Table Of Contents

Configuring Redundancy

Understanding How Supervisor Engine Redundancy Works

Configuring Redundant Supervisor Engines

Synchronization Process Initiation

Redundant Supervisor Engine Configuration Guidelines and Restrictions

Verifying Standby Supervisor Engine Status

Forcing a Switchover to the Standby Supervisor Engine

High Availability

High-Availability Overview

High-Availability Supported Features

Versioning Overview

CLI Commands

Loading a Different (but Compatible) Image on the Standby Supervisor Engine

Supervisor Engine Synchronization Examples

Synchronizing the Runtime Image with the Bootstring

Synchronizing the Boot Images on the Active and Standby Supervisor Engines

MSFC Redundancy

Dual MSFC Redundancy

Hardware and Software Requirements

Layer 3 Redundancy for a Single Chassis

Routing Protocol Peering

Access Control List Configuration

Dual MSFC Operational Model for Redundancy and Load Sharing

Understanding Failure Scenarios

Configuring Redundancy with HSRP

Configuration Examples

MSFC Configuration Synchronization Overview

Enabling or Disabling Configuration Synchronization

High-Availability Redundancy Configuration Examples

Single Router Mode Redundancy

Hardware and Software Requirements

Configuration Guidelines

Configuring Single Router Mode Redundancy

Upgrading Images with Single Router Mode Enabled

Getting Out of Single Router Mode

Manual-Mode MSFC Redundancy

Hardware and Software Requirements

Guidelines for Configuring Manual-Mode MSFC Redundancy

Accessing the Standby MSFC

Manually Booting the MSFC

Setting the MSFC Configuration Register

MSFC Recovery Procedures

Configuring Redundancy

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This chapter describes how to configure redundant supervisor engines and how to configure redundancy on Multilayer Switch Feature Cards (MSFCs) on the Catalyst 6000 family switches.

This chapter consists of these sections:

•Understanding How Supervisor Engine Redundancy Works

•Configuring Redundant Supervisor Engines

•MSFC Redundancy

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Caution Dual MSFCs in a single chassis are designed to be used in redundant mode only and must have identical configurations. See the "MSFC Redundancy" section for detailed information.

We do not support configurations where the MSFCs are not configured identically.

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Note Except where specifically differentiated, the information and procedures in this chapter apply to both Supervisor Engine 2 with Layer 3 Switching Engine II (Policy Feature Card 2 or PFC2) and Supervisor Engine 1 with Layer 3 Switching Engine II.

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Note The term MSFC is used to refer to the MSFC and MSFC2 except where specifically differentiated.

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For more information about installing redundant Catalyst 6000 family supervisor engines, refer to the Catalyst 6000 Family Module Installation Guide. For syntax and usage information for the commands used in this chapter, refer to the Catalyst 6000 Family Command Reference publication.

Understanding How Supervisor Engine Redundancy Works

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Note Redundant supervisor engines must be of the same type with the same model feature card.

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When you install two supervisor engines, the first supervisor engine to come online becomes the active module; the second supervisor engine goes into standby mode. All administrative and network management functions, such as SNMP, command-line interface (CLI) console, Telnet, Spanning Tree Protocol (STP), Cisco Discovery Protocol (CDP), and VLAN Trunk Protocol (VTP) are processed on the active supervisor engine.

On the standby supervisor engine, the console port is inactive, the module status shows as "standby," and the status for the uplink ports is shown normally.

You must install redundant supervisor engines in slots 1 and 2 of the chassis. Redundant supervisor engines are hot swappable. The system continues to operate with the same configuration after switching over to the redundant supervisor engine.

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Note To allow you to control the booting of each supervisor engine separately, the configuration registers are not synchronized between the supervisor engines.

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Note The switchover time from the active to the standby supervisor engine does not include spanning tree convergence time.

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At power-up, both supervisor engines run initial module-level diagnostics. Assuming both supervisor engines pass this level of diagnostics, the two supervisor engines communicate over the backplane, allowing them to cooperate during switching-bus diagnostics. The supervisor engine in slot 1 becomes active, and the supervisor engine in slot 2 enters standby mode. If the software versions of the two supervisor engines are different, or if the NVRAM configuration of the two supervisor engines is different, the active supervisor engine automatically downloads its software image and configuration to the standby supervisor engine.

If the background diagnostics on the active supervisor engine detect a major problem or an exception occurs, the active supervisor engine resets. The standby supervisor engine detects that the active supervisor engine is no longer running and becomes active. The standby supervisor engine can detect if the active supervisor engine is not functioning and can force a reset, if necessary. If the reset supervisor engine comes online again, it enters standby mode.

