Restoring operation after disconnecting a stacking cable

If a stacking cable becomes disconnected from one of the switches in the stack, the effect depends on the stacking topology in use:

  • Ring—There is little effect. The stack topology is temporarily changed to a chain topology. To recover, simply reconnect the stacking cable; this restores the ring topology and the previous stack configuration.

  • Chain—The following occur:
    • The smaller section (fragment) of the stack caused by the disconnection becomes Inactive (the Stack Status value shown in the output of the show stacking command is Inactive.

    • If the two resulting fragments are the same size, the fragment that contains the Commander will be Active, and the other fragment becomes Inactive.

      This only occurs when OOBM is enabled and configured for all members of the stack. If OOBM is not enabled and configured for all members of the stack, then each fragment will be Active. See OOBM and active and inactive fragments for more information.

    • Both fragments will have a Commander and a Standby selected (if there is more than one switch in each fragment).

    • When the stacking cable is reconnected to reform the chain:
      • The Commander and Standby of the Active fragment retain those roles for the resulting stack. If the original Commander was not in that fragment, then the stack will have a new Commander when the stack is reformed.

      • The switches in the Inactive fragment reboot and assume their new roles in the reformed chain.