Cisco Content Services Switch Redundancy Configuration Guide

Cisco Content Services Switch
Redundancy Configuration Guide
Software Version 8.10
November 2005
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Text Part Number: OL-8243-01
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Cisco Content Services Switch Redundancy Configuration Guide
Copyright © 2005 Cisco Systems, Inc. All rights reserved.
CONTENTS
Preface xiii
Audience xiv
How to Use This Guide xiv
Related Documentation xv
Symbols and Conventions xviii
Obtaining Documentation xix
Cisco.com xix
Product Documentation DVD xx
Ordering Documentation xx
Documentation Feedback xxi
Cisco Product Security Overview xxi
Reporting Security Problems in Cisco Products xxii
Obtaining Technical Assistance xxiii
Cisco Technical Support & Documentation Website xxiii
Submitting a Service Request xxiv
Definitions of Service Request Severity xxiv
Obtaining Additional Publications and Information xxv
CHAPTER
1
Configuring VIP and Virtual Interface Redundancy 1-1
Overview of CSS Redundancy 1-2
When to Use VIP and Virtual Interface Redundancy 1-2
When to Use ASR 1-3
When to Use Box-to-Box Redundancy 1-3
Overview of VIP and Virtual Interface Redundancy 1-4
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VIP Redundancy 1-4
Virtual Interface Redundancy 1-6
Fate Sharing 1-7
Examples of VIP and Virtual Interface Redundancy Configurations 1-9
Active-Backup VIP and Virtual Interface Redundancy with Fate
Sharing 1-9
Active-Active VIP and Virtual Interface Redundancy 1-11
Shared VIP Redundancy 1-14
VIP and Virtual Interface Redundancy Configuration Quick Start 1-16
Configuring VIP and Virtual Interface Redundancy 1-19
Configuring a Circuit IP Interface 1-19
Configuring a Virtual Router 1-20
Configuring a Redundant VIP 1-22
Configuring a Redundant Virtual Interface 1-23
Configuring VRID Peering 1-24
Background 1-25
Overview of VRID Peering 1-25
Configuration Requirements and Restrictions 1-27
VRID Peering Quick Start 1-28
Configuring a Reporter 1-29
Configuring the Reporter Type 1-30
Configuring the Virtual Routers That You Want to Monitor 1-31
Activating a Reporter 1-32
Suspending a Reporter 1-32
Configuring a Critical Reporter 1-32
Configuring a Critical Service 1-33
Configuring a Critical Physical Interface 1-35
Overview 1-36
Configuration Requirements and Restrictions 1-36
Critical Phy Quick Start 1-37
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Configuring a Reporter 1-38
Configuring the Reporter Type 1-39
Configuring the Physical Interfaces That You Want to Monitor 1-41
Activating a Reporter 1-42
Suspending a Reporter 1-42
Configuring a Critical Reporter 1-42
Synchronizing a VIP Redundancy Configuration 1-43
Script Functions 1-45
Before You Begin 1-45
Running the Configuration Synchronization Script 1-46
Config Sync Lock File 1-48
Setting the LOCAL_VIPR_IP and REMOTE_VIPR_IP Variables 1-48
Logging Configuration Synchronization Script Result Messages 1-49
Displaying VIP and Virtual Interface Redundancy Configurations 1-50
Displaying Redundant Virtual Interfaces 1-50
Displaying Redundant VIPs 1-52
Displaying Virtual Router Configurations 1-53
Resetting the Virtual Router State Changes Counter 1-56
Displaying IP Critical Services 1-57
Displaying Reporter Configurations 1-59
Using the show reporter Command 1-59
Resetting the Reporter State Transitions Counter 1-61
Displaying a Reporter Configuration in the Running-Config 1-61
Displaying Critical Reporter Information 1-61
Displaying Critical Reporters in the Running-Config 1-62
CHAPTER
2
Configuring Adaptive Session Redundancy 2-1
Overview of CSS Redundancy 2-2
When to Use VIP and Virtual Interface Redundancy 2-2
When to Use ASR 2-3
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Contents
When to Use Box-to-Box Redundancy 2-3
Configuring Adaptive Session Redundancy 2-4
Stateful Failover 2-5
Inter-Switch Communications 2-6
Redundant Indexes 2-7
Configuration Requirements and Restrictions 2-8
Upgrading to WebNS Version 7.40 and Higher 2-11
ASR Quick Start 2-11
Configuring Inter-Switch Communications 2-15
Configuring Redundant Services 2-16
Configuring Redundant Content Rules 2-17
Configuring Redundant Source Groups 2-18
Source Group Port-Mapping Behavior in an ASR Configuration 2-19
Synchronizing ASR Configurations 2-19
Displaying ASR Information 2-19
Displaying Inter-Switch Communications Ports 2-20
Displaying Dormant Flow Information 2-21
Displaying ASR Information for Content Rules, Services, and Source
Groups 2-23
Displaying ASR Status and Global Index Values 2-23
Displaying Summary ASR Information 2-23
CHAPTER
3
Configuring Box-to-Box Redundancy 3-1
Overview of CSS Redundancy 3-2
When to Use VIP and Virtual Interface Redundancy 3-2
When to Use ASR 3-3
When to Use Box-to-Box Redundancy 3-3
Redundancy Protocol Overview 3-4
Redundancy Configuration Quick Start 3-6
Cabling Redundant CSSs 3-9
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Configuring Redundancy 3-10
Configuring IP Redundancy 3-11
Configuring Redundant Circuits 3-13
Configuring the Redundancy Protocol 3-13
Configuring the VRRP Backup Timer 3-14
Synchronizing a Redundant Configuration 3-15
Before You Begin 3-15
Running the Configuration Synchronization Script 3-16
Config Sync Lock File 3-19
Setting the REMOTE_IP Variable 3-19
Logging Configuration Synchronization Script Result Messages 3-20
Using the Redundancy Force-Master Command 3-20
Configuring Multiple Redundant Uplink Services 3-21
Using the redundancy-phy Command 3-23
Configuring Stateless Redundancy Failover 3-24
Before You Begin 3-25
Environmental Considerations 3-25
General Configuration Requirements 3-26
Configuration Restrictions 3-26
Configuring CSS Parameters 3-26
Synchronizing the CSS Configurations 3-28
Box-to-Box Redundancy Configuration 3-28
Layer 2 and Layer 3 Configuration and Convergence 3-29
Configuration Example 3-29
VIP and Interface Redundancy Configuration 3-32
Layer 2 and Layer 3 Configuration and Convergence 3-32
Configuration Example 3-33
Alternative Configurations 3-36
Managing Your Configuration 3-36
Other Considerations 3-36
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Contents
Displaying Redundant Configurations 3-37
INDEX
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F I G U R E S
Figure 1-1
Example of VIP and Virtual Interface Redundancy
Figure 1-2
Example of Asymmetric Flows Without Fate Sharing
Figure 1-3
Example of Active-Backup VIP and Virtual Interface Redundancy
1-9
Figure 1-4
Example of Active-Active VIP and Virtual Interface Redundancy
1-12
Figure 1-5
Example of Shared VIP Redundancy
Figure 2-1
Example of CSS 11506 Matching Module Configurations for ISC
Figure 3-1
Redundancy Configuration Example
Figure 3-2
Multiple Redundant Uplink Services Configuration Example
Figure 3-3
Example Box-to-Box Redundancy Configuration for Stateless
Redundancy Failover 3-31
Figure 3-4
Example of VIP and Virtual Interface Redundancy Configuration for Stateless
Redundancy Failover 3-35
1-5
1-8
1-15
2-6
3-5
3-22
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Figures
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T A B L E S
Table 1-1
VIP and Virtual Interface Redundancy Configuration Quick Start
Table 1-2
Independent VR States and Conditions
Table 1-3
Dependent VR States and Conditions
Table 1-4
Effect of Independent VR States on Reporter Dependent States
Table 1-5
VRID Peering Configuration Quick Start
Table 1-6
Critical Phy Configuration Quick Start
Table 1-7
Effect of Interface State on Reporter and Virtual Router State Based on Reporter
Type 1-40
Table 1-8
Field Descriptions for the show redundant-interfaces Command
Table 1-9
Field Descriptions for show redundant-vips Command
Table 1-10
Field Descriptions for the show virtual-routers Command
Table 1-11
Field Descriptions for the show critical-services Command
Table 1-12
Field Descriptions for the show reporter Command
Table 1-13
Field Descriptions for the show critical-reporters Command
Table 2-1
ASR Configuration Quick Start
Table 2-2
Field Descriptions for the show isc-ports Command
Table 2-3
Field Descriptions for the show dormant flows Command
Table 2-4
Field Descriptions for the flow statistics dormant Command
Table 2-5
Field Descriptions for the show session-redundant Command
Table 3-1
Redundancy Configuration Quick Start
3-7
Table 3-2
RJ-45 Fast Ethernet Connector Pinouts
3-10
Table 3-3
Field Descriptions for the show redundancy Command
1-16
1-26
1-26
1-27
1-28
1-37
1-51
1-52
1-54
1-57
1-60
1-62
2-12
2-20
2-21
2-22
2-24
3-38
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Tables
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Preface
This guide provides instructions for configuring the redundancy features of the
Cisco 11500 Series Content Services Switches (CSS). Information in this guide
applies to all CSS models except where noted.
The CSS software is available in a Standard or optional Enhanced feature set. The
Enhanced feature set contains all of the Standard feature set and also includes
Network Address Translation (NAT) Peering, Domain Name Service (DNS),
Demand-Based Content Replication (Dynamic Hot Content Overflow), Content
Staging and Replication, and Network Proximity DNS. Proximity Database and
Secure Management, which includes Secure Shell Host and SSL strong
encryption, are optional features.
This preface contains the following major sections:
•
Audience
•
How to Use This Guide
•
Related Documentation
•
Symbols and Conventions
•
Obtaining Documentation
•
Documentation Feedback
•
Cisco Product Security Overview
•
Obtaining Technical Assistance
•
Obtaining Additional Publications and Information
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Preface
Audience
Audience
This guide is intended for the following trained and qualified service personnel
who are responsible for configuring the CSS:
•
Web master
•
System administrator
•
System operator
How to Use This Guide
This guide is organized as follows:
Chapter
Description
Chapter 1,
Configuring VIP and Virtual
Interface Redundancy
Configure VIP and virtual interface
redundancy on a CSS to maintain network
integrity.
Chapter 2,
Configuring Adaptive Session
Redundancy
Configure Adaptive Session Redundancy
(ASR) on a CSS to provide stateful failover
of flows.
Chapter 3,
Configuring Box-to-Box
Redundancy
Configure box-to-box redundancy between
two mirrored CSSs.
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Related Documentation
Related Documentation
In addition to this guide, the Content Services Switch documentation includes the
following publications.
Document Title
Description
Release Note for the
Cisco 11500 Series
Content Services Switch
This release note provides information on
operating considerations, caveats, and command
line interface (CLI) commands for the Cisco 11500
series CSS.
Cisco 11500 Series
Content Services Switch
Hardware Installation
Guide
This guide provides information for installing,
cabling, and powering the Cisco 11500 series CSS.
In addition, this guide provides information about
CSS specifications, cable pinouts, and hardware
troubleshooting.
Cisco Content Services
Switch Getting Started
Guide
This guide describes how to perform initial
administration and configuration tasks on the CSS,
including:
•
Booting the CSS for the first time and a routine
basis, and logging in to the CSS
•
Configuring the username and password,
Ethernet management port, static IP routes,
and the date and time
•
Configuring DNS server for hostname
resolution
•
Configuring sticky cookies with a sticky
overview and advanced load-balancing method
using cookies
•
Installing the CSS Cisco View Device Manager
(CVDM) browser-based user interface used to
configure the CSS
•
A task list to help you find information in the
CSS documentation
•
Troubleshooting the boot process
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Preface
Related Documentation
Document Title
Description
Cisco Content Services
Switch Administration
Guide
This guide describes how to perform administrative
tasks on the CSS, including upgrading your CSS
software and configuring the following:
Cisco Content Services
Switch Routing and
Bridging Configuration
Guide
•
Logging, including displaying log messages
and interpreting sys.log messages
•
User profile and CSS parameters
•
SNMP
•
RMON
•
XML documents to configure the CSS
•
CSS scripting language
•
Offline Diagnostic Monitor (Offline DM)
menu
This guide describes how to perform routing and
bridging configuration tasks on the CSS, including:
•
Management ports, interfaces, and circuits
•
Spanning-tree bridging
•
Address Resolution Protocol (ARP)
•
Routing Information Protocol (RIP)
•
Internet Protocol (IP)
•
Open Shortest Path First (OSPF) protocol
•
Cisco Discovery Protocol (CDP)
•
Dynamic Host Configuration Protocol (DHCP)
relay agent
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Related Documentation
Document Title
Description
Cisco Content Services
Switch Content
Load-Balancing
Configuration Guide
This guide describes how to perform CSS content
load-balancing configuration tasks, including:
Cisco Content Services
Switch Global Server
Load-Balancing
Configuration Guide
•
Flow and port mapping
•
Services
•
Service, global, and script keepalives
•
Source groups
•
Loads for services
•
Server/Application State Protocol (SASP)
•
Dynamic Feedback Protocol (DFP)
•
Owners
•
Content rules
•
Sticky parameters
•
HTTP header load balancing
•
Content caching
•
Content replication
This guide describes how to perform CSS global
load-balancing configuration tasks, including:
•
Domain Name System (DNS)
•
DNS Sticky
•
Content Routing Agent
•
Client-Side Accelerator
•
Network proximity
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Preface
Symbols and Conventions
Document Title
Description
Cisco Content Services
Switch Security
Configuration Guide
This guide describes how to perform CSS security
configuration tasks, including:
Cisco Content Services
Switch SSL Configuration
Guide
Cisco Content Services
Switch Command
Reference
•
Controlling access to the CSS
•
Secure Shell Daemon protocol
•
Radius
•
TACACS+
•
Firewall load balancing
This guide describes how to perform CSS SSL
configuration tasks, including:
•
SSL certificate and keys
•
SSL termination
•
Backend SSL
•
SSL initiation
•
HTTP data compression
This reference provides an alphabetical list of all
CLI commands including syntax, options, and
related commands.
Symbols and Conventions
This guide uses the following symbols and conventions to identify different types
of information.
Caution
A caution means that a specific action you take could cause a loss of data or
adversely impact use of the equipment.
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Obtaining Documentation
Warning
Note
A warning describes an action that could cause you physical harm or damage
the equipment.
A note provides important related information, reminders, and recommendations.
Bold text indicates a command in a paragraph.
Courier text
indicates text that appears on a command line, including the CLI
prompt.
Courier bold text
indicates commands and text you enter in a command line.
Italics text indicates the first occurrence of a new term, book title, emphasized
text, and variables for which you supply values.
1.
A numbered list indicates that the order of the list items is important.
a. An alphabetical list indicates that the order of the secondary list items is
important.
•
A bulleted list indicates that the order of the list topics is unimportant.
– An indented list indicates that the order of the list subtopics is
unimportant.
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Cisco documentation and additional literature are available on Cisco.com. Cisco
also provides several ways to obtain technical assistance and other technical
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Systems.
Cisco.com
You can access the most current Cisco documentation at this URL:
http://www.cisco.com/techsupport
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Preface
Obtaining Documentation
You can access the Cisco website at this URL:
http://www.cisco.com
You can access international Cisco websites at this URL:
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Preface
Documentation Feedback
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Cisco Product Security Overview
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Cisco Product Security Overview
If you prefer to see advisories and notices as they are updated in real time, you
can access a Product Security Incident Response Team Really Simple Syndication
(PSIRT RSS) feed from this URL:
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Reporting Security Problems in Cisco Products
Cisco is committed to delivering secure products. We test our products internally
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•
Emergencies — security-alert@cisco.com
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•
Nonemergencies — psirt@cisco.com
In an emergency, you can also reach PSIRT by telephone:
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•
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Obtaining Technical Assistance
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Obtaining Technical Assistance
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Obtaining Additional Publications and Information
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publications. For current Cisco Press titles and other information, go to Cisco
Press at this URL:
http://www.ciscopress.com
•
Packet magazine is the Cisco Systems technical user magazine for
maximizing Internet and networking investments. Each quarter, Packet
delivers coverage of the latest industry trends, technology breakthroughs, and
Cisco products and solutions, as well as network deployment and
troubleshooting tips, configuration examples, customer case studies,
certification and training information, and links to scores of in-depth online
resources. You can access Packet magazine at this URL:
http://www.cisco.com/packet
•
iQ Magazine is the quarterly publication from Cisco Systems designed to
help growing companies learn how they can use technology to increase
revenue, streamline their business, and expand services. The publication
identifies the challenges facing these companies and the technologies to help
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Preface
Obtaining Additional Publications and Information
solve them, using real-world case studies and business strategies to help
readers make sound technology investment decisions. You can access iQ
Magazine at this URL:
http://www.cisco.com/go/iqmagazine
or view the digital edition at this URL:
http://ciscoiq.texterity.com/ciscoiq/sample/
•
Internet Protocol Journal is a quarterly journal published by Cisco Systems
for engineering professionals involved in designing, developing, and
operating public and private internets and intranets. You can access the
Internet Protocol Journal at this URL:
http://www.cisco.com/ipj
•
Networking products offered by Cisco Systems, as well as customer support
services, can be obtained at this URL:
http://www.cisco.com/en/US/products/index.html
•
Networking Professionals Connection is an interactive website for
networking professionals to share questions, suggestions, and information
about networking products and technologies with Cisco experts and other
networking professionals. Join a discussion at this URL:
http://www.cisco.com/discuss/networking
•
World-class networking training is available from Cisco. You can view
current offerings at this URL:
http://www.cisco.com/en/US/learning/index.html
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C H A P T E R
1
Configuring VIP and Virtual Interface
Redundancy
This chapter describes how to plan for and configure virtual IP (VIP) redundancy
and virtual interface redundancy on the CSS. Information in this chapter applies
to all CSS models except where noted.
This chapter provides the following major sections:
•
Overview of CSS Redundancy
•
Overview of VIP and Virtual Interface Redundancy
•
VIP and Virtual Interface Redundancy Configuration Quick Start
•
Configuring VIP and Virtual Interface Redundancy
•
Displaying VIP and Virtual Interface Redundancy Configurations
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Overview of CSS Redundancy
Overview of CSS Redundancy
Redundancy helps to ensure:
•
High availability for your network applications
•
Users do not experience long network delays or black holes due to a single
point of failure.
A CSS provides three types of redundancy.
•
Virtual IP (VIP) and virtual interface redundancy - Provides redundant VIP
addresses and redundant virtual interfaces for fate sharing (the redundant
interfaces and redundant VIPs fail over together to the backup CSS) and
server default gateways. For details, see this chapter.
•
Adaptive Session Redundancy (ASR) - Provides session-level redundancy
(stateful failover) to continue active flows without interruption if the master
CSS fails over to the backup CSS. For details, refer to Chapter 2, Configuring
Adaptive Session Redundancy.
•
Box-to-box redundancy - Provides chassis-level redundancy between two
identically configured CSSs. For details, refer to Chapter 3, Configuring
Box-to-Box Redundancy.
The following sections provide information about when (and when not) to use the
different types of redundancy.
When to Use VIP and Virtual Interface Redundancy
Typically, you configure VIP redundancy on the public side of CSS peers that are
positioned in front of a server farm. You configure virtual interface redundancy
on the private-side interfaces attached to the Layer 2 device in front of the servers.
Configure VIP redundancy:
•
With virtual interface redundancy to provide fate sharing
•
When you have a common subnet between the two CSSs on which the VIPs
reside
•
As a prerequisite to configuring ASR (requires active-backup VIP
redundancy)
•
To provide active-active CSS behavior (both CSSs processing flows)
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Overview of CSS Redundancy
Configure interface redundancy:
•
With VIP redundancy to provide fate sharing
•
When you need a default gateway for the back-end servers
•
Instead of VIP redundancy on the client side of the CSS when the VIPs are
on a subnet different from the subnet of your uplinks
When to Use ASR
ASR provides session-level redundancy for applications where active flows
(including TCP and UDP) must continue without interruption, even if the master
CSS fails over to the backup CSS.
Configure ASR:
•
If you require stateful failover for mission-critical applications (for example,
enterprise applications; long-lived flows, such as HTTP or FTP file transfers;
and e-commerce)
•
After you have first configured active-backup VIP and virtual interface
redundancy
When to Use Box-to-Box Redundancy
Configure box-to-box redundancy when you:
•
Expect the behavior of the CSSs to be active/standby (only the master CSS
processes flows)
•
Can configure a dedicated Fast Ethernet (FE) link between the CSSs for the
redundancy protocol
Do not configure box-to-box redundancy when you:
•
Expect the behavior of the CSSs to be active-active (both CSSs processing
flows). Use VIP redundancy instead.
•
Cannot configure a dedicated FE link between the CSSs.
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Overview of VIP and Virtual Interface Redundancy
Overview of VIP and Virtual Interface Redundancy
This section provides information about:
Note
•
VIP Redundancy
•
Virtual Interface Redundancy
•
Fate Sharing
•
Examples of VIP and Virtual Interface Redundancy Configurations
When using VIP or VIP interface redundancy with zone-based Global Server
Load Balancing (GSLB), both the master and backup CSSs provide DNS
information over their APP sessions. In this configuration, we recommend that
you configure the master and backup CSSs in their own separate zones. A CSS in
a GSLB configuration expects to receive zone-based information from only one
CSS source within another zone. If the CSS receives information from more than
one CSS within the zone, the CSS ignores the additional information, potentially
causing unexpected results to DNS queries.
VIP Redundancy
When you configure a pair of CSSs to process client requests for the same VIP
address, the VIP address is considered redundant. A typical use of VIP
redundancy is with a virtual interface redundancy configuration where the master
CSS processes all client requests to a VIP with a Web-server farm behind the
CSSs and connected to the CSSs through a Layer 2 switch (Figure 1-1). If the
master CSS becomes unavailable, the backup CSS becomes master and processes
all client requests for the VIP.
Note
The CSS does not support VIP redundancy and box-to-box redundancy
configurations simultaneously. For information about box-to-box redundancy,
refer to Chapter 3, Configuring Box-to-Box Redundancy.
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Overview of VIP and Virtual Interface Redundancy
To set up CSSs for VIP redundancy, you must configure a virtual router (VR) on
each CSS that will participate in the redundant configuration. A VR is an entity
within a CSS with which you associate an existing VIP. A VIP becomes redundant
when you associate it with a VR. You can configure a maximum of 255 VRs for
each VLAN.
Note
Figure 1-1
The VIP address must already exist in at least one active content rule or source
group.
