A "high availability" system comprises one or more switches under the
control of multiple control processors ("CPs"). One of the CPs is deemed
to be "active," while the other CP is kept in a "standby" mode. