Troubleshooting issues with adding or removing members in the stack

Cause

Various problems described below could be causing issues with adding or removing members in the stack.

Problem:

Cannot add a new switch to an existing stack.

Solution:

Identify root cause. Possible reasons for a member not joining an existing stack are:

  • The switch being added has already been a member of another stack and has a different stack ID.

  • The maximum number of switches is already configured.

  • The switch being added has been statically provisioned, but switch type and MAC address in the configuration do not match the switch being added.

  • There is a problem with the stack cable.

  • There is a problem with the stack physical cabling (illegal topology).

Problem:

The entire stack does not come up after a boot.

Solution:

There are several reasons why all members do not join the stack:

  • There is a problem with the stack cable.

  • Physical cabling was changed.

  • Stack booted on incorrect configuration.

  • One or more of the switches has a hardware problem (for example, bad power supply, back stacking module, corrupt flash).

Problem:

One or more of the members keeps rebooting and does not join the stack.

Possible reasons:

  • An unresponsive member.

  • Heartbeat loss—a stack that has a member no longer in the stack or a member failing after joining the stack.

  • Illegal topology.

Problem:

After initial boot sequence, the activity and Link LEDs of an interface are not on and the ports are not passing traffic.

Solutions:

  • Identify the “inactive fragment” and provide alternatives for recovery.

  • Verify that all OOBMs are connected so that there is uninterrupted access.

Problem:

After a reboot, the selected Command or Standby are not the expected switches.

Solutions:

Check to see if the log files provide a reason why the Commander and Standby were chosen and which rule they matched.