Example of VIP and Virtual Interface Redundancy
VLAN2
192.1.1.2
Web Servers
VLAN1
10.1.1.2
CSS-2
Redundant Interface
192.1.1.254
Backup
VIP Active
192.1.1.100
Client
Redundant Interface
10.1.1.254
Active
VLAN2
192.1.1.1
VLAN1
10.1.1.1
119693
CSS-1
L2 Switch
Virtual routers providing redundancy for a VIP address are considered a VR pair.
Each VR pair has the same VR identifier (VRID) and runs on the same VLAN,
but runs on a different CSS. Once the VRs are configured, the CSSs negotiate for
mastership using Virtual Router Redundancy Protocol (VRRP). A VR in a
redundant VIP configuration that is designated as:
•
Master processes all client requests directed to the VIP
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Overview of VIP and Virtual Interface Redundancy
•
Backup may be either a:
– Backup VR, which forwards all client requests directed to the VIP to the
master CSS
– Shared backup VR, which processes all client requests it receives and
does not forward requests for the VIP to the master CSS
A CSS designated as the master of a VIP automatically sends a gratuitous ARP
for the VIP when the CSS becomes the master, either at startup or upon failover.
This process enables the Layer 2 switch to learn where to forward packets that are
directed to the VIP from clients. The CSS transmits one ARP request packet and
one ARP reply packet for every gratuitious ARP invocation.
For an example of VIP and virtual interface redundancy, see Figure 1-1.
Virtual Interface Redundancy
Virtual interface redundancy is a form of IP address redundancy that applies only
to IP interfaces (not VIPs). A typical interface IP address on a CSS defines the
interface in use on a particular VLAN. In a virtual interface redundancy
configuration, the CSS designated as master maintains control over the redundant
virtual interface. Each CSS will also have its own circuit IP address that you can
use for Telnet, SNMP, or Cisco View Device Manager (CVDM) user interface.
The typical use for virtual interface redundancy is with a VIP redundancy
configuration in which:
•
Web servers are positioned behind a Layer 2 switch
•
CSSs with the redundant virtual interface are positioned in front of the Layer
2 switch
•
The servers are configured with a default route (gateway) pointing to the
redundant virtual interface IP address on the private side of the CSS
•
Upstream routers use the IP address of the public-side redundant virtual
interface as the next hop
You must configure VRs with the same VRIDs on the subnets that are common to
both CSSs. Once you associate the new VRIDs with the redundant virtual
interface IP addresses, the CSSs uses VRRP to negotiate mastership of the
redundant virtual interfaces.
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Overview of VIP and Virtual Interface Redundancy
A CSS designated as the master of a redundant virtual interface automatically
sends out gratuitous ARPs for the redundant virtual interface’s IP address when
the CSS becomes the master, either at startup or upon failover. This process
enables a Layer 2 switch to learn where to forward packets that are directed to the
redundant virtual interface from the servers or the clients and allows a server’s
default route to always point to the CSS designated as the master of the redundant
virtual interface. The CSS transmits one ARP request packet and one ARP reply
packet for every gratuitious ARP invocation.
For an example of VIP and virtual interface redundancy, see Figure 1-1.
Note
Virtual interface redundancy does not support a CSS configured as a shared
backup.
You can also configure virtual interface redundancy on the uplinks of the CSSs
when the VIPs reside on a subnet different from that of the uplinks. In this case,
you cannot configure VIP redundancy on the public side of the CSSs. You will
need to configure static routes on the upstream routers pointing to the redundant
virtual interface on the CSS as the router’s next hop gateway to the subnet where
the VIPs reside.
Fate Sharing
Fate sharing means that, when the redundant VIP fails over on the public side of
the network from the master to the backup CSS, the redundant virtual interfaces
on the public and the private sides of the network also fail over from the master
to the backup CSS. If you do not configure virtual interface redundancy with VIP
redundancy, asymmetric flows may result (Figure 1-2). Asymmetric flows occur
when a CSS is master on the public side, but backup on the private side, which
breaks the connection between the client and the server.
To ensure that the redundant VIP and the redundant virtual interfaces fail over at
the same time, you must bind the front and the back instances of VRRP (the VRs)
so that the same CSS processes both inbound and outbound flows. You
accomplish this by defining as critical services the IP addresses of the upstream
router (the CSS default gateway) and the downstream Layer 2 switch that
connects to the servers.
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Overview of VIP and Virtual Interface Redundancy
For example, the CSS provides a scripted keepalive (ap-kal-pinglist) that will
check the health of the upstream router and the downstream Layer 2 switch. When
you configure this keepalive, if either device fails, the critical service goes down
and the redundant VIP and the redundant virtual interfaces fail over together to
the backup CSS. For details on configuring critical services, see the “Configuring
a Critical Service” section.
Figure 1-2
Example of Asymmetric Flows Without Fate Sharing
Web Servers
L2 Switch
VLAN2
192.1.1.2
VLAN1
10.1.1.2
CSS-2
Redundant Interface
192.1.1.254
Backup
Client
VIP Active
192.1.1.100
Active
Active
Redundant Interface
10.1.1.254
Backup
VLAN2
192.1.1.1
VLAN1
10.1.1.1
119694
CSS-1
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Overview of VIP and Virtual Interface Redundancy
Examples of VIP and Virtual Interface Redundancy Configurations
The following sections provides examples of the most commonly used VIP and
virtual interface redundancy configurations.
Active-Backup VIP and Virtual Interface Redundancy with Fate Sharing
Figure 1-3 shows an active-backup VIP and virtual interface redundancy
configuration. CSS-1 is configured as the master for VIP address 192.1.1.100 and
virtual interface address 10.1.1.254. If CSS-1 fails, CSS-2 (the backup CSS) will
assume mastership of all flows destined to VIP address 192.1.1.100 and virtual
interface address 10.1.1.254.
Figure 1-3
Example of Active-Backup VIP and Virtual Interface Redundancy
VLAN2
192.1.1.2
Web Servers
VLAN1
10.1.1.2
CSS-2
Redundant Interface
192.1.1.254
Backup
Client
VIP Active
192.1.1.100
Redundant Interface
10.1.1.254
Active
VLAN2
192.1.1.1
VLAN1
10.1.1.1
119693
CSS-1
L2 Switch
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Overview of VIP and Virtual Interface Redundancy
CSS-1 Configuration
circuit VLAN1
ip address 10.1.1.1 255.255.255.0
ip virtual-router 1 priority 101 preempt
ip redundant-interface 1 10.1.1.254
ip critical-service 1 upstream_downstream
circuit VLAN2
ip address 192.1.1.1 255.255.255.0
ip virtual-router 2 priority 101 preempt
ip redundant-vip 2 192.1.1.100
ip redundant-interface 2 192.1.1.254
ip critical-service 2 upstream_downstream
CSS-2 Configuration
circuit VLAN1
ip address 10.1.1.2 255.255.255.0
ip virtual-router 1
ip redundant-interface 1 10.1.1.254
ip critical-service 1 upstream_downstream
circuit VLAN2
ip address 192.1.1.2 255.255.255.0
ip virtual-router 2
ip redundant-vip 2 192.1.1.100
ip redundant-interface 2 192.1.1.254
ip critical-service 2 upstream_downstream
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Overview of VIP and Virtual Interface Redundancy
Active-Active VIP and Virtual Interface Redundancy
A CSS can serve simultaneously as a master to one VR and as a backup to a
different VR. This is called active-active VIP and virtual interface redundancy.
All redundant VIP addresses will share the state of the VR to which they are
associated. The same VR cannot be active on both CSSs simultaneously.
Figure 1-4 shows an active-active VIP and virtual interface redundancy
configuration with:
•
CSS-1 configured as:
– VLAN1 IP address 10.1.1.1.
– VLAN2 IP address 192.1.1.1.
– Master VR for VIP address 192.1.1.100, virtual interface address
192.1.1.254, and virtual interface address 10.1.1.254.
– Backup VR for VIP address 192.1.1.101, virtual interface address
192.1.1.253, and virtual interface address 10.1.1.253. CSS-1 will
forward all client requests it receives for VIP address 192.1.1.101 and
virtual interface address 192.1.1. 253, and all server requests for virtual
interface address 10.1.1.253 to CSS-2.
•
CSS-2 configured as:
– VLAN1 IP address 10.1.1.2.
– VLAN2 IP address 192.1.1.2
– Master VR for VIP address 192.1.1.101, virtual interface address
192.1.1.253, and virtual interface address 10.1.1.253.
– Backup VR for VIP address 192.1.1.100, virtual interface address
192.1.1.254, and virtual interface address 10.1.1.254. CSS-2 will
forward all client requests it receives for VIP address 192.1.1.100 and
virtual interface address 192.1.1. 254, and all server requests for virtual
interface address 10.1.1.254 to CSS-1.
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Overview of VIP and Virtual Interface Redundancy
Figure 1-4
Example of Active-Active VIP and Virtual Interface Redundancy
VLAN2
192.1.1.2
VLAN1
10.1.1.2
L2 Switch
Redundant Interface
192.1.1.253
CSS-2
Active
Active
VIP Active
192.1.1.101
Redundant Interface
10.1.1.253
VIP Active
192.1.1.100
Redundant Interface
10.1.1.254
Default Gateway
10.1.1.253
Client
Active
VLAN2
192.1.1.1
CSS-1
VLAN1
10.1.1.1
Default Gateway
10.1.1.254
119695
Redundant Interface
192.1.1.254
Active
CSS-1 Configuration
circuit VLAN1
ip address 10.1.1.1 255.255.255.0
ip virtual-router 1 priority 101 preempt
ip virtual-router 2
ip redundant-interface 1 10.1.1.254
ip redundant-interface 2 10.1.1.253
ip critical-service 1 upstream_downstream
ip critical-service 2 upstream_downstream
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Overview of VIP and Virtual Interface Redundancy
circuit VLAN2
ip address 192.1.1.1 255.255.255.0
ip virtual-router 3 priority 101 preempt
ip virtual-router 4
ip redundant-vip 3 192.1.1.100
ip redundant-vip 4 192.1.1.101
ip redundant-interface 3 192.1.1.254
ip redundant-interface 4 192.1.1.253
ip critical-service 3 upstream_downstream
ip critical-service 4 upstream_downstream
CSS-2 Configuration
circuit VLAN1
ip address 10.1.1.2 255.255.255.0
ip virtual-router 1
ip virtual-router 2 priority 101 preempt
ip redundant-interface 1 10.1.1.254
ip redundant-interface 2 10.1.1.253
ip critical-service 1 upstream_downstream
ip critical-service 2 upstream_downstream
circuit VLAN2
ip address 192.1.1.2 255.255.255.0
ip virtual-router 3
ip virtual-router 4 priority 101 preempt
ip redundant-vip 3 192.1.1.100
ip redundant-vip 4 192.1.1.101
ip redundant-interface 3 192.1.1.254
ip redundant-interface 4 192.1.1.253
ip critical-service 3 upstream_downstream
ip critical-service 4 upstream_downstream
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Overview of VIP and Virtual Interface Redundancy
Shared VIP Redundancy
In a shared VIP redundancy configuration, both the master and the backup VRs
process flows destined to the same VIP. However, only the master VR (CSS-1)
responds to ARP requests for the VIP address 192.1.1.100.
Note
Shared VIP redundancy is not supported with VRID peering. See the
“Configuring VRID Peering” section.
A shared VIP redundancy configuration has the following requirements:
•
Direct uplink connections to routers (no common Layer 2 connection
between CSSs)
•
Direct connection between the CSSs to enable the backup CSS to forward
ARP requests to the master CSS
•
Mirrored content on the servers
•
Direct connection from the servers to the CSSs eliminating the need for fate
sharing
•
Session- or flow-based (not packet-by-packet) ECMP router upstream to
preserve flow state
Figure 1-5 shows a shared VIP redundancy configuration with:
•
CSS-1 configured as master VR for VIP address 192.1.1.100
•
CSS-2 configured as shared backup for VIP address 192.1.1.100
Notice that CSS-2 (shared backup VR for VIP 192.1.1.100) forwards the ARP
request for 192.1.1.100 to CSS-1 for a response.
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Overview of VIP and Virtual Interface Redundancy
Example of Shared VIP Redundancy
Router
192.1.3.1
ARP 192.1.1.100
VLAN2
192.1.1.2
Ip route 192.1.1.0
255.255.255.0 192.1.2.1.1
Ip route 192.1.1.0
255.255.255.0 192.1.3.1.1
Web Servers
CSS-2
Backup
VIP Active
192.1.1.100
Client
ECMP
Upstream
Router
Mirrored
Content
Master
VLAN2
192.1.1.1
192.1.2.1
VLAN1
10.1.1.2
CSS-1
VLAN1
10.1.1.1
Router
83843
Figure 1-5
Web Servers
CSS-1 Configuration
circuit VLAN1
ip address 10.1.1.1 255.255.255.0
circuit VLAN2
ip address 192.1.1.1 255.255.255.0
ip virtual-router 1
ip redundant-vip 1 192.1.1.100 shared
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Configuring VIP and Virtual Interface Redundancy
CSS-2 Configuration
circuit VLAN1
ip address 10.1.1.2 255.255.255.0
circuit VLAN2
ip address 192.1.1.2 255.255.255.0
ip virtual-router 1
ip redundant-vip 1 192.1.1.100 shared
VIP and Virtual Interface Redundancy Configuration
Quick Start
Table 1-1 provides a quick overview of the steps required to configure
active-backup VIP and virtual interface redundancy with fate sharing for CSS-1.
Each step includes the CLI command required to complete the task. For a
complete description of each feature and all the options associated with the CLI
command, see the sections following Table 1-1.
Table 1-1
VIP and Virtual Interface Redundancy Configuration Quick Start
Task and Command Example
1.
Enter config mode.
# config
(config)#
2.
Enter service mode and configure a service to be used as a critical service
or use an existing service.
(config)# service upstream_downstream
(config-service[upstream_downstream])#
(config-service[upstream_downstream])#
ap-kal-pinglist “191.1.1.20 10.1.1.20”
(config-service[upstream_downstream])#
(config-service[upstream_downstream])#
(config-service[upstream_downstream])#
(config-service[upstream_downstream])#
ip address 192.1.1.75
keepalive type script
keepalive frequency 2
keepalive maxfailure 2
keepalive retryperiod 2
active
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Table 1-1
VIP and Virtual Interface Redundancy Configuration Quick Start
(continued)
Task and Command Example
3.
Enter circuit mode for VLAN1.
(config)# circuit VLAN1
(config-circuit[VLAN1])#
4.
Configure a circuit IP address.
(config-circuit[VLAN1])# ip address 10.1.1.1/24
(config-circuit-ip[VLAN1-10.1.1.1])#
5.
Configure the VR. If you do not have a preference as to which router
becomes master, you may leave the default priority at 100. If you have a
preference, assign a higher priority to one router using the priority option.
When you want a VR to assume mastership in all circumstances, include the
preempt keyword.
(config-circuit-ip[VLAN1-10.1.1.1])# ip virtual-router 1 priority
101 preempt
6.
Configure the redundant virtual interface.
(config-circuit-ip[VLAN1-10.1.1.1])# ip redundant-interface 1
10.1.1.254
7.
Configure an existing service as a critical service for the VR.
(config-circuit-ip[VLAN1-10.1.1.1])# ip critical-service 1
upstream_downstream
8.
Enter circuit mode for the next desired circuit VLAN.
(config)# circuit VLAN2
(config-circuit[VLAN2])#
9.
Configure a circuit IP address.
(config-circuit[VLAN2])# ip address 192.1.1.1/24
(config-circuit-ip[VLAN2-192.1.1.1])#
10. Configure the VR.
(config-circuit-ip[VLAN2-192.1.1.1])# ip virtual-router 2
priority 101 preempt
11. Configure the redundant VIP on the VR.
(config-circuit-ip[VLAN2-192.1.1.1])# ip redundant-vip 2
192.1.1.100
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Table 1-1
Configuring VIP and Virtual Interface Redundancy
VIP and Virtual Interface Redundancy Configuration Quick Start
(continued)
Task and Command Example
12. Configure the redundant virtual interface on the VR.
(config-circuit-ip[VLAN2-192.1.1.1])# ip redundant-interface 2
192.1.1.254
13. Configure the critical service for the VR.
(config-circuit-ip[VLAN2-192.1.1.1])# ip critical-service 2
upstream_downstream
14. (Recommended) Verify the configuration.
(config)# show virtual-routers
You would configure CSS-2 in a similar manner, with the exception of the
priority and preempt options of the ip virtual-router command.
The following running-config example shows the results of entering the
commands listed in Table 1-1.
!************************* INTERFACE *************************
interface 2/1
bridge vlan 2
!************************** CIRCUIT **************************
circuit VLAN1
ip address 10.1.1.1 255.255.255.0
ip virtual-router 1 priority 101 preempt
ip redundant-interface 1 10.1.1.254
ip critical-service 1 upstream_downstream
circuit VLAN2
ip address 192.1.1.1 255.255.255.0
ip virtual-router 2 priority 101 preempt
ip redundant-vip 2 192.1.1.100
ip critical-service 2 upstream_downstream
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!************************** SERVICE **************************
service upstream-downstream
ip address 192.1.1.10
keepalive type script ap-kal-pinglist “192.1.1.20 10.1.1.20"
keepalive frequency 2
keepalive maxfailure 2
keepalive retryperiod 2
active
Configuring VIP and Virtual Interface Redundancy
You must configure each CSS that is part of a redundant configuration. The
following sections describe how to configure VIP and virtual interface
redundancy.
•
Configuring a Circuit IP Interface
•
Configuring a Virtual Router
•
Configuring a Redundant VIP
•
Configuring a Redundant Virtual Interface
•
Configuring VRID Peering
•
Configuring a Critical Service
•
Configuring a Critical Physical Interface
•
Synchronizing a VIP Redundancy Configuration
Configuring a Circuit IP Interface
Because this chapter is dedicated to configuring VIP and virtual interface
redundancy, it contains only those circuit IP commands that pertain to this feature.
For a complete description of all circuit IP commands, refer to the Cisco Content
Services Switch Routing and Bridging Configuration Guide.
Before you can configure VIP and virtual interface redundancy, you must
configure a circuit IP interface and assign it an IP address. To enter a specific
circuit configuration mode, enter the circuit command and VLAN as shown in the
following example:
(config)# circuit VLAN2
(config-circuit[VLAN2])#
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Note
When you use the circuit command, enter the word “VLAN” in uppercase letters
and do not include a space between VLAN and the VLAN number (for example,
VLAN1).
To assign an IP address to a circuit, use the ip address command from the specific
circuit mode. Enter the IP address and a subnet mask in CIDR bitcount notation
or dotted-decimal notation. The subnet mask range is /8 to /32. For example, to
configure an IP address and subnet mask for VLAN1, enter:
(config-circuit[VLAN2])# ip address 192.1.1.1 /24
When you specify an IP address, the mode changes to the specific
circuit-ip-VLAN-IP address as shown:
(config-circuit-ip[VLAN2-192.1.1.1])#
Configuring a Virtual Router
To create a virtual router (VR) on a CSS and configure the identifier and priority
that is used when negotiating control of associated VIPs, use the ip virtual-router
command. You must configure the VR before you can configure redundant VIPs.
A VR’s role as a master or backup is determined during negotiations between all
VRs with the same VRID and residing on the same VLAN.
Note
In a VRID peering or critical phy configuration, suspending a reporter that is
configured as a critical reporter causes all VRs associated with it to go down,
which causes a failover from master to backup. See the “Configuring VRID
Peering” and the “Configuring a Critical Physical Interface” sections.
The syntax and options for the IP interface command are:
ip virtual-router vrid {priority number} {preempt}
The variables and options are:
•
vrid - The virtual router identifier (VRID). Enter an integer between 1 and
255. You can configure 255 VRs per VLAN. Virtual routers are considered
peers when they have the same VRID and reside in the same VLAN.
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•
priority number - The optional priority of the VR with respect to its peers.
The default priority value is 100. Enter an integer between 1 and 255. A VR
with the highest priority usually becomes master. However, a higher priority
VR will not assume mastership from a lower priority master unless you
include the preempt option.
When a VR is the master, it handles the traffic directed to its associated VIPs.
To set a VR so that it will always be master, set its priority to 255 and
configure it with the preempt option.
•
preempt - The optional keyword that allows a higher priority VR to assert
mastership over a lower priority VR. By default, a VR does not become
master if the current master has a lower priority.
For example, if a CSS with a VR that has a low priority boots before other
CSSs, that VR becomes the master. When another CSS with a VR that has a
higher priority boots, it will not take the mastership from the first router
unless you specify the preempt option on the higher priority VR. This option
does not have an effect if the priority of the two VRs is identical. You can use
this option with or without the priority option. You can configure only one
VR as the master of a particular VIP.
Caution
Never configure the preempt option on the same VR on both CSSs. Such a
configuration may result in both CSSs becoming master, which will cause
network problems.
Because a VR’s priority is dependent on the state of the critical services, the
priority field status in the show virtual router display may be different than the
priority you configured. The priority may be different when you:
•
Assign a priority of 255 to a VR and that VR gains mastership, the CSS
automatically reconfigures that VR’s priority to 254. This action ensures that
you can assign a different VR a priority of 255.
•
Configure critical services. The critical service types are:
– scripted - the priority changes to 0 when one service in the scripted
group goes down.
– redundancy uplink - the priority changes to 0 when all of the services
in the uplink group go down.
– local - the priority changes to 0 when all of the services in the local group
go down. Local services include all services other than scripted and
uplink.
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For information about configuring critical services, see the “Configuring a
Critical Service” section.
For example:
(config-circuit-ip[VLAN2-192.1.1.1])# ip virtual-router 2 priority 1
preempt
To remove the VR from the CSS, enter:
(config-circuit-ip[VLAN2-192.1.1.1])# no ip virtual-router 2
Configuring a Redundant VIP
To associate an existing VIP with a VR and, if required, configure the VR as a
shared backup, use the ip redundant-vip command. A shared backup VR
processes client requests. A redundant VIP configuration can consist of only two
CSSs.
Note
Before you use this command, the VIP must already be configured in at least one
active content rule or source group. Additionally, if you defined the content rule
or source group VIP using the range option, you must configure an identical range
for the redundant VIP. For information about configuring VIPs in content rules
and source groups, refer to the Cisco Content Services Switch Content
Load-Balancing Configuration Guide.
The syntax of this IP mode command is:
ip redundant-vip vrid vip_address {range number} {shared}
The variables and options are:
•
vrid - The ID for an existing VR.
•
vip_address - The address for the redundant VIP. This address must already
be configured in at least one active content rule or source group. Enter an IP
address in dotted-decimal notation (for example, 192.1.1.100).
•
range number - The optional keyword and variable if an IP address range is
specified in the content rule or source group. You cannot specify a range that
differs from the range in the content rule. Also, you cannot specify address
ranges that overlap. Enter a number from 0 to 65535. The default is 1.