If you hot insert a second supervisor engine, the second module communicates with the active supervisor engine after completing its initial module-level diagnostics. Because the active supervisor engine is already switching traffic on the backplane, no switching-bus diagnostics are run for the second supervisor engine because running diagnostics can disrupt normal traffic. The second supervisor engine immediately enters standby mode. The active supervisor engine downloads the software image and configuration to the standby supervisor engine, if necessary.

The supervisor engines use two Flash images: the boot image and the runtime image. The boot image filename is specified in the BOOT environment variable, which is stored in NVRAM. The runtime image is the boot image that the ROM monitor uses to boot the supervisor engine. After the system boots, the runtime image resides in dynamic RAM (DRAM).

When you power up or reset a switch with redundant supervisor engines, synchronization occurs to ensure that the runtime and boot images on the standby supervisor engine are the same as the images on the active supervisor engine.

The supervisor engines can have different runtime and boot images. If the boot image and the runtime image are the same, and you change the BOOT environment variable or overwrite or destroy the current boot image on the Flash device that was used to boot the system, the runtime and boot images will differ. Whenever you reconfigure the boot image, the active supervisor engine synchronizes its current boot image with the standby supervisor engine.

The boot image is read directly into the Flash file system. You can perform operations (such as copy, delete, undelete, and so on) on files stored on Flash memory devices, and you can store the boot image of the active supervisor engine in the standby supervisor engine bootflash. For more information about using the Flash file system, see "Working With the Flash File System."

The supervisor engine has a Flash PC card (PCMCIA) slot (slot0) in addition to the onboard Flash memory; this slot can hold a Flash PC card that can store additional boot images.

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Note Throughout this publication, the term Flash PC card is used in place of the term PCMCIA card.

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Because you can store multiple boot images, you must specify the name of the boot file image and the location of the image file in the Flash file system in order to boot and synchronize properly. For information about how to specify the name and location of the boot image, see "Modifying the Switch Boot Configuration."

In the synchronization process, the active supervisor engine checks the standby supervisor engine runtime image to make sure it matches its own runtime image. The active supervisor engine checks three conditions:

•If it needs to copy its boot image to the standby supervisor engine

•If the standby supervisor engine bootstring needs to be changed

•If the standby supervisor engine needs to be reset

The following section describes the conditions that can initiate Flash synchronization. For examples of how the system synchronizes the supervisor engine Flash images with various configurations, see the "Supervisor Engine Synchronization Examples" section.

Configuring Redundant Supervisor Engines

These sections describe how to configure redundant supervisor engines:

•Synchronization Process Initiation

•Redundant Supervisor Engine Configuration Guidelines and Restrictions

•Verifying Standby Supervisor Engine Status

•Forcing a Switchover to the Standby Supervisor Engine

•High Availability

•Supervisor Engine Synchronization Examples

Synchronization Process Initiation

These conditions initiate the synchronization of the runtime and boot images on the active and standby supervisor engines:

•Time stamp mismatch between the runtime images on the active and standby supervisor engines—The active supervisor engine synchronizes its runtime image with the standby supervisor engine if the time stamps of their respective runtime images differ when the system is booted or reset.

•Time stamp mismatch between the boot images on the active and standby supervisor engines—The active supervisor engine synchronizes its boot image with the standby supervisor engine if the time stamps of their respective boot images differ when the system is booted or reset, or if you change the BOOT environment variable.

•Current boot image overwritten—If you overwrite the current boot image stored on one of the Flash devices, the file system management module detects this event and initiates synchronization. The active supervisor engine copies its new boot image to the standby supervisor engine.

•BOOT environment variables changed—If you change the BOOT environment variables to specify a different default boot image, the active supervisor engine initiates boot-image synchronization. The NVRAM configuration module detects this event and calls the Flash synchronization function with the next probable boot filename by looking at the boot configuration parameter.

•Flash PC cards with same boot-image filename—If you change the Flash device on either the active or standby supervisor engine and the new Flash device contains a boot image that has the same name (but a different time stamp) as the boot image from the previous Flash device, the Flash file management module initiates synchronization.

•Current runtime image deleted—If you delete the current runtime image from the Flash device, the Flash file management module prompts you to verify that you want to delete the current runtime image. If you confirm the deletion, the Flash file management module initiates Flash synchronization and informs the NVRAM configuration module of the change. The NVRAM configuration module examines the BOOT environment variable to determine the next probable image to boot and calls the Flash synchronization function using the new image name.

