route.
The default route is immediately added to the routing table.
To remove a default route, enter the following command string from the
top level of the Administration Console:
ip route noDefault
The default route is immediately removed from the routing table.
The LANplex system uses the Address Resolution Protocol (ARP) to find the
MAC addresses corresponding to the IP addresses of hosts and routers on
the same subnets. An ARP cache is a table of known IP addresses and their
corresponding MAC addresses.
9-14
CHAPTER 9: ADMINISTERING IP ROUTING
Displaying the ARP
Cache
Top-Level Menu
system
ethernet interface
fddi
route
atm
➧ display
➧ arp
bridge
atmArpServer remove
➧ ip
flush
multicast
ipx
udpHelper
appletalk routing
snmp
icmpRouterDiscovery
analyzer rip
script
ping
logout
statistic s
You can display the contents of the ARP cache for your system.
To display the contents of the ARP cache, enter the following command
string from the top level of the Administration Console:
ip arp display
Example display of the contents of the ARP cache:
IP routing is enabled, RIP is active,
ICMP router discovery is disabled
IP address
158.101.112.2
158.101.112.7
158.101.116.7
158.101.112.14
158.101.116.16
158.101.116.17
158.101.116.18
158.101.112.22
158.101.116.19
158.101.112.28
158.101.112.29
158.101.116.27
Removing an ARP
Cache Entry
Top-Level Menu
system
ethernet interface
route
fddi
➧ arp
atm
display
bridge
atmArpServer➧ remove
multicast
➧ ip
flush
udpHelper
ipx
appletalk routing
icmpRouterDiscovery
snmp
analyzer rip
ping
script
statistics
logout
I/F
1
1
2
1
2
2
2
1
2
1
1
2
Hardware address
00-40-0b-40-64-e6
08-00-20-76-a2-f2
00-80-3e-02-68-00
08-00-09-4e-24-20
00-80-3e-02-8e-6a
00-80-3e-02-8e-7f
00-80-3e-02-8e-94
08-00-20-04-d1-5e
00-80-3e-02-8e-2b
08-00-09-8c-de-3a
08-00-09-82-d8-1b
00-80-3e-1d-75-00
Circuit
-/-/-/-/-/-/-/-/-/-/-/-/-
You might want to remove an entry from the ARP cache if the MAC address
has changed. To remove an entry from the ARP cache:
1 From the top level of the Administration Console, enter:
ip arp remove
2 Enter the IP address you want to remove.
The address is immediately removed from the table. If necessary, the system
subsequently uses ARP to find the new MAC address corresponding to that
IP address.
Administering ATM ARP Servers
Flushing the ARP
Cache
Top-Level Menu
system
ethernet interface
route
fddi
display
➧ arp
atm
atmArpServer remove
bridge
multicast ➧ flush
➧ ip
udpHelper
ipx
appletalk routing
icmpRouterDiscovery
snmp
analyzer rip
ping
script
statistics
logout
Administering
ATM ARP Servers
9-15
You might want to delete all entries from the ARP cache if the MAC address
has changed.
To remove all entries from the ARP cache, from the top level of the
Administration Console, enter:
ip arp flush
The ARP cache entries are immediately removed from the table.
If you are running classical IP over ATM with SVCs, you need to define an
ATM ARP server for each LIS. Each LIS must connect to a single ATM network
and must belong to the same IP subnet.
The atmArpServer menu also includes the arp option, which allows you to
administer the ATM ARP cache.
Displaying ATM
ARP Servers
Top-Level Menu
system
ethernet interface
fddi
route
atm
arp
➧ display
bridge
➧ atmArpServer define
➧ ip
multicast
remove
ipx
udpHelper
arp
appletalk routing
snmp icmpRouterDiscovery
analyzer rip
script ping
logout statistics
To display a list of ATM ARP servers, from the top level of the Administration
Console, enter:
ip atmArpServer display
Example:
IP routing is enabled, RIP is active,
ICMP router discovery is disabled
Index
1
Port
1
IP Address
158.101.1.1
Subnet Mask
255.255.255.0
ATM address
47-0000-00-000000-0000-0000-00cc-000000000000-ff
9-16
CHAPTER 9: ADMINISTERING IP ROUTING
Defining an ATM
ARP Server
Top-Level Menu
system
ethernet interface
fddi
route
atm
arp
display
bridge
➧ atmArpServer➧ define
➧ ip
multicast
remove
ipx
udpHelper
arp
appletalk routing
snmp icmpRouterDiscovery
analyzer rip
script ping
logout statistics
Determine the location of the ATM ARP server you want to use. You can
define the ATM ARP server externally on another LANplex system or on an
ATM switch, such as 3Com’s CELLplex™ 7000 system.
1 To define an ATM ARP server, from the top level of the Administration
Console, enter:
ip atmArpServer define
2 Enter the number of the ATM port where you want to define the ATM ARP
server.
3 Enter the IP address of the ATM port you want to define.
4 Enter the subnet mask. To accept the default value, shown in brackets, press
the [Return] key at the prompt.
Example:
Select ATM port [1]
Enter IP address: 158.101.20.30
Enter subnet mask [255.255.0.0]
Removing an ATM
ARP Server
Top-Level Menu
system
ethernet interface
fddi
route
atm
arp
display
bridge
➧ atmArpServer define
➧ ip
multicast ➧ remove
ipx
udpHelper
arp
appletalk routing
snmp icmpRouterDiscovery
analyzer rip
script ping
logout statistics
To delete a currently defined ATM ARP server, from the top level of the
Administration Console, enter:
ip atmArpServer remove
The systems prompts you for one or more index numbers associated with
the ATM ARP servers that you want to remove. The ATM ARP server display
shows the index number assigned to each ATM ARP server. The system also
displays the current index numbers in the prompt.
Example:
Select ATM ARP server index(es) [1-2,all]: 1
Administering ATM ARP Servers
Displaying the ATM
ARP Cache
9-17
To display the contents of the ATM ARP cache, from the top level of the
Administration Console, enter:
Top-Level Menu
ip atmArpServer
system
ethernet interface
fddi
route
display
atm
arp
define
bridge
remove➧ display
➧ atmArpServer
➧ ip
remove
multicast ➧ arp
ipx
flush
udpHelper
Example:
appletalk routing
snmp icmpRouterDiscovery
analyzer rip
script ping
IP routing is enabled, RIP
logout statistics
arp display
is active,
ICMP router discovery is disabled
IP address
158.101.112.2
158.101.112.7
158.101.116.7
158.101.112.14
Removing an ATM
ARP Cache Entry
Top-Level Menu
system
ethernet interface
fddi
route
display
atm
arp
define
bridge
remove display
➧ atmArpServer
➧ ip
multicast ➧ arp ➧ remove
ipx
flush
udpHelper
appletalk routing
snmp icmpRouterDiscovery
analyzer rip
script ping
logout statistics
ATM Address
47-005-80-ffe100-0000-f21a-2130-80000212d0f-18
47-005-80-ffe100-0000-f22a-2130-80000211d01-18
47-005-81-ffe100-0000-f21a-2130-80000112d01-18
47-005-81-ffe100-0000-f21a-2130-80000112d01-18
Circuit
1/32
1/33
2/20
2/22
To remove an entry from the ATM ARP cache, from the top level of the
Administration Console, enter:
ip atmarpserver arp remove
Enter the ATM address you want to remove.
The address is immediately removed from the table.
9-18
CHAPTER 9: ADMINISTERING IP ROUTING
Flushing the ATM
ARP Cache
To remove all entries from the ATM ARP cache, from the top level of the
Administration Console, enter:
Top-Level Menu
system
ethernet interface
fddi
route
display
atm
arp
define
bridge
remove display
➧ atmArpServer
➧ ip
remove
multicast ➧ arp
ipx
➧ flush
udpHelper
appletalk routing
snmp icmpRouterDiscovery
analyzer rip
script ping
logout statistics
ip atmarpserver arp flush
The ATM ARP cache entries are immediately removed from the table.
Administering
UDP Helper
UDP Helper allows you to send User Datagram Protocol (UDP) packets
between routed networks. This protocol provides support for UDP services
such as BOOTP or DHCP (Dynamic Host Configuration Protocol), that rely on
the BOOTP relay agent. For example, by configuring the logical BOOTP port,
you can boot hosts through the router. UDP Helper also provides a relay
agent for DHCP broadcasts. UDP packets that rely on the BOOTP relay agent
are modified and then forwarded through the router.
The following ports for the UDP services are mentioned in this section on
UDP Helper:
■
BOOTP (including DHCP) = 67
■
TIME = 37
■
DNS = 53
UDP Helper allows you to configure the amount of time a UDP packet is
forwarded between subnetworks. UDP packets are discarded based on the
hop count and the seconds value only for BOOTP and DHCP.
Administering UDP Helper
Displaying UDP
Helper Information
Top-Level Menu
system
ethernet
interface
fddi
route
➧ display
atm
arp
define
bridge
atmArpServer remove
➧ ip
multicast
hopCountLimit
ipx
➧ udpHelper threshold
appletalk
routing
snmp
icmpRouterDiscovery
analyzer
rip
script
ping
logout
statistics
Defining a Port and
an IP Forwarding
Address
Top-Level Menu
system
ethernet
interface
fddi
display
route
atm
arp
➧ define
bridge
atmArpServer remove
➧ ip
multicast
hopCountLimit
ipx
➧ udpHelper threshold
appletalk
routing
snmp
icmpRouterDiscovery
analyzer
rip
script
ping
logout
statistics
Removing a Port or
an IP Forwarding
Address
You can display the hop count and threshold configuration and list the
ports with their IP forwarding addresses that are defined for your LANplex
system.
To display UDP Helper information, enter the following command string
from the top level of the Administration Console:
ip udpHelper display
Example:
BOOTP relay hopcount limit is 4, BOOTP relay threshold is 0.
UDP port
67
forwarding address
<158.101.1.112
You can define port numbers and IP forwarding addresses for the UDP
Helper. You may have up to 32 combinations of port numbers/IP forwarding
addresses per router. You may also have multiple IP address entries for the
same ports.
To define port numbers and IP forwarding addresses:
1 From the top level of the Administration Console, enter:
ip udpHelper define
2 Enter the port numbers and IP forwarding addresses you want to define.
You can remove a port number or IP forwarding address defined for UDP
Helper.
To remove a port number or IP forwarding address:
Top-Level Menu
system
ethernet
interface
fddi
route
display
atm
arp
define
bridge
atmArpServer
➧ remove
➧ ip
multicast hopCountLimit
ipx
➧ udpHelper threshold
appletalk
routing
snmp
icmpRouterDiscovery
analyzer
rip
script
ping
logout
statistics
9-19
1 From the top level of the Administration Console, enter:
ip udpHelper remove
2 Enter the UDP port number that you want to remove.
3 Enter the IP forwarding address that you want to remove.
The port numbers and IP forwarding addresses you specified are
immediately removed.
9-20
CHAPTER 9: ADMINISTERING IP ROUTING
Setting the BOOTP
Hop Count Limit
You can set the maximum hop count for a packet to be forwarded through
the router. The range is 0 through 16. The default is 4.
Top-Level Menu
system
ethernet interface
1
route
fddi
display
arp
atm
atmArpServer define
bridge
remove
multicast
➧ ip
➧ udpHelper ➧ hopCountLimit
ipx
threshold
2
appletalk routing
icmpRouterDiscovery
snmp
analyzer rip
ping
script
statistics
logout
Setting the BOOTP
Relay Threshold
Top-Level Menu
system
interface
ethernet
route
fddi
display
arp
atm
atmArpServer define
bridge
remove
multicast
➧ ip
hopCountLimit
➧ udpHelper
ipx
➧ threshold
routing
appletalk
icmpRouterDiscovery
snmp
rip
analyzer
ping
script
statistics
logout
Enabling and
Disabling IP
Routing
Top-Level Menu
system
ethernet interface
route
fddi
arp
atm
atmArpserver
bridge
multicast
➧ ip
udpHelper
ipx
➧ routing
appletalk
icmpRouterDiscovery
snmp
analyzer rip
ping
script
statistics
logout
To set the hop count limit:
From the top level of the Administration Console, enter:
ip udpHelper hopCountLimit
Enter the BOOTP relay hop count limit.
You can set the maximum time limit that a packet is forwarded through the
router. If you use 0 as threshold value, the router ignores the seconds field. If
you use a non zero value, the router uses that value along with the hop
count value to determine whether to forward the UDP packet.
To set the BOOTP relay threshold:
1 From the top level of the Administration Console, enter:
ip udpHelper threshold
2 Enter the BOOTP relay threshold value.
You can control whether the system forwards or discards IP packets
addressed to other hosts. When you enable IP routing, the switching
module acts as a normal IP router, forwarding IP packets from one subnet to
another when required. When you disable IP routing, the system discards
any IP packets not addressed directly to one of its defined IP interfaces.
By default, IP routing is disabled on the system.