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•
Caution
shared - The optional keyword to enable shared VIP redundancy. When you
use this option, the master and backup VRs share the processing of traffic
directed to the VIP, so the backup does not forward packets to the master.
Configure each VIP identically on both CSSs.
Do not connect Layer 2 devices between the CSSs and the routers in a shared VIP
redundancy configuration. In addition, each router must be connected to only one
CSS. Otherwise, all traffic will go to the master CSS, thus defeating the purpose
of shared VIP redundancy.
For example:
(config-circuit-ip[VLAN2-192.1.1.1])# ip redundant-vip 2 192.1.1.100
range 10 shared
To remove a VIP from a VR, enter:
(config-circuit-ip[VLAN1-192.1.1.1])# no ip redundant-vip 1
192.1.1.100
Configuring a Redundant Virtual Interface
Servers use the IP address of a redundant virtual interface as a default gateway to
guarantee that packets are sent to the CSS containing the master VR. To
accomplish this goal, configure a redundant virtual interface with the same VR as
a redundant VIP that is configured in a rule that refers to the server. This
configuration ensures that the master CSS for a VIP is the same CSS that is master
for the redundant virtual interface. If the master CSS fails over to the backup CSS,
both the VIP and the redundant interface fail over together. This configuration is
called fate sharing. For details, see the “Fate Sharing” section.
We recommend that you also configure a redundant virtual interface on the public
side of each CSS. This configuration provides a single IP address as the next hop
for the upstream routers.
To configure a redundant virtual interface, use the ip redundant-interface
command.
The syntax of this IP mode command is:
ip redundant-interface vrid ip_address
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The variables are:
•
vrid - Identifier of a previously-configured VR.
•
ip_address - Address for the redundant interface. Enter an IP address in
dotted-decimal notation (for example, 10.1.1.254).
Note
You cannot use an IP address that already exists for a VIP, redundant
VIP, source group, service, log host, or IP interface address on a
circuit. If you do, the following error message appears: Address
conflicts with local I/F, VIP, service, or source group.
For example:
(config-circuit-ip[VLAN1-10.1.1.1])# ip redundant-interface 1
10.1.1.254
To remove an interface from a VR, enter:
(config-circuit-ip[VLAN1-10.1.1.1])# no ip redundant-interface 1
10.1.1.254
Note
The CSS does not support a traceroute of a redundant IP interface.
Configuring VRID Peering
To ensure that the state of the virtual routers (VRs) on both the public and the
private sides of a CSS remain synchronized, configure VRID peering in a VIP and
virtual interface redundancy configuration. VRID peering groups VRs that are
configured on the same CSS so that, when one VR in the group changes state (for
example, from master to backup), all VRs in the group change state at the same
time. This feature helps to prevent asymmetric flows, which cause network
address translation (NAT) to fail and break the client-server connection.
This section contains the following topics:
•
Background
•
Overview of VRID Peering
•
Configuration Requirements and Restrictions
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•
VRID Peering Quick Start
•
Configuring a Reporter
•
Configuring the Reporter Type
•
Configuring the Virtual Routers That You Want to Monitor
•
Activating a Reporter
•
Suspending a Reporter
•
Configuring a Critical Reporter
•
Resetting the Reporter State Transitions Counter
Background
In a VIP and virtual interface redundancy configuration, you typically configure
a pair of virtual routers (VRs) running VRRP to negotiate mastership of the
redundant VIPs on the client side of the network and another pair of VRs to
negotiate mastership of the redundant interfaces on the server side of the network.
In addition, you can use critical services to provide fate sharing so that the
redundant VIPs and the redundant interfaces change state together from master to
backup. A CSS uses polling keepalives to monitor the states of critical services.
Because a link on either the public side or the private side of a CSS can go down
and then up very quickly in between keepalive polling times, it is possible for a
VR on one CSS to be the master for the redundant VIP and a VR on the other CSS
to be the master for the redundant virtual interface. This loss of synchronization
between VRs can occur even when you have configured critical services. While
this unsynchronized VR state is permitted, it may not be desirable in all cases.
Unsynchronized VRs produce asymmetric flows, which cause NAT to fail. In this
case, packets from a server will be routed to the CSS that is master for the
redundant virtual interface (default gateway), while packets from a client will be
routed to the other CSS that is master for the redundant VIP.
Overview of VRID Peering
VRID peering works by grouping two or more VR peers with a software agent
called a reporter that monitors the states of the VRs. VRs are considered peers
when they are configured on the same CSS. The reporter ensures that the states of
the VR peers are synchronized by sending internal state update messages to the
monitored VRs when necessary.
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The internal state of a virtual router is called an independent VR state because it
does not depend on the state of its VR peers. The VR peer reporter state is called
a dependent VR state because it depends on the states of all VRs configured on
the reporter.
Table 1-2 lists the independent VR states and describes the conditions required for
each state.
Table 1-2
Independent VR States and Conditions
Independent State
Conditions
Down
Circuit where the VR runs is down or one of the critical
services configured on the VR failed
Backup
Circuit where the VR runs is up, there are no failures on
the critical services configured on the VR, and VRRP has
determined that the VR should be in the backup state
Master
Circuit where the VR runs is up, there are no failures on
the critical services configured on the VR, and VRRP has
determined that the VR should be in the master state
The reporter that is responsible for monitoring the VR peers determines the
dependent state of the VRs. Table 1-3 lists the dependent VR states and describes
the conditions required for each state.
Table 1-3
Dependent VR States and Conditions
Dependent State
Conditions
Down
At least one of the VR peers in a reporter group is in the
Down state. The VRs will hold the VIPs and redundant
virtual interfaces that they control in the Down state.
Backup
At least one of the VR peers in a reporter group is in the
Backup state and none is in the Down state. The VRs will
hold the VIPs and redundant virtual interfaces that they
control in the Backup state.
Master
All VR peers in a reporter group are in the Master state.
The VRs transmit VRRP messages announcing that they
are in the Master state. VIPS and redundant virtual
interfaces controlled by the VRs become masters.
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When two or more VRs are configured on a reporter, their dependent state is that
of the lowest independent state of all the VR peers in the group. Table 1-4 shows
the effects of independent VR states on reporter dependent states for two VRs.
Table 1-4
Effect of Independent VR States on Reporter Dependent States
VR1 Independent State
VR2 Independent State
Reporter Dependent State
Down
Down
Down
Down
Backup
Down
Down
Master
Down
Backup
Down
Down
Backup
Backup
Backup
Backup
Master
Backup
Master
Down
Down
Master
Backup
Backup
Master
Master
Master
Configuration Requirements and Restrictions
The following requirements and recommendations apply to the configuration and
use of VRID peering on a Cisco 11500 series CSS.
•
Ensure that you have configured VIP and virtual interface redundancy
properly. See the “Configuring VIP and Virtual Interface Redundancy”
section.
•
VRID peering is not supported with shared VIP redundancy.
•
Ensure that a VR exists before you attempt to configure it on a reporter. See
the “Configuring a Virtual Router” section.
•
All VRs associated with a VRID peering reporter must have the same priority
and preempt configurations.
•
Do not configure the same IP address and VRID on more than one reporter.
•
You can configure a maximum of 128 reporters on a CSS.
•
You can configure a maximum of four reporters of type VRID peer on a CSS.
•
You can configure a maximum of eight VRIDs on a reporter of type VRID
peer.
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VRID Peering Quick Start
Table 1-5 provides a quick overview of the steps required to configure VRID
peering. Each step includes the CLI command required to complete the task. For
a complete description of each feature and all the options associated with the CLI
command, see the sections following Table 1-5.
Table 1-5
VRID Peering Configuration Quick Start
Task and Command Example
1.
Enter config mode.
# config
(config)#
2.
Enter reporter configuration mode and create a new reporter. See the
“Configuring a Reporter” section.
(config)# reporter r1
(config-reporter[r1])#
3.
Configure the VRID peering type on the reporter. See the “Configuring the
Reporter Type” section.
(config-reporter[r1])# type vrid-peering
4.
Specify the VRs that you want to monitor. See the “Configuring the Virtual
Routers That You Want to Monitor” section.
(config-reporter[r1])# vrid 192.168.100.5 1
(config-reporter[r1])# vrid 172.16.27.12 2
5.
Activate the reporter. See the “Activating a Reporter” section.
(config-reporter[r1])# active
6.
Associate the reporter with an existing VRID. See the “Configuring a
Critical Reporter” section.
(config-circuit-ip[VLAN1-192.168.100.5])# ip critical-reporter 1 r1
(config-circuit-ip[VLAN2-172.16.27.12])# ip critical-reporter 2 r1
7.
(Recommended) Verify the reporter configuration. See the “Displaying a
Reporter Configuration in the Running-Config” section.
(config-circuit-ip[VLAN2-172.16.27.12])# show reporter r1
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Table 1-5
VRID Peering Configuration Quick Start (continued)
Task and Command Example
8.
(Recommended) Verify the VRID peering configuration. See the
“Displaying Critical Reporter Information” section.
(config-circuit-ip[VLAN2-172.16.27.12])# show running-config
reporter
The following running-config example shows the results of entering the
commands in Table 1-5.
!************************** CIRCUIT **************************
circuit VLAN1
ip address 192.168.100.5 255.255.255.0
ip virtual-router 1 priority 101 preempt
ip critical-reporter 1 r1
circuit VLAN2
ip address 172.16.27.12 255.255.255.0
ip virtual-router 2 priority 101 preempt
ip critical-reporter 2 r1
!************************** REPORTER **************************
reporter r1
type vrid-peering
vrid 192.168.100.5 1
vrid 172.16.27.12 2
active
Configuring a Reporter
A reporter is a software agent that monitors the states of all VRs associated with
it. When a VR state change is necessary, the reporter sends a state update message
to its associated VRs. To configure a reporter and enter reporter configuration
mode, use the reporter command in global configuration mode. You can
configure a maximum of 128 reporters on a CSS.
This command has the following syntax:
reporter reporter_name
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The reporter_name variable specifies the name of the reporter you are creating.
Enter an unquoted text string with no spaces from 1 to 31 characters.
For example, enter:
(config)# reporter r1
To remove an existing reporter from the running-config, enter:
(config-reporter[r1])# no reporter r1
Note
If you remove a reporter from the running-config using the no reporter
command, the CSS removes all the attributes associated with that reporter from
the running-config.
Configuring the Reporter Type
A VRID peer is a type of reporter that monitors the states of associated VRs and
ensures that the VR states are synchronized. To configure the reporter type, use
the type command in reporter configuration mode. You can configure a maximum
of four reporters of type vrid-peering on a CSS.
Note
The CSS supports reporters of type vrid-peering only with non-shared
active-backup and active-active VIP redundancy configurations.
This command has the following syntax.
type reporter_type
For example, to configure a reporter as a VRID peering type, enter:
(config-reporter[r1])# type vrid-peering
To remove the VRID peering type or to reconfigure the reporter type as a critical
phy type:
1.
Suspend the reporter. See the “Suspending a Reporter” section.
Note
If the reporter is configured as a critical reporter, suspending it causes
the associated VR to transition to Backup or Down.
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2.
Remove the VRID peering reporter attributes using the no vrid ip_address
vrid command. See the “Configuring the Virtual Routers That You Want to
Monitor” section.
3.
Remove the VRID peering reporter type using the no type command or
reconfigure the reporter type as a critical phy type using the type
critical-phy-all-up or the type critical-phy-any-up command. For details
about configuring a critical phy, see the “Configuring a Critical Physical
Interface” section.
4.
If you reconfigured the reporter type as a critical phy type, add the physical
interfaces using the phy interface_name command, then activate the reporter
using the active command. See the “Configuring the Physical Interfaces That
You Want to Monitor” section and the “Activating a Reporter” section.
Configuring the Virtual Routers That You Want to Monitor
To configure the VRs that you want a reporter to monitor, use the vrid command
in reporter configuration mode. This command allows you to configure a
maximum of eight VRIDs on a reporter of type vrid-peering.
This command has the following syntax:
vrid ip_address vrid
Note
You cannot configure the same circuit IP address and VRID on more than one
reporter.
The variables for this command are:
•
ip_address - The circuit IP address of the CSS in dotted-decimal notation.
•
vrid - The VR identifier (VRID). Enter the VRID of an existing VR. You can
configure a maximum of eight VRIDs on one reporter. For details on
configuring a VR, see the “Configuring a Virtual Router” section.
For example:
(config-reporter[r1])# vrid 192.168.12.7 1
Note
You cannot remove the last remaining VR from an active reporter. To remove the
VR, first suspend the reporter, and then remove the VR.
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To remove a VR from a reporter, enter:
(config-reporter[r1])# no vrid 192.168.12.7 1
Activating a Reporter
You must activate a reporter before it can monitor the state of its configured
VRIDs. To activate a reporter, use the active command in reporter configuration
mode. A reporter remains in the Suspended state until you activate it.
For example, enter:
(config-reporter[r1])# active
Suspending a Reporter
You can suspend an active reporter to temporarily stop using the reporter or to
change the reporter configuration. To suspend the reporter, enter the suspend
command in reporter configuration mode. When you are ready to resume using
the reporter again, reactivate the reporter using the active command. See the
“Activating a Reporter” section.
Note
Suspending a reporter that is configured as a critical reporter causes all VRs
associated with it to go down, which causes a failover from master to backup. See
the “Configuring a Critical Reporter” section.
For example, enter:
(config-reporter[r1])# suspend
Configuring a Critical Reporter
To associate a reporter with a VR, use the ip critical-reporter command in circuit
configuration mode. You can associate more than one critical reporter with a VR
provided that the critical reporters are of different types. See the “Configuring a
Critical Physical Interface” section.
If any critical reporter is suspended or goes down, all VRs associated with it go
down. To ensure that the VR states are synchronized, configure a critical reporter
on both the front-side and the back-side VRs.
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The syntax of this command is:
ip critical-reporter vrid reporter_name
The variables are:
•
vrid - The virtual router identifier (VRID) of an existing VR. Enter an integer
between 1 and 255.
•
reporter_name - The name of an existing reporter. Enter an unquoted text
string with no spaces from 1 to 31 characters.
For example, to associate reporter r1 with a VR that has a VRID of 1, enter:
(config-circuit-ip[VLAN1-192.168.7.9])# ip critical-reporter 1 r1
To remove a critical reporter from the running-config, enter:
(config-circuit-ip[VLAN1-192.168.7.9])# no ip critical-reporter 1 r1
Configuring a Critical Service
Configure a critical service to monitor the health of upstream and downstream
devices. When one or all critical services go down (depending on the type of
critical service you configure), the associated VR also goes down, which causes
a failover from master CSS to backup CSS. There are three types of critical
services that you can configure:
•
A scripted critical service, as defined by the (config-service) keepalive type
script command or the (config-service) keepalive type named command,
that is constantly scanning for service and network availability. The keepalive
sets the service to a down state whenever network or service availability is a
problem. The VR goes down if any associated scripted service goes down.
The CSS provides a scripted keepalive called ap-kal-pinglist that you can use
to check the health of, for example, an upstream router (192.1.1.254) running
Hot Standby Router Protocol (HSRP) and a downstream Layer 2 switch
(10.1.1.200) as critical services.
For example, create the service as follows:
(config)# service upstream_downstream
(config-service[upstream_downstream])# ip address 192.1.1.254
(config-service[upstream_downstream])# keepalive type script
ap-kal-pinglist “192.1.1.254 10.1.1.200”
(config-service[upstream_downstream])# active
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•
A redundancy uplink critical service, as defined by the (config-service) type
redundancy-up command. The VR goes down when all associated
redundancy uplink services go down regardless of any configured keepalive
type. Refer to Chapter 3, Configuring Box-to-Box Redundancy, in the
“Configuring Multiple Redundant Uplink Services” section.
Note
•
You cannot add redundant uplink services to a content rule.
Local critical services for any service other than scripted or redundancy
uplink, such as a Web service. The VR goes down when all associated local
critical services go down.
To associate a critical service with a VR, use the ip critical-service command.
The syntax of the ip critical-service command is:
ip critical-service vrid service_name
The variables are:
•
vrid - The ID for an existing VR.
•
service_name - The name of the service. To see a list of services, enter ip
critical-service vrid ?.
For example:
(config-circuit-ip[VLAN2-192.1.1.1])# ip critical-service 1
upstream_downstream
To remove a critical service from a VR, enter:
(config-circuit-ip[VLAN2-192.1.1.1])# no ip critical-service 1
upstream_downstream
Note
If you configure different critical services on the two CSSs and you intend to
synchronize the CSS configurations using the commit_VipRedundConfig script,
do not use the -a script argument. This argument copies the master CSS
configuration to the backup CSS configuration, which makes the two configs
identical. For details on synchronizing a VIP and virtual interface redundancy
configuration, see the “Synchronizing a VIP Redundancy Configuration” section.
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The show service command displays the current service type only. It does,
however, display the keepalive type, so you can determine from it the behavior of
a configured critical service. To display critical service-specific information, use
the show critical-services command. See the “Displaying IP Critical Services”
section.
SNMP values returned for services show the current service type only. To
determine the critical service behavior of a particular service, you need to
examine the service keepalive type. For more information about SNMP, refer to
the Cisco Content Services Switch Administration Guide.
Configuring a Critical Physical Interface
Configure a critical physical interface (critical phy) on a CSS to provide an
additional failover catalyst for a virtual router (VR) in a VIP and interface
redundancy configuration. A critical phy improves the failover time of a VR (as
compared with a critical service) by reacting quickly to a Down state of monitored
physical interfaces. This feature is intended to complement critical services, not
replace them. For details on critical services, see the “Configuring a Critical
Service” section.
This section contains the following topics:
•
Overview
•
Configuration Requirements and Restrictions
•
Critical Phy Quick Start
•
Configuring a Reporter
•
Configuring the Reporter Type
•
Configuring the Physical Interfaces That You Want to Monitor
•
Activating a Reporter
•
Suspending a Reporter
•
Configuring a Critical Reporter
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Overview
A critical phy monitors the health of its associated physical interfaces and causes
a VR to fail over to the backup CSS if one or all (depending on the configuration)
monitored interfaces go down. Unlike a critical service, a critical phy does not
depend on the state of a keepalive for its operation. Therefore, a critical phy is not
susceptible to reporting delays and packet loss due to network congestion and
packet storms, which, in the case of a critical service, may cause the CSS to
incorrectly report a server as unavailable. When you associate a critical phy with
a VR, the critical phy provides rapid VR failover in the event of a physical link
failure.
To configure a critical phy, you create a software agent called a reporter, a
general-purpose monitoring mechanism. Then you specify the reporter type of
critical-phy and configure the reporter to monitor the health of one or more
physical interfaces. To complete the configuration, you modify your VIP and
virtual interface redundancy configuration to associate a critical reporter with an
existing VR.
Configuration Requirements and Restrictions
The following requirements and recommendations apply to the configuration and
use of critical phys on a Cisco 11500 series CSS:
•
Ensure that VIP and virtual interface redundancy is configured properly (see
the “Configuring VIP and Virtual Interface Redundancy” section).
•
If you associate more than one critical reporter with the same VR, ensure that
you do not configure the same physical interfaces (ports) on two different
reporter types (for example, ports 1/1 and 1/2 on a reporter of type
critical-phy-all-up and ports 1/1 and 1/2 on a reporter of type
critical-phy-any-up). Otherwise, unexpected VR failovers may occur.
•
Do not configure the Ethernet management port or the console port as
critical-phy interfaces to be monitored by a reporter.
•
Do not use critical-phy interfaces as InterSwitch Communications (ISC) ports
in an ASR environment.
•
Do not use critical-phy interfaces as ports to be monitored by the Switch Port
Analyzer (SPAN) feature.
•
Do not use critical-phy interfaces as redundancy-phy interfaces in a
box-to-box redundancy configuration.
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Critical Phy Quick Start
Table 1-6 provides a quick overview of the steps required to configure a critical
phy on a reporter. Each step includes the CLI command required to complete the
task. For a complete description of each feature and all the options associated with
the CLI command, see the sections following Table 1-6.
Table 1-6
Critical Phy Configuration Quick Start
Task and Command Example
1.
Enter config mode.
# config
(config)#
2.
Enter reporter configuration mode and create a new reporter. See the
“Configuring a Reporter” section.
(config)# reporter r1
(config-reporter[r1])#
3.
Configure the reporter type. See the “Configuring the Reporter Type”
section.
(config-reporter[r1])# type critical-phy-all-up
4.
Specify the physical interfaces that you want to monitor.
(config-reporter[r1])# phy 1/1
(config-reporter[r1])# phy 1/2
5.
Activate the reporter.
(config-reporter[r1])# active
6.
Exit reporter mode.
(config-reporter[r1])# exit
(config)#
7.
Enter circuit configuration mode.
(config)# circuit VLAN1
(config-circuit[VLAN1])# ip address 192.168.7.9
(config-circuit-ip[VLAN1-192.168.7.9])#
8.
Associate the reporter with an existing VRID.
(config-circuit-ip[VLAN1-192.168.7.9])# ip critical-reporter 1 r1
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Table 1-6
Critical Phy Configuration Quick Start (continued)
Task and Command Example
9.
(Recommended) Verify the reporter configuration.
(config-circuit-ip[VLAN1-192.168.7.9])# show reporter r1
10. (Recommended Verify the critical phy configuration.
(config-circuit-ip[VLAN1-192.168.7.9])# show running-config
reporter
11. (Recommended) Verify the VR and critical reporter configurations.
(config-circuit-ip[VLAN1-192.168.7.9])# show running-config
circuit
The following running-config example shows the results of entering the
commands in Table 1-6.
!************************** CIRCUIT **************************
circuit VLAN1
ip address 192.168.7.9 255.255.255.0
ip virtual-router 1 priority 101 preempt
ip critical-reporter 1 r1
!************************** REPORTER **************************
reporter r1
type vrid-peering
phy 1/1
phy 1/2
active
Configuring a Reporter
A reporter is a software agent that the CSS uses to monitor the health of physical
interfaces when you configure the reporter as a critical phy type and associate
physical interfaces with it. To configure a reporter and enter reporter
configuration mode, use the reporter command in global configuration mode.
This command has the following syntax:
reporter reporter_name
The reporter_name variable specifies the name of the reporter you are creating.
Enter an unquoted text string with no spaces from 1 to 31 characters.
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For example, enter:
(config)# reporter r1
To remove an existing reporter and all of its attributes from the running-config,
enter:
(config-reporter[r1])# no reporter r1
Configuring the Reporter Type
A critical phy is a type of reporter that determines how the reporter reacts to a
Down state of the associated physical interfaces. To configure a critical phy type
on a reporter, use the type command in reporter configuration mode. This
command has the following syntax.
type reporter_type
Note
If you associate more than one reporter with the same VR, we recommend that
you do not configure the same physical interfaces (ports) on two different reporter
types (for example, ports 1/1 and 1/2 on a reporter of type critical-phy-all-up and
ports 1/1 and 1/2 on a reporter of type critical-phy-any-up). Otherwise,
unexpected VR failovers may occur.