Redundant Supervisor Engine Configuration Guidelines and Restrictions

These conditions and events can cause the synchronization of images between redundant supervisor engines to fail or to produce unexpected results:

•Downloading a new image to the active supervisor engine

When you download a new image to the active supervisor engine, it is copied to the file system (in bootflash or on a Flash PC card in the Flash PC card slot). Because you may or may not have configured this image as the boot image, the newly downloaded image is not copied to the standby supervisor engine automatically.

To initiate the synchronization function between the active and standby supervisor engines, you must configure this newly downloaded image as the boot image on the active supervisor engine. Synchronization occurs when you change the boot variable. To run the new image, you must reset the system.

•Unable to find the current runtime image

If the active supervisor engine is unable to find the current runtime image on any of the Flash devices, it signals an error condition. In this case, if the standby supervisor engine is inserted or reset, Flash synchronization does not occur. In addition, the STATUS LED on the standby supervisor engine turns red and the system generates a syslog error message.

•Active supervisor engine in slot 2

When the active supervisor engine is in slot 2, the standby supervisor engine is in slot 1. If you change the configuration to specify a new boot image and then reset the system, the supervisor engine in slot 1 becomes the active supervisor engine and loads its default boot image, canceling the configuration changes you have just made. To avoid this problem, the switch prompts you for Flash synchronization as soon as you change the boot file configuration.

Verifying Standby Supervisor Engine Status

You can verify the status of the standby supervisor engine using a number of CLI commands.

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Note The show module output provides information about installed daughter cards. The show test command provides information about onboard application-specific integrated circuits (ASICs).

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To verify the status of the standby supervisor engine, perform one or more of these tasks:

Task	Command
Show the status of the standby supervisor engine.	show module [mod]
Show the state of the standby supervisor engine uplink ports.	show port [mod[/port]]
Show diagnostic test results for the standby supervisor engine.	show test [mod]

This example shows how to check the status of the standby supervisor engine using the show module and show test commands:

Console> (enable) show module 2

Mod Slot Ports Module-Type               Model               Status

--- ---- ----- ------------------------- ------------------- --------

2   2    2     1000BaseX Supervisor      WS-X6K-SUP1-2GE     ok

Mod Module-Name         Serial-Num

--- ------------------- -----------

2                       SAD02330231

Mod MAC-Address(es)                        Hw     Fw         Sw

--- -------------------------------------- ------ ---------- -----------------

2   00-e0-14-0e-f5-6c to 00-e0-14-0e-f5-6d 0.404  4.2(2038)  4.2(0.24)VAI50

    00-e0-14-0e-f5-6e to 00-e0-14-0e-f5-6f

    00-10-7b-bb-2b-00 to 00-10-7b-bb-2e-ff

Mod Sub-Type            Sub-Model           Sub-Serial  Sub-Hw

--- ------------------- ------------------- ----------- ------

2   L2 Switching Engine WS-F6020            SAD02350211 0.101

Console> (enable)

Console> (enable) show test 2

Module 2 : 2-port 1000BaseX Supervisor

Network Management Processor (NMP) Status: (. = Pass, F = Fail, U = Unknown)

  ROM:  .   Flash-EEPROM: .   Ser-EEPROM: .   NVRAM: .   EOBC Comm: .

Line Card Status for Module 1 : PASS

Port Status :

  Ports 1  2

  -----------

        .  .

Line Card Diag Status for Module 2  (. = Pass, F = Fail, N = N/A)

 Module 2

  Cafe II Status :

        NewLearnTest:             .

        IndexLearnTest:           .

        DontForwardTest:          .

        DontLearnTest:            .

        ConditionalLearnTest:     .

        BadBpduTest:              .

        TrapTest:                 .

 Loopback Status [Reported by Module 2] :

  Ports 1  2

  -----------

        .  .

Console> (enable) 

Forcing a Switchover to the Standby Supervisor Engine

You can force a switchover to the standby supervisor engine by resetting the active supervisor engine.

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Note Resetting the active supervisor engine disconnects any open Telnet sessions.

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To force a switchover to the standby supervisor engine, perform this task in privileged mode:

Task	Command
Reset the active supervisor engine (where mod is the number of the active supervisor engine).	reset mod

In addition, you can also force a switchover to the standby supervisor engine by setting the CISCO-STACK-MIB moduleAction variable to reset(2) on the active supervisor engine. When the switchover occurs, the system sends a standard SNMP warm-start trap to the configured trap receivers.

This example shows the console output on the active supervisor engine when you force a switchover from the active to the standby supervisor engine:

Console> (enable) reset 1

This command will force a switch-over to the standby Supervisor module.

Do you want to continue (y/n) [n]? y

Console> (enable) 12/07/1998,17:04:39:SYS-5:Module 1 reset from Console//

System Bootstrap, Version 3.1(2)

Copyright (c) 1994-1997 by cisco Systems, Inc.