To enable or disable IP routing:
1 From the top level of the Administration Console, enter:
ip routing
2 Enter the IP routing state (enable or disable).
Enabling and Disabling ICMP Router Discovery
Enabling and
Disabling ICMP
Router Discovery
9-21
The Internet Control Message Protocol (ICMP) Router Discovery protocol
(RFC 1256) allows an appropriately configured end station to locate one or
more routers on the LAN to which it is attached. The end station then
automatically installs a default route to each of the routers running ICMP
Router Discovery. You do not need to manually configure a default route.
While IP traffic may initially be directed to any of the routers on the LAN,
ICMP redirect messages will subsequently channel the IP traffic to the
correct router.
Only certain end stations, such as Solaris® workstations, can be configured
to work with the ICMP Router Discovery protocol. Refer to the
documentation for your workstation to determine whether you can
configure it to work with this protocol.
Top-Level Menu
system
ethernet interface
route
fddi
arp
atm
atmArpserver
bridge
multicast
➧ ip
udpHelper
ipx
routing
appletalk
➧ icmpRouterDiscovery
snmp
analyzer rip
ping
script
statistics
logout
Enter the ICMP Router Discovery mode (enabled or disabled). This
protocol is disabled by default.
Setting the RIP
Mode
You can select a RIP mode that is appropriate for your network. RIP can
operate in any of three modes:
To enable ICMP Router Discovery, from the top level of the Administration
Console, enter
ip icmpRouterDiscovery
■
Off — The station ignores all incoming RIP packets and does not generate
any RIP packets of its own.
■
Active — The station processes all incoming RIP packets, responds to
explicit requests for routing information, and broadcasts periodic and
triggered RIP updates.
■
Passive — The station processes all incoming RIP packets and responds to
explicit requests for routing information, but it does not broadcast periodic
or triggered RIP updates.
9-22
CHAPTER 9: ADMINISTERING IP ROUTING
By default, RIP operates in passive mode.
RIP default mode
To set the RIP operating mode:
Top-Level Menu
system
ethernet interface
route
fddi
arp
atm
atmArpServer
bridge
multicast
➧ ip
udpHelper
ipx
routing
appletalk
icmpRouterDiscovery
snmp
analyzer ➧ rip
ping
script
statistics
logout
1 From the top level of the Administration Console, enter:
ip rip
2 Enter the RIP mode (off, passive, or active). To use the value in
brackets, press [Return] at the prompt.
Example:
Select RIP mode (off,passive,active) [passive]: active
Pinging an IP
Station
Pinging uses the Internet Control Message Protocol (ICMP) echo facility to
send an ICMP echo request packet to the IP station you specify. It then
waits for an ICMP echo reply packet. Possible responses from pinging:
■
Alive
■
No answer
■
Network is unreachable
A network is unreachable when there is no route to that network.
To ping an IP station:
Top-Level Menu
system
ethernet interface
route
fddi
arp
atm
atmArpServer
bridge
multicast
➧ ip
udpHelper
ipx
appletalk routing
icmpRouterDiscovery
snmp
analyzer rip
script ➧ ping
statistics
logout
1 From the top level of the Administration Console, enter:
ip ping
2 Enter the IP address of the station you want to ping.
IP Address: 192.9.200.40
You may receive one of the following responses:
192.9.200.40 is alive
OR
no answer from 192.9.200.40
For a remote IP address, you can also receive the following response:
Network is unreachable
Displaying IP Statistics
Displaying IP
Statistics
To display IP statistics, enter the following from the top level of the
Administration Console:
Top-Level Menu
system
ethernet interface
route
fddi
arp
atm
atmArpServer
bridge
multicast
➧ ip
udpHelper
ipx
routing
appletalk
icmpRouterDiscovery
snmp
rip
analyzer
ping
script
➧ statistics
logout
ip statistics
9-23
Example:
IP routing is enabled, RIP is active, ICMP router discovery is
disabled.
inReceives
51213
forwDatagrams
49743
outNoRoutes
273
inDelivers
3227
inHdrErrors
7
outRequests
2285
inAddrErrors
0
Table 9-2 describes the IP statistics.
.
Table 9-2 IP Statistics
Field
Description
inReceives
Total number of IP datagrams received, including those with errors
forwDatagrams
Number of datagrams that the IP station attempted to forward
inDelivers
Number of datagrams that the IP station delivered to local IP client
protocols
outRequests
Number of datagrams that local IP client protocols passed to IP for
transmission.
outNoRoutes
Number of datagrams that the IP station discarded because there
was no route to the destination
inHdrErrors
Number of datagrams that the IP station discarded because the IP
header contained errors
inAddrErrors
Number of datagrams that the IP station discarded because of an
error in the source or destination IP address
9-24
CHAPTER 9: ADMINISTERING IP ROUTING
ADMINISTERING
IP MULTICAST ROUTING
10
This chapter describes how to set up your LANplex® system to use IP
multicast routing. You should have previously defined IP interfaces and
routes as described in Chapter 9: Administering IP Routing, before you
define any IP multicast interfaces.
This appendix includes information on how to display or configure the
following parameters:
■
Enabling and disabling the Distance Vector Multicast Routing Protocol
(DVMRP)
■
Enabling and disabling the Internet Group Membership Protocol (IGMP)
■
Administering IP multicast interfaces
■
Administering multicast tunnels
■
The Route display
■
The Cache display
To use IP multicast routing on the LANplex system, you must have already
defined one or more IP interfaces. See Chapter 9, Administering IP Routing.
10-2
CHAPTER 10: ADMINISTERING IP MULTICAST ROUTING
Enabling and
Disabling DVMRP
DVMRP is the simple Distance Vector Multicast Routing Protocol, similar to
the IP Routing Information Protocol. Multicast routers exchange distance
vector updates that contain lists of destinations and the distance in hops to
each destination. The routers maintain this information in a routing table.
To run multicast routing, you must enable DVMRP, which enables DVMRP on
all IP interfaces that have not been disabled.
To enable or disable DVMRP, from the top level of the Administration
Console, enter:
Top-Level Menu
system
ethernet
interface
fddi
➧ dvmrp
route
atm
igmp
arp
bridge
atmArpServerinterfaces
➧ ip
➧ multicast tunnel
ipx
udpHelper routeDisplay
appletalk routing
cacheDisplay
snmp
icmpRouterDiscovery
analyzer
rip
script
ping
logout
statistics
ip multicast dvmrp
The interface prompts you to enable or disable DVMRP. The default is
disabled.
Example:
dvmrp mode (enabled/disabled)[disabled]: enabled
Enabling and
Disabling IGMP
IGMP enables a router or switch to determine whether group members
exist in a subnetwork, or “leaf,” of the Spanning Tree. It uses two search
methods to make this determination:
■
Query mode — The router or switch with the lowest IP address in the LAN
broadcasts a query to all other members of the subnetwork to determine
whether they are also in the group. End-stations respond to the query with
IGMP packets, which report the multicast group to which they belong.
■
Snooping mode — A router or switch performs dynamic multicast
filtering based on IGMP snooping. This procedure ensures that multicast
packets are flooded only to the appropriate ports within a routing interface.
Administering IP Multicast Interfaces
Top-Level Menu
system
ethernet interface
dvrmp
fddi
route
➧ igmp
atm
arp
bridge
atmArpServer interface
tunnel
➧ ip
➧ multicast
ipx
udpHelper routeDisplay
cacheDisplay
appletalk routing
snmp
icmpRouterDiscovery
analyzer
rip
script
ping
logout
statistics
10-3
When you select the IGMP option, the interface prompts you to enable or
disable IGMP snooping mode and IGMP query mode. Both are enabled by
default. Under most conditions, IGMP snooping mode and IGMP query
mode should remain enabled.
To enable or disable IGMP, from the top level of the Administration Console,
enter:
ip multicast igmp
The interface prompts you to enable or disable IGMP query mode and IGMP
snooping mode.
Example:
Enter igmp snooping mode
(enabled/disabled)[enabled]:enabled
Enter igmp query mode (enabled/disabled) [enabled]: enabled
Administering IP
Multicast
Interfaces
The IP multicast interface selections allow you to enable and disable
multicast characteristics on previously defined IP interfaces. A multicast
interface has three characteristics, explained next.
DVMRP Metric Value
The DVMRP metric value determines the cost of a multicast interface. The
higher the cost, the less likely it is that the packets will be routed over the
interface. The default value is 1.
Time To Live (TTL) Threshold
The TTL threshold determines whether the interface will forward multicast
packets to other switches and routers in the subnetWORK. If the interface
TTL is greater than the packet TTL, then the interface does not forward the
packet. The default value is 1, which means that the interface will forward
all packets.
10-4
CHAPTER 10: ADMINISTERING IP MULTICAST ROUTING
Rate Limit
The rate limit determines how fast multicast traffic can travel over the
interface in kilobytes per second. Multicast traffic may not exceed this rate
limit or the LANplex system will drop packets in order to maintain the set
rate. The default is set to 0, which implies no rate limit. In all other instances,
the lower the rate limit, the more limited the traffic over the interface.
Displaying
Multicast Interfaces
Top-Level Menu
system interface
dvmrp
ethernet route
igmp ➧ display
fddi
arp
atm
➧ interface enable
atmArpServer
bridge ➧ multicast tunnel disable
➧ ip
udpHelper routeDisplay
cacheDisplay
ipx
routing
appletalk icmpRouterDiscovery
snmp
rip
analyzer ping
script
statistics
logout
Index
1
To display a multicast interface:
1 From the top level of the Administration Console, enter:
ip multicast interface display
2 Enter the index numbers of the interfaces you want to display.
Example multicast interface configuration:
Local Address
158.101.112.32
Metric
Threshold
1
pkts
1
in:0
port
3
port
3 groups
port
4 groups
peers
RateLimit
0
pkts out:0
State
queries
158.101.112.204
158.101.112.202
224.2.127.255
224.2.143.24
224.2.143.24
224.2.127.225
(3.6) (0x8e)
(3.6) (0x8f)
(3.6) (0x8e)
Administering IP Multicast Interfaces
Disabling Multicast
Interfaces
Top-Level Menu
system
ethernet interface
route
dvmrp
fddi
arp
igmp display
atm
atmArpServer
bridge
➧ interface enable
➧ multicast tunnel ➧ disable
➧ ip
udpHelper routeDisplay
ipx
cacheDisplay
appletalk routing
icmpRouterDiscovery
snmp
analyzer rip
ping
script
statistics
logout
Enabling Multicast
Interfaces
Top-Level Menu
system
ethernet interface
route
dvmrp
fddi
arp
igmp display
atm
bridge ➧ multicast ➧ interface➧ enable
udpHelper tunnel disable
➧ ip
routing
routeDisplay
ipx
cacheDisplay
appletalk icmpRouterDiscovery
rip
snmp
analyzer ping
statistics
script
logout
10-5
To disable multicast routing on an interface:
1 From the top level of the Administration Console, enter:
ip multicast interface disable
2 Enter the index number of the interface you want to disable.
The interface is disabled.
Multicast routing is enabled on all existing IP interfaces when you have not
specifically disabled it. You can use this option to change the characteristics
of an existing interface or to enable an interface that you had previously
disabled.
To enable a multicast interface or modify the multicast characteristics of an
existing IP interface:
1 From the top level of the Administration console, enter:
ip multicast interface enable
2 Enter the index number(s) of the interface(s) you want to enable.
3 Enter the DVMRP metric value of the chosen interface(s).
4 Enter the Time To Live (TTL) threshold of the chosen interface(s).
5 Enter the rate limit of the chosen interface(s).
Example:
Enter
Enter
Enter
Enter
an IP interface index [1]: 2
Interface DVMRP metric [1]: 1
Interface TTL threshold [1]:
interface rate limit in KBits/sec [0]:
10-6
CHAPTER 10: ADMINISTERING IP MULTICAST ROUTING
Administering
Multicast Tunnels
A multicast tunnel allows multicast packets to cross several unicast routers
to a destination router that supports multicast. A tunnel has two end points.
The local end point is associated with an interface on the LANplex router.
When you define the tunnel, you specify the associated index on the local
LANplex router and then the characteristics of the tunnel. Tunnel
characteristics are the same as the those of an interface. You also specify the
IP address of the remote multicast router.
Not all multicast configurations require a tunnel. The only configurations
that require a tunnel are those that require a connection between two
multicast internetworks through one or more unicast routers.
Displaying
Multicast Tunnels
Top-Level Menu
system
ethernet interface
dvmrp
route
fddi
igmp ➧ display
arp
atm
interface define
bridge atmArpServer
➧ multicast ➧ tunnel remove
➧ ip
udpHelper routeDisplay
ipx
appletalk routing cacheDisplay
icmpRouterDiscovery
snmp
analyzer rip
ping
script
logout statistics
Index
1
To display the IP multicast tunnel(s) on the router, from the top level menu
of the Administration Console, enter:
ip multicast tunnel display
Example IP multicast tunnel configuration:
Local Address
Remote Address Metric Threshold RateLimit State
158.101.112.204 137.39.229.98 2
255
pkts in:320069 pkts out:0
peers 137.39.229.98
500
(3.8) (0xe)
Administering Multicast Tunnels
Defining a
Multicast Tunnel
Top-Level Menu
system
interface
ethernet route
dvmrp
fddi
arp
igmp
display
atm
atmArpServer
interface
bridge ➧ multicast➧ tunnel ➧ define
remove
➧ ip
udpHelper routeDisplay
ipx
routing cacheDisplay
appletalk icmpRouterDiscovery
snmp
rip
analyzer ping
script
statistics
logout
10-7
To define an IP multicast tunnel:
1 From the top level of the Administration Console, enter:
ip multicast tunnel define
2 Enter the index number(s) of the interface(s) with which you want to
associate a multicast tunnel.
