Software Configuration Guide, Cisco IOS Release 15.2(2)E (Catalyst 2960, 2960-S, 2960-SF and 2960-Plus Switches)
Managing Switch Stacks
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Managing Switch Stacks

Contents

Managing Switch Stacks

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to http:/​/​www.cisco.com/​go/​cfn. An account on Cisco.com is not required.

Prerequisites for Switch Stacks

Restrictions for Switch Stacks

Information About Switch Stacks

Switch Stack Overview

A switch stack is a set of up to Catalyst switch connected through their ports. One of the switch controls the operation of the stack and is called the stack master. The stack master and the other switch in the stack are stack members. Layer 2 protocol present the entire switch stack as a single entity to the network.


Note


A switch stack is different from a switch cluster. A switch cluster is a set of switch connected through their LAN ports, such as the 10/100/1000 ports. For more information about how switch stacks differ from switch clusters, see the “Planning and Creating Clusters” chapter in the Getting Started with Cisco Network Assistant on Cisco.com.
The master is the single point of stack-wide management. From the master, you configure:
  • System-level (global) features that apply to all members
  • Interface-level features for each member

Every member is uniquely identified by its own stack member number.

All members are eligible masters. If the master becomes unavailable, the remaining members elect a new master from among themselves. One of the factors is the stack member priority value. The switch with the highest stack-member priority-value becomes the master.

The system-level features supported on the master are supported on the entire stack.

The master contains the saved and running configuration files for the stack. The configuration files include the system-level settings for the stack and the interface-level settings for each member. Each member has a current copy of these files for back-up purposes.

You manage the stack through a single IP address. The IP address is a system-level setting and is not specific to the master or to any other member. You can manage the stack through the same IP address even if you remove the master or any other member from the stack.

You can use these methods to manage stacks:
  • Network Assistant (available on Cisco.com)
  • Command-line interface (CLI) over a serial connection to the console port of any member
  • A network management application through the Simple Network Management Protocol (SNMP)

    Note


    Use SNMP to manage network features across the stack that are defined by supported MIBs. The switch does not support MIBs to manage stacking-specific features such as stack membership and election.
  • CiscoWorks network management software.

Switch Stack Membership

A standalone switch is a switch stack with one stack member that also operates as the stack master. You can connect one standalone switch to another (Figure - Creating a Switch Stack from Two Standalone switch) to create a switch stack containing two stack members, with one of them as the stack master. You can connect standalone switch to an existing switch stack (Figure - Adding a Standalone switch to a Switch Stack) to increase the stack membership.

If you replace a stack member with an identical model, the new switch functions with exactly the same configuration as the replaced switch, assuming that the new switch is using the same member number as the replaced switch.

The operation of the switch stack continues uninterrupted during membership changes unless you remove the stack master or you add powered-on standalone switch or switch stacks.


Note


To prevent interrupted stack operations, make sure the switch that you add to or remove from the stack are powered off.

After adding or removing stack members, make sure that the switch stack is operating at full bandwidth (Gb/s). Press the Mode button on a stack member until the Stack mode LED is on. The last two port LEDs on all switch in the stack should be green. If one or both of these LEDs are not green, the stack is not operating at full bandwidth.


  • Adding powered-on switch (merging) causes the stack master of the merging switch stacks to elect a stack master from among themselves. The new stack master keeps its role and configuration and so do its members. All remaining switch, including the former masters, reload and join the stack as members. They change their member numbers to the lowest available numbers and use the configuration of the new master.
  • Removing powered-on members divides (partitions) the stack into two or more switch stacks, each with the same configuration. This can create an IP address configuration conflict in your network. If you want the stacks to remain separate, change the IP address or addresses of the newly created stacks.
Figure 1. Creating a Switch Stack from Two Standalone Switches



Figure 2. Adding a Standalone Switch to a Switch Stack



Master Election

The stack master is elected based on one of these factors in the order listed:
  1. The switch that is currently the stack master.

  2. The switch with the highest stack member priority value.


Note


We recommend you assign the highest priority value to the switch that you want to be the master. The switch is then re-elected as master if a re-election occurs.
A stack master keeps its role unless one of these events occurs:
  • The stack is reset.*
  • The master is removed from the stack.
  • The master is reset or powered off.
  • The master fails.
  • The stack membership is increased by adding powered-on standalone switch or switch stacks.*

In the events marked by an asterisk (*), the current stack master might be re-elected based on the listed factors.

When you power on or reset an entire stack, some stack members might not participate in the master election.

  • All members participate in re-elections.

  • Members that are powered on within the same 20-second time frame participate in the master election and have a chance to become the master.

  • Members that are powered on after the 20-second time frame do not participate in this initial election and only become members.

The new master is available after a few seconds. In the meantime, the switch stack uses the forwarding tables in memory to minimize network disruption. The physical interfaces on the other available stack members are not affected while a new stack master is elected and is resetting.

When a new master is elected and the previous stack master becomes available, the previous master does not resume its role as stack master.

For all powering considerations that affect stack master elections, see the “Switch Installation” chapter in the hardware installation guide.

Stack MAC Address

The MAC address of the master determines the stack MAC address.

When the stack initializes, the MAC address of the master determines the bridge ID that the stack in the network.

If the master changes, the MAC address of the new master determines the new bridge ID. However, when the persistent MAC address feature is enabled, there is an approximate 4-minute delay before the stack MAC address changes. During this time period, if the previous master rejoins the stack, the stack continues to use its MAC address as the stack MAC address, even if the switch is now a member and not a master. If the previous master does not rejoin the stack during this period, the stack takes the MAC address of the new stack master as the stack MAC address. See the Enabling Persistent MAC Address section for more information.

Member Numbers

The member number (1 to ) identifies each member in the stack. The member number also determines the interface-level configuration that a member uses.

A new, out-of-the-box switch (one that has not joined a stack or has not been manually assigned a member number) ships with a default member number of 1. When it joins a stack, its default stack member number changes to the lowest available member number in the stack.

Members in the same stack cannot have the same member number.
  • If you manually change the member number by using the switch current-stack-member-number renumber new-stack-member-number global configuration command, the new number goes into effect after that member resets (or after you use the reload slot stack-member-number privileged EXEC command) and only if that number is not already changed.

    You can also change the stack member number is by using the SWITCH_NUMBER environment variable.

    If the number is being used by another member in the stack, the switch selects the lowest available number in the stack.

    If you manually change the member number and no interface-level configuration is associated with that number, that member resets to its default configuration.

    You cannot use the switch current-stack-member-number renumber new-stack-member-number global configuration command on a provisioned switch. If you do, the command is rejected.

  • If you move a stack member to a different switch stack, the stack member keeps its number only if the number is not being used by another member in the stack. If it is being used by another member in the stack, the switch selects the lowest available number in the stack.
See the following sections for information about stack member configuration:
  • The procedure to change a member number, see the Assigning a Member Number section.

  • The SWITCH_NUMBER environment variable, see the Controlling Environment Variables section.