System Bootstrap, Version 3.1(2)

Copyright (c) 1994-1997 by cisco Systems, Inc.

Presto processor with 32768 Kbytes of main memory

Autoboot executing command: "boot bootflash:cat6000-sup.5-4-1a.bin"

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

Uncompressing file:  ###########################################################

System Power On Diagnostics

NVRAM Size .. .................512KB

ID Prom Test ..................Passed

DPRAM Size ....................16KB

DPRAM Data 0x55 Test ..........Passed

DPRAM Data 0xaa Test ..........Passed

DPRAM Address Test ............Passed

Clearing DPRAM ................Done

System DRAM Memory Size .......32MB

DRAM Data 0x55 Test ...........Passed

DRAM Data 0xaa Test ...........Passed

DRAM Address Test  ............Passed

Clearing DRAM .................Done

EARLII ........................Present

EARLII RAM Test ...............Passed

EARL Serial Prom Test .........Passed

Level2 Cache ..................Present

Level2 Cache test..............Passed

Boot image: bootflash:cat6000-sup.5-4-1a.bin

Downloading epld sram device please wait ...

Programming successful for Altera 10K50 SRAM EPLD

This module is now in standby mode.

Console is disabled for standby supervisor

This example shows the console output on the standby supervisor engine when you force a switchover from the active to the standby supervisor engine:

Cisco Systems Console

Enter password:

12/07/1998,17:04:43:MLS-5:Multilayer switching is enabled

12/07/1998,17:04:43:MLS-5:Netflow Data Export disabled

12/07/1998,17:04:44:SYS-5:Module 2 is online

12/07/1998,17:04:45:SYS-5:Module 5 is online

12/07/1998,17:04:45:SYS-5:Module 7 is online

12/07/1998,17:04:45:SYS-5:Module 3 is online

12/07/1998,17:04:52:MLS-5:Route Processor 172.20.52.6 added

12/07/1998,17:05:10:SYS-5:Module 8 is online

12/07/1998,17:05:14:SYS-5:Module 9 is online

12/07/1998,17:05:22:SYS-5:Module 4 is online

12/07/1998,17:06:13:SYS-5:Module 1 is in standby mode

Supervisor image synchronization process will start in 10 seconds

12/07/1998,17:06:37:SYS-5:Ports on standby supervisor(Module 1) are UP

12/07/1998,17:06:41:SYS-5:Active supervisor is synchronizing the NMP image.

12/07/1998,17:06:44:SYS-5:The active supervisor has synchronized the NMP image.

Console>

High Availability

High availability allows you to minimize the switchover time from the active supervisor engine to the standby supervisor engine if the active supervisor engine fails.

Prior to this feature, fast switchover ensured that a switchover to the standby supervisor engine happened quickly. However, with fast switchover, because the state of the switch features before the switchover was unknown, you had to reinitialize and restart all the switch features when the standby supervisor engine assumed the active role.

High availability removes this limitation; high availability allows the active supervisor engine to communicate with the standby supervisor engine, keeping feature protocol states synchronized. Synchronization between the supervisor engines allows the standby supervisor engine to take over in the event of a failure.

In addition, high availability provides a versioning option that allows you to run different software images on the active and standby supervisor engines.

These features are discussed in these sections:

•High-Availability Overview

•High-Availability Supported Features

•Versioning Overview

•CLI Commands

•Loading a Different (but Compatible) Image on the Standby Supervisor Engine

High-Availability Overview

For high availability, a system database is maintained on the active supervisor engine and updates are sent to the standby supervisor engine for any change of data in the system database. The active supervisor engine communicates and updates the standby supervisor engine when any state changes occur, ensuring that the standby supervisor engine knows the current protocol state of supported features. The standby supervisor engine knows the current protocol states for all modules, ports, and VLANs; the protocols can initialize with this state information and start running immediately.

The active supervisor engine controls the system bus (backplane), sends and receives packets to and from the network, and controls all modules. Protocols run on the active supervisor engine only.

The standby supervisor engine is isolated from the system bus and does not switch packets. But it does receive packets from the switching bus to learn and populate its Layer 2 forwarding table for Layer 2-switched flows. The standby supervisor engine also receives packets from the switching bus to learn and populate the Multilayer Switching (MLS) table for Layer 3-switched flows. The standby supervisor engine does not participate in forwarding any packets and does not communicate with any modules.

If you enable high availability when the standby supervisor engine is running, image version compatibility is checked and if found compatible, the database synchronization is started. High availability compatible features continue from the saved states on the standby supervisor engine after a switchover.