3 Enter the IP address of the destination multicast router.
The IP address of the destination multicast router must be a remote address.
The destination router cannot be directly connected to the same
subnetworks as the local IP address.
4 Enter the DVMRP metric value of the tunnel.
5 Enter the Time To Live (TTL) threshold of the tunnel.
6 Enter the rate limit of the tunnel.
Example:
Enter
Enter
Enter
Enter
Enter
Removing a
Multicast Tunnel
Top-Level Menu
system
ethernet interface
fddi
route
dvmrp
atm
arp
display
igmp
bridge
atmArpSErver
interface define
➧ ip
➧ multicast ➧ tunnel ➧ remove
ipx
udpHelper routeDisplay
appletalk routing
cacheDisplay
snmp
icmpRouterDiscovery
analyzer rip
script
ping
logout
statistics
an IP
remote
tunnel
tunnel
tunnel
interface index [1]: 2
IP address: 192.9.200.40
DVMRP metric [1]: 1
TTL threshold [1]:
rate limit [0]:
To remove an IP multicast tunnel:
1 From the top level of the Administration Console, enter:
ip multicast tunnel remove
2 Enter the index number(s) of the interfaces associated with the tunnel you
want to remove.
Example:
Enter an IP interface index [1]: 2
The tunnel is removed.
10-8
CHAPTER 10: ADMINISTERING IP MULTICAST ROUTING
Displaying Routes
Top-Level Menu
system
ethernet interface
fddi
dvmrp
route
atm
igmp
arp
bridge
interface
atmArpServer
➧ ip
➧ multicast tunnel
ipx
udpHelper➧ routeDisplay
appletalk routing
cacheDisplay
snmp
icmpRouterDiscovery
analyzer rip
script
ping
logout statistics
To display all available routes in the IP multicast routing table:
1 From top level of the Administration Console, enter:
ip multicast routeDisplay
The DVMRP status and IGMP status appear on the screen.
The following display shows all available multicast routes:
Multicast Routing Table (2598 entries)
Origin-Subnet
From-Gateway
Metric Tmr
157.88.29.1/32
137.39.229.98
18
25
137.39.2.254/32
137.39.229.98
5
25
131.215.125.236/32 137.39.229.98
14
25
130.118.106.254/32 137.39.229.98
10
25
129.127.118.12/32 137.39.229.98
10
25
129.127.110.12/32 137.39.229.98
10
25
129.127.110.11/32 137.39.229.98
13
25
129.127.110.5/32
137.39.229.98
10
25
129.95.63.12/32
137.39.229.98
13
25
129.95.63.11/32
137.39.229.98
31
25
129.95.63.9/32
137.39.229.98
13
25
129.95.63.8/32
137.39.229.98
13
25
129.95.63.6/32
137.39.229.98
13
25
129.95.63.2/32
137.39.229.98
13
25
129.95.48.4/32
137.39.229.98
13
25
129.95.48.3/32
137.39.229.98
13
25
129.95.48.2/32
137.39.229.98
13
25
Table 10-1 describes the fields in the route display.
In-If Out-Ifs
T1
I1
T1
I1
T1
I1
T1
I1
T1
I1
T1
I1
T1
I1
T1
I1
T1
I1
T1
I1*
T1
I1
T1
I1
T1
I1
T1
I1
T1
I1
T1
I1
T1
I1
Displaying the Multicast Cache
10-9
Table 10-1 Field Attributes for Multicast route display
Field
Description
Origin-Subnet
The source address and the number of bits in the subnetwork
From-Gateway
The interface address of the gateway
Metric
The hop count
Tmr
The amount of time, in seconds, since the routing table entry was
last reset
In-If1
Interface number on which that gateway is connected. Traffic is
expected to originate on this interface.
T represents the tunnel; P denotes that a prune has been sent to
this tunnel.
Displaying the
Multicast Cache
Out-If1
Set of interfaces on which the traffic will be flooded out. I represents the interface.
1In-If and Out-If
Together, these attributes define a Spanning Tree configuration. Interfaces
that comprise loops are disabled
The IP multicast cache contains the IP source address and destination
address for packets observed on the system. The multicast cache shows you
how information is routed over interfaces and ports in your system.
To display all learned routes in the multicast cache:
Top-Level Menu
system
interface
ethernet
dvmrp
route
fddi
igmp
arp
atm
atmArpServer interfaces
bridge
tunnel
➧ multicast
➧ ip
udpHelper routeDisplay
ipx
➧ cacheDisplay
routing
appletalk
icmpRouterDiscovery
snmp
rip
analyzer
ping
script
statistics
logout
1 From the top level of the Administration Console, enter:
ip multicast cacheDisplay
You are prompted for the multicast source address.
2 Enter the multicast source subnetwork address.
You are prompted for the multicast group address.
3 Enter the multicast group address.
The DVMRP status and IGMP status appear on the screen.
10-10
CHAPTER 10: ADMINISTERING IP MULTICAST ROUTING
Example:
Enter multicast source address [131.188.0.0]
Enter multicast group address [244.2.0.2]
DVMRP is enabled, IGMP snooping is enabled
The following display shows the multicast cache configuration:
Multicast Routing Cache Table (125 entries)
Origin
Mcast-group
CTmr Age PTmr In-If
>202.242.133.128/26 224.2.0.1
202.242.133.139
2 packets
>128.84.247/24
224.2.0.1
128.84.247.53
43 packets
128.84.247.156
33 packets
>128.138.213/24
224.2.0.1
128.138.213.1
23 packets
>128.206.212/24
224.2.0.1
128.206.212.69
8 packets
>131.136.234/24
224.2.0.1
131.136.234.103
12 packets
>138.39.25/24
224.2.0.1
138.39.25.48
46 packets
>192.5.28/24
224.2.0.1
192.5.28.43
178 packets
>199.94.220/24
224.2.0.1
199.94.220.184
10 packets
>199.104.80/24
224.2.0.1
199.104.80.5
4 packets
>132.197.248/21
224.2.0.1
132.197.248.20
1 packets
>131.188/16
224.2.0.1
131.188.2.54
*2492 packets
>149.127/16
224.2.0.1
149.127.6.181
56 packets
Out-Ifs
7m
11m
6m T1P
I1p
2m
36m
2m T1P
I1p
3m
2h
2m T1P
I1p
92s
36m
60s T1P
I1p
3m
57m
3m T1P
I1p
103s
4h
71s T1P
I1p
80s
2h
48s T1P
I1p
104s
1h
72s T1P
I1p
3m
32m
3m T1P
I1p
4m
6m
4m T1P
I1p
3m
5h
3m T1P
184408 bytes
2m
5h 90s T1P
I1p
I1p
Displaying the Multicast Cache
10-11
Table 10-2 describes the fields in the cache display.
Table 10-2 Information in the cache display
Field
Description
Origin
The source of the incoming packets. Entries preceded by an angle
bracket (>) indicate a multicast subnetwork. Entries without an
angle bracket, beneath the subnetwork entries, are multicast
routers within that subnetwork.
Mcast-group
The destination multicast group
CTmr
Cache timer. The amount of time in seconds (s), minutes (m), and
hours (h), that a cache entry has to remain in the cache
Age
Number of seconds (s), minutes (m), or hours (h) that the cache
entry has existed.
PTmr
The time remaining, in seconds (s), minutes (m), or hours (h), before
another prune will be sent to prune the Spanning Tree.
In-If
Interface number on which that gateway is connected. Traffic is
expected to originate from this interface.
T represents the tunnel; P denotes that a prune has been sent to
this tunnel.
Out-If
Set of interfaces on which the traffic will be flooded out. I represents the interface.
10-12
CHAPTER 10: ADMINISTERING IP MULTICAST ROUTING
ADMINISTERING IPX ROUTING
11
This chapter describes how to set up your LANplex® system to use the
Internet Packet Exchange (IPX) protocol to route packets. For more
information about how IPX works, see Part III of this Guide.
You can display and configure the following on your LANplex system:
■
IPX interfaces
■
Routes
■
Servers
■
IPX forwarding
■
Routing Information Protocol (RIP)
■
Enhanced RIP mode
■
Service Advertising Protocol (SAP)
■
IPX statistics
11-2
CHAPTER 11: ADMINISTERING IPX ROUTING
Administering
Interfaces
An IPX interface defines the relationship between an IPX Virtual LAN
(VLAN) and the IPX network. Every IPX interface has one IPX VLAN
associated with it. Each switching module has one IPX interface
defined for each subnet directly connected to it. You must first define a
VLAN, as described in Chapter 8: Administering VLANs, before you
define an associated interface.
An IPX interface has the following information associated with it:
■
IPX network address — The network administrator sets this 4-byte
address. Each address within the network should be unique.
■
Cost — This number, between 1 and 15, is used when calculating route
metrics. Unless your network has special requirements, such as the
need for redundant paths, you should assign a cost of 1 to each
interface.
■
Encapsulation format — IPX routing uses four Ethernet encapsulation
formats and two FDDI encapsulation formats. The Ethernet
encapsulation formats are Ethernet Type II, Novell 802.3 raw, 802.2 LLC,
and 802.3 SNAP. The FDDI encapsulation formats are FDDI 802.2 and
FDDI SNAP.
The two FDDI encapsulation formats correspond to the Ethernet 802.2
LLC and 802.3 SNAP encapsulation formats. If you select either of these
Ethernet encapsulation formats, the corresponding FDDI encapsulation
format is automatically selected for shared Ethernet and FDDI ports.
■
State — The status of the IPX interface indicates whether the interface
is available for communications (Up) or unavailable (Down).
■
VLAN index — The VLAN index indicates which bridge ports are
associated with the IPX interface. When the interface prompts you for
this option, it displays a list of available VLAN indexes and the ports
associated with them.
Administering Interfaces
Displaying IPX
Interfaces
11-3
You can display a table that shows all IPX interfaces and their parameter
settings configured for the system.
To display IPX interface information:
Top-Level Menu
system
ethernet ➧ interface
fddi
route
➧ display
atm
server
define
bridge
forwarding modify
ip
rip
remove
enhanced
➧ ipx
appletalk sap
statistics
snmp
analyzer
script
logout
From the Administration Console top-level menu, enter:
ipx interface display
As shown in the following example, the current configuration is
displayed. It contains IPX forwarding, RIP, and SAP information for the
system as well as IPX interface information.
IPX forwarding is enabled, RIP is active, SAP is active.
Index
1
2
3
Defining an IPX
Interface
IPX address
45469f30
5d41a110
6d321a22
Cost
1
1
1
Format
802.2
802.2
802.2
State
Up
Up
Up
VLAN index
2
1
4
When you define an interface, you define the interface’s IPX address,
cost, format, and the associated IPX VLAN index.
You must define an IPX VLAN before you define the IPX interface to
associate with that VLAN.
To define an IPX interface:
Top-Level Menu
system
ethernet ➧ interface
fddi
display
route
atm
server
➧ define
bridge
forwarding modify
ip
rip
remove
enhanced
➧ ipx
appletalk sap
statistics
snmp
analyzer
script
logout
1 From the Administration Console top-level menu, enter:
ipx interface define
You are prompted for the interface’s parameters. To use the value in
brackets, press [Return] at the prompt.
2 Enter the IPX network address of the interface.
3 Enter the cost of the interface.
4 Enter the format of the interface.
5 Enter the index of the IPX VLAN associated with this interface.
11-4
CHAPTER 11: ADMINISTERING IPX ROUTING
Example:
Enter IPX Address: 0x45469f30
Enter Cost [1]: 1
Enter Frame Format (Ethernet II: 0, 802.2: 1, Raw 802.3: 2, SNAP: 3): 1
IPX VLANs:
Index
Ports
3
1-8
4
9-12
Select VLAN index: 3
Modifying an
Interface
You might want to change the configuration of an interface that you
have already defined.
To modify an IPX interface:
Top-Level Menu
system
ethernet ➧ interface
fddi
display
route
atm
define
server
bridge
forwarding ➧ modify
ip
rip
remove
enhanced
➧ ipx
appletalk sap
statistics
snmp
analyzer
script
logout
Removing an
Interface
1 From the Administration Console top-level menu, enter:
ipx interface modify
You are prompted for the interface parameters. Press [Return] at the
prompts for which you do not want to modify the value.
2 Modify the existing interface parameters by entering a new value at the
prompt.
You may want to remove an interface if you no longer perform routing
on the ports associated with the interface.
