Patent ID: 6898189
Filing Date: 2005-05-24
Classification: H04L

Abstract:
1. In an intermediate network device having a plurality of ports for forwarding messages in a computer network and two or more supervisors, each supervisor including at least one spanning tree protocol (STP) engine configured to transition the ports of the device among a plurality of spanning tree port states, a method for continuing operation of a spanning tree protocol despite crashes or failures, the method comprising the steps of: designating a first supervisor to be an active supervisor and a second supervisor to be a standby supervisor for the network device; running the spanning tree protocol at the active supervisor such that the STP engine at the active supervisor elects at least one root of the computer network and directs the ports to transition among the spanning tree port states; storing the spanning tree port states of the ports at the standby supervisor; in response to a failure at the active supervisor, running the spanning tree protocol at the standby supervisor; and utilizing the stored spanning tree port states of the ports at the standby supervisor to run the spanning tree protocol at the standby supervisor.