Troubleshooting a Stack

Use this section to diagnose and troubleshoot problems with your stacked switches.

The show stacking, show stacking configuration, show stacking-support, and show stacking stack-ports commands can help you identify switches and stack ports that are improperly configured, not properly cabled, or powered down.

The commands can help you spot common problems like the following.

Incorrect Software Version

If a node appears in the stack as expected but does not appear to be operating as configured, use the show slot {slot {detail} | detail } command to see if there is a license mismatch or if the node is running an incorrect software version. For more information, see Managing Licenses on a Stack.

Note

Note

If a correctly cabled and powered-on X450a or X450e node does not appear in the stack: The node might be running an version that is earlier than 12.0. Upgrade the version using the same procedure you would use if the node was not part of the stack.

Stacking Not Enabled

If the show stacking command displays the status as Disabled for any node in the stack, use the enable stacking command to enable stacking on that node. You can issue the command from the master node, and you can reboot the disabled node from the master node to activate the slot number configuration.

Choice of Master Node

If the switch with the highest priority was not elected master, it might be because the stack nodes nodes were powered up at different times. Reboot all nodes in the stack simultaneously.

The following topics contain information for troubleshooting problems related to the choice of the master node:

Choice of Backup and Standby Nodes

About five minutes after a master node takes control of the stack, you might see one of the following messages:

Warning: The Backup stack node is not as powerful or as capable as the Master stack node. This configuration is not recommended for successful use of the failover feature.
Notice: There are Standby stack nodes which are more powerful and more capable than the Master and/or Backup stack nodes. This configuration is not recommended for optimal stack performance. We recommend that you reconfigure the stacking master-capability and/or priority parameters to allow the higher performing and more capable nodes to become Master and/or Backup stack nodes.

In each case, to optimize your use of the failover feature, follow the guidelines in Configuring the Master, Backup, and Standby Roles.

Loss of Saved Files

Note that saved files (backup configurations, script, etc.) are lost on a node that becomes a non-master when implementing stacking. Disabling or deleting the stacking configuration does not restore the files.

Refer to the following topics for help with troubleshooting other problems in your stack.