To remove an IPX interface definition:
Top-Level Menu
system
ethernet ➧ interface
fddi
display
route
atm
define
server
bridge
forwarding modify
ip
rip
➧ remove
enhanced
➧ ipx
appletalk sap
statistics
snmp
analyzer
script
logout
1 From the Administration Console top-level menu, enter:
ipx interface remove
2 Enter the index number(s) of the interface(s) you want to remove.
The interface is removed.
Administering Routes
Administering
Routes
11-5
Your system maintains a table of routes to other IPX networks. You can
either use the Routing Information Protocol (RIP) to exchange routing
information automatically or make static entries in this table using the
Administration Console.
Each routing table entry contains the following information:
■
Address — The 4-byte IPX network address of a segment currently
known to the router.
■
Hops — The number of routers that must be crossed to reach the
network segment. The maximum number of routers a packet can cross
is 15. Exception: An IPX NetBIOS packet can cross no more than 7
routers.
■
Tics — An estimate of how long it will take the packet to reach this
segment. A tic is approximately 55 milliseconds.
■
Node — The 6-byte address of the router that can forward packets to
the segment. A node address of all zeroes (00-00-00-00-00-00) means
that the route is connected directly to the router.
■
Age — The number of seconds that have elapsed since the last time
the route was heard from.
11-6
CHAPTER 11: ADMINISTERING IPX ROUTING
Displaying the
Routing Table
You can display the routing tables for the system to determine which
routes are configured and if they are operational.
To display the contents of the routing table, from the Administration
Console top-level menu, enter:
Top-Level Menu
system
interface
ethernet
fddi
➧ route ➧ display
atm
server
static
bridge
forwardingremove
ip
rip
flush
enhanced
➧ ipx
sap
appletalk
statistics
snmp
analyzer
script
logout
ipx route display
The example displays the configuration of IPX forwarding, RIP, and SAP,
as well as the routing table.
IPX forwarding is enabled, RIP is active, SAP is active
Interface
2
2
2
Defining a Static
Route
Address
45469f02
c2c028ca
aaaaaaaa
Hops
5
4
6
Tics
6
28
671
Node
08-00-02-04-80-b6
08-00-02-04-80-b6
08-00-02-04-80-b6
Before you define static routes on the system, you must define at least
one IPX interface. See the section “Defining an IPX Interface” on
page 11-3. Static routes remain in the table until you remove them or
until you remove the corresponding interface. Static routes take
precedence over dynamically learned routes to the same destination.
You can set up to 16 static routes.
To define a static route:
Top-Level Menu
system
ethernet interface
fddi
➧ route
display
atm
server
➧ static
bridge
forwarding remove
ip
rip
flush
enhanced
➧ ipx
appletalk sap
statistics
snmp
analyzer
script
logout
Age
44
85
85
1 From the Administration Console top-level menu, enter:
ipx route static
2 Enter the 4-byte IPX network address of the route.
3 Enter the cost of the route.
4 Enter the interface number of the route.
Administering Routes
11-7
5 Enter the node address of the route.
A static route is defined in the following example:
Enter
Enter
Enter
Enter
Removing a Route
Top-Level Menu
system
ethernet interface
fddi
➧ route
display
atm
static
server
bridge
forwarding ➧ remove
ip
rip
flush
enhanced
➧ ipx
sap
appletalk
statistics
snmp
analyzer
script
logout
Flushing Routes
IPX address: 0x45469f30
Cost: 1
Interface number: 1
node address: 08-00-3e-22-15-78
To remove a route:
1 From the Administration Console top-level menu, enter:
ipx route remove
2 Enter the 4-byte IPX network address.
The route is immediately deleted from the routing table.
Flushing deletes all dynamically learned routes from the routing table.
To flush all learned routes from the Administration Console top-level
menu, enter:
Top-Level Menu
system
ethernet interface
fddi
➧ route
display
atm
static
server
bridge
forwarding remove
ip
rip
➧ flush
enhanced
➧ ipx
appletalk sap
statistics
snmp
analyzer
script
logout
ipx route flush
All learned routes are immediately deleted from the routing table.
11-8
CHAPTER 11: ADMINISTERING IPX ROUTING
Administering
Servers
Your system maintains a table of servers that reside on other IPX
networks. You can either use the Service Advertising Protocol (SAP) to
exchange server information automatically or make static entries in this
server table using the Administration Console.
Each server table contains the following information:
■
Name — The user-defined name of the server.
■
Type — The type of service provided by the server.
■
Node — The 6-byte address of the server that can forward packets to
the segment.
■
Socket — The 2-byte socket address on which the server will receive
service requests.
■
Hop — The number of networks that must be crossed to reach the
server. The maximum number is fifteen.
■
Age — The number of seconds that have elapsed since the last time a
server in the table was heard from.
Administering Servers
Displaying the
Server Table
Top-Level Menu
system
ethernet interface
route
fddi
➧ display
atm
➧ server
static
bridge
forwarding remove
ip
rip
flush
enhanced
➧ ipx
appletalk sap
statistics
snmp
analyzer
script
logout
11-9
You can display the server table for the system to determine which
servers are learned and if they are operational.
To display the contents of the server table, from the Administration
Console top-level menu, enter:
ipx server display
IPX forwarding is enabled, RIP is active, SAP is active
Interface
2
2
Defining a Static
Server
Name Type Network
GB201 39b 8c141bfe
GB3COM2 39b af0bc60f
Node Socket Hops
08-00-02-04-80-b6
8059
4
00-00-00-00-00-01
85fa
4
Before you define static servers on the system, you must define at least
one IPX interface. See the section “Defining an IPX Interface” on
page 11-3. Static servers remain in the table until you remove them or
until you remove the corresponding interface. Static servers take
precedence over dynamically learned servers to the same destination.
You can have a maximum of eight static servers.
To define a static server:
Top-Level Menu
system
ethernet interface
route
fddi
display
atm
➧ server
➧ static
bridge
forwarding remove
ip
rip
flush
enhanced
➧ ipx
appletalk sap
statistics
snmp
analyzer
script
logout
Age
73
85
1 From the Administration Console top-level menu, enter:
ipx server static
2 Enter the interface number of the server.
3 Enter the service type of the server.
4 Enter the service name of the server.
5 Enter the IPX network address of the server.
6 Enter the socket value of the server.
7 Enter the node address of the server.
11-10
CHAPTER 11: ADMINISTERING IPX ROUTING
8 Enter the number of hops to the server.
Example:
Enter
Enter
Enter
Enter
Enter
Enter
Enter
Removing a Server
Top-Level Menu
system
ethernet interface
route
fddi
display
atm
➧ server
static
bridge
forwarding ➧ remove
ip
rip
flush
enhanced
➧ ipx
sap
appletalk
statistics
snmp
analyzer
script
logout
Flushing Servers
Interface number: 1
service type: 4
service name: gb201
IPX address: 0x8c14a238
socket: 0x8059
node address: 00-00-2e-f3-56-01
hops: 2
To remove a server:
1 From the Administration Console top-level menu, enter:
ipx server remove
2 Enter the service type of the server.
3 Enter the service name of the server.
The server is immediately deleted from the server table.
Flushing deletes all dynamically learned servers from the server table.
To flush all learned servers:
Top-Level Menu
system
ethernet interface
route
fddi
display
atm
➧ server
static
bridge
forwarding remove
ip
rip
➧ flush
enhanced
➧ ipx
sap
appletalk
statistics
snmp
analyzer
script
logout
From the Administration Console top-level menu, enter:
ipx server flush
All learned servers are immediately deleted from the server table.
Setting IPX Forwarding
Setting IPX
Forwarding
You can control whether the system forwards or discards IPX packets
addressed to other routers. When you enable IPX forwarding, the system
acts as a normal IPX router, forwarding IPX packets from one network to
another when required. When you disable IPX forwarding, the system
discards any IPX packets not addressed directly to one of its defined IPX
interfaces.
By default, IPX forwarding is disabled.
IPX forwarding default
Top-Level Menu
system
ethernet interface
route
fddi
server
atm
bridge ➧ forwarding
ip
rip
enhanced
➧ ipx
appletalk sap
statistics
snmp
analyzer
script
logout
11-11
To enable or disable IPX forwarding:
1 From the Administration Console top-level menu, enter:
ipx forwarding
2 Enter the IPX forwarding state (enabled or disabled). To use the value in
brackets, press [Return] at the prompt.
Setting the RIP
Mode
You can select a RIP mode that is appropriate for your network. RIP can
operate in any of three modes:
■
Off — The system ignores all incoming RIP packets and does not generate
any RIP packets of its own.
■
Passive — The system processes all incoming RIP packets, but does not
broadcast periodic or triggered RIP updates, or respond to RIP requests.
■
Active — The system processes all incoming RIP packets, responds to
explicit requests for routing information, and broadcasts periodic and
triggered RIP updates.
11-12
CHAPTER 11: ADMINISTERING IPX ROUTING
RIP default mode
By default, RIP is off.
To set the RIP operating mode:
Top-Level Menu
system
ethernet interface
route
fddi
server
atm
forwarding
bridge
ip
➧ rip
enhanced
➧ ipx
appletalk sap
statistics
snmp
analyzer
script
logout
Setting the
Enhanced RIP
Mode
Enhanced RIP default
1 From the Administration Console top-level menu, enter:
ipx rip
2 Enter the RIP mode (off, passive, or active). To use the value in
brackets, press [Return] at the prompt.
Standard IPX RIP packets can include up to 50 route advertisements, but
some routers allow up to 68. Enhanced RIP mode increases the number of
entries in a RIP packet that the system will accept. Enhanced RIP mode
allows the system greater interoperability with routers that do not explicitly
follow the IPX router implementation guidelines.
By default, enhanced RIP is disabled.
To enable or disable enhanced RIP mode:
Top-Level Menu
system
ethernet interface
route
fddi
server
atm
forwarding
bridge
rip
ip
➧ enhanced
➧ ipx
appletalk sap
statistics
snmp
analyzer
script
logout
1 From the Administration Console top-level menu, enter:
ipx enhanced
2 Enter the enhanced RIP state (enabled or disabled). To use the value in
brackets, press [Return] at the prompt.
Setting the SAP Mode
Setting the SAP
Mode
SAP default mode
You can select a SAP mode that is appropriate for your network. SAP can
operate in any of three modes:
■
Off — The system ignores all incoming SAP packets and does not generate
any SAP packets of its own.
■
Passive — The system processes all incoming SAP packets, but it does not
broadcast periodic or triggered SAP updates or respond to SAP requests.
■
Active — The system processes all incoming SAP packets, responds to
explicit requests for routing information, and broadcasts periodic and
triggered SAP updates.
By default, SAP is off.
To set the SAP operating mode:
Top-Level Menu
system
ethernet interface
route
fddi
server
atm
forwarding
bridge
rip
ip
enhanced
➧ ipx
appletalk ➧ sap
statistics
snmp
analyzer
script
logout
11-13
1 From the Administration Console top-level menu, enter:
ipx sap
2 Enter the SAP mode (off, passive, or active). To use the value in
brackets, press [Return] at the prompt.
11-14
CHAPTER 11: ADMINISTERING IPX ROUTING
Displaying
Statistics
The Administration Console allows you to display four types of IPX-related
statistics:
Displaying IPX
Summary Statistics
■
IPX summary statistics
■
IPX RIP statistics
■
IPX SAP statistics
■
IPX forwarding statistics
To display IPX summary statistics, from the Administration Console
top-level menu, enter:
ipx statistics summary
Top-Level Menu
system
ethernet interface
route
fddi
➧ summary
server
atm
rip
forwarding sap
bridge
rip
ip
forwarding
enhanced
➧ ipx
appletalk sap
➧ statistics
snmp
analyzer
script
logout
Example:
IPX forwarding is enabled, RIP is active, SAP is active
Received
1170878
Transmitted
565099
Dropped
0
Msg Pool Empty
0
Table 11-1 describes the IPX summary statistics.
Table 11-1 IPX Summary Statistics
Field
Description
Received
Number of IPX packets received
Transmitted
Number of IPX packets transmitted
Dropped
Number of IPX packets dropped
Msg Pool Empty Number of IPX RIP or IPX SAP messages delivered to the IPX
application that were dropped due to resource limitations
Displaying Statistics
Displaying IPX RIP
Statistics
11-15
To display IPX RIP statistics, from the Administration Console top-level
menu, enter:
ipx statistics rip
Top-Level Menu
system
ethernet interface
route
fddi
summary
server
atm
➧ rip
forwarding sap
bridge
rip
ip
forwarding
enhanced
➧ ipx
appletalk sap
➧ statistics
snmp
analyzer
script
logout
Example below:
IPX forwarding is enabled, RIP is active, SAP is active
RIP Received
106195
RIP Transmitted
7929
RIP dropped
0
RIP Responses
100552
RIP Requests
5643
RIP Entries
2
Table 11-2 describers the IPX RIP statistics.