When you disable high availability, the database synchronization is not done and all features must restart on the standby supervisor engine after a switchover.

If you change high availability from enabled to disabled, synchronization from the active supervisor engine is stopped and the standby supervisor engine discards all current synchronization data.

If you change high availability from disabled to enabled, synchronization from the active to standby supervisor engine is started (provided the standby supervisor engine is present and its image version is compatible).

NVRAM synchronization occurs irrespective of high availability being enabled or disabled (provided there are compatible NVRAM versions on the two supervisor engines).

If you do not install a standby supervisor engine during system bootup, the active supervisor engine detects this and the database updates are not queued for synchronization. Similarly, when you reset or remove the standby supervisor engine, the synchronization updates are not queued and any pending updates in the synchronization queue are discarded. When you hot insert or restart a second supervisor engine that becomes the standby supervisor engine, the active supervisor engine downloads the entire system database to the standby supervisor engine. Only after this global synchronization is completed, the active supervisor engine queues and synchronizes the individual updates to the standby supervisor engine.

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Note When you hot insert or restart a second supervisor engine, it might take a few minutes for the global synchronization to complete.

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High-Availability Supported Features

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Note MLS flows are preserved from the active supervisor engine to the standby supervisor engine.

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Note High availability does not preserve routing table entries on the active MSFC because high availability is not run on the MSFC IOS software. However, you can configure both MSFCs on the active and standby supervisor engines with the same configuration to preserve routing table entries across the active and standby MSFCs. You can then configure HSRP on the MSFCs to provide automatic routing backup. See the "MSFC Redundancy" section for detailed information.

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High availability for the Catalyst 6000 family switch is classified into three categories (see Table 22-1):

•Supported features—High availability is fully supported; the feature's database is synchronized from the active supervisor engine to the standby supervisor engine.

•Compatible features—High availability is not supported; the feature's database is not synchronized from the active supervisor engine to the standby supervisor engine. However, the feature can be enabled (operational) with high availability.

•Incompatible features—High availability is not supported; the feature's database is not synchronized from the active supervisor engine to the standby supervisor engine. The feature cannot be enabled if high availability is enabled and similarly, high availability cannot be enabled if the feature is enabled.

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Note Timers and statistics are not synchronized from the active to the standby supervisor engine.

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Table 22-1 High Availability Feature Support 

Supported Features	Compatible Features	Incompatible Features
CEF	ASLB	Dynamic VLAN
COPS-DS	CDP	GVRP
COPS-PR	GMRP	Port security
DTP	IGMP snooping	Protocol filtering
EtherChannel	RMON
IOS ACLs	RSVP
MLS	SNMP
PAgP	Telnet sessions
QoS	UplinkFast
SPAN	VTP pruning
STP
Trunking
UDLD
VACLs
VTP

Versioning Overview

When you enable high-availability versioning, you can have two different but compatible images on the active and standby supervisor engines. The active supervisor engine exchanges image version information with the standby supervisor engine and determines whether the images are compatible for enabling high availability. If the active and standby supervisor engines are not running compatible image versions, you cannot enable high availability.

Image versioning is supported in supervisor engine software release 5.4(1)CSX and later releases. With versioning enabled, high availability is fully supported with the active and standby supervisor engines running different images as long as the images are compatible. The only fully compatible images are as follows:

•5.5(3) and 5.5(4)

•6.1(3) and 6.1(4)

Images that are compatible with all modules except Gigabit Ethernet switching modules are as follows:

•5.4(3) and 5.4(4)

•5.5(3) and 5.5(5)

•5.5(4) and 5.5(5)

Images that are compatible with Gigabit Ethernet switching modules but not compatible with 10/100BASE-T modules are as follows:

•5.5(6a) and 5.5(7)

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Note Attempting to run incompatible image versions could result in configuration loss.

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Note When you install two supervisor engines, the first supervisor engine to come online becomes the active module; the second supervisor engine goes into standby mode. If two supervisor engines are installed in your system, at power up the supervisor engine in slot 1 becomes active, and the supervisor engine in slot 2 enters standby mode. If the software versions of the two supervisor engines are different, or if the NVRAM configuration of the two supervisor engines is different, and if you do not enable versioning, the active supervisor engine automatically downloads its software image and configuration to the standby supervisor engine.

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CLI Commands

This section describes the CLI commands for high availability and versioning.

Enabling or Disabling High Availability

High availability is disabled by default. To enable or disable high availability, perform this task in privileged mode:

Task	Command
Enable or disable high availability.	set system highavailability {enable | disable}

This example shows how to enable high availability:

Console> (enable) set system highavailability enable

System high availability enabled.