The reporter_type variable has one of the following values:
•
critical-phy-all-up - If any critical interface goes down, the reporter goes
down and mastership of the associated VR transitions from the master CSS to
the backup CSS. To prevent a VR failover, all interfaces must remain up.
•
critical-phy-any-up - If all associated critical interfaces go down, the
reporter goes down and mastership of the associated VR transitions from the
master CSS to the backup CSS. As long as one critical interface stays up, the
reporter and the VR remain up.
You can change the critical phy reporter type without suspending the reporter.
However, if you want to reconfigure a critical phy reporter as a VRID peering
reporter, you must first suspend the reporter to remove the critical phy reporter
attributes. See the “Suspending a Reporter” section.Then you can configure the
reporter as a VRID peering reporter and activate it. For details about VRID
peering, see the “Configuring VRID Peering” section.
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You can configure a maximum of 128 reporters of any combination of types on a
CSS, depending on available memory.
When you configure a critical phy, the states of the monitored physical interfaces
affect the reporter state, which in turn affects the VR state, depending upon the
type of configured reporter as shown in Table 1-7.
Table 1-7
Effect of Interface State on Reporter and Virtual Router State Based
on Reporter Type
Reporter Type
Interface State
Reporter State
Virtual Router State
critical-phy-all-up
All Up
Up
Up
critical-phy-all-up
All Down
Down
Down
critical-phy-all-up
One or More Down Down
Down
critical-phy-any-up All Up
Up
Up
critical-phy-any-up All Down
Down
Down
critical-phy-any-up One or More Up
Up
Up
For example, enter:
(config-reporter[r1])# type critical-phy-all-up
To remove the critical phy type (either critical-phy-all-up or
critical-phy-any-up) or to reconfigure the reporter type as a vrid-peering type:
1.
Suspend the reporter. See the “Suspending a Reporter” section.
Note
If the reporter is configured as a critical reporter, suspending it causes
the associated VR to transition to Backup or Down.
2.
Remove the critical phy reporter attributes using the no phy interface_name
command. See the “Configuring the Physical Interfaces That You Want to
Monitor” section.
3.
Remove the critical phy reporter type using the no type command or
reconfigure the reporter type as a VRID peering type using the type
vrid-peering command. For details about configuring VRID peering, see the
“Configuring VRID Peering” section.
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4.
If you reconfigured the reporter type as a VRID peering type, add the VRIDs
using the vrid ip_address vrid command, and then activate the reporter using
the active command. See the “Configuring the Virtual Routers That You Want
to Monitor” section and the “Activating a Reporter” section.
Configuring the Physical Interfaces That You Want to Monitor
To configure one or more physical interfaces that you want a reporter to monitor,
use the phy command in reporter configuration mode. You can configure a
maximum of 128 interfaces on a reporter.
Note
If you associate more than one reporter with the same VR, we recommend that
you do not configure the same physical interfaces (ports) on two different reporter
types (for example, ports 1/1 and 1/2 on a reporter of type critical-phy-all-up and
ports 1/1 and 1/2 on a reporter of type critical-phy-any-up). Otherwise,
unexpected VR failovers may occur.
This command has the following syntax:
phy interface_name
The interface_name variable is the name of the physical interface that you want
to monitor. Enter an interface name in interface port format (for example, e1 on a
CSS 11501) or slot/port format (for example, 1/1 on a CSS 11503 and
CSS 11506). See the following configuration examples.
To configure Ethernet port 1 on a CSS 11501, enter:
(config-reporter[r1])# phy e1
To configure Ethernet port 1 on a CSS 11503 or 11506, enter:
(config-reporter[r1])# phy 1/1
Note
You cannot remove the last remaining physical interface from an active reporter.
To remove the interface, first suspend the reporter, and then remove the interface.
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To remove Ethernet port 1 from the list of interfaces to monitor on a CSS 11501,
enter:
(config-reporter[r1])# no phy e1
To remove Ethernet port 1 from the list of interfaces to monitor on a CSS 11503
or 11506, enter:
(config-reporter[r1])# no phy 1/1
Activating a Reporter
Before a CSS can use a reporter to monitor the health of the configured critical
interfaces, you must activate the reporter using the active command. A reporter
remains in a suspended state until you activate it.
For example, enter:
(config-reporter[r1])# active
Suspending a Reporter
You can suspend an active reporter to temporarily stop using the reporter or to
change the reporter configuration. To suspend the reporter, enter the suspend
command in reporter configuration mode. When you are ready to resume using
the reporter again, reactivate the reporter using the active command. See the
“Activating a Reporter” section.
For example, enter:
(config-reporter[r1])# suspend
Note
Suspending a reporter that is configured as a critical reporter causes all VRs
associated with it to go down, which causes a failover from master to backup. See
the “Configuring a Critical Reporter” section.
Configuring a Critical Reporter
To associate a reporter with a VR, use the ip critical-reporter command in circuit
configuration mode. You can associate more than one critical reporter with a VR.
If any critical reporter is suspended or goes down, all VRs associated with it go
down and cause a failover from master to backup.
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Note
If you associate more than one reporter with the same VR, we recommend that
you do not configure the same physical interfaces (ports) on two different reporter
types (for example, ports 1/1 and 1/2 on a reporter of type critical-phy-all-up and
ports 1/1 and 1/2 on a reporter of type critical-phy-any-up). Otherwise,
unexpected VR failovers may occur.
The syntax of this command is:
ip critical-reporter vrid reporter_name
The variables for this command are:
•
vrid - The virtual router identifier (VRID) of an existing VR. Enter an integer
between 1 and 255. Virtual routers are considered peers when they have the
same VRID and reside in the same VLAN.
•
reporter_name - The name of an existing reporter. Enter an unquoted text
string with no spaces from 1 to 31 characters.
For example, enter:
(config-circuit-ip[VLAN1-192.168.7.9])# ip critical-reporter 1 r1
To remove a critical reporter, enter:
(config-circuit-ip[VLAN1-192.168.7.9])# no ip critical-reporter 1 r1
Synchronizing a VIP Redundancy Configuration
To ensure that your remote CSS can perform the same tasks as your local CSS in
the event of a master CSS failure, the running-config on the remote CSS must be
identical (with some modifications) to the running-config on the local CSS. To
automate this configuration synchronization process, you can run the
commit_VipRedundConfig script on the local CSS to copy the local CSS
running-config to the remote CSS running-config.
There are two types of configuration synchronization:
•
Complete - On CSSs that have an identical chassis (the same CSS model),
produces a running-config on the remote CSS that mirrors the running-config
on the local CSS.
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To perform a complete configuration, run the script play
commit_vip_redundancy command with the -a argument. For more
information on running this script and argument, see the “Running the
Configuration Synchronization Script” section. Consider running a complete
synchronization when you need to replicate interface and circuit
configurations including redundant VIPs on a circuit.
This type of synchronization copies reporter configurations for both VRID
peering (see the “Configuring VRID Peering” section) and critical phy (see
the “Configuring a Critical Physical Interface” section) with the following
exceptions:
– If you configure a critical physical interface on a reporter on the local
CSS and that interface does not exist on the remote CSS or is of a
different interface type (Gigabit Ethernet or Fast Ethernet), the script
exits and the synchronization does not complete.
– If you configure one or more VRID IP addresses on a reporter on the
local CSS for VRID peering, the script preserves any configured VRID
IP addresses on the remote CSS. If the remote CSS configuration does
not contain a VRID IP address that corresponds with one in the local CSS
configuration, the remote CSS lacks that VRID IP address when the
script finishes. The script does copy the reporter configuration from the
local CSS to the remote CSS. The script exits with the File copy Vipr
Config Sync Complete message and indicates that any byte differences
between the local and remote configurations exist because the script did
not find a corresponding VRID IP address on the remote CSS.
•
Partial (default) - On CSSs with incompatible configurations, synchronizes
all parameter values in the configuration except the interface and circuit
configurations including redundant VIPs on a circuit.
For example, the master is a CSS 11506 and the backup is a CSS 11503. The
script maintains the current remote interface and circuit configurations
automatically. For CSSs with configured reporters, the script does not copy
the reporter configurations to the remote CSS regardless of chassis types.
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Script Functions
The configuration synchronization script performs all the necessary steps to
update the backup CSS with the master's running configuration. The script:
•
Saves the master running-config to the startup-config.
•
Archives the startup-config.
•
Copies the startup-config to a temporary file (tmp.cfg).
•
Calls a function that converts the master VRRP/APP IP addresses to the
backup VRRP/APP IP addresses in tmp.cfg.
•
If the local VR priority is configured, configures a priority of 100 on the
remote VR. If you want to determine mastership based on a different priority,
manually configure the remote VR priority as required.
•
Uses the rcmd command to:
– Copy tmp.cfg to a temp file on the backup (newconfig)
– Check newconfig and copy it to the startup-config
– Clear the backup CSS running-config and script play newconfig
The script performs some verifications before executing the above steps. It checks
to see if the local switch is a backup for any VRIDs and asks you if you want to
continue, thereby changing the state on the two CSSs. The script also checks the
backup to see if it is the master for any VRIDs. If the state is Interface (IF) Down,
the script asks you if you want to continue without synchronizing those VRIDs on
interfaces that are Down.
Before You Begin
Before you run the configuration synchronization script, ensure that you have
configured VIP/interface redundancy and the Application Peering Protocol
(APP). For details on configuring VIP/interface redundancy, see the “Configuring
VIP and Virtual Interface Redundancy” section. For details on configuring APP,
refer to the Cisco Content Services Switch Global Server Load-Balancing
Configuration Guide.
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The synchronization script does not support the following configurations:
•
Active/active shared VIP
•
Any configuration where some independent VIP addresses are a master while
other VIP addresses are a backup
Running the Configuration Synchronization Script
To run the configuration synchronization script, use the script play
commit_vip_redundancy command in SuperUser mode. The syntax is:
script play commit_vip_redundancy “arguments”
Note
When you run the commit_vip_redundancy script, if a local VR priority is
configured, the script configure a VR priority of 100 on the remote CSS. If you
want to determine the mastership based on a different priority, manually configure
the remote CSS priority.
By default, the synchronization script synchronizes all parameter values in the
configuration except the interface and circuit configurations (including redundant
VIPs). When you need to replicate interface and circuit configurations, you can
manually configure them on the backup CSS, or consider running the
synchronization script with the -a argument to replicate them.
You can also run the configuration synchronization script using the predefined
alias that comes with all CSSs by entering:
# commit_VipRedundConfig “arguments”
You can specify the script arguments in any order. The arguments for the
commit_vip_redundancy script are:
•
ip address - The IP addresses of the master and backup APP sessions. This is
the only required argument for this script. Use the following syntax when
entering the addresses:
“local master IP address remote backup IP address”
For details on automating the entry of the IP address, see “Setting the
LOCAL_VIPR_IP and REMOTE_VIPR_IP Variables” later in this section.
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•
-a (All) - Synchronizes the configuration completely. Use this argument only
when the master and backup CSSs have identical chassis. This argument
synchronizes the entire configuration including the interface and circuit
modes. Consider using this argument to replicate interface and circuit
configurations including redundant VIPs on a circuit.
Note
•
Caution
Do not use this argument if you have different critical services or
critical reporters configured on the two CSSs.
-d (Debug) - Debug switch for the commit_vip_redundancy script, which
displays the current task being performed as the script progresses. Debug
messages display even when you specify the -s argument.
Before you use the -f argument to remove a config sync lock file, ensure that no
one else is running the config sync script on the CSS. Otherwise, if you remove
the lock file and then run the script again while the script is in use, the resulting
configurations may have some discrepancies.
•
-f - After an abnormal script termination, removes the lock file so that you can
run the script again. This argument overrides all other specified arguments
and the script exits immediately after removing the lock file. For details on
the lock file, see “Setting the LOCAL_VIPR_IP and REMOTE_VIPR_IP
Variables” later in this section.
•
-norlog (No Remote Log) - Reduces the number of log messages that the CSS
sends to the configured log host during the script.
•
-notrap - Reduces the number of traps that the CSS sends to the configured
trap host during the script.
•
-nv (No Verify) - Informs the script not to verify that the configuration
synchronization was successful. However, the script does inform you if the
script fails.
Note
•
By default, the script verifies the configuration synchronization.
-s (Silent) - Suppresses script progress messages and displays only the result
of running the script: Commit Successful or Commit Failed. The -d argument
overrides the -s argument.
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For example, on the master CSS, run the following script, which uses the defaults
of verify on and partial synchronization, plus the IP addresses set as variables and
the script alias name:
# commit_VipRedundConfig
The following output appears:
# commit_VipRedundConfig
Verifying app and redundancy configs ...
Checking vip redundancy state ...
Working \
Verifying running-config copy success ...
Commit successful!
In this example, the script:
•
Performs a partial configuration synchronization (default)
•
Verifies that the configuration synchronization was successful (default)
For more information about scripts, refer to the Cisco Content Services Switch
Administration Guide.
Config Sync Lock File
When you run the script, the software creates a lock file (vipr_config_sync_lock)
in the script directory so that you cannot run the script from another session on
the CSS. If the lock file exists and you run the script, the following message
appears:
The script is in use by another session.
If the script terminates abnormally, the software does not remove the lock file.
The next time you run the script, the above message appears. If you are certain
that the script is not in use by another session, use the -f argument to remove the
lock file.
When you run the script with the -f argument, the following message appears and
the script exits:
VIPR Config Sync lock file removed.
Now you can run the script again.
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Setting the LOCAL_VIPR_IP and REMOTE_VIPR_IP Variables
To eliminate the need to specify IP addresses each time you run the configuration
synchronization script, you can set the value of two variables (LOCAL_VIPR_IP
and REMOTE_VIPR_IP) to IP addresses and save them in your user profile. Once
you set the variables and save them in your user profile, the variables will always
be available after you log in to the CSS. Set the LOCAL_VIPR_IP variable to the
IP address of the master CSS and set the REMOTE_VIPR_IP variable to the IP
address of the backup CSS.
To set the variables, enter:
# set LOCAL_VIPR_IP “master_ip_address” session
# set REMOTE_VIPR_IP “backup_ip_address” session
To save the variable in your user profile, enter:
# copy profile user-profile
Now you can run the configuration synchronization script without typing an
IP address.
Note
If you already created the MASTER_VIPR_IP and BACKUP_VIPR_IP variables
in an earlier release, the script will use the new variables instead, if present.
Logging Configuration Synchronization Script Result Messages
You can specify that script result messages (script success or failure messages) be
sent to the current logging device automatically each time you run the
configuration synchronization script. To log the script result messages, enable
logging on NETMAN with level info-6 or debug-7 by entering:
(config)# logging subsystem netman level info-6
Note
Log messages are generated with or without the -s (silent) argument specified. See
the “Running the Configuration Synchronization Script” section.
For example, if the APP session to the backup CSS is not running, the CSS
generates the following log message:
vipr config sync: app session is DOWN
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For ease of tracking, each log message contains the string “vipr config sync”.
Displaying VIP and Virtual Interface Redundancy
Configurations
The CSS provides show commands to enable you to display VIP and virtual
interface redundancy configurations. The following sections describe the
commands and provide tables describing the output fields.
•
Displaying Redundant Virtual Interfaces
•
Displaying Redundant VIPs
•
Displaying Virtual Router Configurations
•
Displaying IP Critical Services
•
Displaying Reporter Configurations
Displaying Redundant Virtual Interfaces
To display a list of all redundant virtual interfaces configured on the CSS, use the
show redundant-interfaces command. This command also displays the status
(Enable or Disable) of the DNS server (if configured) on the redundant virtual
interface and the number of DNS packets processed by the interface. You may
provide an interface IP address option to display only the redundant virtual
interfaces present on a particular interface. You may also include a VRID to
display only the redundant virtual interface information for a particular VR.
The syntax of this command is:
show redundant-interfaces {ip_address {vrid}}
The optional variables are:
•
ip_address - The address for the redundant virtual interface. Enter an IP
address in dotted-decimal notation (for example, 192.168.11.1).
•
vrid - The ID for an existing VR.
For example, to view all redundant interfaces on the CSS, enter:
(config) # show redundant-interfaces
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Table 1-8 describes the fields in the show redundant-interfaces command
output.
Table 1-8
Field Descriptions for the show redundant-interfaces Command
Field
Description
Interface Address
IP interface address associated with the redundant virtual
interface.
VRID
Assigned identifier associated with the VR.
Redundant Address IP address of the redundant virtual interface.
Range
Not applicable. This field is always set to 1.
State
Current state of the redundant virtual interface. Possible
states are:
•
Master - The redundant virtual interface is the master
of the flows between the CSS and the network device
connected to the redundant virtual interface
•
Backup - The redundant virtual interface is the
backup for the flows between the CSS and the
network device connected to the redundant virtual
interface
•
Idle - The redundant virtual interface is idle
Master IP
IP address of the master VR.
State Changes
Number of times the redundant virtual interface state has
changed.
Last Change
Date and time of the redundant virtual interface state last
state change.
DNS Server
Status of the DNS server configured on the redundant
interface. Possible states are Enable or Disable.
DNS Packets
Processed
Number of DNS request packets that the redundant
interface has processed.
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Displaying Redundant VIPs
To display a list of all redundant VIPs configured on the CSS, use the show
redundant-vips command. You could provide an interface IP address option to
display only the VIPs present on a particular interface. You can also include a
VRID to display only the VIP information for a particular VR.
The syntax of this command is:
show redundant-vips {ip_address {vrid}}
The optional variables are:
•
ip_address - The address for the redundant interface. Enter an IP address in
dotted-decimal notation (for example, 192.168.11.1).
•
vrid - The ID for an existing VR.
For example, to view all redundant VIPs on the CSS, enter:
(config)# show redundant-vips
Table 1-9 describes the fields in the show redundant-vips command output.
Table 1-9
Field Descriptions for show redundant-vips Command
Field
Description
Interface Address
The IP interface address associated with the
redundant VIP.
VRID
The assigned identifier associated with the
VR.
Redundant Address
The IP address of the VIP.
Range
The range associated with the VIP.
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Table 1-9
Field Descriptions for show redundant-vips Command (continued)
Field
Description
State
Current state of the redundant VIP. Possible
states are:
•
Master - The redundant VIP is the master
•
Backup - The redundant VIP is the
backup
•
Backup Shared - The redundant VIP is a
shared backup
•
Idle - The redundant VIP is idle
Master IP
The IP address of the master VR.
State Changes
The number of times the VIP state has
changed.
Last Change
The data and time of the VIP last state change.
Displaying Virtual Router Configurations
To display a list of all VRs configured on the CSS, including their configuration
and state information, use the show virtual-routers command. If VRID peering
(see the “Configuring VRID Peering” section) or critical phy (see the
“Configuring a Critical Physical Interface” section) is configured on the CSS, this
command also displays any critical reporters associated with the VRs.
You may provide an interface IP address option to display only the VRs present
on a particular interface. You may also include a VRID to display only the
information for a particular VR.
The syntax of this command is:
show virtual-routers {ip_address {vrid}}
The optional variables are:
•
ip_address - The address of the interface. Enter an IP address in
dotted-decimal notation (for example, 192.168.11.1).
•
vrid - The ID for an existing VR.
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For example, to view all VRs on the CSS, enter:
(config)# show virtual-routers
Table 1-10 describes the fields in the show virtual-routers command output.
Table 1-10 Field Descriptions for the show virtual-routers Command
Field
Description
Interface Address
The interface IP address associated with the VR.
VRID
The configured identifier of the VR.
Priority
The priority currently being advertised by the VR.
Because the priority is dependent on the state of the
critical services, the priority may be different than the
one configured.
Config. Priority
The configured priority.
State
Current operational state of the VR. Possible states are:
•
Master - The VR is the master.
•
Backup - The VR is the backup.
•
Idle - The VR does not have any redundant virtual
interfaces, VIPs, or reporters associated with it.
•
Down - The VR is down. See the Fail Reason field
for an explanation of the failure.
Master IP
The IP address of the master VR.
State Changes
The number of times the VR state has changed since the
CSS was booted.
Last Change
The data and time of the last VR state change.
Preempt
The state of the preempt option on the VR. If enabled,
the state is True; if disabled, the state is False.
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Table 1-10 Field Descriptions for the show virtual-routers Command
(continued)
Field
Description
Last Fail Reason
The reason that the failover occurred. Codes reported
for the Last Fail Reason persist until another failure
event occurs. Possible reasons are:
Critical-Services
•
IF Down - The IP interface associated with the VR
is down.
•
Critical Svc Down, Reporter is Down - One or
more critical services and critical reporters
associated with the VR are down.
•
Critical Phy Down, VRID Peering Down - A
critical-phy reporter for the VR and VRID peering
are down.
•
Critical Svc Down - One or more critical services
associated with the VR are down.
•
Critical Phy Down - A critical-phy reporter for the
VR is down.
•
VRID Peering Down - VRID peering is down.
The names of the critical services associated with the
VR.
State
The current condition of the critical service. Possible
states are Up, Down, or Suspended.
Type
The type of critical service. Possible types are Scripted,
RedundancyUp, or Local.
Critical-Reporters
The names of the critical reporters associated with the
VR.
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Table 1-10 Field Descriptions for the show virtual-routers Command
(continued)
Field
Description
State
The current condition of the critical reporters
associated with the VR. Possible states for VRID
peering are Master, Backup, Down, or Suspended.
Possible states for critical phy are Up, Down, or
Suspended.
Type
The type of critical reporter. Possible types are
vrid-peering, critical-phy-all-up, or
critical-phy-any-up.
Resetting the Virtual Router State Changes Counter
The show virtual-routers command displays a State Changes field that records
the number of times that a VR changed state since the CSS was booted. To set this
counter to zero, use the zero virtual-router state-changes command in any
mode.
The syntax of this command is:
zero virtual-router state-changes [all|circuit ip_address [all|vrid number]]
The variables and options for this command are:
•
all - Zeroes the State Changes counter of all VRs configured on the CSS
•
circuit ip_address - Specifies a circuit IP address where VRs are configured
•
all - Zeroes the State Changes counter of all VRs on the specified circuit
•
vrid number - Zeroes the State Changes counter of the specified VR on the
specified circuit
For example, to reset the State Changes counter for all VRs configured on the
circuit with an IP address of 192.168.1.7, enter:
(config)# zero virtual-router state-changes circuit 192.168.1.7 all
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Displaying IP Critical Services
To display a list of all critical services configured on the CSS, use the show
critical-services command. You can provide an interface IP address option to
display only the critical services present on a specific interface. You may also
include a VRID to display only the critical service information for a specific VR.