Table 11-2 IPX RIP Statistics
Field
Description
RIP Received
Number of IPX RIP packets received
RIP Transmitted
Number of IPX RIP packets transmitted
RIP Dropped
Number of IPX RIP packets dropped
RIP Responses
Number of IPX RIP responses that have been processed
RIP Requests
Number of IPX RIP requests that have been processed
RIP Entries
Number of routes in the routing table
11-16
CHAPTER 11: ADMINISTERING IPX ROUTING
Displaying IPX SAP
Statistics
To display IPX SAP statistics, from the Administration Console top-level
menu, enter:
ipx statistics sap
Top-Level Menu
system
ethernet interface
route
fddi
summary
server
atm
rip
forwarding ➧ sap
bridge
rip
ip
forwarding
enhanced
➧ ipx
sap
appletalk
➧ statistics
snmp
analyzer
script
logout
Example:
IPX forwarding is enabled, RIP is active, SAP is active
SAP Received
1064015
SAP Transmitted
22493
SAP dropped
0
SAP Responses
1063532
SAP Requests
45
SAP Entries
0
SAP GNS Responses
0
SAP GNS Requests
438
Table 11-1 describes the IPX SAP statistics.
Table 11-3 IPX SAP Statistics
Field
Description
SAP Received
Number of IPX SAP packets received
SAP Transmitted
Number of IPX SAP packets transmitted
SAP Dropped
Number of IPX SAP packets dropped
SAP Responses
Number of IPX SAP Responses that have been processed
SAP Requests
Number of IPX SAP Requests that have been processed
SAP Entries
Number of servers in the server table
SAP GNS Responses
Number of IPX SAP Get Nearest Service Responses that have
been received
SAP GNS Requests
Number of IPX SAP Get Nearest Service Requests processed
Displaying Statistics
Displaying IPX
Forwarding
Statistics
To display IPX Forwarding statistics, from the Administration Console
top-level menu, enter:
ipx statistics forwarding
Top-Level Menu
system
ethernet interface
route
summary
fddi
server
rip
atm
forwarding sap
bridge
rip
ip
➧ forwarding
Example:
enhanced
➧ ipx
appletalk sap
➧ statistics
snmp
analyzer
script
IPX forwarding is enabled, RIP is active, SAP is active
logout
Received
1335653
Transmitted
565105
Forwarded
0
Hdr Errors
13758
Hop Count Errors
0
Addr Errors
13758
No Routes
2
Misc Errors
411
NetBIOS Rx
150604
NetBIOS Tx
125781
Host Rx
1171190
Host Tx
565105
NetBIOS Max Hops
0
Table 11-4 describes the IPX forwarding statistics.
11-17
11-18
CHAPTER 11: ADMINISTERING IPX ROUTING
Table 11-4 IPX Forwarding Statistics
Field
Description
Received
Number of IPX forwarding packets received
Transmitted
Number of IPX forwarding packets transmitted
Forwarded
Number of IPX packets forwarded by the IPX router
Hdr Errors
Number of IPX packets dropped due to IPX Network
layer header errors
Hop Count Errors
Number of IPX packets dropped due to exceeded
maximum transport control
Addr Errors
Number of IPX packet dropped due to IPX Address
errors in network layer header
No Routes
Number of IPX packets dropped because the IPX route
is unknown
Misc Errors
Number of multicasts attempted to be forwarded
NetBIOS Rx
Number of IPX NetBIOS packets received
NetBIOS Tx
Number of IPX NetBIOS packets transmitted
NetBIOS Max Hops
Number of IPX NetBIOS packets that exceeded the
transport control maximum
Host Rx
Number of IPX packets delivered to the IPX host’s RIP
and SAP applications
Host Tx
Number of IPX packets transmitted from IPX host’s RIP
and SAP applications
ADMINISTERING APPLETALK®
ROUTING
12
This chapter describes how to set up your LANplex® system to use the
AppleTalk protocol to route packets. For more information on how
AppleTalk routing works, see Chapter 7: Routing with AppleTalk.
You can display and configure the following:
■
AppleTalk interfaces
■
Routes
■
AARP cache
■
Zones
■
AppleTalk forwarding
■
Checksum generation and verification
■
AppleTalk statistics
12-2
CHAPTER 12: ADMINISTERING APPLETALK® ROUTING
Administering
Interfaces
An AppleTalk interface defines the relationship between an AppleTalk
Virtual LAN (VLAN) and the AppleTalk network. Every AppleTalk interface
has one AppleTalk VLAN associated with it. Each switching module has one
AppleTalk interface defined for each subnet directly connected to it.
You must first define a VLAN, as described in Chapter 8, before you define an
associated AppleTalk interface.
You can configure a maximum of 32 interfaces per router.
An AppleTalk interface has several elements associated with it:
■
Seed Interface — You can configure the interface to be a seed interface or
non-seed interface. Seed interfaces initialize the network with the
configuration information the administrator enters. These include network
range, address, zone name, and ports. Non-seed interfaces wait and listen
for a seed interface and then take this configuration initialization
information from the first seed interface they detect. After the non-seed
interface obtains a network configuration, it begins to participate in the
routing of the network.
■
Network Range — A range of numbers used to designate a network
segment’s identity. This element allows the physical segment between two
LANplex systems to be a range of multiple networks.
■
Address — The AARP address based on the network range and the
network node (1-253).
■
Zone — The default zone name, as well as up to 15 additional defined
zones.
■
State — This is the status of the AppleTalk interface, which indicates
whether the interface is available for communications (up) or unavailable
(down).
■
VLAN Index— The number of the AppleTalk VLAN associated with the
AppleTalk interface. The VLAN index indicates which bridge ports are
associated with the AppleTalk interface. When the menu prompts you for
this option, it displays a list of available VLAN indexes and their ports.
Administering Interfaces
Displaying
AppleTalk Interfaces
12-3
You can display a table that shows all AppleTalk interfaces and their
parameter settings configured for the system.
To display the AppleTalk interfaces defined on the router, from the
Administration Console top-level menu, enter:
Top-Level Menu
system
ethernet ➧ interface
fddi
route
➧ display
atm
aarp
define
bridge
zone
remove
ip
forwarding
ipx
checksum
➧ appletalk ping
statistics
snmp
analyzer
script
logout
Defining an
Interface
appletalk interface display
Example:
DDP forwarding is enabled.
Index
1
2
3
Network Range
20112-20112
20124-20124
20125-20125
Address
20112.27
20124.1
20125.1
State
enabled
enabled
enabled
VLAN index
3
2
4
When you define an interface, you define the interface’s network range,
zone name, and the VLAN index associated with the interface. You must
define an AppleTalk VLAN before you define the AppleTalk interface to
associate with that VLAN.
To define an AppleTalk interface:
Top-Level Menu
system
ethernet ➧ interface
fddi
display
route
atm
aarp
➧ define
bridge
zone
remove
ip
forwarding
ipx
checksum
➧ appletalk ping
statistics
snmp
analyzer
script
logout
1 At the Administration Console’s top-level menu, enter:
appletalk interface define
You are prompted for the interface’s parameters. To use the value in
brackets, press [Return] at the prompt.
The following message appears:
Configure seed interface? (n,y) [y]:
2 Enter n (no) or y (yes).
3 Enter the start of the network range associated with the interface.
4 Enter the end of the network range associated with the interface.
5 Enter the default zone name.
The default zone name is used by clients that have not been configured to
use a particular zone.
12-4
CHAPTER 12: ADMINISTERING APPLETALK® ROUTING
6 Enter the zone name.
You can enter up to 16 zone names per interface.
7 Type q after entering all the zone names.
8 Enter the index of the AppleTalk VLAN associated with this interface.
Example:
Enter Start of Network Range:10000
Enter End of Network Range: 10100
Enter Default Zone:engineering
Enter Zone Name:q
Appletalk VLANs:
Index
Ports
3
1-8
4
9-12
Select VLAN index: 3
Removing an
Interface
You might want to remove an interface if you no longer perform routing on
the ports associated with the interface.
To remove an AppleTalk interface:
Top-Level Menu
system
ethernet ➧ interface
fddi
display
route
atm
define
aarp
bridge
zone
➧ remove
ip
forwarding
ipx
checksum
➧ appletalk ping
statistics
snmp
analyzer
script
logout
1 At the Administration Console’s top-level menu, enter:
appletalk interface remove
2 Enter the index number(s) of the interface(s) you want to remove.
The interface is no longer defined on the router.
Administering Routes
Administering
Routes
12-5
Your system maintains a table of routes to other AppleTalk networks. The
routing table is generated automatically by the Routing Table Maintenance
Protocol (RTMP). RTMP defines 1) the rules for exchanging information
between routers so that the routers can maintain their routing tables, and 2)
the rules for the information contained within each routing table.
Each routing table entry contains the following information:
■
Network Range
A range of numbers used to designate a network segment’s identity
■
Distance
The distance in hops to the destination network
■
Interface
The defined interface number
■
State
The status (good, suspect, bad, or really bad) of each route
Displaying the
Routing Table
You can display the routing tables for the system to determine which routes
are configured and if they are operational.
To display the contents of the routing table:
Top-Level Menu
system
ethernet interface
fddi
➧ route
➧ display
atm
aarp
flush
bridge
zone
ip
forwarding
ipx
checksum
➧ appletalk ping
statistics
snmp
analyzer
script
logout
From the Administration Console top-level menu, enter:
appletalk route display
12-6
CHAPTER 12: ADMINISTERING APPLETALK® ROUTING
The following example shows a routing table display:
g
Network Range
1-1
3
10-14
15-19
61
100-100
201-300
2010-2015
10009-10009
10010-10010
10060-10060
10110-10113
10116-10117
10118-10118
10119-10119
10120-10120
10122-10122
10310-10329
10410-10410
11010-11019
Flushing all Routes
Top-Level Menu
system
ethernet interface
fddi
➧ route
display
atm
aarp
➧ flush
bridge
zone
ip
forwarding
ipx
checksum
➧ appletalk ping
statistics
snmp
analyzer
script
logout
Distance
10
4
6
7
6
10
7
2
5
7
8
5
5
6
4
7
9
10
8
9
Interface
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
State
good
good
good
good
good
good
good
good
good
good
good
good
good
good
good
good
good
good
good
good
Flushing deletes all dynamically learned routes from the routing table.
To flush all learned routes:
1 At the Administration Console’s top-level menu, enter:
appletalk route flush
Administering the AARP Cache
Administering
the AARP Cache
12-7
AARP allows hardware addresses to be mapped to an AppleTalk protocol
address. AppleTalk uses dynamically assigned 24-bit addresses, unlike the
statically-assigned 48-bit addresses used by Ethernet and token ring.
To make the address mapping process easier, AARP uses an Address
Mapping Table (AMT). The most recently used addresses are maintained in
the AMT. If an address is not in the AMT, AARP sends a request to the
desired protocol address and the hardware address is added to the table
when the destination node replies.
AARP is also responsible for registering a node’s dynamically assigned
address on the network. This process is described below:
■
AARP randomly assigns an address.
■
AARP broadcasts AARP probe packets to this address to determine if
another node is already using the address.
■
If there is no reply, the address becomes that node’s address.
■
If there is a reply, AARP repeats this process until an available address is
discovered.
In the Administration Console, you can:
■
Display the cache
■
Remove entries
■
Flush the cache
12-8
CHAPTER 12: ADMINISTERING APPLETALK® ROUTING
Displaying the
AARP Cache
Top-Level Menu
system
ethernet interface
route
fddi
➧ display
atm
➧ aarp
remove
bridge
zone
flush
ip
forwarding
ipx
checksum
➧ appletalk ping
statistics
snmp
analyzer
script
logout
You can display the AARP cache for the system to determine which routes
are configured and if they are operational.
To display the contents of the AARP cache:
From the Administration Console top-level menu, enter:
appletalk aarp display
The following example shows an AARP cache display:
AARP Address
20112.125
20112.177
20112.192
20112.150
20112.1
20125.193
20125.76
20125.67
20124.41
20112.225
20112.135
20112.147
20112.132
20112.112
20112.148
20112.244
20112.21
20112.131
20124.35
20112.97
20112.4
20112.180
20112.108
20112.56
20112.110
20112.155
20112.243
20112.253
20125.104
20112.236
MAC Address
00-20-af-0b-e1-7c
00-00-89-01-91-f0
00-00-89-01-91-f3
00-00-89-01-8b-51
08-00-02-04-80-b6
08-00-07-d7-69-1f
08-00-07-66-62-9d
08-00-07-ee-10-a2
08-00-07-7c-c3-d8
00-20-af-0b-d8-f1
00-20-af-9e-68-62
00-00-94-41-de-79
08-00-09-7f-98-c5
08-00-07-7c-20-61
08-00-07-ac-56-4b
00-20-af-0b-ff-72
08-00-07-dc-e5-c4
08-00-07-54-88-b1
08-00-07-57-ec-58
08-00-07-9e-09-86
08-00-07-ec-98-3d
08-00-07-f7-cf-de
08-00-07-4f-74-7e
08-00-07-bc-10-fc
00-40-10-56-1a-b5
08-00-07-6c-88-77
08-00-07-66-72-c7
08-00-20-12-75-bf
08-00-07-66-2b-c2
00-80-3e-02-81-66
Interface
1
1
1
1
1
3
3
3
2
1
1
1
1
1
1
1
1
1
2
1
1
1
1
1
1
1
1
1
3
1
Age (secs)
211
20
6
18
31
388
862
851
864
270
174
26
24
121
1098
35
8932
397
368
1925
121
110
5833
120
110
5536
4940
70
848
3841
Administering the AARP Cache
Removing an Entry
in the Cache
Top-Level Menu
system
ethernet interface
route
fddi
display
atm
➧ aarp
➧ remove
bridge
zone
flush
ip
forwarding
ipx
checksum
➧ appletalk ping
statistics
snmp
analyzer
script
logout
Flushing All Cache
Entries
Top-Level Menu
system
ethernet interface
route
fddi
display
atm
➧ aarp
remove
bridge
zone
➧ flush
ip
forwarding
ipx
checksum
➧ appletalk ping
statistics
snmp
analyzer
script
logout
To remove an AARP cache entry:
1 At the Administration Console’s top-level menu, enter:
appletalk aarp remove
2 Enter the AARP address at the prompt.
The entry is removed.