  • Member numbers and configurations, see the Stack Configuration Files section.

  • Merging stacks, see the Stack Membership section.

Member Priority Values

A higher priority value for a stack member increases the chance that it will be elected stack master and keep its member number. The priority value can be 1 to 15. The default priority value is 1.


Note


We recommend that you assign the highest priority value to the switch that you want to be the stack master. The switch is then re-elected as master if a re-election occurs.


The new priority value takes effect immediately but does not affect the current master until the current master or the stack resets.

Stack Offline Configuration

You can use the offline configuration feature to provision (to configure) a new switch before it joins the stack. You can configure the member number, the switch type, and the interfaces associated with a switch that is not yet part of the stack. That configuration is the provisioned configuration. The switch to be added to the stack and to get this configuration is the provisioned switch.

The provisioned configuration is automatically created when a switch is added to a stack and when no provisioned configuration exists. You can manually create the provisioned configuration by using the switch stack-member-number provision type global configuration command.

When you configure the interfaces for a provisioned switch (for example, as part of a VLAN), the information appears in the stack running configuration whether or not the provisioned switch is part of the stack. The interface for the provisioned switch is not active and does not appear in the display of a specific feature (for example, in the show vlan user EXEC command output). Entering the no shutdown interface configuration command has no effect.

The startup configuration file ensures that the stack can reload and can use the saved information whether or not the provisioned switch is part of the stack.

Effects of Adding a Provisioned Switch to a Switch Stack

When you add a provisioned Switch to the switch stack, the stack applies either the provisioned configuration or the default configuration. This table lists the events that occur when the switch stack compares the provisioned configuration with the provisioned switch.

Table 1 Results of Comparing the Provisioned Configuration with the Provisioned Switch

Scenario

Result

The stack member numbers and the Switch types match.

  1. If the stack member number of the provisioned switch matches the stack member number in the provisioned configuration on the stack, and

  2. If the Switch type of the provisioned switch matches the Switch type in the provisioned configuration on the stack.

The switch stack applies the provisioned configuration to the provisioned switch and adds it to the stack.

The stack member numbers match but the Switch types do not match.

  1. If the stack member number of the provisioned switch matches the stack member number in the provisioned configuration on the stack, but

  2. The Switch type of the provisioned switch does not match the Switch type in the provisioned configuration on the stack.

The switch stack applies the default configuration to the provisioned switch and adds it to the stack.

The provisioned configuration is changed to reflect the new information.

The stack member number is not found in the provisioned configuration.

 

The switch stack applies the default configuration to the provisioned switch and adds it to the stack.

The provisioned configuration is changed to reflect the new information.

The stack member number of the provisioned switch is not found in the provisioned configuration.

 

The switch stack applies the default configuration to the provisioned switch and adds it to the stack.

If you add a provisioned switch that is a different type than specified in the provisioned configuration to a powered-down switch stack and then apply power, the switch stack rejects the (now incorrect) switch stack-member-number provision type global configuration command in the startup configuration file. However, during stack initialization, the nondefault interface configuration information in the startup configuration file for the provisioned interfaces (potentially of the wrong type) is executed. Depending on the differences between the actual Switch type and the previously provisioned switch type, some commands are rejected, and some commands are accepted.


Note


If the switch stack does not contain a provisioned configuration for a new Switch, the Switch joins the stack with the default interface configuration. The switch stack then adds to its running configuration with a switch stack-member-number provision type global configuration command that matches the new Switch. For configuration information, see the Provisioning a New Member for a Switch Stack section.


Effects of Replacing a Provisioned Switch in a Switch Stack

When a provisioned switch in a switch stack fails, it is removed from the stack, and is replaced with another Switch, the stack applies either the provisioned configuration or the default configuration to it. The events that occur when the switch stack compares the provisioned configuration with the provisioned switch are the same as those when you add a provisioned switch to a stack.

Effects of Removing a Provisioned Switch from a Switch Stack

If you remove a provisioned switch from the switch stack, the configuration associated with the removed stack member remains in the running configuration as provisioned information. To completely remove the configuration, use the no switch stack-member-number provision global configuration command.

Stack Software Compatibility Recommendations

All stack members must run the same Cisco IOS software version to ensure compatibility in the stack protocol version among the members.

Stack Protocol Version

Each software image includes a stack protocol version. The stack protocol version has a major version number and a minor version number (for example 1.4, where 1 is the major version number and 4 is the minor version number). Both version numbers determine the level of compatibility among the stack members.

switch with the same Cisco IOS software version have the same stack protocol version. Such switch are fully compatible, and all features function properly across the switch stack. A switch with the same Cisco IOS software version as the stack master can immediately join the switch stack.

If an incompatibility exists, the fully functional stack members generate a system message that describes the cause of the incompatibility on the specific stack members. The stack master sends the message to all stack members.

For more information, see the Major Version Number Incompatibility Among Switches procedure and the Minor Version Number Incompatibility Among Switches procedure.

Major Stack Protocol Version Number Incompatibility Among Stack-Capable Switches

Switch with different major Cisco IOS software versions usually have different stack protocol versions. Switch with different major version numbers are incompatible and cannot exist in the same switch stack.

Minor Version Number Incompatibility Among Switches

switch with the same major version number but with a different minor version number as the master are considered partially compatible. When connected to a stack, a partially compatible switch enters version-mismatch mode and cannot join the stack as a fully functioning member. The software detects the mismatched software and tries to upgrade (or downgrade) the switch in version-mismatch mode with the stack image or with a tar file image from the stack flash memory. The software uses the automatic upgrade (auto-upgrade) and the automatic advise (auto-advise) features.

The port LEDs on switch in version-mismatch mode will also stay off. Pressing the Mode button does not change the LED mode.


Note


Auto-advise and auto-copy identify which images are running by examining the info file and by searching the directory structure on the switch stack. If you download your image by using the copy tftp: command instead of by using the archive download-sw privileged EXEC command, the correct directory structure is not properly created. For more information about the info file, see the tar File Format of Images on a Server or Cisco.com section.


Understanding Auto-Upgrade and Auto-Advise

When the software detects mismatched software and tries to upgrade the Switch in VM mode, two software processes are involved: automatic upgrade and automatic advise.

  • The automatic upgrade (auto-upgrade) process includes an auto-copy process and an auto-extract process. By default, auto-upgrade is enabled (the boot auto-copy-sw global configuration command is enabled). You can disable auto-upgrade by using the no boot auto-copy-sw global configuration command on the stack master. You can check the status of auto-upgrade by using the show boot privileged EXEC command and by checking the Auto upgrade line in the display.
    • Auto-copy automatically copies the software image running on any stack member to the Switch in VM mode to upgrade (auto-upgrade) it. Auto-copy occurs if auto-upgrade is enabled, if there is enough flash memory in the Switch in VM mode, and if the software image running on the switch stack is suitable for the Switch in VM mode.