The syntax of this command is:
show critical-services {ip_address {vrid}}
The optional variables are:
•
ip_address - The address for the redundant interface. Enter an IP address in
dotted-decimal notation (for example, 192.168.11.1).
•
vrid - The ID for an existing VR.
For example, to view all critical services on the CSS, enter:
# show critical-services
Table 1-11 describes the fields for the show critical-services command output.
Table 1-11
Field Descriptions for the show critical-services Command
Field
Description
Interface Address
The IP interface address associated with the VR.
VRID
The assigned identifier associated with the VR.
Service Name
The name of the critical service.
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Table 1-11
Configuring VIP and Virtual Interface Redundancy
Field Descriptions for the show critical-services Command
(continued)
Field
Description
Service Type
The type of critical service. Possible critical service
types are:
Service State
•
Scripted - A service whose state depends upon
a running script or a named keepalive.
•
Redundancy-up - A service whose state
depends upon the state of an ICMP keepalive on
a router.
•
Local - Every type of service other than a
scripted service or a redundancy uplink service.
Typically, this is a Web server.
The current state of the critical service. The State
field displays the service as either Alive, Dying,
Down, or Suspended. The Dying state reports that a
service is failing according to the parameters
configured in the following service mode
commands: keepalive retryperiod, keepalive
frequency, and keepalive maxfailure. When a
service enters the Down state, the CSS does not
forward any new connections to it (the service is
removed from the load balancing rotation for the
content rule). However, the CSS keeps all existing
connections to the service (connections to that
service are not torn down).
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Displaying Reporter Configurations
To display reporter configurations for VRID peering and critical phy, use the
following commands:
•
show reporter {reporter_name|summary} - Displays the reporter name,
type, state, and the critical interfaces and their link states.
•
show running-config reporter - Displays the configurations of all reporters
configured on the CSS.
•
show running-config reporter reporter_name - Displays the configuration
of the specified reporter.
•
show virtual-routers - Displays the configured virtual router information
and the critical reporter state and type. See the “Displaying Virtual Router
Configurations” section.
•
show critical-reporters - Displays the critical reporters configured for
critical phy.
•
show running-config circuit - Displays the critical reporter associated with
a circuit VLAN for a critical phy.
Using the show reporter Command
To display reporter configuration and statistics for VRID peering or critical phy,
use the show reporter command. The syntax of this command is:
show reporter {reporter_name|summary}
The variables and options for this command are:
•
reporter_name - Name of an existing reporter
•
summary - Displays summary statistics for all configured reporters
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Table 1-12 describes the fields for the show reporter command output.
Table 1-12 Field Descriptions for the show reporter Command
Field
Description
Name
Name of the reporter whose configuration you are
displaying.
State
Current state of the reporter. Possible reporter states
for VRID peering are Master, Backup, Suspended,
or Down. Possible reporter states for critical phy are
Up, Suspended, or Down.
Type
Type of reporter. Possible reporter types are:
•
vrid-peering (see the “Configuring VRID
Peering” section)
•
critical-phy-all-up (see the “Configuring a
Critical Physical Interface” section)
•
critical-phy-any-up (see the “Configuring a
Critical Physical Interface” section)
State Transitions
Number of times the reporter state changed since
the last time the CSS was booted. If the State
Transitions field is 0, the 0 value can be due to a
counter reset through the global configuration mode
zero reporter state-transitions command. The
counter can also be 0 if the reporter is down.
Circuit (VRID peering
only)
Circuit IP address of the CSS.
VRID (VRID peering
only)
Identifier of the VR associated with the reporter.
State (VRID peering
only)
Current state of the VR associated with the reporter.
Possible states of the VR are Master, Backup,
Down, or Unknown.
Interface (critical phy
only)
Interfaces associated with the reporter.
Link (critical phy only)
Current state of the physical link interface. Possible
link states are Up or Down.
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Resetting the Reporter State Transitions Counter
The show reporter command displays a State Transitions field that records the
number of times that a reporter changed state since the CSS was booted. To set
this counter to zero, use the zero reporter state-transitions command in any
command mode.
The syntax of this command is:
zero reporter state-transitions [all|reporter reporter_name]
The variables and options for this command are:
•
all - Zeroes the State Transitions counter of all reporters configured on the
CSS
•
reporter reporter_name - Zeroes the State Transitions counter of the
specified reporter
For example, to reset the State Transitions counter for reporter r1, enter:
(config)# zero reporter state-transitions reporter r1
Displaying a Reporter Configuration in the Running-Config
To display a reporter configuration in the running-config, use the show
running-config reporter command in any mode. This command displays all
reporter configurations on the CSS. To display a specific reporter configuration,
use the show running-config reporter reporter_name command.
Displaying Critical Reporter Information
To display critical reporter configuration information for VRID peering and
critical phy, use the show critical-reporter command in any mode. The syntax of
this command is:
show critical-reporters ip_address vrid
The variables for this command are:
•
ip_address - Specifies the interface address of the virtual router associated
with the critical-reporter
•
vrid - Specifies the VRID of the VR associated with the critical reporter
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Table 1-13 describes the fields for the show critical-reporters command output.
Table 1-13 Field Descriptions for the show critical-reporters Command
Field
Description
Interface Address
IP address of the VR interface.
VRID
Identifier of the VR associated with the reporter.
Reporter Name
Name of the reporter with which the VR is
associated.
Reporter Type
Configured type of the reporter. Possible types are
vrid-peering, critical-phy-all-up, or
critical-phy-any-up.
State
State of the reporter. Possible states are Master,
Backup, Up, Down, or Suspended.
Displaying Critical Reporters in the Running-Config
To display configured critical reporters in the running-config, use the show
running-config circuit command. This command displays all configured circuits
and any critical reporters associated with a virtual router.
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2
Configuring Adaptive Session
Redundancy
This chapter describes how to configure Adaptive Session Redundancy (ASR) for
stateful failover on a CSS.
This chapter contains the following major sections:
•
Overview of CSS Redundancy
•
Configuring Adaptive Session Redundancy
•
Displaying ASR Information
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Overview of CSS Redundancy
Overview of CSS Redundancy
Redundancy helps to ensure:
•
High availability for your network applications
•
Users do not experience long network delays or black holes due to a single
point of failure.
A CSS provides three types of redundancy.
•
Virtual IP (VIP) redundancy and virtual interface redundancy - Provide
redundant VIP addresses and redundant virtual interfaces for fate sharing and
server default gateways. For details, see Chapter 1, Configuring VIP and
Virtual Interface Redundancy.
•
Adaptive Session Redundancy (ASR) - Provides session-level redundancy
(stateful failover) to continue active flows without interruption if the master
CSS fails over to the backup CSS. For details, see this chapter.
•
Box-to-box redundancy - Provides chassis-level redundancy between two
identically configured CSSs. For details, see Chapter 3, Configuring
Box-to-Box Redundancy.
The following sections provide information about when (and when not) to use the
different types of redundancy.
When to Use VIP and Virtual Interface Redundancy
Typically, you configure VIP redundancy on the public side of CSS peers that are
positioned in front of a server farm. You configure virtual interface redundancy
on the private-side interfaces attached to the L2 device in front of the servers.
Configure VIP redundancy:
•
With virtual interface redundancy to provide fate sharing
•
When you have a common subnet between the two CSSs on which the VIPs
reside
•
As a prerequisite to configuring ASR (requires active-backup VIP
redundancy)
•
To provide active-active CSS behavior (both CSSs processing flows)
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Overview of CSS Redundancy
Configure interface redundancy:
•
With VIP redundancy to provide fate sharing
•
When you need a default gateway for the back-end servers
•
Instead of VIP redundancy on the client side of the CSS when the VIPs are
on a subnet different from the subnet of your uplinks
When to Use ASR
ASR provides session-level redundancy for applications where active flows
(including TCP and UDP) must continue without interruption, even if the master
CSS fails over to the backup CSS.
Configure ASR:
•
If you require stateful failover for mission-critical applications (for example,
enterprise applications, long-lived flows, such as HTTP or FTP file transfers,
and e-commerce)
•
After you have first configured active-backup VIP and virtual interface
redundancy
When to Use Box-to-Box Redundancy
Configure box-to-box redundancy when you:
•
Expect the behavior of the CSSs to be active/standby (only the master CSS
processes flows)
•
Can configure a dedicated Fast Ethernet (FE) link between the CSSs for the
VRRP heartbeat
Do not configure box-to-box redundancy when you:
•
Expect the behavior of the CSSs to be active-active (both CSSs processing
flows). Use VIP redundancy instead.
•
Cannot configure a dedicated FE link between the CSSs.
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Configuring Adaptive Session Redundancy
Configuring Adaptive Session Redundancy
Configure Adaptive Session Redundancy (ASR) on Cisco 11500 series CSS peers
in an active-backup VIP redundancy and virtual interface redundancy
environment to provide stateful failover of existing flows. ASR ensures that, if the
master CSS fails, the backup CSS has the necessary flow-state information to
continue any active flows (including TCP and UDP) without interruption when
the backup CSS assumes mastership. “Adaptive” means that you can configure
ASR on a per content rule basis.
Use ASR for:
•
Mission-critical enterprise applications.
•
Long-lived flows such as FTP and HTTP file transfers.
•
E-commerce applications, such as online stock trading or banking where
users must remain connected to a service for the duration of a transaction
even if the master CSS fails.
In an ASR configuration, CSSs replicate flows that are:
•
Fully-resolved (the master CSS has received a SYN/ACK from a server)
•
Set up using content rules, services, and source groups that you specify as
redundant
Note
For implicit or explicit Layer 5 rules, where there is delayed binding, binding is
not complete until the CSS processes the SYN/ACK from the server. If a failover
occurs in the middle of a spanned content request, the master CSS will not receive
the SYN/ACK from the server and the flow will not be replicated on the backup
CSS. No data is lost and users can simply refresh their browsers to restart the
connection.
Note
During an FTP failover, the control channel and/or the data channel need to share
information with the backup CSS. If the current state information has not been
fully transferred across the ISC link to the backup CSS, then the flow may be lost.
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Configuring Adaptive Session Redundancy
This section includes the following topics:
•
Stateful Failover
•
Inter-Switch Communications
•
Redundant Indexes
•
Configuration Requirements and Restrictions
•
ASR Quick Start
•
Configuring Inter-Switch Communications
•
Configuring Redundant Services
•
Configuring Redundant Content Rules
•
Configuring Redundant Source Groups
•
Source Group Port-Mapping Behavior in an ASR Configuration
•
Synchronizing ASR Configurations
Stateful Failover
Active flows that match a redundant content rule, service, or source group on the
master CSS are replicated as dormant flows on the backup CSS peer. A dormant
flow contains all the flow-state information necessary for the backup CSS to take
over the flow if the master CSS fails, including the flow ID assigned by the
session processor (SP) that created the flow. If the master CSS fails, the dormant
flows on the backup CSS become active when the backup CSS assumes
mastership of the VIP. In turn, the active flows on the former master CSS
transition to a dormant state to fully back up the active flows on the new master
CSS.
A master CSS maps a newly activated TCP flow after it receives the first packet
for the flow. If it can resolve a single route back to the source address, a CSS
attempts to map a UDP flow when it activates the flow. Otherwise, the CSS maps
the UDP flow after it receives the first packet of the flow.
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Inter-Switch Communications
In an ASR configuration, CSS peers share redundant flow-state information over
a maximum of two private Inter-Switch Communications (ISC) links after
booting. ISC is a messaging service used by CSSs to exchange flow-state
information. Only one ISC link is active at a time. The other ISC link (if
configured) remains in backup mode until needed.
To prevent incorrect flow and port mapping information from being replicated to
the backup CSS, a CSS does not activate its ISC link if it detects a mismatched
chassis configuration with the other CSS. During its discovery phase and before
activating the link, the ISC protocol exchanges chassis information between the
two CSSs to ensure that:
•
The two chassis have the same number of modules session processors (SPs)
with the same weights. SCMs have a weight of 4; all other CSS modules have
a weight of 6. To display the weights of the modules in your CSS, enter the
show chassis session-processors command.
•
The modules (SPs) are installed in the same order. Skipping slots is permitted
provided that the overall order is the same and the CSS can match up all the
SPs in both chassis.
For example, Figure 2-1 shows two CSS 11506s with slightly different module
installation configurations. Each CSS 11506 has four installed modules, but the
CSS-B configuration skips slot 3. As far as ISC is concerned, the configurations
match because both CSSs have the same number of SPs with the same weights
and installed in the same overall order.
Example of CSS 11506 Matching Module Configurations for ISC
CSS-A
CSS-B
Indicates an SCM with a weight of 4
119623
Figure 2-1
Indicates a module with a weight of 6
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To determine if an ISC link is up, a CSS uses a mechanism called LifeTick. LifeTick
sends an asynchronous message that contains information about the selected path. If
the CSS does not receive a LifeTick message within two seconds, the CSS considers
the ISC link to be down. If a second link is configured, the CSS uses that link for ISC.
Note
For best results, we recommend that you use the Gigabit Ethernet (GE) ports for
the ISC links in all cases. If you are using a CSS 11501, use the GE port for ISC
and the Fast Ethernet (FE) ports for normal traffic.
The ISC links use the GE ports or the FE ports on the CSS session processors
(SPs) to send ISC messages containing flow-state information. Once you
configure the ISC ports, those ports are dedicated to ISC and you cannot use those
same ports for non-ISC traffic.
Note
You must connect the ISC ports directly to the two CSSs. You cannot use Layer 2
devices on the ISC links between the two CSSs. Also, the ISC links must be
dedicated to passing only ISC traffic.
For new flows, CSSs exchange flow states in real time over the ISC links. For
existing flows, CSSs exchange flow states at bootup and at VIP redundancy
failover.
Redundant Indexes
ASR uses unique global redundant indexes to keep track of content rules, services,
and source groups configured on the redundant CSS peers. Set up the redundant
indexes in rules, services, and groups using the redundant-index command. You
must then configure identical redundant content rules, services, and source groups
on CSS peers in the ASR configuration.
Each redundant index that you configure on a rule, service, or group must be
unique among all rules, services, or groups configured on a redundant pair of
CSSs. For example, if you configure a rule with a redundant index of 1 on a pair
of CSSs, you cannot configure an index of 1 on another rule. However, you could
configure an index of 1 on a group or service if that value has not already been
used on a group or a service.
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Note
If you run traffic to a configuration that contains discrepancies between the
redundant indexes on the two CSSs, the CPU utilization for each processor on the
CSS may climb to an abnormal level (at 2000 flows/second, approximately
50 percent utilization for each processor). If you set the logging level to notice-5
or higher, the SCM utilization may peak at approximately 90 percent because
each connection generates a redundant index mismatch log entry. For example:
AUG 7 14:12:15 3/1 1124272 SLR-5: Rejected. Redundant global rule index (7)
not found.
Configuration Requirements and Restrictions
The following requirements and restrictions apply to both CSS peers in an ASR
configuration:
•
Ensure that both CSSs have the same number of SPs. Otherwise, the CSSs
cannot activate the ISC link.
•
You cannot configure ASR and an SSL module on the same service. ASR
does not support the replication of flows to an SSL module in the CSS.
•
You cannot configure ASR and HTTP compression on the same service. The
CSS does not allow you to configure a redundant index on a content rule that
has services with compression enabled or to enable compression on a service
in a rule that is configured with a redundant index.
•
Configure VIP and virtual interface redundancy on both CSS peers. For
details, refer to Chapter 1, Configuring VIP and Virtual Interface
Redundancy.
•
Configure a redundant VIP in a redundant content rule or source group. To
activate a redundant content rule or source group, you must associate the rule
or group with a redundant VIP.
•
Ensure that VIP ranges specified in redundant content rules and source
groups are the same as the VIPs associated with virtual routers for VIP
redundancy. If the redundant content rule or source group VIPs are a superset,
ASR is supported only for the VIPs that are associated with the virtual
routers. For the remaining VIPs, the behavior is undefined when a failover
occurs, because it is unclear whether those VIPs are mastered on the new
master CSS or not.
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•
You cannot configure VIP wildcard or double-wildcard caching rules because
they do not require a VIP. For information on wildcard cache rules, refer to
the Cisco Content Services Switch Content Load-Balancing Configuration
Guide.
•
Configure ISC on both CSSs. This allows the CSSs to share flow-state
information.
•
Configure a maximum of two ISC ports on a CSS. Multiple ports must reside
on the same module in the CSS 11503 or CSS 11506 or on the same
CSS 11501. Also, the ports must be of the same type (Gigabit Ethernet or Fast
Ethernet) in both CSSs. For best results, we recommend that you use GE ports
for the ISC links in all cases.
•
Ensure that the ISC ports are not configured in any VLANs. If necessary,
remove the designated ports from all VLANs before configuring ISC. For
details on disabling an interface port from a VLAN, refer to the Content
Services Switch Routing and Bridging Configuration Guide.
•
You must connect the ISC ports directly to the two CSSs. You cannot use
Layer 2 devices on the ISC links between the two CSSs. Also, the ISC links
must be dedicated to passing only ISC traffic.
•
If you configure any ISC ports on an SCM, you can have only one SCM
installed in the CSS 11506.
•
The CSS 11501 does not support redundant GE ISC links for ASR because
the CSS includes only a single GBIC port.
•
Ensure that any service configured with connection limits, marked as
redundant, and used by at least one redundant content rule is used only by
other content rules that are also redundant. If this is not true, there could be
redundant and nonredundant flows connected to the service with connection
limits.
In case of a failover, no information is available for the nonredundant flows
on the backup CSS. Until the server cleans up the nonredundant flow
connections, they continue to contribute to the connection limit on the service
without the backup CSS having any knowledge of how many such
connections exist. Making all flows redundant by imposing the above
restrictions eliminates this problem.
•
When you configure critical services, be sure to change the default keepalive
settings to the following recommended settings for ASR. For example, enter:
service CriticalService
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ip address 192.168.2.1
keepalive frequency 2
keepalive maxfailure 2
keepalive retryperiod 2
active
Note
•
The above keepalive values are a recommended starting point. Some
scripted keepalives may take longer than two seconds to run. You
may need to adjust your keepalive values so that the CSS detects a
failure before your application times out.
Configure as redundant any source groups that you specify in ACL clauses.
Otherwise, ASR does not require source groups. It is helpful to configure
ACLs similarly on the master and backup CSSs. This ensures that the CSSs
share the port-map state during flow setup time, and, at failover time, a CSS
finds the same ACL and source group configured on the peer. Otherwise,
when a flow fails over to the backup, it is possible that the flow may match
on a different ACL clause that has no source group configured or a different
source group (possibly a nonredundant one).
Source groups selected by ACL-checking always take precedence over other
source group matches for a flow. Therefore, if the master and backup CSSs
have different ACL definitions, when a flow fails over to the backup and the
source group selected on the master is not found on the backup, the CSS
rejects the flow. Also, if the flow matches on a different source group through
an ACL, that source group takes precedence over the redundant source group
that was sent from the master.
•
Configure as redundant any preferred service that you configured in an ACL
clause.
•
Configure mutually exclusive port-map ranges on the redundant peers using
the global-portmap command to avoid potential network port collisions.
Keeping the port-map ranges mutually exclusive on the redundant peer also
eliminates the need to dynamically update the global port-map database on
the backup CSS. For more information on port mapping, refer to the Cisco
Content Services Switch Content Load-Balancing Configuration Guide.
•
Adaptive Session Redundancy (ASR) imposes restrictions on the number of
available and eligible source ports in a source group because of the mapping
of resources to the backup CSS with an unknown chassis configuration. For
details, see the “Source Group Port-Mapping Behavior in an ASR
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Configuration” section. For more information about source groups, refer to
the Cisco Content Services Switch Content Load-Balancing Configuration
Guide.
•
Do not configure ASR and stateless redundancy failover on the same CSS.
Such a configuration is not supported. For details on stateless redundancy
failover, refer to Chapter 3, Configuring Box-to-Box Redundancy, in the
“Configuring Stateless Redundancy Failover” section.
•
ASR does not support NAT peering. For details on NAT Peering, refer to the
Content Services Switch Content Load-Balancing Configuration Guide.
Upgrading to WebNS Version 7.40 and Higher
To maximize the number of ports available for PAT in an ASR configuration, the
CSSs must have similar chassis configurations in terms of the total number of
session processors (SPs) and their assigned weights. All CSS module types have
the same assigned weights, except for the SCM. The SSL module and the backup
SCM in a dual SCM configuration are not considered SPs. Therefore, in an ASR
configuration, both CSSs must have the same number of SPs.
If you are upgrading from a version of WebNS software earlier than 7.40, be
aware of the following ASR configuration restrictions in WebNS software
versions 7.40 and higher:
•
If your CSSs have mismatched chassis configurations, ASR does not work
after the upgrade
•
If your CSSs meet the ASR requirement of having the same number of SPs in
each chassis, you must upgrade both CSSs to WebNS Version 7.40
•
During the upgrade process, ASR does not work and you lose any sessions
that are in progress
ASR Quick Start
Table 2-1 provides a quick overview of the steps required to configure ASR for
each CSS in the redundant configuration. Each step includes the CLI command or
a reference to the procedure required to complete the task. For a complete
description of each feature and all the options associated with the CLI command,
see the sections following Table 2-1.
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Table 2-1
ASR Configuration Quick Start
Task and Command Example
1.
Enter config mode.
# config
(config)#
2.
Configure active/backup VIP and virtual interface redundancy. Refer to
Chapter 1, Configuring VIP and Virtual Interface Redundancy earlier in this
chapter.
3.
Configure a maximum of two directly connected (no intervening L2
devices) ISC links on Gigabit Ethernet or Fast Ethernet ports between the
two redundant CSSs. See “Configuring Inter-Switch Communications”
later in this chapter.
(config)# interface 1/1
(config-if[ 1/1])# isc-port-one
(config)# interface 1/2
(config-if[ 1/2])# isc-port-two
4.
Configure services that are targets of redundant content rules. For more
information on services, refer to the Cisco Content Services Switch Content
Load-Balancing Configuration Guide.
(config)# service server1
(config-service[server1])# ip address 192.168.100.100
(config-service[server1])# redundant-index 1
(config-service[server1])# active
5.
Configure redundant content rules and add the redundant services. For more
information on content rules, refer to the Cisco Content Services Switch
Content Load-Balancing Configuration Guide.
(config)# owner arrowpoint
(config-owner[arrowpoint])# content rule1
(config-owner-content[arrowpoint-rule1]# vip address 192.1.1.100
(config-owner-content[arrowpoint-rule1]# protocol tcp
(config-owner-content[arrowpoint-rule1]# port 80
(config-owner-content[arrowpoint-rule1]# url “/redundant.html”
(config-owner-content[arrowpoint-rule1]# add service server1
(config-owner-content[arrowpoint-rule1]# redundant-index 5
(config-owner-content[arrowpoint-rule1]# active
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Table 2-1
ASR Configuration Quick Start (continued)
Task and Command Example
6.