To flush all AARP cache entries:
1 At the Administration Console’s top-level menu, enter:
appletalk aarp flush
12-9
12-10
CHAPTER 12: ADMINISTERING APPLETALK® ROUTING
Displaying the
Zone Table
AppleTalk allows for the logical grouping of nodes into zones to make
navigation through the network easier. This is done with the Zone
Information Protocol (ZIP). ZIP helps routers maintain a mapping of network
numbers to zones in the entire network. To do this, ZIP creates and
maintains a Zone Information Table (ZIT) in each router. The entries in this
table match the network numbers with the zone names.
In the Administration Console, you can display the zone table either by
network numbers or by zones.
To display the zone table:
Top-Level Menu
system
ethernet interface
route
fddi
aarp
atm
bridge ➧ zone
➧ network
ip
forwarding
ipx
checksum ➧ zone
➧ appletalk ping
statistics
snmp
analyzer
script
logout
From the Administration Console top-level menu, enter:
appletalk zone display network
OR
appletalk zone display zone
Configuring Forwarding
12-11
Depending on the command entered, the zone table is displayed by
network or zone. An example of each type of display is shown below:
Zone Table by Network Numbers
DDP forwarding is enabled.
Network 1-1 has 1 known zone
Munich GmbH
Network 3 has 1 known zone
Ethernet A5D85800
Network 10-14 has 1 known zone
Freds_Ethernet
Network 15-19 has 1 known zone
Freds_Token
Network 61 has 1 known zone
DevMacNet
Network 100-100 has 1 known zone
France Les Ulis
Network 201-300 has 1 known zone
Fred_Wilma
Network 2010-2015 has 1 known zone
NY
Network 10009-10009 has 2 known zones
Hemel NSOPS
3Com Arpeggio
Network 10010-10010 has 1 known zone
Marlow EUR
Configuring
Forwarding
Top-Level Menu
system
interface
ethernet
route
fddi
aarp
atm
zone
bridge
ip
➧ forwarding
ipx
checksum
➧ appletalk ping
statistics
snmp
analyzer
script
logout
Zone Table by Zones
DDP forwarding is enabled.
Zone Holmdel is assigned to 2 networks
21105-21105
21010-21010
Zone NY is assigned to 2 networks
63535-63535
2010-2015
Zone Manchester UK is assigned to 1 network
10310-10329
Zone DC8 is assigned to 1 network
30110-30129
Zone Chicago is assigned to 1 network
22030-22030
Zone Startek-Enet1 is assigned to 1 network
20033-20033
Zone Startek-TR1 is assigned to 1 network
20037-20037
Zone Test GmbH is assigned to 1 network
12010-12012
Zone Madrid3Com is assigned to 1 network
14010-14029
Zone NSDEng is assigned to 1 network
32910-32910
You can control whether the router forwards or discards AppleTalk packets
addressed to other hosts. When you enable forwarding, the router processes
packets as usual, forwarding AppleTalk packets from one subnet to another
when required. When you disable IP forwarding, the router discards any
AppleTalk packets not addressed directly to one of its defined interfaces.
1 At the Administration Console’s top-level menu, enter:
appletalk forwarding
2 Enter enable or disable at the prompt.
12-12
CHAPTER 12: ADMINISTERING APPLETALK® ROUTING
Configuring
Checksum
Checksum is a simple method used for detecting errors in the transmission
of data. Checksum generation totals the bytes comprising the data and
adds this sum to the end of the data packet. Checksum verification allows
you to verify the integrity of the data that is routed. You can enable or
disable checksum generation and verification states.
To enable or disable checksum generation/verification:
Top-Level Menu
system
interface
ethernet
route
fddi
aarp
atm
zone
bridge
forwarding
ip
ipx
➧ checksum
➧ appletalk ping
statistics
snmp
analyzer
script
logout
Pinging an
AppleTalk Node
1 At the Administration Console’s top-level menu, enter:
appletalk checksum
2 Enter enable or disable at the checksum generation prompt.
3 Enter enable or disable at the checksum verification prompt.
The AppleTalk Echo Protocol (AEP) sends a datagram (an Echo Request)
from one node to another, which causes the destination node to return or
echo, the datagram (an Echo Reply) to the sender. This allows you to
determine whether a node is accessible before any sessions are started.
To ping an AppleTalk node:
Top-Level Menu
system
ethernet interface
route
fddi
aarp
atm
zone
bridge
forwarding
ip
checksum
ipx
➧ appletalk ➧ ping
statistics
snmp
analyzer
script
logout
1 At the Administration Console’s top-level menu, enter:
appletalk ping
You are prompted for a node address.
2 Enter the address of the node you want to ping.
If the node is accessible, you receive a response.
Viewing Appletalk Statistics
Viewing Appletalk
Statistics
Displaying DDP
Statistics
Top-Level Menu
system
ethernet interface
route
fddi
➧ ddp
aarp
atm
rtmp
zone
bridge
zip
forwarding nbp
ip
checksum
ipx
➧ appletalk ping
➧ statistics
snmp
analyzer
script
logout
12-13
You can view statistics specific to the following AppleTalk protocols:
■
Datagram Delivery Protocol (DDP)
■
Routing Table Maintenance Protocol (RTMP)
■
Zone Information Protocol (ZIP)
■
Name Binding Protocol (NBP)
To display DDP statistics:
From the Administration Console top-level menu, enter:
appletalk statistics ddp
The following is an example of DDP summary statistics:
DDP forwarding is enabled.
inReceives
131131
inForwards
113171
inLocals
17906
inNoRoutes
22
inNoClients
0
inTooShorts
0
inTooLongs
0
inShortDdps
0
inCsumErrors
0
inBcastErrors
0
inTooFars
0
inDiscards
54
outLocals
15600
Table 12-1 describes the AppleTalk DDP statistics you can view.
Table 12-1 AppleTalk Statistics
Field
Description
inReceives
Total number of packets received, including those with errors
inForwards
Total number of packets forwarded, including those with errors
inLocals
Number of DDP datagrams for which this entity was their final DDP
destination
inNoRoutes
Number of DDP datagrams dropped because a route could not be
found
inNoClients
Number of DDP datagrams dropped because of an unknown DDP
type
continued
12-14
CHAPTER 12: ADMINISTERING APPLETALK® ROUTING
Table 12-1 AppleTalk Statistics (continued)
Displaying RTMP
Information
Top-Level Menu
system
ethernet interface
route
fddi
summary
aarp
atm
➧ rtmp
zone
bridge
zip
forwarding nbp
ip
checksum
ipx
➧ appletalk ping
➧ statistics
snmp
analyzer
script
logout
Field
Description
inTooShorts
Number of input DDP datagrams dropped because the received
data length was less than the data length specified in the DDP
header or the received data length was less than the length of the
expected DDP header
inTooLongs
Number of input DDP datagrams dropped because they exceeded
the maximum DDP datagram size
inShortDdps
Number of input DDP datagrams dropped because this entity was
not their final destination and their type was short DDP
inCsumErrors
Number of DDP datagrams which were dropped because of a
checksum error
inBcastErrors
Number of DDP datagrams for which this DDP entity was their final
destination, and which were dropped because of a broadcast error
inTooFars
Number of input datagrams dropped because this entity was not
their final destination and their hop count would exceed 15
inDiscards
Number of DDP Datagrams thrown out during the routing process
outLocals
Number of host-generated DDP datagrams
To display RTMP statistics:
From the Administration Console top-level menu, enter:
appletalk statistics rtmp
An example of summary statistics is shown below:
DDP forwarding is enabled.
inDatas
7204
inRequests
0
routeEqChgs
0
routeLessChgs
0
inVersionErrs
0
inOtherErrs
119
outDatas
4865
outRequests
6
routeDeletes routeOverflows
0
0
Table 12-2 describes the RTMP statistics you can view.
Viewing Appletalk Statistics
12-15
Table 12-2 RTMP Statistics
Displaying ZIP
Information
Top-Level Menu
system
interface
ethernet
route
fddi
ddp
aarp
atm
rtmp
zone
bridge
➧ zip
forwarding
ip
nbp
checksum
ipx
➧ appletalk ping
➧ statistics
snmp
analyzer
script
logout
Field
Description
inDatas
Number of good RTMP data packets received
inRequests
Number of good RTMP request packets received
outDatas
Number of good RTMP data packets sent
outRequests
Number of RTMP request packets sent
routeEqChgs
Number of times RTMP changes the Next Internet Router in a
routing entry because the hop count advertised in a routing table
was equal to the current hop count for a particular network
routeLessChgs
Number of times RTMP changes the Next Internet Router in a
routing entry because the hop count advertised in a routing table
was less than the current hop count for a particular network
routeDeletes
Number of times RTMP deletes a route because it was aged out of
the table
routeOverflows
Number of times RTMP attempted to add a route to the RTMP table
but failed due to lack of space
inVersionErrs
Number of RTMP packets received that were rejected due to a
version mismatch
inOtherErrs
Number of RTMP packets received that were rejected for an error
other than due to a version mismatch
To display ZIP statistics:
From the Administration Console top-level menu, enter:
appletalk statistics zip
12-16
CHAPTER 12: ADMINISTERING APPLETALK® ROUTING
An example of summary statistics is shown below:
DDP forwarding is enabled.
inQueries
248
inReplies
14
inExReplies
0
inGniReplies
22
inLocalZones
30
inZoneLists
0
inObsoletes
0
inZoneCons
0
inZoneInvs
22
outQueries
9
outReplies
0
outGniReplies
182
outLocalZones
0
outZoneInvs
outAddrInvs
inGniRequests
182
inErrors
0
outExReplies outGniRequests
277
13
outZoneLists
30
Table 12-3 describes the ZIP statistics you can view:
Table 12-3 ZIP Statistics
Field
Description
inQueries
Number of ZIP queries received
inReplies
Number of ZIP replies received
inExReplies
Number of ZIP extended replies received
inGniRequests
Number of ZIP GetNetInfo request packets received
inGniReplies
Number of ZIP GetNetInfo reply packets received
inLocalZones
Number of Zip GetLocalZones requests packets received
inZoneLists
Number of Zip GetZoneLists requests packets received
inObsoletes
Number of ZIP Takedown or ZIP Bringup packets received
inZoneCons
Number of times a conflict has been detected between this entity’s
zone information and another entity’s zone information
inZoneInvs
Number of times this entity has received a ZIP GetNetInfo reply with
the zone invalid bit set because the corresponding GetNetInfo
request had an invalid zone name
inErrors
Number of ZIP packets received that were rejected for any error
outQueries
Number of ZIP queries sent
outReplies
Number of ZIP replies sent
outExReplies
Number of ZIP extended replies sent
outGniRequests
Number of ZIP GetNetInfo packets sent
continued
Viewing Appletalk Statistics
12-17
Table 12-3 ZIP Statistics (continued)
Displaying NBP
Information
Field
Description
outGniReplies
Number of ZIP GetNetInfo reply packets sent out of this port
outzoneInvs
Number of times this entity has sent a ZIP GetNetInfo reply with the
zone invalid bit set in response to a GetNetInfo request with an
invalid zone name
outAddrInvs
Number of times this entity had to broadcast a ZIP GetNetInfo reply
because the GetNetInfo request had an invalid address
The NBP handles the translations between the numeric internet address and
the alphanumeric entity names used by AppleTalk.
To display NBP statistics:
Top-Level Menu
system
ethernet interface
route
fddi
ddp
aarp
atm
rtmp
zone
bridge
zip
forwarding
ip
➧ nbp
checksum
ipx
➧ appletalk ping
➧ statistics
snmp
analyzer
script
logout
From the Administration Console top-level menu, enter:
appletalk statistics nbp
An example of summary statistics is shown below:
P forwarding is enabled.
inLkupReqs
3093
inErrors
0
inBcastReqs
611
inFwdReqs
5951
inLkupReplies
0
12-18
CHAPTER 12: ADMINISTERING APPLETALK® ROUTING
Table 12-4 describes the NBP statistics you can view.