Console> (enable) 

This example shows how to disable high availability:

Console> (enable) set system highavailability disable

System high availability disabled.

Console> (enable) 

Enabling or Disabling High-Availability Versioning

High-availability versioning is disabled by default. To enable or disable high-availability versioning, perform this task in privileged mode:

Task	Command
Enable or disable high-availability versioning.	set system highavailability versioning {enable | disable}

This example shows how to enable high-availability versioning:

Console> (enable) set system highavailability versioning enable

Image versioning enabled.

Console> (enable) 

This example shows how to disable high-availability versioning:

Console> (enable) set system highavailability versioning disable

Image versioning disabled.

Console> (enable) 

Showing High-Availability Settings and Operational Status

The show system highavailability command displays the following:

•High-availability setting (enabled or disabled)

•Versioning setting (enabled or disabled)

•High-availability operational status (based on whether the standby supervisor engine is present and operational). The operational status field displays one of the following:

–OFF (high-availability-not-enabled): The high availability option in NVRAM is disabled.

–OFF (standby-supervisor-not-present): The standby supervisor engine is not installed.

–OFF (standby-supervisor-image-incompatible): The standby supervisor engine is running a different image than the active supervisor engine and it is not version compatible (the versioning option in NVRAM is enabled). No synchronization is done (even a configuration change in NVRAM on the active supervisor engine cannot be propagated to the standby supervisor engine because of the version incompatibility).

–OFF (standby-supervisor-image-nvram-only-compat): The standby supervisor engine is running a different image than the active supervisor engine (versioning option in NVRAM is enabled) and the image is only NVRAM compatible (that is, a configuration change in NVRAM on the active supervisor engine is propagated to the standby supervisor engine). However, high availability cannot be supported.

–OFF (standby-supervisor-not-operational-yet): The standby supervisor engine is detected but is not operational (not online yet).

–OFF (high-availability-not-operational-yet): The standby supervisor engine is operational (online), but high availability is not operational yet (when the system is booted from reset, it takes a few minutes before high availability is operational).

–ON: High availability is operational. The active supervisor engine's features have started queuing their state changes for synchronizing to the standby supervisor engine.

To show the high-availability configuration and operational states, perform this task:

Task	Command
Show high-availability configuration and operational states.	show system highavailability

This example shows how to disable high availability and versioning:

Console> (enable) show system highavailability

Highavailability: disabled

Highavailability versioning: disabled

Highavailability Operational-status: OFF (high-availability-not-enabled)

Console> (enable)

This example shows how to enable high availability:

Console> (enable) set system highavailability enable

System high availability enabled.

Console> (enable)

Console> (enable) show system highavailability

Highavailability: enabled

Highavailability versioning: disabled

Highavailability Operational-status: ON

Console> (enable)

Loading a Different (but Compatible) Image on the Standby Supervisor Engine

Use this procedure to load a new image on the standby supervisor engine that is different from the image on the active supervisor engine. From the active supervisor engine console port, perform these steps (active supervisor engine is in slot 1):

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Step 1 Enable high availability versioning.

Console> (enable) set system highavailability enable

System high availability enabled.

Console> (enable) 

Step 2 Download the new image to the active supervisor engine bootflash.

Console> (enable) copy tftp:image2.bin bootflash

IP address or name of remote host []? 172.20.52.3

8763532 bytes available on device bootflash, proceed (y/n) [n]? y

... display text truncated

Console> (enable)

Step 3 Copy the new image to the standby supervisor engine bootflash.

Console> (enable) copy bootflash:image2.bin 2/bootflash:

5786532 bytes available on device bootflash, proceed (y/n) [n]? y

... display text truncated

Console> (enable)

Step 4 Modify the BOOT environment variable so the standby supervisor engine boots the new image.

Console> (enable) set boot system flash bootflash:image2.bin prepend 2

BOOT variable = bootflash:image2.bin,1;slot0:image1.bin,1

Console> (enable)

Step 5 To boot the new image, reset the standby supervisor engine.

Console> (enable) reset 2

This command will reset the system.

Do you want to continue (y/n) [n]? y 

... display text truncated

Console> (enable)

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Supervisor Engine Synchronization Examples

These sections contain examples that show what happens when the synchronization function encounters certain conditions:

•Synchronizing the Runtime Image with the Bootstring

•Synchronizing the Boot Images on the Active and Standby Supervisor Engines

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Note In the following examples, the number 1 following the filename in the bootstring (for example, bootflash:f1,1) indicates the number of Trivial File Transfer Protocol (TFTP) boot retries that are attempted. However, the supervisor engine does not support TFTP booting. The number is included in these examples to be consistent with Cisco IOS conventions.