Configure redundant source groups and add the redundant services. For
more information on source groups, refer to the Cisco Content Services
Switch Content Load-Balancing Configuration Guide.
(config)# group group1
(config-group[group1])#
(config-group[group1])#
(config-group[group1])#
(config-group[group1])#
7.
vip address 192.1.1.100
add service server1
redundant-index 4
active
Configure global port mapping (port translation) with mutually exclusive
port ranges on the CSS peers to avoid potential port collisions. For more
information on CSS port mapping, refer to the Cisco Content Services
Switch Content Load-Balancing Configuration Guide.
For example, on one CSS peer, enter:
(config)# global-portmap base-port 3000 range 30000
On the other CSS peer, enter:
(config)# global-portmap base-port 33100 range 30000
8.
Configure the same redundant services, content rules, and source groups on
the other CSS peer (synchronize the configurations).
9.
Use the show session-redundant all command to verify your
configuration.
# show session-redundant all
The following running-config example shows the results of entering the
commands in Table 2-1 (in bold text) and the commands used to configure VIP
and virtual interface redundancy (see Chapter 1, Configuring VIP and Virtual
Interface Redundancy).
!*************************** GLOBAL ***************************
global-portmap base-port 3000 range 30000
!************************* INTERFACE *************************
interface 1/1
isc-port-one
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interface 1/2
isc-port-two
interface 2/1
bridge vlan 2
!************************** CIRCUIT **************************
circuit VLAN1
ip address 10.1.1.1 255.255.255.0
ip virtual-router 1 priority 101 preempt
ip redundant-interface 1 10.1.1.254
ip critical-service 1 upstream_downstream
circuit VLAN2
ip address 192.1.1.1 255.255.255.0
ip virtual-router 2 priority 101 preempt
ip redundant-vip 2 192.1.1.100
ip critical-service 2 upstream_downstream
!************************** SERVICE **************************
service server1
ip address 10.1.1.50
redundant-index 1
active
service upstream_downstream
ip address 192.1.1.50
keepalive type script ap-kal-pinglist “192.1.1.20 10.1.1.20"
keepalive frequency 2
keepalive maxfailure 2
keepalive retryperiod 2
active
!*************************** OWNER ***************************
owner arrowpoint
content rule1
vip address 192.1.1.100
protocol tcp
port 80
url “/redundant.html”
add service server1
redundant-index 5
active
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!*************************** GROUP ***************************
group group1
vip address 192.1.1.100
add service server1
redundant-index 4
active
Configuring Inter-Switch Communications
Inter-Switch Communications (ISC) is a messaging service that CSS peers use to
exchange flow-state information in an ASR configuration. If the master CSS fails,
the backup CSS already has the flow-state information necessary to continue the
current flows without interruption. Using ISC, CSSs exchange state information:
•
For existing flows at boot-up time and at VIP redundancy failover
•
For new flows in real time (after the CSS receives a SYN/ACK from the
server)
To prevent incorrect flow and port mapping information from being replicated to
the backup CSS, the CSS does not bring up the ISC link if it detects a mismatched
chassis configuration with the other CSS. During the discovery phase, the ISC
protocol exchanges chassis information between the two CSSs and ensures that
both chassis have the same number of SPs before bringing up the link.
To enable ISC between two CSSs in an ASR configuration, use the isc-port-one
and isc-port-two commands in interface configuration mode. You can configure
a maximum of two ISC ports on each CSS. The two ports must be of the same type
(Gigabit Ethernet or Fast Ethernet) and must be on the same module in the CSS
11503 or CSS 11506 or on the same CSS 11501. When you configure two ISC
ports, the first port is active and the second port remains in a backup state. The
backup link is used only if the active link fails. For best results, we recommend
that you configure ISC on the GE ports.
The CSS 11501 does not support redundant GE ISC links for ASR because that
CSS model includes only one GE port.
You must connect the ISC ports directly to the two CSSs. You cannot use Layer 2
devices on the ISC links between the two CSSs. Also, the ISC links must be
dedicated to passing only ISC traffic.
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For example, to enable both ISC ports on a CSS 11506, enter:
(config)# interface 1/1
(config-if[ 1/1])# isc-port-one
(config-if[ 1/1])# interface 1/2
(config-if[ 1/2])# isc-port-two
To disable both ISC ports on a CSS 11506, enter:
(config)# interface 1/1
(config-if[ 1/1])# no isc-port-one
(config-if[ 1/1])# interface 1/2
(config-if[ 1/2])# no isc-port-two
Configuring Redundant Services
To configure the global service index for a redundant service, use the
redundant-index command. A CSS uses the global service index to keep track of
redundant services and associated flow-state information.
The syntax for this service configuration mode command is:
redundant-index index
The variable index is a unique number you assign to a redundant service. Enter a
unique integer from 0 to 32767, where a value of 0 disables ASR for a service.
The default is 0, but it does not appear in the running-config even if you configure
it explicitly.
For example:
(config-service[server1])# redundant-index 5
To disable ASR for a service, enter:
(config-service[server1])# no redundant-index
Note
If you issue the no redundant-index command on an active redundant service for
live redundancy peers, the command automatically suspends the service. Flows
already mapped by a CSS are not affected. However, if a failover occurs during
the life of an active flow that matches on such a suspended service, the backup
CSS cannot map the flow because it cannot find the service with the same global
index as that on the original master.
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For more information on configuring services, refer to the Cisco Content Services
Switch Content Load-Balancing Configuration Guide.
Configuring Redundant Content Rules
To configure the global content index for a redundant content rule, use the
redundant-index command. A CSS uses the global content index to keep track
of redundant content rules and associated flow-state information.
The syntax for this content configuration mode command is:
redundant-index index
The variable index is a unique number you assign to a redundant content rule.
Enter a unique integer from 0 to 32767, where a value of 0 disables ASR on a
content rule. The default is 0, but it does not appear in the running-config even if
you configure it explicitly.
For example:
(config-owner-content[arrowpoint-rule1]# redundant-index 1
To disable ASR on a content rule, enter:
(config-owner-content[arrowpoint-rule1]# no redundant-index
Note
If you issue the no redundant-index command on an active redundant content
rule for live redundancy peers, the command automatically suspends the content
rule. Flows already mapped by a CSS are not affected. However, if a failover
occurs during the life of an active flow that matches on such a suspended content
rule, the backup CSS cannot map the flow because it cannot find the content rule
with the same global index as that on the original master.
For more information on configuring content rules, refer to the Cisco Content
Services Switch Content Load-Balancing Configuration Guide.
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Configuring Redundant Source Groups
If you configured source groups in ACLs, you must configure those source groups
as redundant. Otherwise, ASR does not require source groups. To configure the
global source group index for a redundant source group, use the redundant-index
command. A CSS uses the global source group index to keep track of redundant
content rules and associated flow-state information.
The syntax for this group configuration mode command is:
redundant-index index
The variable index is a number you assign to a redundant source group. Enter a
unique integer from 0 to 32767, where a value of 0 disables ASR for a source
group. The default is 0, but it does not appear in the running-config even if you
configure it explicitly.
For example, to enable ASR for a source group:
(config-group[group1])# redundant-index 4
To disable ASR for a source group, enter:
(config-group[group1])# no redundant-index
Note
If you issue the no redundant-index command on an active redundant source
group on live redundancy peers, the command automatically suspends the source
group. Flows already mapped by a CSS are not affected. However, if a failover
occurs during the life of an active flow that matches on such a suspended source
group, the backup CSS cannot map the flow because it cannot find the source
group with the same global index as that on the original master.
For more information on configuring source groups, refer to the Cisco Content
Services Switch Content Load-Balancing Configuration Guide.
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Source Group Port-Mapping Behavior in an ASR Configuration
Because Adaptive Session Redundancy (ASR) requires that both CSSs have the
same number of SPs in each chassis, each CSS uses the same port-selection
algorithm in an ASR configuration as in a non-ASR configuration. This behavior
means that ASR imposes no further restrictions on source group port mapping.
For more information about source groups and port mapping, refer to the Cisco
Content Services Switch Content Load-Balancing Configuration Guide.
Synchronizing ASR Configurations
You must synchronize configurations on both CSS peers to ensure that the
ASR-specific configurations on the master CSS and the backup CSS are the same.
This is critical to the proper functioning of ASR.
For ASR, you must manually configure on each peer:
•
ISC
•
Redundant content rules
•
Redundant services
•
Redundant source groups
Displaying ASR Information
Use the commands described in the following sections to display information for:
•
Inter-Switch Communications (ISC)
•
Dormant flows
•
ASR status and global redundant indexes
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Displaying Inter-Switch Communications Ports
Use the show isc-ports command to display the following information:
•
Ports configured for ISC on a CSS
•
Status of the ISC link
•
Reason the ISC link failed if it is down
Table 2-2 describes the fields in the show isc-ports output.
Table 2-2
Field Descriptions for the show isc-ports Command
Field
Description
Inter-Switch
Communications
Configuration
Lists the CSS ports (in slot/port format) configured for
ISC port one and ISC port two. If ISC is not configured,
the command displays the following messages:
Inter-Switch Port One is not configured.
Inter-Switch Port Two is not configured.
Inter-Switch
Communications
Status
Indicates whether ISC is Up or Down and, if Up, on
which CSS port ISC is currently active.
Port # Communication Indicates why the ISC link failed. Use this field to help
Failure Reason
you troubleshoot the ISC link if it fails. Possible
reasons are:
•
None - ISC link is up.
•
No Interface Assigned - An interface was not
assigned to the ISC port.
•
No Physical Link - There is no physical link on the
ISC port.
•
No Discovery Response - The remote CSS did not
respond to the Hello message from the local CSS
during the discovery phase of the ISC protocol.
•
Wrong Protocol Version - Different ISC protocol
versions are running on the two CSSs.
•
Mismatched Chassis - The CSSs have different
chassis configurations (different number of SPs).
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Displaying Dormant Flow Information
To display information about the current dormant flows on the backup CSS in an
ASR configuration, use the show dormant flows command. Dormant flows are
flows on the backup CSS that become active if the master CSS fails and the
backup CSS becomes the master.
The syntax for this command is:
show dormant flows {source_address {destination_address}}
The optional variables for this command are:
•
source_address - Displays dormant flows for the specified source IP address.
Enter the IP address in dotted-decimal notation (for example, 192.168.11.1).
•
destination_address - Displays dormant flows for the specified destination IP
address. Enter the IP address in dotted-decimal notation (for example,
192.168.11.1).
Table 2-3 describes the fields in the show dormant flows output.
Table 2-3
Field Descriptions for the show dormant flows Command
Field
Description
Src Address
The source address for the flow.
SPort
The source port for the flow.
Dst Address
The destination address for the flow.
DPort
The destination port for the flow.
NAT Dst Address
The network address translation (NAT) destination
address.
Prt In
Not applicable. A dormant flow does not have a port
associated with it.
OutPort
Not applicable. A dormant flow does not have a port
associated with it.
To display summary information about redundant dormant flows, use the flow
statistics dormant command.
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Table 2-4 describes the field in the flow statistics dormant output.
Table 2-4
Field Descriptions for the flow statistics dormant Command
Field
Description
Redundant Flow
Statistics - Slot n,
Subslot n
Inactive redundant flow statistics for the module in the
specified slot and subslot in the backup CSS.
Dormant Flow
Count
Total number of inactive redundant flows in the
specified module in the backup CSS.
UDP Flows
Number of inactive redundant UDP flows in the
specified module in the backup CSS.
TCP Flows
Number of inactive redundant TCP flows in the
specified module in the backup CSS.
Redundant Flow
Statistics - Aggregate
Total Inactive redundant flow statistics for all of the
modules in the backup CSS.
Total UDP Flows
Total number of inactive redundant UDP flows in the
backup CSS.
Total TCP Flows
Total number of inactive redundant TCP flows in the
backup CSS.
Total Flows
The total number of inactive redundant flows in the
backup CSS from active redundant flows on the master
CSS. The dormant flows contain all the flow-state
information necessary for the backup CSS to master the
flows if the master CSS fails. If the master CSS fails,
the backup CSS becomes the master CSS and the
dormant flows become active flows.
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Displaying ASR Information
Displaying ASR Information for Content Rules, Services, and
Source Groups
The following sections describe how to display ASR information specific to
content rules, services, and source groups.
Displaying ASR Status and Global Index Values
To display information about ASR status and global redundant indexes, use the
following commands:
•
show rule
•
show service
•
show group
The relevant fields in the output of these commands are:
•
Session Redundancy - The state of ASR for the content rule, service, or
source group. Possible values are: Enabled or Disabled
•
Redundancy Global Index - The unique global index value for ASR
configured for the content rule, service, or source group using the
redundant-index command.
For complete details on the show rule, show service, and show group commands,
refer to the Cisco Content Services Switch Content Load-Balancing Configuration
Guide.
Displaying Summary ASR Information
To display summary ASR information about redundant content rules, services,
and source groups, use the show session-redundant command.
The syntax for this global configuration mode command is:
show session-redundant [rule|service|group|all]
The optional keywords are:
•
rule - Displays summary ASR information for redundant content rules.
•
service - Displays summary ASR information for redundant services.
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•
group - Displays summary ASR information for redundant source groups.
•
all - Displays summary ASR information for content rules, services, and
source groups.
For example, to view summary ASR information for redundant content rules,
enter:
(config)# show session-redundant rule
Table 2-5 describes the fields.
Table 2-5
Field Descriptions for the show session-redundant Command
Field
Description
Session Redundant Content Rules
Content Rule
The redundant content rule name.
Content Rule
State
The current state of the redundant content rule. Possible
states are: Active or Suspend.
VIP Address
The virtual IP address of the redundant content rule in
dotted decimal notation.
Redundancy
Global Index
The ASR global index configured for the redundant
content rule.
Redundancy State The state of the CSS peer: Master, Backup, or Suspend.
Rule Redundant
Services 1
The name of the redundant service and its global index
value configured on the rule.
Session Redundant Services
Service
The name of the redundant service.
Service State
The current state of the redundant service. Possible
states are: Alive, Dying, or Down.
IP Address
The virtual IP address of the redundant service in
dotted-decimal notation.
Redundancy
Global Index
The ASR global index configured for the redundant
service.
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Table 2-5
Field Descriptions for the show session-redundant Command
(continued)
Field
Description
Session Redundant Source Groups
Source Group
The name of the redundant source group.
Source Group
State
The current state of the redundant source group.
Possible states are: Active or Suspend.
VIP Address
The virtual IP address of the redundant source group.
Redundancy
Global Index
The ASR global index configured for the redundant
source group.
Group Redundant Services
Source
Services
The redundant source services configured in this
redundant source group, their keepalive state, and
global index. If no source services are configured in
this source group, the value is NONE.
Destination
Services
The redundant destination services configured in this
redundant source group and their keepalive state. If no
destination services are configured in this source group,
the value is NONE.
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3
Configuring Box-to-Box Redundancy
This chapter describes how to configure redundancy between two identically
configured Cisco Content Services Switches (CSSs). Information in this chapter
applies to all CSS models, except where noted.
This chapter contains the following major sections:
•
Overview of CSS Redundancy
•
Redundancy Protocol Overview
•
Redundancy Configuration Quick Start
•
Cabling Redundant CSSs
•
Configuring Redundancy
•
Synchronizing a Redundant Configuration
•
Using the Redundancy Force-Master Command
•
Configuring Multiple Redundant Uplink Services
•
Using the redundancy-phy Command
•
Configuring Stateless Redundancy Failover
•
Displaying Redundant Configurations
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Overview of CSS Redundancy
Overview of CSS Redundancy
Redundancy helps to ensure:
•
High availability for your network applications
•
Users do not experience long network delays or black holes due to a single
point of failure.
A CSS provides three types of redundancy.
•
Virtual IP (VIP) redundancy and virtual interface redundancy - Provide
redundant VIP addresses and redundant virtual interfaces for fate sharing and
server default gateways. For details, see Chapter 1, Configuring VIP and
Virtual Interface Redundancy.
•
Adaptive Session Redundancy (ASR) - Provides session-level redundancy
(stateful failover) to continue active flows without interruption if the master
CSS fails over to the backup CSS. For details, see Chapter 2, Configuring
Adaptive Session Redundancy.
•
Box-to-box redundancy - Provides chassis-level redundancy between two
identically configured CSSs. For details, see this chapter.
The following sections provide information about when (and when not) to use the
different types of redundancy.
When to Use VIP and Virtual Interface Redundancy
Typically, you configure VIP redundancy on the public side of CSS peers that are
positioned in front of a server farm. You configure virtual interface redundancy
on the private-side interfaces attached to the Layer 2 device in front of the servers.
Configure VIP redundancy:
•
With virtual interface redundancy to provide fate sharing
•
When you have a common subnet between the two CSSs on which the VIPs
reside
•
As a prerequisite to configuring ASR (requires active-backup VIP
redundancy)
•
To provide active-active CSS behavior (both CSSs processing flows)
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Overview of CSS Redundancy
Configure interface redundancy:
•
With VIP redundancy to provide fate sharing
•
When you need a default gateway for the back-end servers
•
Instead of VIP redundancy on the client side of the CSS when the VIPs are
on a subnet different from the subnet of your uplinks
When to Use ASR
ASR provides session-level redundancy for applications where active flows
(including TCP and UDP) must continue without interruption, even if the master
CSS fails over to the backup CSS.
Configure ASR:
•
If you require stateful failover for mission-critical applications (for example,
enterprise applications, long-lived flows, such as HTTP or FTP file transfers,
and e-commerce)
•
After you have first configured active-backup VIP and virtual interface
redundancy
Do not configure Inter-Switch Communications (ISC) links where you have an
Layer 2 device between the redundant CSS peers.
When to Use Box-to-Box Redundancy
Configure box-to-box redundancy when you:
•
Expect the behavior of the CSSs to be active/standby (only the master CSS
processes flows)
•
Can configure a dedicated Fast Ethernet (FE) link between the CSSs for the
VRRP heartbeat
Do not configure box-to-box redundancy when you:
•
Expect the behavior of the CSSs to be active-active (both CSSs processing
flows). Use VIP redundancy instead.
•
Cannot configure a dedicated FE link between the CSSs.
•
Require the connection of an Layer 2 device between the redundant CSS
peers.
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Redundancy Protocol Overview
Redundancy Protocol Overview
The CSS redundancy protocol provides chassis-level redundancy between two
CSSs. This feature protects the network and ensures that users have continuous
access to servers and content.
Using the redundancy protocol CLI commands, you can configure two CSSs in a
master and backup redundancy configuration. In a redundant configuration, the
master CSS sends a redundancy protocol message (heartbeat) every second to
inform the backup CSS that it is alive.
If the master CSS fails and does not send a message within 3 seconds, the backup
CSS:
•
Becomes the master CSS.
•
Begins sending out redundancy protocol messages.
•
Sends out gratuitous Address Resolution Protocol (ARP) messages to update
the ARP tables on neighboring nodes and the forwarding tables of attached
bridging devices (for example, Layer 2 switches) with the new master CSS IP
address. The CSS transmits one ARP request packet and one ARP reply
packet for every gratuitous ARP invocation.
If a former master comes back online, it becomes a backup CSS automatically
when it receives the master CSS messages, unless you explicitly designated the
CSS to be the master when you configured it. For details on IP redundancy, see
“Configuring IP Redundancy” later in this chapter.
Caution
When you use access control lists (ACLs) in a redundant configuration, ensure
that you permit all traffic on the redundant circuit between the master and backup
CSSs. For information on ACLs, refer to the Cisco Content Services Switch
Security Configuration Guide.
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Redundancy Protocol Overview
Figure 3-1 shows an example of a redundant configuration with multiple VLANs.
Table 3-1 uses this figure to define the command examples necessary to configure
the redundancy protocol.
Figure 3-1
Redundancy Configuration Example
VLAN3 - 192.168.10.x
CSS1 e2 to e7
CSS2 e2 to e7
Hub1
Server1, Server2
Server1
192.168.10.30
Server2
192.168.10.31
Hub1
CSS1 (master)
VLAN3 - 192.168.10.1
VLAN2
CSS2 (backup)
VLAN3 - 192.168.10.1
172.7.6.2 e1
172.7.6.1 e1
Router1
192.168.20.100
VLAN1 - 192.168.20.x
CSS1 e8 to e12
CSS2 e8 to e12
Hub2
Router1, Router2
Redundant link
Hub2
VLAN1 - 192.168.20.1
VIP 192.168.20.254
Router2
192.168.20.101
Second default
gateway
Internet
49641
VLAN1 - 192.168.20.1
VIP 192.168.20.254
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Redundancy Configuration Quick Start
Redundancy Configuration Quick Start
Table 3-1 provides the steps required to configure the redundant configuration
shown in Figure 3-1. Each step includes the CLI command required to complete
the task. For a complete description of each feature, refer to the sections following
Table 3-1.
Listed below are the basic steps to configure redundancy:
1.
Caution
Install only one crossover cable on the master and redundant CSS before you
power them on.
If you power on the CSSs before you install the cable, both units boot up as the
master CSS and cause network problems. Do not remove the crossover cable from
a redundant configuration or each CSS will become master
Note
You must connect only one crossover cable directly to the Gigabit
Ethernet (GE) ports (software version 7.10.1.02 and greater) or the
Fast Ethernet (FE) ports on the redundant CSSs. Do not use Layer 2
devices between the two CSSs on the redundant link.
2.
Configure each server’s default gateway as the CSS’s circuit VLAN IP
address.
3.
Configure redundancy on the existing master CSS and save the
running-config to startup-config.
4.
FTP the startup-config to a PC. Edit the file by including the backup CSS
circuit VLAN IP addresses.
5.
FTP the startup-config to the backup CSS. Reboot the backup CSS with the
new startup-config.
As an alternative method, you can use CLI commands to manually configure the
backup CSS with all necessary configurations including the redundancy protocol.
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Redundancy Configuration Quick Start
Note
If you make configuration changes to the master CSS startup-config, you must
make the same changes to the backup CSS startup-config. To learn how to
synchronize the running-configs of the master CSS and the backup CSS, see
“Synchronizing a Redundant Configuration” later in this chapter.
Table 3-1
Redundancy Configuration Quick Start
Task and Command Example
1.
Install the crossover cable before you power up the CSSs. Make the
CSS-to-CSS connection using a Category 5 crossover cable. This table uses
port 1/1 on the master CSS and port 1/1 on the backup CSS as examples.
2.
Configure each server’s default gateway as the CSS circuit VLAN IP
address.