Table 12-4 NBP Statistics
Field
Description
inLkupReqs
Number of NBP Lookup Requests received
inBcastsReqs
Number of NBP Broadcast Requests received
inFwdReqs
Number of NBP Forward Requests received
inLkupReplies
Number of NBP Lookup Replies received
inErrors
Number of NBP packets received that were rejected for any error
REMOTE MONITORING (RMON)
AND THE LANPLEX® SYSTEM
V
Chapter 13
Remote Monitoring (RMON) Technology
REMOTE MONITORING (RMON)
TECHNOLOGY
13
This chapter provides an overview of RMON and describes the specific
LANplex® RMON implementation.
What Is RMON?
The Remote Monitoring (RMON) Management Information Base (MIB)
provides a way to monitor and analyze a local area network LAN from a
remote location. RMON is defined by the Internet Engineering Task Force
(IETF) in documents RFC 1271 and RFC 1757. A typical RMON
implementation has two components:
■
The Probe — Connects to a LAN segment, examines all the LAN traffic on
that segment and keeps a summary of statistics (including historical data) in
its local memory.
■
The Management Console — Communicates with the probe and collects
the summarized data from it. The console does not need to reside on the
same network as the probe, and can manage the probe through SNMP.
The RMON specification consists almost entirely of the definition of the MIB.
The RMON MIB contains standard MIB variables defined to collect
comprehensive network statistics that alert a network administrator to
significant network events. If the embedded RMON agent operates full time,
it will collect data on the correct port at the time the relevant network
event occurs.
This chapter includes the following information about RMON:
■
Benefits of RMON
■
LANplex RMON implementation
■
The Management Information Base (MIB)
■
Alarms
13-2
CHAPTER 13: REMOTE MONITORING (RMON) TECHNOLOGY
Benefits of RMON
Traditional network management applications poll network devices such as
switches, bridges, and routers at regular intervals from a network
management console. The console gathers statistics, identifies trends, and
can highlight network events. The console polls network devices constantly
to determine if the network is within its normal operating conditions.
As network size and traffic levels grow, however, the network management
console can become overburdened by the amount of data it must collect.
Frequent console polling also generates significant network traffic that
itself can create problems for the network itself.
An RMON implementation offers solutions to both of these problems:
LANplex RMON
Implementation
■
The RMON probe looks at the network on behalf of the network
management console without affecting the characteristics and performance
of the network itself.
■
The RMON MIB reports by exception rather than by sending constant or
frequent information to the network management console. The RMON
probe informs the network management console directly if the network
enters an abnormal state. The console can then use more information from
the probe, such as history information, to diagnose the abnormal condition.
The LANplex Extended Switching software offers full time embedded RMON
support through SNMP for four RMON Groups. When combined with the
Roving Analysis Port (RAP) function, RMON support for these groups
provides a comprehensive and powerful mechanism for managing your
network.
You can gain access to the RMON capabilities of the LANplex 2500 system
only through SNMP applications such as Transcend® Enterprise Manager
software, not through the serial interface or telnet. For more information
about the details of managing 3Com devices using RMON, see the user
documentation of the Transcend Network Management Application for
Windows.
The LANplex system supports four of the RMON groups defined by the IETF.
Table 13-1 lists these supported groups.
LANplex RMON Implementation
13-3
Table 13-1 RMON Groups Supported in the LANplex® System
3Com Transcend
RMON Agents
Group
Group
Number
Statistics
1
Maintains utilization and error statistics for the
segment being monitored
History
2
Gathers and stores periodic statistical samples
from the statistics group.
Alarm
3
Allows you to define thresholds for any MIB
variable and trigger an alarm.
Events
9
Allows you to define actions based on alarms.
You can generate traps, log the alarm, or both.
Purpose
RMON requires one probe per LAN segment. Because a segment is a
portion of the LAN separated by a bridge or router, the cost of
implementing many probes in a large network can be high.
To solve this problem, 3Com has built an inexpensive RMON probe into the
Transcend SmartAgent software in each LANplex 2500 system. This probe
allows you to deploy RMON widely around the network at a cost no more
than that for traditional network monitors.
Placing probe functionality inside the LANplex 2500 system has these
advantages:
■
You can integrate RMON with normal device management
■
The LANplex system can manage conditions proactively
The LANplex system associates statistics with individual ports and then
takes action based on these statistics. For example, the system can generate
a log event and send an RMON trap if errors on a port exceed a user-set
threshold.
You must assign an IP address to the LANplex system to manage RMON. See
the LANplex® 2500 Administration Console User Guide for information on
how to assign an IP address.
Figure 13-1 shows an example of a LANplex RMON implementation. The
LANplex 2500 system in this figure has two Fast Ethernet connections in
addition to the 10BASE-T connections.
13-4
CHAPTER 13: REMOTE MONITORING (RMON) TECHNOLOGY
Management
console
LAN
LANplex® 2500 system with embedded RMON probe
Fast Ethernet ports
Ethernet ports
File Servers
Figure 13-1 Embedded RMON Implemented on the LANplex System
Management
Information Base
(MIB)
A MIB is a structured set of data that describes the way the network is
functioning. The management software, known as the agent, gains access to
this set of data and extracts the information it needs. The agent can also
store data in the MIB.
The organization of a MIB allows a Simple Network Management Protocol
(SNMP) network management package such as the Transcend Enterprise
Manager application suite to manage a network device without a specific
description of that device. 3Com ships SNMP MIB files with LANplex
Extended Switching System software as ASN.1 files.
MIB Objects
The data in the MIB consists of objects that represent features of the
equipment that an agent can control and manage. Examples of objects in
the MIB include a port that you can enable or disable and a counter that
you can read.
A counter is a common type of MIB object used by RMON. A counter object
might record the number of frames transmitted onto the network. The MIB
might contain an entry for the counter object something like the one in
Figure 13-2 for the counter object.
Management Information Base (MIB)
13-5
etherStatsPkts OBJECT-TYPE
SYNTAX
Counter
ACCESS
read-only
STATUS
mandatory
DESCRIPTION
This is a total number of packets
received, including bad packets,
broadcast packets, and multicast
packets.
::= { etherStatsEntry 5 }
Figure 13-2 Example of an RMON MIB Counter Object
The displayed information includes these items:
■
The formal name of the counter is etherStatsPkts. (Ethernet, Statistics,
Packets)
■
The access is read-only
■
The number of the counter’s column in the table: 5
The name of the table in which the counter resides is 3CometherStatTable,
although this does not appear in the display.
You do not need to know the contents of every MIB object to manage a
network. Most network management applications, including Transcend
Enterprise Manager Software, make the MIB transparent. However, knowing
how different management features are derived from the MIB allows you to
better understand how to use the information that they provide.
13-6
Alarms
CHAPTER 13: REMOTE MONITORING (RMON) TECHNOLOGY
The LANplex system supports the following syntax for alarms: counters,
gauges, integers and timeticks. These mechanisms report information about
the network to the network administrator. Counters, for example, hold and
update the number of occurrences of a particular event through a port,
module, or switch on the network. Alarms monitor the counters and report
instances of when counters exceed their set threshold.
Counters are useful when you compare their values at specific time intervals
to determine rates of change. The time intervals can be short or long,
depending on what you measure. Occasionally, reading counters can give
you misleading results.
Counters are not infinite, which makes rate comparisons an efficient way to
use them. When counters reach a predetermined limit, they return to 0 (roll
over). A single low counter value might accurately represent a condition on
the network. It might simply indicate that a roll over has occurred.
When you disable a port, the application might not update some of the
statistics counters associated with it.
An alarm calculates the difference in counter values over a set time interval
and remembers the high and low values. When the value of a counter
exceeds a preset threshold, the alarm reports this occurrence.
You can assign alarms with Transcend Enterprise Manager or any other
SNMP network management application to monitor any counter, gauge,
time tick, or integer. Consult the documentation for your management
application for details on setting up alarms.
Alarms
Setting Alarm
Thresholds
Example of an
Alarm Threshold
13-7
Thresholds determine when an alarm reports that a counter has exceeded a
certain value. You can set alarm thresholds through the network manually,
and choose any value for them that is appropriate for your application. The
network management software monitors the counters and thresholds
continually during normal operations to provide data for later calibration.
Figure 13-3 shows a counter with thresholds set manually.
Counter
Manually set high threshold
(user-specified)
Manually set low threshold
(user-specified)
Time
Figure 13-3 Manually Set Thresholds
You can associate an alarm with the high threshold, the low threshold, or
both. The actions taken because of an alarm depend on the network
management application.
13-8
CHAPTER 13: REMOTE MONITORING (RMON) TECHNOLOGY
RMON Hysteresis
Mechanism
The RMON hysteresis mechanism provides a way to prevent small
fluctuations in counter values from causing alarms. This mechanism
generates an alarm only under the following conditions:
■
The counter value exceeds the high threshold after previously exceeding
the low threshold. (An alarm does not occur if the value has not fallen
below the low threshold before rising above the high threshold.)
■
The counter value exceeds the low threshold after previously exceeding the
high threshold. (An alarm does not occur if the value has not risen above
the high threshold before falling below the low threshold.
In Figure 13-3, for example, an alarm occurs the first time the counter
exceeds the high threshold , but not at the second time. At the first
instance, the counter is rising from the low threshold, while in the second
instance, it is not.
APPENDIX
VI
Appendix A
Technical Support
TECHNICAL SUPPORT
A
3Com provides easy access to technical support information through a
variety of services. This appendix describes these services.
On-line Technical
Services
3Com offers worldwide product support 24 hours a day, seven days a week,
through the following on-line systems:
■
■
■
■
3Com Bulletin
Board Service
3Com Bulletin Board Service (3ComBBS)
World Wide Web site
3ComForum on CompuServe® online service
3ComFactsSM automated fax service
3ComBBS contains patches, software, and drivers for all 3Com products, as
well as technical articles. This service is available via analog modem or ISDN
24 hours a day, seven days a week.
Access by Analog Modem
To reach the service by modem, set your modem to 8 data bits, no parity,
and 1 stop bit. Call the telephone number nearest you:
Country
Data Rate
Telephone Number
Australia
up to 14400 bps
(61) (2) 9955 2073
France
up to 14400 bps
(33) (1) 69 86 69 54
Germany
up to 9600 bps
(49) (89) 627 32 188 or (49) (89) 627 32 189
Hong Kong
up to 14400 bps
(852) 2537 5608
Italy (fee required)
up to 14400 bps
(39) (2) 273 00680
Japan
up to 14400 bps
(81) (3) 3345 7266
Singapore
up to 14400 bps
(65) 534 5693
Taiwan
up to 14400 bps
(886) (2) 377 5840
U.K.
up to 28800 bps
(44) (1442) 278278
U.S.
up to 28800 bps
(1) (408) 980 8204
A-2
APPENDIX A: TECHNICAL SUPPORT
Access by Digital Modem
ISDN users can dial in to 3ComBBS using a digital modem for fast access up
to 56 Kbps. To access 3ComBBS using ISDN, dial the following number:
(408) 654-2703
World Wide Web Site
Access the latest networking information on 3Com’s World Wide Web site by
entering our URL into your Internet browser:
http://www.3Com.com/
This service features news and information about 3Com products, customer
service and support, 3Com’s latest news releases, selected articles from
3TECH™ journal (3Com’s award-winning technical journal), and more.
3ComForum on
CompuServe®
3ComForum is a CompuServe® service containing patches, software, drivers,
and technical articles about all 3Com products, as well as a messaging
section for peer support. To use 3ComForum, you need a CompuServe
account.
To use 3ComForum:
1 Log on to CompuServe.
2 Enter go threecom
3 Press [Return] to see the 3ComForum Main menu.
Support from Your Network Supplier
3ComFacts™
Automated Fax Service
A-3
3Com Corporation’s interactive fax service, 3ComFacts, provides data sheets,
technical articles, diagrams, and troubleshooting instructions on 3Com
products 24 hours a day, seven days a week.
Call 3ComFacts using your Touch-Tone® telephone at one of these
international access numbers:
Country
Telephone Number
Hong Kong
(852) 2537 5610
U.K.
(44) (1442) 278279
U.S.
(1) (408) 727 7021
Local access numbers are available within the following countries:
Support from
Your Network
Supplier
Country
Telephone Number
Country
Telephone Number
Australia
800 123853
Netherlands
06 0228049
Belgium
0800 71279
Norway
800 11062
Denmark
800 17319
Portugal
0505 442607
Finland
98 001 4444
Russia (Moscow only)
956 0815
France
05 90 81 58
Spain
900 964445
Germany
0130 8180 63
Sweden
020 792954
Italy
1678 99085
U.K.
0800 626403
If additional assistance is required, contact your network supplier. Many
suppliers are authorized 3Com service partners who are qualified to provide
a variety of services, including network planning, installation, hardware
maintenance, application training, and support services.
When you contact your network supplier for assistance, have the following
information ready:
■
Diagnostic error messages
■
A list of system hardware and software, including revision levels
■
Details about recent configuration changes, if applicable
If you are unable to contact your network supplier, see the following section
on how to contact 3Com.