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Note These examples are not intended to cover every possible condition.

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Synchronizing the Runtime Image with the Bootstring

This section contains four examples in which the active supervisor engine runtime image is synchronized with the standby supervisor engine.

Example 1: Runtime image not synchronized

The configuration for example 1 is as follows:

•The active supervisor engine configuration is as follows (if the image in the standby supervisor engine is identical to the image in the active supervisor engine, the output is the same):

–Runtime image: bootflash:f1

–Boot string: bootflash:f1,1

–Bootflash: f1

•The time stamp for f1 on the active supervisor engine is the same as f1 on the standby supervisor engine.

•The expected results are as follows:

–The active supervisor engine f1 image is not copied to the standby supervisor engine.

–The standby supervisor engine bootstring is not modified.

–The standby supervisor engine is not reset.

Example 2: File copied, bootstring changed, standby supervisor engine reset

The configuration for example 2 is as follows:

•The active supervisor engine configuration is as follows:

–Runtime image: bootflash:f1

–Boot string: bootflash:f1,1

–Bootflash: f1

•The standby supervisor engine configuration is as follows:

–Runtime image: bootflash:f2

–Boot string: bootflash:f2,1

–Bootflash: f2

•The time stamp for f1 on the active supervisor engine is not the same as f2 on the standby supervisor engine.

•The expected results are as follows:

–The active supervisor engine copies f1 to the standby supervisor engine and renames the file RTSYNC_f1.

–The standby supervisor engine bootflash is modified to the following: f2, RTSYNC_f1.

–The standby supervisor engine bootstring is modified to the following: bootflash:RTSYNC_f1,1;f2,1;.

–The standby supervisor engine is reset.

Example 3: File not copied, bootstring changed, standby supervisor engine reset

The configuration for example 3 is as follows:

•The active supervisor engine configuration is as follows:

–Runtime image: bootflash:f1

–Boot string: bootflash:f1,1

–Bootflash: f1

•The standby supervisor engine configuration is as follows:

–Runtime image: bootflash:f2

–Boot string: bootflash:f2,1

–Bootflash: f1,f2

•The time stamp for f1 on the active supervisor engine is the same as f1 on the standby supervisor engine but is not the same as f2 on the standby supervisor engine.

•The expected results are as follows:

–The active supervisor engine runtime image is synchronized to the standby supervisor engine.

–The active supervisor engine f1 image is not copied to the standby supervisor engine.

–The standby supervisor engine boot string is modified to the following: f1,1;f2,1;.

–The standby supervisor engine is reset.

Example 4: Oldest bootflash file deleted, bootflash squeezed

The configuration for example 4 is as follows:

•The active supervisor engine configuration is as follows:

–Runtime image: bootflash:f1

–Boot string: bootflash:f1,1

–Bootflash: f1

•The standby supervisor engine configuration is as follows:

–Runtime image: bootflash:f2

–Boot string: bootflash:f2,1;

–Bootflash: f2, f3, f4 (less than 1 MB left on device)

•The time stamp for f1 on the active supervisor engine is not the same as f2 on the standby supervisor engine. The f2 time stamp is older than f3, and the f3 time stamp is older than f4.

•The expected results are as follows:

–The active supervisor engine runtime image is synchronized with the standby supervisor engine.

–The active supervisor engine attempts to copy its f1 image to the standby supervisor engine.

–Because there is not enough space on the standby supervisor engine bootflash, the redundant synchronization function finds the oldest file, deletes it, and squeezes bootflash.

–The active supervisor engine copies the f1 image to the standby supervisor engine and renames it RTSYNC_f1.

–The standby supervisor engine bootflash is modified to the following: f3, f4, RTSYNC_f1.

–The standby supervisor engine boot string is modified to the following: RTSYNC_f1,1;f2,1;.

–The standby supervisor engine is reset.

Synchronizing the Boot Images on the Active and Standby Supervisor Engines

This section contains four examples in which the bootstrings on the active and standby supervisor engines are synchronized.

Example 1: Unable to allocate the boot image

The configuration for this example is as follows:

•The active supervisor engine configuration is as follows:

–Runtime image: bootflash:f1

–Boot string: bootflash:f1,1;

–Bootflash: f1

•The standby supervisor engine configuration is as follows:

–Runtime image: bootflash:f1

–Boot string: bootflash:f1,1;

–Bootflash: f1

•The time stamp for f1 on the active supervisor engine is the same as f1 on the standby supervisor engine.

•The system attempts to modify the active supervisor engine bootstring to the following: f2,1;.

•The expected results are as follows:

–The active supervisor engine is unable to allocate f2, causing the synchronization to fail.

–An error is recorded in syslog.

–The active supervisor engine f1 image is not copied to the standby supervisor engine.

–The standby supervisor engine bootstring is not modified.

–The standby supervisor engine is not reset.

Example 2: File copied, bootflash modified, standby supervisor engine not reset

The configuration for this example is as follows:

•The active supervisor engine configuration is as follows:

–Runtime image: bootflash:f1

–Boot string: bootflash:f1,1;

–Bootflash: f1,f2

•The standby supervisor engine configuration is as follows:

–Runtime image: bootflash:f1

–Boot string: bootflash:f1,1;

–Bootflash:

•The time stamp for f1 on the active supervisor engine is the same as f1 on the standby supervisor engine.

•You modify the active supervisor engine bootstring to the following: f2,1;.

•The expected results are as follows:

–The active supervisor engine copies its f2 image to the standby supervisor engine and renames it BTSYNC_f2.

–The standby supervisor engine bootflash is modified to the following: f1, BTSYNC_f2.

–The standby supervisor engine bootstring is modified to the following: bootflash:BTSYNC_f2,1;f1,1;.

–The standby supervisor engine is not reset.

Example 3: File not copied, bootstring modified, standby supervisor engine not reset

The configuration for this example is as follows:

•The active supervisor engine configuration is as follows:

–Runtime image: bootflash:f1

–Boot string: bootflash:f1,1;

–Bootflash: f1,f2

•The standby supervisor engine configuration is as follows:

–Runtime image: bootflash:f1

–Boot string: bootflash:f1,1;

–Bootflash: f1,f2

•The time stamp for f1 on the active supervisor engine is the same as f1 on the standby supervisor engine; the time stamp for f2 on the active supervisor engine is the same as f2 on the standby supervisor engine.

•The active supervisor engine bootstring is modified to the following: f2,1; f1,1;.

•The expected results are as follows:

–The active supervisor engine f1 image is not copied to the standby supervisor engine.

–The standby supervisor engine bootstring is modified to the following: bootflash:f2,1;bootflash:f1,1;.

–The standby supervisor engine is not reset.

Example 4: File copied, oldest file deleted, bootflash squeezed, bootstring modified, standby supervisor engine not reset

The configuration for this example is as follows:

•The active supervisor engine configuration is as follows:

–Runtime image: bootflash:f1

–Boot string: bootflash:f1,1;

–Bootflash: f1,f2

•The standby supervisor engine configuration is as follows:

–Runtime image: bootflash:f1

–Boot string: bootflash:f1,1;

–Bootflash: f0,f1,f3 (less than 1 MB left on device)

•The time stamp for f1 on the active supervisor engine is the same as f1 on the standby supervisor engine. The time stamp for f0 is older than f1, and the time stamp for f1 is older than f3.

•The active supervisor engine bootstring is modified to the following: bootflash:f2,1;bootflash:f1,1;

•The expected results are as follows:

–The active supervisor engine attempts to copy its f2 image to the standby supervisor engine.

–Because there is not enough space available on the standby supervisor engine bootflash, the redundant synchronization function finds the oldest file (f0), deletes it, and squeezes bootflash.

–The active supervisor engine copies its f2 image to the standby supervisor engine and renames it BTSYNC_f2.

–The standby supervisor engine bootflash is modified to the following: f1, f3, BTSYNC_f2.

–The standby supervisor engine boot string is modified to the following: bootflash:BTSYNC_f2,1;bootflash:f1,1;.

MSFC Redundancy

MSFC redundancy is described in these sections:

•Dual MSFC Redundancy

•Single Router Mode Redundancy

•Manual-Mode MSFC Redundancy

Dual MSFC Redundancy

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Caution You must configure both MSFCs identically. Table 22-2 summarizes the identical requirements and the exceptions for Layer 3 redundancy for a single switch chassis.

We do not support configurations where the MSFCs are not configured identically.

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These sections describe how to configure MSFC redundancy:

•Hardware and Software Requirements

•Layer 3 Redundancy for a Single Chassis

•Routing Protocol Peering

•Access Control List Configuration

•Dual MSFC Operational Model for Redundancy and Load Sharing

•Understanding Failure Scenarios

Hardware and Software Requirements

To configure Layer 3 redundancy, you must have at least one of the following configurations:

•A single chassis with two identical supervisor engine daughter card configurations:

–Supervisor Engine 1 with Policy Feature Card (PFC) and MSFC or MSFC2 (both supervisor engines must have the same type of MSFC)

–Supervisor Engine 2 with PFC2 and MSFC2

•