3.
Enter the ip redundancy command on the master CSS to enable
CSS-to-CSS redundancy.
(config)# ip redundancy
4.
Configure an interface on the master CSS for a redundant connection to the
backup CSS. For information on configuring interfaces, refer to the Cisco
Content Services Switch Routing and Bridging Configuration Guide.
(config)# interface 1/1
5.
Assign the interface to the redundant connection VLAN. For information on
bridging the interface to a VLAN, refer to the Cisco Content Services Switch
Routing and Bridging Configuration Guide.
(config-if[e1])# bridge vlan 2
6.
Enter circuit mode for the redundant VLAN. For information on configuring
circuits, refer to the Cisco Content Services Switch Routing and Bridging
Configuration Guide.
(config-if[e1])# circuit VLAN2
(config-circuit[VLAN2])#
7.
Assign an IP address and subnet mask to circuit VLAN2. For information
on configuring a circuit IP address, refer to the Cisco Content Services
Switch Routing and Bridging Configuration Guide.
(config-circuit[VLAN2])# ip address 172.7.6.1/24
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Table 3-1
Redundancy Configuration Quick Start (continued)
Task and Command Example
8.
Enable the redundancy protocol on the redundant IP interface.
(config-circuit-ip[VLAN2-172.7.6.1])# redundancy-protocol
(config-circuit-ip[VLAN2-172.7.6.1])# exit
9.
Define the other circuits as redundant circuits.
(config-if[1/1])# circuit VLAN1
(config-circuit[VLAN1])# redundancy
(config-if[1/1])# circuit VLAN3
(config-circuit[VLAN3])# redundancy
10. From SuperUser mode, save the master CSS running-config to the
startup-config.
# copy running-config startup-config
11. FTP the startup-config to a PC for editing.
12. Using a text editor, edit the startup-config by including the backup CSS
circuit VLAN IP address for the redundant connection (in Figure 3-1, circuit
VLAN2, IP address 172.7.6.2/24). Do not change the backup CSS VIP. The
master and backup CSS must have the same VIP. If you have multiple VIPs,
you must configure them on both the master and backup CSSs.
13. FTP the new file to the backup CSS and, if necessary, rename it
startup-config.
14. Reboot the backup CSS.
15. Enter the show redundancy command to display the redundancy
configuration and ensure that the backup CSS is configured properly.
16. Cable all hubs (or switches) to the backup CSS.
The following running-config example shows the results of entering the
commands in Table 3-1.
!*************************** GLOBAL ***************************
ip redundancy
!************************* INTERFACE *************************
interface 1/1
bridge vlan 2
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Cabling Redundant CSSs
interface 2/1
bridge vlan 3
!************************** CIRCUIT **************************
circuit VLAN1
redundancy
ip address 172.27.16.23 255.255.255.0
circuit VLAN2
ip address 172.7.6.1 255.255.255.0
redundancy-protocol
circuit VLAN3
redundancy
Cabling Redundant CSSs
When you set up a redundant CSS configuration, install only one Category 5
crossover cable directly to the two CSSs to connect the master and backup
interfaces. The CSS does not support more than one redundancy link between the
two CSSs.
Caution
If you power on the CSSs before you install the cable, both CSSs boot up as the
master CSS and cause network problems. Do not remove the crossover cable from
a redundant configuration or each CSS will become master.
Note
You must connect the crossover cable directly to the Gigabit Ethernet (GE) ports
(software version 7.10.1.02 and greater) or the Fast Ethernet (FE) ports before
you power on the redundant CSSs. Do not use Layer 2 devices between the two
CSSs on the redundant link.
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Configuring Redundancy
Table 3-2 lists the pinouts for the CSS Fast Ethernet connectors and the crossover
pinouts.
Table 3-2
RJ-45 Fast Ethernet Connector Pinouts
Signal Name
Pin Number
Crossover Cable
Pinouts
RX +
1
3
RX -
2
6
TX +
3
1
Unconnected
4
4
Unconnected
5
5
TX -
6
2
Unconnected
7
7
Unconnected
8
8
Configuring Redundancy
Configuring the redundancy protocol requires you to:
Note
•
Configure the master and backup CSSs for redundancy using the
ip redundancy command.
•
Enable the redundancy protocol on the master and backup circuit VLAN
using the redundancy-protocol command.
•
Enable the circuit VLAN for redundancy using the redundancy command.
The CSS does not support IP redundancy and VIP redundancy simultaneously.
For information on VIP redundancy, refer to Chapter 1, Configuring VIP and
Virtual Interface Redundancy.
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Configuring Redundancy
Configuring IP Redundancy
Use the ip redundancy command to enable CSS-to-CSS redundancy on two CSSs
interfaced with a crossover cable. By default, redundancy is disabled on CSSs
until you issue this command on both CSSs.
When you include the master option with this command, you can designate which
CSS is the master CSS. Initially, booting two CSSs interfaced with a crossover
cable determines which is the master and which is the backup. The CSS that boots
first is the master CSS. If the CSSs boot at the same time, the CSS with the
numerically higher IP address becomes the master.
Note
You cannot use the ip redundancy master command with either the type
redundancy-up command (redundancy uplink service) or the redundancy-phy
command (physical link redundancy). If necessary, disable the appropriate
command using no type redundancy-up or no redundancy-phy before using the
ip redundancy master command.
When you issue the ip redundancy master command on a CSS, it becomes the
master CSS. You can issue this command on either the current master or backup.
If you issue this option on the backup CSS, it becomes the master and the other
CSS becomes the backup automatically.
If you designate a master CSS, it regains its master status after it goes down and
then comes up again. For example, when the master CSS goes down, the backup
CSS becomes master. However, when the former designated master CSS comes
up again, it becomes the master again.
If you have no requirement to designate a CSS as the master when both CSSs are
up, do not include the master option when enabling redundancy on the master
CSS. In this configuration, if the master CSS goes down, the backup CSS
becomes master. When the former master CSS comes up again, it becomes the
backup CSS.
The syntax for this global configuration mode command is:
•
ip redundancy - Enables CSS-to-CSS redundancy on the backup CSS. If you
have no requirement to define a CSS as the master CSS, use this command on
both CSSs in the redundant configuration.
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Configuring Redundancy
•
ip redundancy master - Enables CSS-to-CSS redundancy on the CSS that
you want to designate as the master CSS. (Be sure to issue ip redundancy on
the backup CSS.) You can issue ip redundancy master on a CSS:
– Whether or not it was initially booted as the master or the backup. If you
issue this command on the backup CSS, it becomes the master and the
other CSS becomes the backup CSS automatically.
– When CSS-to-CSS redundancy is currently enabled.
For example:
(config)# ip redundancy
Caution
You cannot issue the ip redundancy master command on both the master and
backup CSSs. This can cause severe network problems. Before you disable
redundancy, ensure that you disconnect or disable all redundant circuits to prevent
duplicate IP addresses from occurring on the network.
To disable CSS-to-CSS redundancy, enter:
(config)# no ip redundancy
Note
The no ip redundancy command deletes the redundancy and
redundancy-protocol commands from the running-config of the CSS.
Before the CSS disables redundancy, it displays the following message:
WARNING: Disabling redundancy may result in duplicate
IP addresses on the network.
Be sure you disconnect or disable all redundant circuits before you
disable redundancy.
Do you want to disable redundancy? [y/n]:
Type y to disable redundancy. Type n to cancel disabling redundancy.
To unassign the CSS as the master CSS, enter:
(config)# no ip redundancy master
Note
The no ip redundancy master command does not disable CSS-to-CSS
redundancy.
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Configuring Redundancy
Configuring Redundant Circuits
To configure a circuit as a redundant circuit, use the redundancy command. The
redundancy command is available in circuit configuration mode.
Note
The redundancy command causes the specified VLAN to become silent when in
backup mode.
When you configure redundancy, configure it on circuits (VLANs) that contain
network IP addresses shared by the redundant CSSs (in Figure 3-1, these are
VLAN1 and VLAN3). Do not configure redundancy on the circuit (VLAN)
configured specifically for redundancy communications (in Figure 3-1, this is
VLAN2).
The example below configures VLAN1 as a redundant circuit, which contains a
shared network IP address (in Figure 3-1, this is 192.168.20.1).
For example:
(config-circuit[VLAN1])# redundancy
To remove a circuit from the redundancy configuration, enter:
(config-circuit[VLAN1])# no redundancy
Configuring the Redundancy Protocol
To configure the redundancy protocol on the circuit (VLAN) connecting the two
CSSs, enter the redundancy-protocol command in IP interface configuration
mode. Enter the command for the circuit you configured specifically for
redundancy communications (in Figure 3-1, this is VLAN2).
Note
The CSS box-to-box redundancy protocol is supported on CSS Gigabit Ethernet
(GE) ports in software version 7.10.1.02 and greater.
For example:
(config-circuit-ip[VLAN2-172.7.6.1])# redundancy-protocol
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Configuring Redundancy
To stop running a redundancy protocol on an interface, enter:
(config-circuit-ip[VLAN2-172.7.6.1])# no redundancy-protocol
Configuring the VRRP Backup Timer
Configure the vrrp-backup-timer command on both redundant CSSs to specify
the time interval in seconds that the backup CSS waits to assume mastership when
the master CSS goes down. Because timer values greater than the 3-second
default cause longer failover times, use this command only in environments where
the CPU utilization on the CSS is close to 100 percent. After you set the timer
value, you need to reissue the redundancy-protocol command on the redundant
circuit between the CSSs for the new timer value to take effect. For details on
configuring the redundancy protocol, see “Configuring the Redundancy Protocol”
earlier in this chapter.
Note
If you intend to use the commit_redundancy script to synchronize your redundant
configuration, be sure to specify the -a argument in the script play command to
ensure that the script copies the timer configuration setting from the master CSS
to the backup CSS. For details on synchronizing your redundant configuration,
see “Synchronizing a Redundant Configuration” later in this chapter.
The syntax for this global configuration mode command is:
vrrp-backup-timer wait_time
The variable for this command is wait_time. Enter an integer from 3 to 120
seconds. The default is 3 seconds.
For example:
(config)# vrrp-backup-timer 15
To reset the timer to the default value of 3 seconds, enter:
(config)# no vrrp-backup-timer
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Synchronizing a Redundant Configuration
To ensure that your backup CSS can perform the same tasks as your master CSS
in the event of a master CSS failure, the running-config on the backup must be
identical to the running-config on the master. To automate this configuration
synchronization process, you can run a script (commit_redundancy) on the master
CSS that copies the master CSS running-config to the backup CSS
running-config.
There are two types of configuration synchronization:
•
Complete - On CSSs that have an identical chassis (the same CSS model),
produces a running-config on the backup CSS that exactly matches the
running-config on the master CSS.
•
Partial (default) - On CSSs with an incompatible configuration syntax,
synchronizes all parameter values in the configuration except the interface
and circuit configurations. For example, the master is a CSS 11506 and the
backup is a CSS 11501. The script maintains the current backup interface and
circuit configurations automatically.
Before You Begin
Before you run the configuration synchronization script, ensure that you have set
up the redundancy circuit between the two CSSs and that the Application Peering
Protocol (APP) is running on that circuit. For details on configuring the
redundancy circuit, see “Configuring Redundancy” earlier in this chapter. For
details on configuring APP, refer to the Cisco Content Services Switch Global
Server Load-Balancing Configuration Guide.
If you configure the restrict user-database command on a CSS, only users with
administrative or technician privileges can configure the username command. To
be consistent with the restrict user-database command, the
commit_redundancy script does not modify the privilege level of the
administrative or technician users on the backup CSS.
To run commit_redundancy successfully users with administrative and
technician privileges must be identical on both CSSs. You cannot have a local
user (configured with the username command) on the master CSS and an
administrative or technician user with the same username on the backup CSS.
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For more information about the restrict user-database command, refer to the
Cisco Content Services Switch Security Configuration Guide. For more
information about configuring administrators (username_offdm command) and
technicians (username_technician command), refer to the Cisco Content
Services Switch Command Reference.
Running the Configuration Synchronization Script
To run the configuration synchronization script, use the script play
commit_redundancy command in SuperUser mode. The syntax is:
script play commit_redundancy “arguments”
You can also run the configuration synchronization script using the predefined
alias that comes with all CSSs by entering:
# commit_RedundConfig “arguments”
The arguments for the commit_redundancy script are:
Caution
•
ip address - The IP address of the backup CSS. This is the only required
argument for this script. For details on automating the entry of the IP address,
see “Setting the REMOTE_IP Variable” later in this section.
•
-a (All) - Performs a complete configuration synchronization. Use this option
only when the master CSS and the backup CSS have identical chassis (see
Table 3-3).
•
-d (Debug) - Debug switch for the commit_redundancy script, which displays
the current task being performed as the script progresses. Debug messages
display even when you specify the -s argument.
Before you use the -f argument to remove a config sync lock file, ensure that no
one else is running the config sync script on the CSS. Otherwise, if you remove
the lock file and then run the script again while the script is in use, the resulting
configurations may have some discrepancies.
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•
-f - After an abnormal script termination, removes the lock file so that you
can run the script again. This argument overrides all other specified
arguments and the script exits immediately after removing the lock file. For
details on the lock file, see “Setting the REMOTE_IP Variable” later in this
section.
•
-int (Interface) - Does not clear the interfaces on the backup CSS so that the
link does not go down. Do not use this argument with the -a argument. If you
do and the interface settings are different on the master and the backup CSSs,
the configurations will not match and the script will not finish successfully.
•
-nv (No Verify) - Informs the script not to verify that the configuration
synchronization was successful. The script does inform you if the script fails.
Note
•
-s (Silent) - Suppresses script progress messages and displays only the result
of running the script: Config Sync Successful or Config Sync Failed.
Note
Note
The script verifies the configuration synchronization by default.
The -s option is not compatible with running the commit_redundancy
script on the backup CSS. If you run the script on the backup CSS
using the -s option, the script exits and no configuration changes are
made.
You can specify the script arguments in any order.
For example:
CSS11503# script play commit_redundancy “10.7.100.93 -d -s”
The following output appears:
Verifying that IP redundancy is activated on Master switch.
Verifying that app session is up with backup switch.
Making sure app session is up.
Checking Master redundancy-config for redundancy-protocol set and if
so storing it in variable MASTER_IP.
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Verify that the IP Address specified is the Backup IP Address.
Making sure app session is up.
Saving Master running-config to startup-config and archiving
startup-config.
Copying running-config to startup-config.
Archiving startup-config.
Copying startup-config to a temp file tmp.cfg.
Swapping Master and Backup ip addresses in tmp.cfg for app
Removing CIRCUIT and INTERFACE modes from tmp.cfg.
Checking if IP redundancy master is set.
Using rcmd to copy tmp.cfg to a file on Backup switch.
Retrieving circuit info for redundancy-protocol link.
Archiving copy to Backup startup-config.
Archiving Backup current startup-config.
Restoring startup-config (new copy) to startup-config.
Clearing running-config.
Script playing the copy script of the Master running-config.
Making sure app session is down.
Copy success being verified by comparing byte sizes of archived
running-configs of the Master switch and the Backup switch.
Making sure app session is up.
Comparing the byte count now.
Config Sync Successful.
In this example, the script:
•
Performs a partial configuration synchronization (default)
•
Displays the current task being performed as the script progresses (-d)
•
Suppresses progress messages (-s)
•
Verifies that the configuration synchronization was successful (-v)
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For more information on scripts, refer to the Cisco Content Services Switch
Administration Guide.
Config Sync Lock File
When you run the script, the software creates a lock file (config_sync_lock) in the
script directory so that you cannot run the script from another session to the CSS.
If the lock file exists and you run the script, the following message appears:
The script is in use by another session.
If the script terminates abnormally, the software does not remove the lock file.
The next time you run the script, the above message appears. If you are certain
that the script is not in use by another session, then you can use the -f argument
to remove the lock file.
When you run the script with the -f argument, the following message appears and
the script exits:
Config Sync lock file removed.
Now you can run the script again.
Setting the REMOTE_IP Variable
To eliminate the need to specify a remote IP address each time you run the
commit_redundancy configuration synchronization script, you can set the value
of the variable REMOTE_IP to an IP address and save it in your user profile. Once
you set the variable and save it in your user profile, the variable will always be
available after you log in to the CSS.
Set the REMOTE_IP variable to the APP session IP address configured on the
local CSS. The APP session address is the circuit IP address for the remote CSS.
To set the variable, enter:
# set REMOTE_IP “remote_ip_address” session
To save the variable in your user profile, enter:
# copy profile user-profile
If you already created the BACKUP_IP variable in an earlier release, the script
will use the new variable instead, if present.
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Using the Redundancy Force-Master Command
Logging Configuration Synchronization Script Result Messages
You can specify that script result messages (script success or failure messages) be
sent to the current logging device automatically each time you run the
configuration synchronization script. To log the script result messages, enable
logging on NETMAN with level info-6 or debug-7 by entering:
(config)# logging subsystem netman level info-6
Note
Log messages are generated with or without the -s (silent) argument specified. See
“Running the Configuration Synchronization Script” earlier in this chapter.
For example, if the APP session to the backup CSS is not running, the following
log message will be generated:
config sync: app session is DOWN
For ease of tracking, each log message contains the string “config sync”.
Using the Redundancy Force-Master Command
Use the redundancy force-master command to configure a backup CSS as a
master temporarily. This is a temporary setting because it is not copied to the
running-config. This command is useful in a redundant configuration when you
need to take the master CSS offline for maintenance or an upgrade.
By issuing the redundancy force-master command on the backup CSS in global
configuration mode, you set that CSS to master and ensure that users have
continuous access to servers and content. The forced master CSS remains the
master:
•
Until it goes down and comes back up as the backup, or
•
You manually make the other CSS the master, using either the redundancy
force-master command or the ip redundancy master command.
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Configuring Multiple Redundant Uplink Services
Note
If you explicitly designated the master CSS using the ip redundancy master
command, you cannot use the redundancy force-master command on the backup
CSS. In this case, you must unassign the master CSS by issuing the no ip
redundancy master command before you can use the redundancy force-master
command on the backup CSS.
Configuring Multiple Redundant Uplink Services
Within a redundant configuration, the CSS allows you to configure multiple
redundancy uplink critical services (up to a maximum of 512). Use the type
redundancy-up command to designate one or more routers as type
redundancy-up critical services. (A typical configuration contains 10 or fewer
routers.) This critical service type enables the master CSS to ping a router service
using the default keepalive Internet Control Message Protocol (ICMP). If the
master CSS fails or it detects that all router uplink critical services have failed,
the backup CSS becomes the master.
In a redundant configuration that does not configure the routers as type
redundancy-up critical services, a backup CSS becomes master only when the
current master CSS fails. In this configuration, a switchover does not occur when
the router services fail.
Note
You cannot add redundancy uplink critical services to a content rule.
Figure 3-2 shows a typical redundant configuration. When CSS1 fails or CSS1
cannot communicate with both the Router1 critical service and the Router2
critical service, CSS2 becomes the master CSS automatically.
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Configuring Multiple Redundant Uplink Services
Figure 3-2
Multiple Redundant Uplink Services Configuration Example
Internet
Router1
Router2
Hub1
CSS1
(master)
Redundant link
CSS2
(backup)
49642
Hub2
Server1
Note
Server2
Server3
Server4
If you explicitly designated the master CSS using the ip redundancy master
command, you cannot use the type redundancy-up command on the CSS. In this
case, you must unassign the master CSS by issuing the no ip redundancy master
command before you can use the type redundancy-up command.
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Using the redundancy-phy Command
Use the type redundancy-up command to configure each router service as a
redundancy uplink critical service. For example:
(config-service[router1])# type redundancy-up
(config-service[router1])# ip address 192.168.1.1
(config-service[router1])# active
Use the show redundancy command to display critical services. See the
“Displaying Redundant Configurations” section.
For example:
CSS1(config)# show redundancy
Using the redundancy-phy Command
Use the redundancy-phy command in interface mode to add an interface to the
physical link configuration list. If any physical link in the configuration list goes
down, the master CSS fails over to the backup CSS. You can configure a
maximum of 32 interfaces. The CSS saves this configuration information to the
running-config.
For example:
(config-if[2/1])# redundancy-phy
Note
If you configure the redundancy-phy command on an interface of the master
CSS and then make any change to the port settings of that interface using the phy
command (for example, changing auto-negotiate to 100Mbits-FD), the master
CSS fails over to the backup CSS. To prevent the failover from occurring, enter
the no redundancy-phy command on the interface first, change the port settings,
and then reenter the redundancy-phy command.
You cannot use the redundancy-phy command if you used the ip redundancy
master command to configure the master CSS. In this case, you must enter the no
ip redundancy master command before you can use the redundancy-phy
command.
To disable a configured interface and delete it from the physical link list, enter:
(config-if)# no redundancy-phy
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Configuring Stateless Redundancy Failover
Note
If you configure the redundancy-phy command on an interface and
then disable the interface using the admin-shutdown command, the
master CSS fails over to the backup CSS. To prevent the CSS from
failing over when you administratively disable the interface, remove
the redundancy-phy command by entering no redundancy-phy
before you enter the admin-shutdown command on that interface.
When you use the redundancy-phy command and both CSSs are connected to a
Layer 2 switch, be sure to monitor physical link failure only on the critical
physical links and not on the redundant link between the two CSSs. This will
avoid the detection of a physical link down and possible thrashing when one of
the CSSs is rebooting or transitioning between master and backup states.
Configuring Stateless Redundancy Failover
Use the redundancy-l4-stateless command in content or group configuration
mode to enable stateless redundancy failover in a box-to-box redundancy or a VIP
and virtual interface redundancy configuration. Stateless redundancy failover
allows critical TCP/IP traffic to continue in case of a failure at the load-balancing
CSS by allowing the backup CSS to set up a mid-stream TCP flow. This feature
is disabled by default.
The default behavior of a CSS is to set up load-balanced TCP flows only when it
receives a TCP frame that begins with SYN. When stateless redundancy failover
is enabled and a failover occurs, the backup CSS establishes a mid-stream flow
for any existing TCP sessions. The CSS still exhibits the default behavior for all
new flows. To restore the default behavior of the CSS for all flows after issuing
the redundancy-l4-stateless command, use the no redundancy-l4-stateless
command.
Note
This feature affects only TCP/IP sessions. UDP behaves normally because UDP
is not a a session-oriented protocol.
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Configuring Stateless Redundancy Failover
Before You Begin
Before you attempt to implement stateless redundancy failover for the first time,
read this section in its entirety. You should already be familiar with the following
concepts:
•
Redundancy
•
Layer 3 and layer 4 content rules
•
Virtual IP addresses (VIPs)
•
Load balancing
•
Source groups
•
Services
•
Keepalives
•
Convergence
Environmental Considerations
Stateless redundancy failover requires a very specific redundant CSS
configuration, where the state of the CSS can be determined after a failure. This
feature supports redundant routes in the high-availability topology surrounding
the CSSs. However, the topology must not balance packets in a TCP/IP socket
connection across more than one Ethernet port on the CSS.