A-4
APPENDIX A: TECHNICAL SUPPORT
Support from
3Com
If you are unable to receive support from your network supplier, technical
support contracts are available from 3Com.
In the U.S. and Canada, call (800) 876-3266 for customer service.
If you are outside the U.S. and Canada, contact your local 3Com sales office
to find your authorized service provider. Use one of these numbers:
Country
Telephone Number
Country
Telephone Number
Australia*
1800 678 515
Japan
(81) (3) 3345 7251
Mexico
(525) 531 0591
0800 71429
Netherlands*
06 0227788
Brazil
(55) (11) 546 0869
Norway*
800 11376
Canada
(416) 498 3266
Singapore
(65) 538 9368
Denmark*
800 17309
South Africa
(27) (11) 803 7404
900 983125
Belgium*
Finland*
0800 113153
Spain*
France*
05 917959
Sweden*
020 795482
Germany*
0130 821502
Taiwan
(886) (2) 577 4352
Hong Kong
(852) 2501 1111
United Arab Emirates (971) (4) 349049
Ireland*
1 800 553117
U.K.*
0800 966197
Italy*
1678 79489
U.S.
(1) (408) 492 1790
* These numbers are toll-free.
Returning Products
for Repair
Before you return a product directly to 3Com for repair, you must first call
for a Return Materials Authorization (RMA) number. A product sent to 3Com
without an RMA number will be returned to the sender unopened, at the
sender’s expense.
To obtain an RMA number, call or fax:
10/22/96
Country
Telephone Number
Fax Number
U.S. and Canada
(800) 876 3266, option 2
(408) 764 7120
Europe
31 30 60 29900, option 5
(44) (1442) 275822
Outside Europe, U.S., and Canada
(1) (408) 492 1790
(1) (408) 764 7290
INDEX
Numerics
3Com Bulletin Board Service (3ComBBS) A-1
3Com sales offices A-4
3ComFacts A-3
A
AARP 7-10
AARP cache
administering 12-7
displaying 12-8
removing an entry from 12-9
address
classes 4-3
IP to MAC, translating 9-13
MAC 3-3
network 3-3
Address Resolution Protocol. See ARP
Administration Console
menu descriptions 1-2
top-level menu 1-2
ADSP 7-10
advertisement address
adding 9-8
in a define interface command 9-5
removing 9-8
AEP 7-8
alarm thresholds
examples of 13-7
setting 13-7
AppleTalk
address resolution protocol (AARP) 7-10
checksum 12-12
configuring forwarding 12-11
data stream protocol (ADSP) 7-10
echo protocol (AEP) 7-8
interface, displaying 12-3
main menu 1-6
name binding protocol (NBP) 7-9
network layer 7-6
nodes 7-2
physical layer 7-5
printer access protocol (PAP) 7-10
protocols, about 7-1
protocols, and OSI levels 7-4
routing table maintenance protocol (RTMP) 7-6
routing tables 7-8
session layer protocol (ASP) 7-10
statistics, viewing 12-13
transaction protocol (ATP) 7-9
zone information protocol (ZIP) 7-9
zones 7-3
AppleTalk networks 7-2
extended 7-2
nonextended 7-2
AppleTalk node
pinging an 12-12
AppleTalk routing 7-1
ARP
defined 4-7, 9-13
location in OSI reference model 4-1
reply 4-8
request 4-8
See also ARP cache 9-13
ARP cache 4-7, 9-13
flushing 9-15
removing an entry from 9-14, 9-19, 9-20
ASP 7-10
ATM ARP cache
displaying 9-17
flushing 9-18
removing an entry 9-17
ATM ARP servers
about 4-10
defining 9-15
nodes that can function as an 4-10
ATP 7-9
B
BOOTP relay threshold 9-20
bridge
menu 1-4
bridge menu 1-3
2
INDEX
bridging/routing
LANplex model 3-4
traditional model 3-4
bulletin board service A-1
learned routes, AppleTalk 12-6
learned routes, IP 9-12
learned routes, IPX 11-7
for 11-9
forwarding
configuring AppleTalk 12-11
C
cache
displaying the IP multicast 10-9
checksum
configuring AppleTalk 12-12
chooser, Macintosh 7-2
CompuServe A-2
conventions
notice icons 2
G
gateway
routing table, and the 4-5
See also router
H
hysteresis mechanism 13-8
D
datagram delivery protocol 7-6
datagrams, statistics 9-23
data-link layer 4-1
DDP statistics 12-13
default route
displayed 9-11
default route, IP
defined 4-7, 9-10
removing 9-13
setting 9-13
defining 9-4
defining an ATM ARP 9-15
ATM ARP server 9-4
direct, route status 9-10
DVMRP
about 5-2
enabling 10-2
metric value 5-5, 10-3
dynamic routes 4-6, 6-14
See also RIP
See also SAP
dynamic routes, IPX 6-9
E
extended network numbers 7-2
extended switching, overview 1-1
F
fax service. See 3ComFacts
flushing
ARP cache 9-15
I
ICMP
defined 4-9
echo (request and reply) 9-22
echo Reply 4-9
echo request 4-9
ping and 9-22
Redirect 4-9
Time Exceeded 4-9
ICMP Router Discovery, enabling 9-21
IGMP
about 5-1
enabling 10-2
interface
administering an IP multicast 10-3
defining an IP 9-6
defining an IP multicast 10-2
interface, AppleTalk
defining an 12-3
displaying an 12-3
removing an 12-4
interface, IP
defining a LIS 9-4
defining a VLAN 9-6
displaying an 9-3
parts of 9-1
removing definition 9-7
interface, IP multicast
disabling 10-5
displaying 10-4
enabling 10-5
parts of 10-1
interface, IPX
defining an 11-3
INDEX
displaying an 11-3
modifying an 11-4
removing an 11-4
Interior Gateway Protocols (IGP) 4-6, 6-9
Internet address. See IP address
Internet Control Message Protocol. See ICMP
Internet Protocol. See references with IP address
intranetwork routing
diagram 3-2
IP
address translation 9-13
ARP cache 9-13
enabling routing 9-20
interface 9-1
main menu 1-4
pinging a station 9-22
RIP mode 9-21, 9-22
route
displaying table 9-11
routes 9-9
statistics, displaying 9-23
IP address
classes of 4-3
defined 4-2
derived from 4-2
division of network and host 4-2
example 4-4
network layer and the 4-1
RIP, and 4-6
routing table, and the 4-5
subnet mask, and the 4-3
subnet part 4-3
IP interface
defining 9-6
displaying 9-3
removing definition 9-7
IP mulitcast routing
interface
disabling 10-5
IP multicast
cache, displaying 10-9
routes, displaying 10-8
IP Multicast menu 1-4
IP multicast routing
about 5-1
algorithms 5-3
interfaces 10-1
administering 10-3
defining 10-2
displaying 10-4
enabling 10-5
MBONE 5-2
rate limit 5-6, 10-4
TTL threshold 10-3
tunnels 5-6, 10-6
IP route
default 9-10, 9-13
defining static 9-11
removing from table 9-12
status 9-10
IP router
transmission process 4-2
IP routing
address classes 4-3
basic elements 4-2
enabling 9-20
ICMP 4-9
OSI reference model 4-1
references 4-11
router interface 4-4
routing table 4-5
transmission errors 4-9
IP routing over ATM 4-10
IPX
forwarding statistics, displaying 11-17
main menu 1-5
RIP statistics, displaying 11-15
route
defining a static 11-6
removing a 11-7
SAP statistics 11-16
static server 11-9
IPX routing
and RIP 6-10
packet format 6-5
router interface 6-8
routing table 6-8
SAP, and 6-10
server table 6-13
L
LANplex
bridging/routing model 3-6
intranetwork router, as an 3-2
ports and IP interfaces 9-6
subnetting with 3-2
learned routes
flushing AppleTalk 12-6
flushing IP 9-12
flushing IPX 11-7
learned, IP route status 9-10
LIS
definition of 4-10
forwarding to nodes within an 4-11
3
4
INDEX
LIS interfaces
characteristics of 9-3
defining 9-4
M
MAC (Media Access Control). See FDDI MAC
MAC address 3-3
ARP and 9-13
bridging in switching modules, and 3-6
compared to IP address 4-2
in ARP Request 4-8
located with ARP 4-7
use in IP routing 4-8
Macintosh, chooser 7-2
management
IP interface 9-1
management console
RMON 13-1
MBONE 5-2
menu
AppleTalk main 1-6
bridge 1-4
IP main 1-4
IPX main 1-5
metric
defined 4-5
metric value
DVMRP 5-5, 10-3
MIB
RMON 13-1, 13-2, 13-4
multicast routing, IP
about 5-1
N
name binding protocol 7-9
named entities 7-2
NBP 7-9
NetWare
defined 6-1
OSI reference model, and the 6-2
protocols 6-1 to 6-3
network address 3-3
network layer, and IP address 4-1
network layer, AppleTalk 7-6
network numbers
extended 7-2
nonextended 7-2
network supplier support A-3
nodes, AppleTalk 7-2
nonextended network numbers 7-2
O
on-line technical services A-1
OSI Reference Model
AppleTalk routing and 7-5
IP routing and 4-1
IPX routing and 6-2
P
PAP 7-10
physical layer, AppleTalk 7-5
pinging
AppleTalk node 12-12
IP station 9-22
port
See also FDDI port
printer access protocol 7-10
probe
RMON 13-1, 13-2
PVC
adding 9-9
removing 9-9
R
rate limit
IP multicast 5-6, 10-4
references
Comer 4-11
Perlman 4-11
routing RFCs 4-11
returning products for repair A-4
RIP
active mode 9-21
broadcast address, and 9-2
default mode 9-22
defined 4-6, 6-10
off mode 9-21
passive mode 9-21
route configuration, and 4-6, 6-9
setting mode 9-21
using for dynamic routes 6-9
RIP statistics
IPX RIP 11-15
RMON
agents 13-3
alarms 13-6
benefits of 13-2
groups 13-3
hysteresis mechanism 13-8
LANplex implementation 13-2
INDEX
management console 13-1
MIB 13-1, 13-2, 13-4
probe 13-1, 13-2
route, IP
default 9-10
defining static 9-11
removing default 9-13
removing from table 9-12
status 9-10
route, IPX
removing a 11-7
router interface, IP
described 4-4
diagram 4-5
routing table, and the 4-5
router interface, IPX
described 6-8
routers, seed 7-4
routes, displaying IP multicast 10-8
routing
and bridging in switching modules 3-4
and bridging, traditional model 3-4
implementation in LANplex 3-4
LANplex system, and the 3-1 to 3-7
See also IP routing, IPX routing, and AppleTalk routing
Routing Information Protocol. See RIP
routing table
display routes 9-11
routing table, AppleTalk 7-8
routing table, IP
contents 4-5, 9-9
default route 4-7
default route, setting 9-13
described 4-5
dynamic routes 4-6
example 4-6
flushing learned routes 9-12
metric 4-5
removing default route 9-13
removing route 9-12
static routes 4-6
routing table, IPX
contents 6-8
described 6-8
displaying 11-6
dynamic routes 6-9
example 6-9
flushing learned routes 11-7
removing a route 11-7
static routes 6-9
RTMP
description of 7-6
S
SAP
aging mechanism 6-14
packet structure 6-11
request handling 6-15
using for dynamic routes 6-14
SAP mode
setting 11-13
SAP statistics, displaying 11-16
seed routers 7-4
segmentation, increasing 3-3
server 9-4, 9-16
defining a static IPX 11-9
server table
contents 6-13
described 6-13
displaying 11-9
Service Advertisement Protocol. See SAP
session layer protocols
AppleTalk 7-9
software
installation 1-1
static route, IP 4-6
status of 9-10
static route, IPX 6-9
defining 11-6
static server, IPX
defining a 11-9
station
See also FDDI station
statistics
AppleTalk, viewing 12-13
IP 9-23
IPX forwarding 11-17
IPX SAP 11-16
ZIP, displaying 12-15
subnet mask
defined 4-3
diagram 4-4
example 4-4
in routing table 4-5
subnetting
defined 4-3
Ethernet switching and 3-2
subnet mask, and the 4-3
with the LANplex 3-2
T
technical support A-1
ThreeComForum A-2
5
6
INDEX
timing out, IP route status 9-10
T-notify
configuring 8-4
transmission errors
ICMP Redirect 4-9
reasons for 4-9
TTL threshold 5-5
IP multicast 10-3
tunnels
IP multicast 5-6, 10-6
V
VLAN
information
defining 8-3
displaying 8-1
modifying 8-4
removing 8-5
VLAN interfaces
about 9-1
characteristics of 9-2
defining 9-6
VLANs
application oriented 2-2
MAC address group 2-2
overlapped IP 2-7
port group 2-1
protocol-sensitive 2-2
routing between 2-8
Z
ZIP 7-9
statistics, displaying 12-15
zone information protocol (ZIP) 7-9
zone information table (ZIT) 7-9
displaying the 12-10
zone, AppleTalk
default 12-3
example of 7-3
naming 12-3