What is the most common cause for a Catalyst 3900 Stack to split?
A. The two most common causes for a stack split are: • one switch in the stack is reset • very heavy traffic goes through the stack backbone The former can be caused by a switch crash or manual reset. In either case, further investigation is required in order to prevent future reoccurence. The latter problem is caused by very heavy broadcast traffic, which causes the heartbeat signal, (used as a keepalive for the stack to stay joined) to timeout. Increase the stack timeout value in order to resolve this issue. The default is 16 seconds and the maximum is 65535 seconds. It is also important to ensure that the latest Catalyst 3900 revision is run. Check Cisco.com in order to confirm this.