Routed paths to the load-balanced VIP should be weighted to ensure that a single
path is preferred for the lifetime of a TCP/IP connection.
Note
Stateless redundancy failover does not support network address translation (NAT)
where maintaining state is required nor does it support Layer 5 content rules.
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Configuring Stateless Redundancy Failover
General Configuration Requirements
The following sections describe the stateless failover requirements that apply to
both box-to-box redundancy and VIP and virtual interface redundancy
configurations.
Configuration Restrictions
The following configuration restrictions apply to all CSSs, except where noted.
•
Stateless redundancy failover is incompatible with service remapping (the
persistence reset remap command). Stateless redundancy failover requires
that the CSS not NAT client source ports. Backend remapping enables CSS
port mapping, which NATs source ports for all flows. For more information
on service remapping, refer to the Cisco Content Services Switch Content
Load-Balancing Configuration Guide.
•
Configuring session-level redundancy and stateless redundancy failover on
the same CSS is not supported.
•
Do not configure a service that changes the destination port on a content rule.
This causes the CSS to NAT (port map) the destination port. If the CSS fails
over, the backup CSS has no knowledge of the original destination port.
Configuring CSS Parameters
The following parameters must match exactly on both redundant CSSs:
•
Stateless redundancy failover command - Include the
redundancy-l4-stateless command in both the content rules and the source
groups associated with the redundant VIP.
•
Content rules - Create identical content rules on both CSSs with the
following parameters. Refer to the Cisco Content Services Switch Content
Load-Balancing Configuration Guide.
– VIP - Assign a virtual IP address to each content rule. No wildcard
addresses are allowed and no VIP ranges on the content rule are allowed.
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– Load-balancing method - Configure the load-balancing method as
source IP address (srcip), the only load-balancing method that is
supported by stateless redundancy failover.
– Failover method - Configure either ‘linear’ (default) or ‘next’ type as the
service failover method. ‘Bypass’ is not supported.
•
Services - For each load-balanced server farm, configure the following
service-related parameters to be the same on both CSSs for each content rule.
Refer to the Cisco Content Services Switch Content Load-Balancing
Configuration Guide.
– Service name - Use identical service names on the master and the backup
CSS. Service names are case-sensitive.
– IP address - Use identical IP addresses on the master and the backup
CSS.
Note
Configured services may not change the CSS destination port. In a
stateless environment, there is no way to determine the original
destination port when the packet returns from the server.
– Service number and order - The CSS orders services internally in
alphabetical order regardless of the order in which you enter them in the
configuration.
– Keepalives - Create keepalives using the global keepalive command,
then associate the services with the keepalives using the keepalive type
named command. Both CSSs must be able to send and receive keepalive
messages with the same servers. This helps to ensure that a redistribution
of the balance method does not occur in a failover event.
– Weight - Routed paths to the load-balanced VIP should be weighted to
ensure that a single path is preferred for the lifetime of a TCP/IP
connection.
•
Source groups - Create a source group with the same VIP as the content rule
VIP on each CSS to NAT source addresses for packets returning from the
server. In case of a failover, the source group will handle the connection setup
for TCP/IP transmissions that arrive at the CSS from the servers. All servers
in the farm must be members of the configured source group. Refer to the
Cisco Content Services Switch Content Load-Balancing Configuration
Guide.
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Configuring Stateless Redundancy Failover
Note
Do not configure source groups for outbound traffic from the servers,
because the backup CSS does not know which ports were NATed by
the source group on the master CSS if a failure occurs at the master
CSS. This restriction also applies to active FTP because the server
initiates the data connection.
Synchronizing the CSS Configurations
You can manually synchronize the CSS configurations by ensuring that the
configurations are exactly the same. In an IP redundancy configuration, you can
run the commit_redundancy configuration synchronization script. The script
automatically synchronizes the master and backup CSS configurations. See
“Synchronizing a Redundant Configuration” earlier in this chapter.
Box-to-Box Redundancy Configuration
For details on box-to-box redundancy, see the earlier sections in this chapter.
In case of a failure on the master CSS, the backup CSS becomes the master CSS.
The following actions occur:
Note
1.
All VLANS become active.
2.
Topology protocols (for example, Spanning Tree) initialize and converge.
3.
All configured interface (circuit) and VIP addresses are acquired by
gratuitous ARP.
4.
The master CSS acquires servers through keepalives.
If your configuration is large or the servers respond slowly, the completion of
step 4 may take several seconds.
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Configuring Stateless Redundancy Failover
Complex topologies surrounding the CSS converge after the CSS has determined
a root bridge and has begun transmission of Address Resolution Protocol (ARP)
and keepalive traffic. If a TCP/IP retransmission from a server arrives at the CSS
before the CSS acquires the server, the CSS sets up the connection properly
through the configured source group path. If a retransmission from a client arrives
at the CSS before all servers have been acquired and the source IP address of the
client indicates a server that is not yet alive, the CSS sets up the connection
according to the failover method configured in the content rule (next or linear).
Layer 2 and Layer 3 Configuration and Convergence
Because IP Redundancy disables the forwarding of traffic through VLANs on the
backup CSS, configure the CSS to provide either a bridged or routed path between
servers and uplink routers. In either case, the CSS must be the default gateway for
load-balanced servers. Refer to the Cisco Content Services Switch Routing and
Bridging Configuration Guide.
If you configure the CSSs with servers and a balance VIP on the same VLANs as
the uplink router (bridged mode), then configure the CSSs to not send ICMP
redirects to the servers, using the no redirect command. Refer to the Cisco
Content Services Switch Content Load-Balancing Configuration Guide.
Configuration Example
The following example configuration (see Figure 3-3) assumes that the:
•
CSSs are acting as routers between two external VLANs in an IP Redundancy
configuration.
•
External VLANS exist on Layer 2 and Layer 3 devices.
•
Layer 2 and Layer 3 devices are not the point of failure.
ip route 0.0.0.0.0.0.0.0.192.168.20.100
ip redundancy
interface e2
bridge vlan 1
description “uplink VLAN”
interface e5
bridge vlan 1
description “uplink VLAN”
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interface e9
bridge vlan 3
description “server VLAN”
interface e12
bridge vlan 3
description “server VLAN”
interface e1
bridge vlan 2
description “Redundancy Protocol Heartbeat”
circuit VLAN1
redundancy
ip address 192.168.20.1 255.255.255.0
circuit VLAN3
redundancy
ip address 192.168.10.1 255.0.0.0
circuit VLAN2
redundancy-protocol
ip address 172.7.6.1 255.255.255.253
service s1
ip address 192.168.10.30
active
service s2
ip address 192.168.10.31
active
owner Redundant-Pool
content web
vip address 192.168.20.254
protocol tcp
port 80
redundancy-l4-stateless
add s1
add s2
balance srcip
active
group Redundant-Pool
vip address 192.168.20.254
redundancy-l4-stateless
add service s1
add service s2
active
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Configuring Stateless Redundancy Failover
Figure 3-3
Example Box-to-Box Redundancy Configuration for Stateless
Redundancy Failover
Server 1
192.168.10.30
Server 2
192.168.10.31
VLAN 3
Hub 1
Master
192.168.10.1
Backup
192.168.10.1
172.7.6.1
192.168.20.1
VIP address
192.168.20.254
172.7.6.2
VLAN 2
Redundant
link
192.168.20.1
VIP address
192.168.20.254
Hub 2
VLAN 1
Internet
37515
Router
192.168.20.100
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Configuring Stateless Redundancy Failover
VIP and Interface Redundancy Configuration
For details on VIP and virtual interface redundancy, refer to Chapter 1,
Configuring VIP and Virtual Interface Redundancy.
Layer 2 and Layer 3 Configuration and Convergence
A CSS that is running Virtual Router Redundancy Protocol (VRRP) does not shut
down any VLANs. Therefore, VRRP configurations may not be configured with
content rule VIP, uplink, and server addresses in the same VLAN (bridged mode).
Instead, the CSSs must be configured so that both CSSs in a redundant pair act as
routers between the uplink VLAN and the server VLAN. The CSS uses a virtual
router address for the default gateway on the servers.
Because both CSSs are active and participating in topology protocols,
convergence time may be reduced in the event of a failure. Additionally, both
CSSs acquire servers with keepalive traffic at all times, so that both CSSs agree
on server availability.
VRRP provides for a redundant routed path out of a VLAN, but does not address
synchronization of more than one VLAN in the decision. Due to this limitation,
ensure that one CSS does not become master for the connection to the uplink
VLAN, while the other CSS is master for the connection to the server VLAN. To
avoid this split state, a CSS can monitor critical external IP addresses as part of
the extended VRRP implementation.
Typically, you configure a single CSS with the highest priority and the preempt
option for each VRID pair (uplink VLAN side/server VLAN side). This ensures
that if the designated CSS is available, both VRIDs will converge there, avoiding
a split state.
To address more complex failure scenarios, use a script keepalive. For details on
script keepalives, refer to the Cisco Content Services Switch Administration
Guide.
In the example that follows, the master CSS relinquishes control of both virtual
interfaces upon loss of contact with either the uplink router or all web servers.
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Configuring Stateless Redundancy Failover
Configuration Example
The following example configuration (see Figure 3-4) assumes that the:
•
CSSs are acting as routers between two external VLANs in a VIP and virtual
interface redundancy configuration.
•
External VLANS exist on Layer 2 and Layer 3 devices.
•
Layer 2 and Layer 3 devices are not the point of failure.
ip route 0.0.0.0 0.0.0.0 192.168.20.100
interface e2
bridge vlan 1
description “uplink VLAN”
interface e5
bridge vlan 1
description “uplink VLAN”
interface e9
bridge vlan 3
description “server VLAN”
interface e12
bridge vlan 3
description “server VLAN”
circuit VLAN1
ip address 192.168.20.1 255.255.255.0
ip virtual-router 1 priority 110 preempt
ip redundant-vip 1 192.168.20.254
ip redundant-interface 1 192.168.20.2
ip critical-service 1 uplink
ip critical-service 1 s1
ip critical-service 1 s2
circuit VLAN3
ip address 192.168.10.1.0.0.0
ip virtual-router 1 priority 110 preempt
ip redundant-vip 1 192.168.10.254
ip redundant-interface 1 192.168.10.2
ip critical-service 1 uplink
ip critical-service 1 s1
ip critical-service 1 s2
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Configuring Stateless Redundancy Failover
service uplink
ip address 192.168.20.100
type redundancy-up
active
service s1
ip address 192.168.10.30
active
service s2
ip address 192.168.10.31
active
owner Redundant-Pool
content web
vip address 192.168.20.254
protocol tcp
port 80
redundancy-l4-stateless
add s1
add s2
balance srcip
active
group Redundant-Pool
vip address 192.168.20.254
redundancy-l4-stateless
add service s1
add service s2
active
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Configuring Stateless Redundancy Failover
Figure 3-4
Example of VIP and Virtual Interface Redundancy Configuration for
Stateless Redundancy Failover
Server 1
192.168.10.30
Server 2
192.168.10.31
VLAN 3
Hub 1
Master
192.168.10.1
Backup
192.168.10.2
VIP
192.168.10.254
192.168.20.1
VIP address
192.168.20.254
192.168.20.2
VIP address
192.168.20.254
Hub 2
VLAN 1
Internet
37516
Router
192.168.20.100
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Configuring Stateless Redundancy Failover
Alternative Configurations
Stateless redundancy failover allows other possible configurations and
topologies. To use this feature in other high-availability environments, see the
other sections in this chapter and to Chapter 1, Configuring VIP and Virtual
Interface Redundancy, for details and examples of CSS redundancy
configurations. Refer to RFC-2338 Virtual Router Redundancy Protocol for
additional information.
Managing Your Configuration
If you need to take a server offline for maintenance, you should also take the
corresponding server offline at the redundant CSS. Failing to synchronize the
state of the server farms results in mismapped connections if a failover occurs
during the maintenance period. You can synchronize the service states in an IP
redundancy configuration automatically by running the configuration
synchronization script (commit_redundancy). For a VIP/interface redundancy
configuration, manually synchronize the service states.
Other Considerations
The following conditions apply to stateless redundancy failover:
•
After a failover, passive mode FTP will not continue because the NAT state
of the data channel cannot be preserved. However, port mode FTP will
continue to function.
•
Because the port-map function of source groups is disabled, connections
originated by the servers in the redundantly balanced farm do not have the
benefit of source port translation. This may affect functions such as DNS.
•
Service records may not be configured to change the destination port of
traffic that is balanced.
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Displaying Redundant Configurations
•
At any given time, some TCP/IP connections may be either in a state where
the client is sending data to the server, or the server is sending data to the
client. Packets that arrive while the topology is converging or before some
services are acquired by keepalive traffic may be forwarded incorrectly. For
example, a service may stop responding to keepalive traffic, but continue to
service a long-lived TCP connection. In this case, the backup CSS would not
have knowledge of the state of the long-lived connection, and would guess
incorrectly when attempting to resume the connection.
•
In a highly critical environment, set goals for connection loss ratio and
convergence time. Then, test various topologies and topology protocol
combinations to verify that the target connection loss ratios and convergence
time goals are reached. This testing should account for all reasonable failure
modes that the high-availability network is designed to withstand. If
warranted by the critical nature of the traffic, you may want to construct a
permanent testbed to validate the system of network components prior to the
deployment of new configurations.
Displaying Redundant Configurations
To display CSS-to-CSS redundancy, use the show redundancy command.
For example:
(config)# show redundancy
When redundancy is not configured, the CSS displays the following status:
(config)# show redundancy
Redundancy: Disabled Redundancy Protocol: Not Running
The output of the show redundancy command varies depending on whether you
issue the command on the master or the backup CSS.
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Table 3-3 describes the fields in the show redundancy output.
Table 3-3
Field Descriptions for the show redundancy Command
Field
Description
Redundancy
Indicates whether or not redundancy is enabled on the
CSS.
Redundancy
Protocol
Indicates whether or not the redundancy protocol is
running on the CSS.
Redundancy State
The current redundancy state of the CSS (Master or
Backup).
MasterMode
Indicates whether the CSS is configured as master. Yes
indicates that the CSS is designated as master through
the ip redundancy master command. No indicates that
the CSS is not the designated master through the ip
redundancy command.
Number of times
redundancy state
changed to
Master/Backup
The number of times that the CSS has changed to master
or backup.
Redundancy
interface
The address for the redundancy interface.
Current State
Duration
How long the CSS has been in its current redundancy
state (master or backup).
Last Fail Reason
A description of the last CSS redundancy failure.
VRID
The virtual router identifier (VRID).
Priority
The priority for the virtual router with its peer. The
default priority value is 100. Enter an integer between 1
and 255.
Physical Link Failure Monitor on
Interface/State
The list of interfaces configured through the
redundancy-phy command and their states. The show
output is sorted numerically by interface port number.
Uplink Enabled
The number of enabled service uplinks.
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Table 3-3
Field Descriptions for the show redundancy Command (continued)
Field
Description
Number Alive
The number of alive (Up state) service uplinks.
Service
Name/State
The list of uplink services and their states. The show
output is sorted numerically by service index number.
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INDEX
configuring 3-10
A
disabling 3-12
Adaptive Session Redundancy
overview 3-1
configuration quick start 2-11
protocol, configuring 3-13
configuration requirements and
restrictions 2-8
stateless failover 3-24, 3-28
synchronizing configurations 3-15
content rule, redundant 2-17
displaying information 2-19
C
index, redundant 2-7
Inter-Switch Communications 2-15
cable, crossover for box-to-box redundancy 3-9
overview 2-4
circuit IP interface, configuring for VIP
redundancy 1-19
redundant index 2-23
running-config example 2-13
service, redundant 2-16
circuits, redundant for box-to-box
redundancy 3-13
source group, redundant 2-10, 2-18
configuration quick start
ASR. See Adaptive Session Redundancy
Adaptive Session Redundancy 2-11
audience xiv
box-to-box redundancy 3-6
critical phy 1-37
VIP redundancy 1-16
B
virtual interface redundancy 1-16
BACKUP_IP variable 3-19
VRID peering 1-28
box-to-box redundancy
configuration synchronization
cabling CSSs 3-9
BACKUP_IP variable 3-19
configuration quick start 3-6
lock file 1-48, 3-19
configurations, displaying 3-37
logging results 1-49, 3-20
overview 1-43, 3-15
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Index
REMOTE_IP variable 3-19
dormant flows 2-5, 2-21
script for box-to-box redundancy 3-16
script for VIP redundancy 1-45, 1-46
content rule, redundant 2-17, 2-23
critical phy
E
example
activating a reporter 1-42
redundancy uplink services 3-21
configuration quick start 1-37
running-config for ASR 2-13
configuration requirements and
restrictions 1-36
running-config for box-to-box
redundancy 3-8
configuring 1-38
running-config for critical phy 1-38
critical reporter, configuring 1-42
overview 1-35
running-config for VIP and virtual interface
redundancy 1-18
physical interfaces, configuring 1-41
running-config for VRID Peering 1-29
suspending a reporter 1-42
stateless redundancy failover for box-to-box
redundancy 3-29
critical reporter, associating with a virtual
router 1-32, 1-42
stateless redundancy failover for VIP
redundancy 3-33
critical services
configuring for box-to-box redundancy 3-21
configuring for VIP redundancy 1-33
displaying for box-to-box redundancy 3-23
displaying for VIP redundancy 1-57
crossover cable pinouts for box-to-box
redundancy 3-10
F
failover
stateful 2-4
stateless 3-24
flows, dormant 2-5, 2-21
D
G
documentation
audience xiv
group, redundant 2-18, 2-23
chapter contents xiv
set xv
symbols and conventions xviii
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Index
LOCAL_VIPR_IP variable, setting 1-48
I
logging, configuration synchronization
results 1-49, 3-20
index, redundant 2-7, 2-16, 2-23
Inter-Switch Communications
configuring 2-15
M
displaying information 2-20
master CSS, temporary 3-20
overview 2-6
restrictions 2-9
IP critical services
P
configuring for VIP redundancy 1-33
physical interfaces
displaying 1-50
IP redundancy. See box-to-box redundancy
configuring for box-to-box redundancy 3-23
IP redundant interface
configuring for critical phy 1-41
configuring for VIP redundancy 1-23
physical link list 3-23
displaying 1-50
protocol
IP redundant VIP, configuring for VIP
redundancy 1-22
box-to-box redundancy 3-4, 3-13
VRRP 1-5
IP virtual router, configuring for VIP
redundancy 1-20
ISC. See Inter-Switch Communications
Q
quick start
K
keepalive
IP critical services 1-33
redundant uplink services 3-21
Adaptive Session Redundancy 2-11
box-to-box redundancy 3-6
critical phy 1-37
VIP redundancy 1-16
virtual interface redundancy 1-16
VRID peering 1-28
L
LifeTick 2-7
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Index
REMOTE_VIPR_IP variable, setting 1-48
R
reporter
redundancy
activating 1-32, 1-42
adaptive session 2-1
configuring 1-29, 1-38
box-to-box 3-1
critical 1-32, 1-42
configuration quick start 1-16, 2-11, 3-6
suspending 1-32, 1-42
configurations, displaying 3-37
type 1-30, 1-39
critical services 1-33
router
interfaces, displaying 1-50
virtual 1-20, 1-22, 1-53
IP redundant VIP 1-22
VRID 1-20, 1-31, 1-33, 1-43
physical interfaces 3-23
running-config example
redundant VIPs, displaying 1-52
ASR 2-13
session 2-4
box-to-box redundancy 3-8
stateless failover 3-24, 3-28, 3-32
critical phy 1-38
synchronizing configurations 1-43, 3-15
VIP and virtual interface redundancy 1-18
uplink configuration example 3-21
VRID peering 1-29
uplink services 3-21
VIP 1-1, 1-4, 1-19
virtual interface 1-1, 1-4, 1-6, 1-19, 1-23
redundancy protocol
S
scripts
box-to-box, overview 3-4
commit_redundancy 3-15
configuring 3-13
commit_vip_redundancy 1-46
redundant
configuration synchronization 1-46, 3-15
circuits, configuring for box-to-box
redundancy 3-13
content rule 2-17, 2-23
index 2-7, 2-16, 2-17, 2-18, 2-23
service, redundant 2-16, 2-23
session redundancy
configuration quick start 2-11
service 2-16, 2-23
configuration requirements and
restrictions 2-8
source group 2-10, 2-18, 2-23
content rule, redundant 2-17
REMOTE_IP variable, setting 3-19
displaying information 2-19
Cisco Content Services Switch Redundancy Configuration Guide
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Index
index, redundant 2-7, 2-23
V
Inter-Switch Communications 2-15
variable
overview 2-4
service, redundant 2-16
LOCAL_VIPR_IP, setting 1-48
source group, redundant 2-10, 2-18
REMOTE_IP, setting 3-19
REMOTE_VIPR_IP, setting 1-48
source group
VIP redundancy
redundant 2-10, 2-18, 2-23
stateful failover 2-4
circuit IP interface, configuring 1-19
stateless redundancy failover
configuration quick start 1-16
box-to-box redundancy configuration 3-28
configurations, displaying 1-50
configuration restrictions 3-26
critical services 1-33
configuration synchronization 3-28
IP virtual router 1-20
CSS parameters, configuring 3-26
overview 1-4
example configuration for box-to-box
redundancy 3-29
redundant interface 1-23
example for VIP redundancy 3-33
running-config example 1-18
overview 3-24
stateless failover 3-24, 3-32
VIP and virtual IP interface redundancy 3-32
synchronizing configurations 1-43
synchronizing redundant configurations 1-43
redundant VIP, configuring 1-22
VIPs, displaying 1-52
with session redundancy 2-8
virtual interface, configuring 1-23
T
virtual interface redundancy
temporary master CSS, for box-to-box
redundancy 3-20
configuration quick start 1-16
configuring 1-19
overview 1-6
running-config example 1-18
U
virtual router
uplink services, configuring redundant 3-21
associating with a critical reporter 1-32, 1-42
configurations, displaying 1-53
Cisco Content Services Switch Redundancy Configuration Guide
OL-8243-01
IN-5
Index
configuring 1-20, 1-24
ID 1-22
VRID peering 1-24
Virtual Router Redundancy Protocol. See
VRRP
VRID peering
background 1-25
configuration quick start 1-28
configuration requirements and
restrictions 1-27
configuring 1-29
critical reporter, configuring 1-32
overview 1-25
VRRP 1-5, 1-45, 3-32
Cisco Content Services Switch Redundancy Configuration Guide
IN-6
OL-8243-01
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