      Note


      A Switch in VM mode might not run all released software. For example, new Switch hardware is not recognized in earlier versions of software.
    • Automatic extraction (auto-extract) occurs when the auto-upgrade process cannot find the appropriate software in the stack to copy to the Switch in VM mode. In that case, the auto-extract process searches all Switch in the stack, whether they are in VM mode or not, for the tar file needed to upgrade the switch stack or the Switch in VM mode. The tar file can be in any flash file system in the switch stack (including the Switch in VM mode). If a tar file suitable for the Switch in VM mode is found, the process extracts the file and automatically upgrades that Switch.

    The auto-upgrade (auto-copy and auto-extract) processes wait for a few minutes after the mismatched software is detected before starting.

    When the auto-upgrade process is complete, the Switch that was in VM mode reloads and joins the stack as a fully functioning member. If you have both StackWise Plus cables connected during the reload, network downtime does not occur because the switch stack operates on two rings.

  • Automatic advise (auto-advise) occurs when the auto-upgrade process cannot find appropriate stack member software to copy to the Switch in VM mode. This process tells you the command (archive copy-sw or archive download-sw privileged EXEC command) and the image name (tar filename) needed to manually upgrade the switch stack or the Switch in VM mode. The recommended image can be the running switch stack image or a tar file in any flash file system in the switch stack (including the Switch in VM mode). If an appropriate image is not found in the stack flash file systems, the auto-advise process tells you to install new software on the switch stack. Auto-advise cannot be disabled, and there is no command to check its status.

    The auto-advise software does not give suggestions when the switch stack software and the software of the Switch in VM mode do not contain the same feature sets. For example, if the switch stack is running the IP base image and you add a Switch that is running the IP services image, the auto-advise software does not provide a recommendation.

    You can use the archive-download-sw /allow-feature-upgrade privileged EXEC command to allow installing an different software image.

Examples of Auto-Advise Messages

When you add a switch that has a different minor version number to the switch stack, the software displays messages in sequence (assuming that there are no other system messages generated by the switch).

This example shows that the switch stack detected a new switch that is running a different minor version number than the switch stack. Auto-copy starts, finds suitable software to copy from a stack member to the switch in VM mode, upgrades the switch in VM mode, and then reloads it:

*Mar 11 20:31:19.247:%STACKMGR-6-STACK_LINK_CHANGE:Stack Port 2 Switch 2 has changed to state UP
*Mar 11 20:31:23.232:%STACKMGR-6-SWITCH_ADDED_VM:Switch 1 has been ADDED to the stack(VERSION_MISMATCH)
*Mar 11 20:31:23.291:%STACKMGR-6-SWITCH_ADDED_VM:Switch 1 has been ADDED to the stack(VERSION_MISMATCH) (Stack_1-3)
*Mar 11 20:33:23.248:%IMAGEMGR-6-AUTO_COPY_SW_INITIATED:Auto-copy-software process initiated for switch number(s) 1
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Searching for stack member to act
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:as software donor...
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Found donor (system #2) for
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:member(s) 1
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:System software to be uploaded:
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:System Type: 0x00000000
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:archiving c2960x-universalk9-mz.150-2.EX1 (directory)
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:archiving c2960x-universalk9-mz.150-2.EX1.bin (4945851 bytes)
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:archiving c2960x-universalk9-mz.150-2.EX1/info(450 bytes)
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:archiving info (104 bytes)
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:examining image...
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:extracting info (104 bytes)
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:extracting c2960x-universalk9-mz.150-2.EX1/info(450 bytes)
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:extracting info (104 bytes)
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Stacking Version Number:1.4
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:System Type: 0x00000000
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Ios Image File Size: 0x004BA200
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Total Image File Size:0x00818A00
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Minimum Dram required:0x08000000
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Image Suffix:universalk9-mz.150-2.EX1
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Image Directory:c2960x-universalk9-mz.150-2.EX1
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Image Name:c2960x-universalk9-mz.150-2.EX1
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Image 1:flash1:c2960x-universalk9-mz.150-2.EX1
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Old image will be deleted after download.
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Extracting images from archive into flash on switch 1...
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:c2960x-universalk9-mz.150-2.EX1 (directory)
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:extracting c2960x-universalk9-mz.150-2.EX1/c2960x-universalk9-mz.150-2.EX1 (4945851 bytes)
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:extracting c2960x-universalk9-mz.150-2.EX1/info (450 bytes)
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:extracting info (104 bytes)
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Installing (renaming):`flash1:update/c2960x-universalk9-mz.150-2.EX1' ->
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: `flash1:c2960x-universalk9-mz.150-2.EX1'
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:New software image installed in flash1:c2960x-universalk9-mz.150-2.EX1
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Removing old image:flash1:c2960x-universalk9-mz.150-2.EX1
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:All software images installed.
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Requested system reload in progress...
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Software successfully copied to
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:system(s) 1
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Done copying software
*Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Reloading system(s) 1

This example shows that the switch stack detected a new switch that is running a different minor version number than the switch stack. Auto-copy launches but cannot find software in the stack to copy to the switch in version-mismatch mode to make it compatible with the stack. The auto-advise process starts and recommends that you download a tar file from the network to the switch in version-mismatch mode:

*Mar 1 00:01:11.319:%STACKMGR-6-STACK_LINK_CHANGE:Stack Port 2 Switch 2 has changed to state UP
*Mar 1 00:01:15.547:%STACKMGR-6-SWITCH_ADDED_VM:Switch 1 has been ADDED to the stack (VERSION_MISMATCH) 
stack_2#
*Mar 1 00:03:15.554:%IMAGEMGR-6-AUTO_COPY_SW_INITIATED:Auto-copy-software process initiated for switch number(s) 1
*Mar 1 00:03:15.554:%IMAGEMGR-6-AUTO_COPY_SW:
*Mar 1 00:03:15.554:%IMAGEMGR-6-AUTO_COPY_SW:Searching for stack member to act
*Mar 1 00:03:15.554:%IMAGEMGR-6-AUTO_COPY_SW:as software donor...
*Mar 1 00:03:15.554:%IMAGEMGR-6-AUTO_COPY_SW:Software was not copied
*Mar 1 00:03:15.562:%IMAGEMGR-6-AUTO_ADVISE_SW_INITIATED:Auto-advise-software process initiated for switch number(s) 1
*Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:
*Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:
*Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:Systems with incompatible software
*Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:have been added to the stack. The
*Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:storage devices on all of the stack
*Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:members have been scanned, and it has
*Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:been determined that the stack can be
*Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:repaired by issuing the following
*Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:command(s):
*Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:
*Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW: archive download-sw /force-reload /overwrite /dest 1 flash1:c2960x-universalk9-mz.150-2.EX1.tar
*Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:

For information about using the archive download-sw privileged EXEC command, see the Working with Software Images section.

Incompatible Software and Stack Member Image Upgrades

You can upgrade a Switch that has an incompatible universal software image by using the archive copy-sw privileged EXEC command. It copies the software image from an existing stack member to the one with incompatible software. That Switch automatically reloads and joins the stack as a fully functioning member.

Switch Stack Configuration Files

The stack master has the saved and running configuration files for the switch stack. All stack members periodically receive synchronized copies of the configuration files from the stack master. If the stack master becomes unavailable, any stack member assuming the role of stack master has the latest configuration files.

The configuration files record these settings:

  • System-level (global) configuration settings such as IP, STP, VLAN, and SNMP settings that apply to all stack members

  • Stack member interface-specific configuration settings that are specific for each stack member


Note


The interface-specific settings of the stack master are saved if the stack master is replaced without saving the running configuration to the startup configuration.

A new, out-of-box switch joining a switch stack uses the system-level settings of that switch stack. If a switch is moved to a different switch stack before it is powered on, that switch loses its saved configuration file and uses the system-level configuration of the new switch stack. If the switch is powered on as a standalone switch before it joins the new switch stack, the stack will reload. When the stack reloads, the new switch may become the stack master, retain its configuration and overwrite the configuration files of the other stack members.

The interface-specific configuration of each stack member is associated with the stack member number. Stack members retain their numbers unless they are manually changed or they are already used by another member in the same switch stack. If the stack member number changes, the new number goes into effect after that stack member resets.

  • If an interface-specific configuration does not exist for that member number, the stack member uses its default interface-specific configuration.

  • If an interface-specific configuration exists for that member number, the stack member uses the interface-specific configuration associated with that member number.

If you replace a failed member with an identical model, the replacement member automatically uses the same interface-specific configuration as the failed switch. You do not need to reconfigure the interface settings. The replacement switch (referred to as the provisioned switch) must have the same stack member number as the failed switch.

You back up and restore the stack configuration in the same way as you would for a standalone switch configuration.

Switch Stack Management Connectivity

You manage the switch stack and the stack member interfaces through the stack master. You can use the CLI, SNMP, and supported network management applications such as CiscoWorks. You cannot manage stack members on an individual Switch basis.

Connectivity to the Switch Stack Through an IP Address

The switch stack is managed through a single IP address. The IP address is a system-level setting and is not specific to the stack master or to any other stack member. You can still manage the stack through the same IP address even if you remove the stack master or any other stack member from the stack, provided there is IP connectivity.


Note


Stack members retain their IP addresses when you remove them from a switch stack. To avoid a conflict by having two devices with the same IP address in your network, change the IP addresses of any Switch that you remove from the switch stack.


For related information about switch stack configurations, see the Switch Stack Configuration Files section.

Connectivity to the Switch Stack Through an SSH Session

The Secure Shell (SSH) connectivity to the stack can be lost if a stack master running the cryptographic version fails and is replaced by a switch that is running a noncryptographic version. We recommend that a switch running the cryptographic version of the software be the stack master. Encryption features are unavailable if the stack master is running the noncryptographic software image.

Connectivity to the Switch Stack Through Console Ports or Ethernet Management Ports

You can connect to the stack master by using one of these methods:

  • You can connect a terminal or a PC to the stack master through the console port of one or more stack members.

  • You can connect a PC to the stack master through the Ethernet management ports of one or more stack members. For more information about connecting to the switch stack through Ethernet management ports, see the Using the Ethernet Management Port section.

Be careful when using multiple CLI sessions to the stack master. Commands that you enter in one session are not displayed in the other sessions. Therefore, it is possible that you might not be able to identify the session from which you entered a command.

We recommend using only one CLI session when managing the switch stack.

Connectivity to Specific Stack Members

If you want to configure a specific member port, you must include the stack member number in the CLI notation.

To access a specific member, see the Accessing the CLI of a Specific Member section.

Switch Stack Configuration Scenarios

Most of these switch stack configuration scenarios assume that at least two switch are connected through their ports.

Table 2 Configuration Scenarios

Scenario

Result

Stack master election specifically determined by existing stack masters

Connect two powered-on switch stacks through the ports.

Only one of the two stack masters becomes the new stack master.

Stack master election specifically determined by the stack member priority value

  1. Connect two switches through their ports.

  2. Use the switch stack-member-number priority new-priority-number global configuration command to set one stack member with a higher member priority value.

  3. Restart both stack members at the same time.

The stack member with the higher priority value is elected stack master.

Stack master election specifically determined by the configuration file

Assuming that both stack members have the same priority value:

  1. Make sure that one stack member has a default configuration and that the other stack member has a saved (nondefault) configuration file.

  2. Restart both stack members at the same time.

The stack member with the saved configuration file is elected stack master.

Stack master election specifically determined by the MAC address

Assuming that both stack members have the same priority value, configuration file, and feature set, restart both stack members at the same time.

The stack member with the lower MAC address is elected stack master.

Stack member number conflict

Assuming that one stack member has a higher priority value than the other stack member:

  1. Ensure that both stack members have the same stack member number. If necessary, use the switch current-stack-member-number renumber new-stack-member-number global configuration command.

  2. Restart both stack members at the same time.

The stack member with the higher priority value retains its stack member number. The other stack member has a new stack member number.

Add a stack member

  1. Power off the new switch.

  2. Through their ports, connect the new switch to a powered-on switch stack.

  3. Power on the new switch.

The stack master is retained. The new switch is added to the switch stack.

Stack master failure

Remove (or power off) the stack master.

One of the remaining stack members becomes the new stack master. All other stack members in the stack remain as stack members and do not reboot.

  1. Through their ports, connect switch.

  2. Power on all switch.

Two switch become stack masters. One stack master has stack members. The other stack master remains as a standalone switch.

Use the Mode button and port LEDs on the switch to identify which switch are stack masters and which switch belong to each stack master.

How to Configure a Switch Stack

Default Switch Stack Configuration

The table shows the default switch stack configuration.

Table 3 Default Switch Stack Configuration
Feature Default Setting
Stack MAC address timer Disabled.
Stack member number 1
Stack member priority value 1
Offline configuration The switch stack is not provisioned.

Persistent MAC address

Disabled.

Enabling the Persistent MAC Address Feature

The MAC address of the master determines the stack MAC address. When a master is removed from the stack and a new master takes over, the MAC address of the new master to become the new stack MAC address. However, you can set the persistent MAC address feature with a time delay before the stack MAC address changes. During this time period, if the previous master rejoins the stack, the stack continues to use that MAC address as the stack MAC address, even if the switch is now a member and not a master. You can also configure stack MAC persistency so that the stack MAC address never changes to the new master MAC address.


Note


When you enter the command to configure this feature, a warning message appears with the consequences of your configuration. You should use this feature cautiously. Using the old stack master MAC address elsewhere in the same domain could result in lost traffic.
You can configure the time period as 0 to 60 minutes.
  • If you enter the command with no value, the default delay is 4 minutes. We recommend that you always enter a value. If the command is entered without a value, the time delay appears in the running-config file with an explicit timer value of 4 minutes.

  • If you enter 0, the stack MAC address of the previous stack master is used until you enter the no stack-mac persistent timer command, which immediately changes the stack MAC address to that of the current stack master. If you do not enter the no stack-mac persistent timer command, the stack MAC address never changes.

  • If you enter a time delay of 1 to 60 minutes, the stack MAC address of the previous stack master is used until the configured time period expires or until you enter the no stack-mac persistent timer command.


Note


If the entire switch stack reloads, it uses the MAC address of the stack master as the stack MAC address.


Follow these steps to enable persistent MAC address:

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    stack-mac persistent timer [0 | time-value]

    4.    end

    5.    copy running-config startup-config


DETAILED STEPS
     Command or ActionPurpose
    Step 1 enable


    Example:
    Switch> enable
    
    
     

    Enables privileged EXEC mode. Enter your password if prompted.

     

    Step 2configure terminal


    Example:
    
    Switch# configure terminal
    
    
     

    Enters the global configuration mode.

     
    Step 3 stack-mac persistent timer [0 | time-value]


    Example:
    Switch(config)# stack-mac persistent timer 7
    
    
     

    Enables a time delay after a stack-master change before the stack MAC address changes to that of the new stack master. If the previous stack master rejoins the stack during this period, the stack uses that MAC address as the stack MAC address.

    You can configure the time period as 0 to 60 minutes.

    • Enter the command with no value to set the default delay of approximately 4 minutes. We recommend that you always enter a value.

      If the command is entered without a value, the time delay appears in the running-config file with an explicit timer value of 4 minutes.

    • Enter 0 to continue using the MAC address of the current stack master indefinitely.

      The stack MAC address of the previous stack master is used until you enter the no stack-mac persistent timer command, which immediately changes the stack MAC address to that of the current stack master.

    • Enter a time-value from 1 to 60 minutes to configure the time period before the stack MAC address changes to the new stack master.

      The stack MAC address of the previous stack master is used until the configured time period expires or until you enter the no stack-mac persistent timer command.

    Note   

    If you enter the no stack-mac persistent timer command after a new stack master takes over, before the time expires, the switch stack moves to the current stack master MAC address.

     
    Step 4end


    Example:
    
    Switch(config)# end
    
    
     

    Returns to privileged EXEC mode.

     
    Step 5copy running-config startup-config


    Example:
    Switch# copy running-config startup-config 
    
    
     

    (Optional) Saves your entries in the configuration file.

     
    What to Do Next

    Use the no stack-mac persistent timer global configuration command to disable the persistent MAC address feature.

    Assigning Stack Member Information

    Assigning a Stack Member Number

    This optional task is available only from the stack master.

    Follow these steps to assign a member number to a stack member:

    SUMMARY STEPS

      1.    enable

      2.    configure terminal

      3.    switch current-stack-member-number renumber new-stack-member-number

      4.    end

      5.    reload slot stack-member-number

      6.    show switch

      7.    copy running-config startup-config


    DETAILED STEPS
       Command or ActionPurpose
      Step 1 enable


      Example:
      Switch> enable
      
      
       

      Enables privileged EXEC mode. Enter your password if prompted.

       

      Step 2configure terminal


      Example:
      
      Switch# configure terminal
      
      
       

      Enters the global configuration mode.

       
      Step 3 switch current-stack-member-number renumber new-stack-member-number


      Example:
      Switch(config)# switch 3 renumber 4
      
      
       

      You can display the current stack member number by using the show switch user EXEC command.

       
      Step 4end


      Example:
      
      Switch(config)# end
      
      
       

      Returns to privileged EXEC mode.

       
      Step 5 reload slot stack-member-number


      Example:
      Switch# reload slot 4
      
      
       

      Resets the stack member.

       
      Step 6show switch


      Example:
      showSwitch
       

      Verify the stack member number.

       
      Step 7copy running-config startup-config


      Example:
      Switch# copy running-config startup-config 
      
      
       

      (Optional) Saves your entries in the configuration file.

       
      Related Concepts
      Setting the Stack Member Priority Value

      This optional task is available only from the stack master.

      Follow these steps to assign a priority value to a stack member:

      SUMMARY STEPS

        1.    enable

        2.    configure terminal

        3.    switch stack-member-number priority new-priority-number

        4.    end

        5.    show switch stack-member-number

        6.    copy running-config startup-config


      DETAILED STEPS
         Command or ActionPurpose
        Step 1 enable


        Example:
        Switch> enable
        
        
         

        Enables privileged EXEC mode. Enter your password if prompted.

         

        Step 2configure terminal


        Example:
        
        Switch# configure terminal
        
        
         

        Enters the global configuration mode.

         
        Step 3 switch stack-member-number priority new-priority-number


        Example:
        Switch(config)# switch 3 priority 2
        
        
         

        You can display the current priority value by using the show switch user EXEC command.

        The new priority value takes effect immediately but does not affect the current stack master. The new priority value helps determine which stack member is elected as the new stack master when the current stack master or switch stack resets.

         
        Step 4end


        Example:
        
        Switch(config)# end
        
        
         

        Returns to privileged EXEC mode.

         
        Step 5 show switch stack-member-number


        Example:
        Switch(config)# show switch
        
        
         

        Verify the stack member priority value.

         
        Step 6copy running-config startup-config


        Example:
        Switch# copy running-config startup-config 
        
        
         

        (Optional) Saves your entries in the configuration file.

         
        Provisioning a New Member for a Switch Stack


        Note


        This task is available only from the stack master.

        To remove provisioned information and to avoid receiving an error message, remove the specified Switch from the stack before you use the no form of this command.

        For example, if you are removing a provisioned Switch in a stack with this configuration:
        • The stack has four members
        • Stack member 1 is the master
        • Stack member 3 is a provisioned switch

        To remove the provisioned information and to avoid receiving an error message, you can remove power from stack member 3, disconnect the StackWise Plus cables between the stack member 3 and Switch to which it is connected, reconnect the cables between the remaining stack members, and enter the no switch stack-member-number provision global configuration command.

        Follow these steps to provision a new member for a switch stack: This procedure is optional.

        SUMMARY STEPS

          1.    enable

          2.    show switch

          3.    configure terminal

          4.    switch stack-member-number provision type

          5.    end

          6.    show running-config

          7.    show switch stack-member-number

          8.    copy running-config startup-config


        DETAILED STEPS
           Command or ActionPurpose
          Step 1 enable


          Example:
          Switch> enable
          
          
           

          Enables privileged EXEC mode. Enter your password if prompted.

           

          Step 2 show switch
           

          Display summary information about the switch stack.

           
          Step 3configure terminal


          Example:
          
          Switch# configure terminal
          
          
           

          Enters the global configuration mode.

           
          Step 4switch stack-member-number provision type
           

          Specify the stack member number for the preconfigured Switch. By default, no Switch are provisioned.

          For stack-member-number, the range is 1 to 9. Specify a stack member number that is not already used in the switch stack. See Step 1.

          For type, enter the model number of a supported Switch that is listed in the command-line help strings.

           
          Step 5end


          Example:
          
          Switch(config)# end
          
          
           

          Returns to privileged EXEC mode.

           
          Step 6show running-config


          Example:
          
          Switch# show running-config 
          
          
           

          Verifies your entries.

           
          Step 7show switch stack-member-number
           
          Verify the status of the provisioned switch. For stack-member-number, enter the same number as in Step 1.  
          Step 8copy running-config startup-config


          Example:
          Switch# copy running-config startup-config 
          
          
           

          (Optional) Saves your entries in the configuration file.

           

          Changing the Stack Membership

          If you remove powered-on members but do not want to partition the stack:

          SUMMARY STEPS

            1.    Power off the newly created stacks.

            2.    Reconnect them to the original stack through their ports.

            3.    Power on the switch.


          DETAILED STEPS
             Command or ActionPurpose
            Step 1 Power off the newly created stacks.    
            Step 2Reconnect them to the original stack through their ports.    
            Step 3Power on the switch.    

            Accessing the CLI of a Specific Stack Member


            Note


            This task is only for debugging purposes, and is only available from the master.

            You can access all or specific members by using the remote command {all | stack-member-number} privileged EXEC command. The stack member number range is 1 to 9.

            You can access specific members by using the session stack-member-number privileged EXEC command. The member number is appended to the system prompt. For example, the prompt for member 2 is Switch-2#, and system prompt for the master is Switch#. Enter exit to return to the CLI session on the master. Only the show and debug commands are available on a specific member.

            Displaying Stack Information

            To display saved configuration changes after resetting a specific member or the stack, use these privileged EXEC commands:

            Table 4 Commands for Displaying Stack Information
            Command Description
            show platform stack passive-links all Display all stack information, such as the stack protocol version.
            show switch Display summary information about the stack, including the status of provisioned switches and switch in version-mismatch mode.
            show switch stack-member-number Display information about a specific member.
            show switch detail Display detailed information about the stack ring.
            show switch neighbors Display the stack neighbors.
            show switch stack-ports Display port information for the stack.

            Troubleshooting Stacks

            Manually Disabling a Stack Port

            If a stack port is flapping and causing instability in the stack ring, to disable the port, enter the switch stack-member-number stack port port-number disable privileged EXEC command. To re-enable the port, enter the switch stack-member-number stack port port-number enable command.


            Note


            Be careful when using the switch stack-member-number stack port port-number disable command. When you disable the stack port, the stack operates at half bandwidth.
            • A stack is in the full-ring state when all members are connected through the stack ports and are in the ready state.
            • The stack is in the partial-ring state when
              • All members are connected through the stack ports, but some all are not in the ready state.
              • Some members are not connected through the stack ports.
            When you enter the switch stack-member-number stack port port-number disable privileged EXEC command and
            • The stack is in the full-ring state, you can disable only one stack port. This message appears:
              Enabling/disabling a stack port may cause undesired stack changes. Continue?[confirm]
            • The stack is in the partial-ring state, you cannot disable the port. This message appears:
              Disabling stack port not allowed with current stack configuration.
            Re-Enabling a Stack Port While Another Member Starts

            Stack Port 1 on Switch 1 is connected to Port 2 on Switch 4. If Port 1 is flapping, disable Port 1 with the switch 1 stack port 1 disable privileged EXEC command.

            While Port 1 on Switch 1 is disabled and Switch 1 is still powered on:
            • Disconnect the stack cable between Port 1 on Switch 1 and Port 2 on Switch 4.
            • Remove Switch 4 from the stack.
            • Add a switch to replace Switch 4 and assign it switch-number 4.
            • Reconnect the cable between Port 1 on Switch 1 and Port 2 on Switch 4 (the replacement switch).
            • Re-enable the link between the Switch. Enter the switch 1 stack port 1 enable privileged EXEC command to enable Port 1 on Switch 1.
            • Power on Switch 4.

            Note


            Caution: Powering on Switch 4 before enabling the Port 1 on Switch 1 might cause one of the switches to reload.

            If Switch 4 is powered on first, you might need to enter the switch 1 stack port 1 enable and the switch 4 stack port 2 enable privileged EXEC commands to bring up the link.


            Understanding the show switch stack-ports summary Output

            Only Port 1 on stack member 2 is disabled.

            Switch# show switch stack-ports summary
            Switch#/ Stack Neighbor Cable Link Link Sync # In
            Port# Port Length OK Active OK Changes Loopback
            Status To LinkOK
            -------- ------ -------- -------- ---- ------ ---- --------- --------
            1/1 OK 3 50 cm Yes Yes Yes 1 No
            1/2 Down None 3 m Yes No Yes 1 No
            2/1 Down None 3 m Yes No Yes 1 No
            2/2 OK 3 50 cm Yes Yes Yes 1 No
            3/1 OK 2 50 cm Yes Yes Yes 1 No
            3/2 OK 1 50 cm Yes Yes Yes 1 No
            Table 5 show switch stack-ports summary Command Output
            Field Description
            Switch#/Port#

            Member number and its stack port number.

            Stack Port Status
            • Absent—No cable is detected on the stack port.
            • Down—A cable is detected, but either no connected neighbor is up, or the stack port is disabled.
            • OK—A cable is detected, and the connected neighbor is up.
            Neighbor Switch number of the active member at the other end of the stack cable.
            Cable Length

            Valid lengths are 50 cm, 1 m, or 3 m.

            If the switch cannot detect the cable length, the value is no cable. The cable might not be connected, or the link might be unreliable.

            Link OK

            This shows if the link is stable.

            The link partner is a stack port on a neighbor switch.

            • No—The link partner receives invalid protocol messages from the port.
            • Yes—The link partner receives valid protocol messages from the port.
            Link Active

            This shows if the stack port is in the same state as its link partner.

            • No—The port cannot send traffic to the link partner.
            • Yes—The port can send traffic to the link partner.
            Sync OK
            • No—The link partner does not send valid protocol messages to the stack port.
            • Yes—The link partner sends valid protocol messages to the port.
            # Changes to LinkOK

            This shows the relative stability of the link.

            If a large number of changes occur in a short period of time, link flapping can occur.

            In Loopback
            • No—At least one stack port on the member has an attached stack cable.
            • Yes—None of the stack ports on the member has an attached stack cable.
            Provisioning a New Member for a Switch Stack: Example

            This example shows how to provision a switch with a stack member number of 2 for the switch stack. The show running-config command output shows the interfaces associated with the provisioned switch:

            Examples of Auto-Advise Messages

            When you add a switch that has a different minor version number to the switch stack, the software displays messages in sequence (assuming that there are no other system messages generated by the switch).

            This example shows that the switch stack detected a new switch that is running a different minor version number than the switch stack. Auto-copy starts, finds suitable software to copy from a stack member to the switch in VM mode, upgrades the switch in VM mode, and then reloads it:

            *Mar 11 20:31:19.247:%STACKMGR-6-STACK_LINK_CHANGE:Stack Port 2 Switch 2 has changed to state UP
            *Mar 11 20:31:23.232:%STACKMGR-6-SWITCH_ADDED_VM:Switch 1 has been ADDED to the stack(VERSION_MISMATCH)
            *Mar 11 20:31:23.291:%STACKMGR-6-SWITCH_ADDED_VM:Switch 1 has been ADDED to the stack(VERSION_MISMATCH) (Stack_1-3)
            *Mar 11 20:33:23.248:%IMAGEMGR-6-AUTO_COPY_SW_INITIATED:Auto-copy-software process initiated for switch number(s) 1
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Searching for stack member to act
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:as software donor...
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Found donor (system #2) for
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:member(s) 1
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:System software to be uploaded:
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:System Type: 0x00000000
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:archiving c2960x-universalk9-mz.150-2.EX1 (directory)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:archiving c2960x-universalk9-mz.150-2.EX1.bin (4945851 bytes)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:archiving c2960x-universalk9-mz.150-2.EX1/info(450 bytes)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:archiving info (104 bytes)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:examining image...
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:extracting info (104 bytes)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:extracting c2960x-universalk9-mz.150-2.EX1/info(450 bytes)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:extracting info (104 bytes)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Stacking Version Number:1.4
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:System Type: 0x00000000
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Ios Image File Size: 0x004BA200
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Total Image File Size:0x00818A00
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Minimum Dram required:0x08000000
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Image Suffix:universalk9-mz.150-2.EX1
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Image Directory:c2960x-universalk9-mz.150-2.EX1
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Image Name:c2960x-universalk9-mz.150-2.EX1
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Image 1:flash1:c2960x-universalk9-mz.150-2.EX1
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Old image will be deleted after download.
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Extracting images from archive into flash on switch 1...
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:c2960x-universalk9-mz.150-2.EX1 (directory)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:extracting c2960x-universalk9-mz.150-2.EX1/c2960x-universalk9-mz.150-2.EX1 (4945851 bytes)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:extracting c2960x-universalk9-mz.150-2.EX1/info (450 bytes)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:extracting info (104 bytes)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Installing (renaming):`flash1:update/c2960x-universalk9-mz.150-2.EX1' ->
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: `flash1:c2960x-universalk9-mz.150-2.EX1'
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:New software image installed in flash1:c2960x-universalk9-mz.150-2.EX1
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Removing old image:flash1:c2960x-universalk9-mz.150-2.EX1
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:All software images installed.
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Requested system reload in progress...
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Software successfully copied to
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:system(s) 1
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Done copying software
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Reloading system(s) 1
            
            

            This example shows that the switch stack detected a new switch that is running a different minor version number than the switch stack. Auto-copy launches but cannot find software in the stack to copy to the switch in version-mismatch mode to make it compatible with the stack. The auto-advise process starts and recommends that you download a tar file from the network to the switch in version-mismatch mode:

            *Mar 1 00:01:11.319:%STACKMGR-6-STACK_LINK_CHANGE:Stack Port 2 Switch 2 has changed to state UP
            *Mar 1 00:01:15.547:%STACKMGR-6-SWITCH_ADDED_VM:Switch 1 has been ADDED to the stack (VERSION_MISMATCH) 
            stack_2#
            *Mar 1 00:03:15.554:%IMAGEMGR-6-AUTO_COPY_SW_INITIATED:Auto-copy-software process initiated for switch number(s) 1
            *Mar 1 00:03:15.554:%IMAGEMGR-6-AUTO_COPY_SW:
            *Mar 1 00:03:15.554:%IMAGEMGR-6-AUTO_COPY_SW:Searching for stack member to act
            *Mar 1 00:03:15.554:%IMAGEMGR-6-AUTO_COPY_SW:as software donor...
            *Mar 1 00:03:15.554:%IMAGEMGR-6-AUTO_COPY_SW:Software was not copied
            *Mar 1 00:03:15.562:%IMAGEMGR-6-AUTO_ADVISE_SW_INITIATED:Auto-advise-software process initiated for switch number(s) 1
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:Systems with incompatible software
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:have been added to the stack. The
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:storage devices on all of the stack
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:members have been scanned, and it has
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:been determined that the stack can be
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:repaired by issuing the following
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:command(s):
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW: archive download-sw /force-reload /overwrite /dest 1 flash1:c2960x-universalk9-mz.150-2.EX1.tar
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:
            
            

            For information about using the archive download-sw privileged EXEC command, see the Working with Software Images section.

            Examples of Auto-Advise Messages

            When you add a switch that has a different minor version number to the switch stack, the software displays messages in sequence (assuming that there are no other system messages generated by the switch).

            This example shows that the switch stack detected a new switch that is running a different minor version number than the switch stack. Auto-copy starts, finds suitable software to copy from a stack member to the switch in VM mode, upgrades the switch in VM mode, and then reloads it:

            *Mar 11 20:31:19.247:%STACKMGR-6-STACK_LINK_CHANGE:Stack Port 2 Switch 2 has changed to state UP
            *Mar 11 20:31:23.232:%STACKMGR-6-SWITCH_ADDED_VM:Switch 1 has been ADDED to the stack(VERSION_MISMATCH)
            *Mar 11 20:31:23.291:%STACKMGR-6-SWITCH_ADDED_VM:Switch 1 has been ADDED to the stack(VERSION_MISMATCH) (Stack_1-3)
            *Mar 11 20:33:23.248:%IMAGEMGR-6-AUTO_COPY_SW_INITIATED:Auto-copy-software process initiated for switch number(s) 1
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Searching for stack member to act
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:as software donor...
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Found donor (system #2) for
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:member(s) 1
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:System software to be uploaded:
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:System Type: 0x00000000
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:archiving c2960x-universalk9-mz.150-2.EX1 (directory)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:archiving c2960x-universalk9-mz.150-2.EX1.bin (4945851 bytes)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:archiving c2960x-universalk9-mz.150-2.EX1/info(450 bytes)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:archiving info (104 bytes)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:examining image...
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:extracting info (104 bytes)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:extracting c2960x-universalk9-mz.150-2.EX1/info(450 bytes)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:extracting info (104 bytes)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Stacking Version Number:1.4
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:System Type: 0x00000000
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Ios Image File Size: 0x004BA200
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Total Image File Size:0x00818A00
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Minimum Dram required:0x08000000
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Image Suffix:universalk9-mz.150-2.EX1
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Image Directory:c2960x-universalk9-mz.150-2.EX1
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Image Name:c2960x-universalk9-mz.150-2.EX1
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Image 1:flash1:c2960x-universalk9-mz.150-2.EX1
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: Old image will be deleted after download.
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Extracting images from archive into flash on switch 1...
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:c2960x-universalk9-mz.150-2.EX1 (directory)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:extracting c2960x-universalk9-mz.150-2.EX1/c2960x-universalk9-mz.150-2.EX1 (4945851 bytes)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:extracting c2960x-universalk9-mz.150-2.EX1/info (450 bytes)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:extracting info (104 bytes)
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Installing (renaming):`flash1:update/c2960x-universalk9-mz.150-2.EX1' ->
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW: `flash1:c2960x-universalk9-mz.150-2.EX1'
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:New software image installed in flash1:c2960x-universalk9-mz.150-2.EX1
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Removing old image:flash1:c2960x-universalk9-mz.150-2.EX1
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:All software images installed.
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Requested system reload in progress...
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Software successfully copied to
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:system(s) 1
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Done copying software
            *Mar 11 20:36:15.038:%IMAGEMGR-6-AUTO_COPY_SW:Reloading system(s) 1
            
            

            This example shows that the switch stack detected a new switch that is running a different minor version number than the switch stack. Auto-copy launches but cannot find software in the stack to copy to the switch in version-mismatch mode to make it compatible with the stack. The auto-advise process starts and recommends that you download a tar file from the network to the switch in version-mismatch mode:

            *Mar 1 00:01:11.319:%STACKMGR-6-STACK_LINK_CHANGE:Stack Port 2 Switch 2 has changed to state UP
            *Mar 1 00:01:15.547:%STACKMGR-6-SWITCH_ADDED_VM:Switch 1 has been ADDED to the stack (VERSION_MISMATCH) 
            stack_2#
            *Mar 1 00:03:15.554:%IMAGEMGR-6-AUTO_COPY_SW_INITIATED:Auto-copy-software process initiated for switch number(s) 1
            *Mar 1 00:03:15.554:%IMAGEMGR-6-AUTO_COPY_SW:
            *Mar 1 00:03:15.554:%IMAGEMGR-6-AUTO_COPY_SW:Searching for stack member to act
            *Mar 1 00:03:15.554:%IMAGEMGR-6-AUTO_COPY_SW:as software donor...
            *Mar 1 00:03:15.554:%IMAGEMGR-6-AUTO_COPY_SW:Software was not copied
            *Mar 1 00:03:15.562:%IMAGEMGR-6-AUTO_ADVISE_SW_INITIATED:Auto-advise-software process initiated for switch number(s) 1
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:Systems with incompatible software
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:have been added to the stack. The
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:storage devices on all of the stack
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:members have been scanned, and it has
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:been determined that the stack can be
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:repaired by issuing the following
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:command(s):
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW: archive download-sw /force-reload /overwrite /dest 1 flash1:c2960x-universalk9-mz.150-2.EX1.tar
            *Mar 1 00:04:22.537:%IMAGEMGR-6-AUTO_ADVISE_SW:
            
            

            For information about using the archive download-sw privileged EXEC command, see the Working with Software Images section.

            Configuration Examples for Switch Stacks

            Enabling the Persistent MAC Address Feature: Example

            This example shows how to configure the persistent MAC address feature for a 7-minute time delay and to verify the configuration:

            Switch(config)# stack-mac persistent timer 7
            		WARNING: The stack continues to use the base MAC of the old Master
            		WARNING: as the stack MAC after a master switchover until the MAC
            		WARNING: persistency timer expires. During this time the Network
            		WARNING: Administrators must make sure that the old stack-mac does
            		WARNING: not appear elsewhere in this network domain. If it does,
            		WARNING: user traffic may be blackholed.
            		Switch(config)# end
            		Switch# show switch
            		Switch/Stack Mac Address : 0016.4727.a900
            		Mac persistency wait time: 7 mins
            		                                           H/W   Current
            		Switch#  Role   Mac Address     Priority Version  State 
            		----------------------------------------------------------
            		*1       Master 0016.4727.a900     1      P2B     Ready
             
            		

            Provisioning a New Member for a Switch Stack: Example

            This example shows how to provision a switch with a stack member number of 2 for the switch stack. The show running-config command output shows the interfaces associated with the provisioned switch:

            show switch stack-ports summary Command Output: Example

            Only Port 1 on stack member 2 is disabled.

            Switch# show switch stack-ports summary
            		Switch#/  Stack   Neighbor   Cable    Link   Link   Sync      #         In  
            		 Port#     Port              Length    OK   Active   OK    Changes   Loopback
            		          Status                                          To LinkOK          
            		--------  ------  --------  --------  ----  ------  ----  ---------  --------
            		  1/1     OK         3      50 cm     Yes    Yes    Yes        1        No 
            		  1/2     Down      None    3 m       Yes    No     Yes        1        No 
            		  2/1     Down      None    3 m       Yes    No     Yes        1        No 
            		  2/2     OK         3      50 cm     Yes    Yes    Yes        1        No 
            		  3/1     OK         2      50 cm     Yes    Yes    Yes        1        No 
            		  3/2     OK         1      50 cm     Yes    Yes    Yes        1        No 
            
            		
            Table 6 show switch stack-ports summary Command Output

            Field

            Description

            Switch#/Port#

            Member number and its stack port number.

            Stack Port Status

            Status of the stack port.

            • Absent—No cable is detected on the stack port.

            • Down—A cable is detected, but either no connected neighbor is up, or the stack port is disabled.

            • OK—A cable is detected, and the connected neighbor is up.

            Neighbor

            Switch number of the active member at the other end of the stack cable.

            Cable Length

            Valid lengths are 50 cm, 1 m, or 3 m.

            If the switch cannot detect the cable length, the value is no cable. The cable might not be connected, or the link might be unreliable.

            Link OK

            Whether the stack cable is connected and functional. There may or may not be a neighbor connected on the other end.

            The link partner is a stack port on a neighbor switch.

            • No—There is no stack cable connected to this port or the stack cable is not functional.

            • Yes—There is a functional stack cable connected to this port.

            Link Active

            Whether a neighbor is connected on the other end of the stack cable.

            • No—No neighbor is detected on the other end. The port cannot send traffic over this link.

            • Yes—A neighbor is detected on the other end. The port can send traffic over this link.

            Sync OK

            Whether the link partner sends valid protocol messages to the stack port.

            • No—The link partner does not send valid protocol messages to the stack port.

            • Yes—The link partner sends valid protocol messages to the port.

            # Changes to LinkOK

            The relative stability of the link.

            If a large number of changes occur in a short period of time, link flapping can occur.

            In Loopback

            Whether a stack cable is attached to a stack port on the member.

            • No—At least one stack port on the member has an attached stack cable.

            • Yes—None of the stack ports on the member has an attached stack cable.

            Additional References for Switch Stacks

            Related Documents

            Related Topic Document Title

            Cabling and powering on a switch stack.

             

            Error Message Decoder

            Description Link

            To help you research and resolve system error messages in this release, use the Error Message Decoder tool.

            https:/​/​www.cisco.com/​cgi-bin/​Support/​Errordecoder/​index.cgi

            Standards and RFCs

            Standard/RFC Title

            None

            MIBs

            MIB MIBs Link

            All supported MIBs for this release.

            To locate and download MIBs for selected platforms, Cisco IOS releases, and , use Cisco MIB Locator found at the following URL:

            http:/​/​www.cisco.com/​go/​mibs

            Technical Assistance

            Description Link

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            To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds.

            Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.

            http:/​/​www.cisco.com/​support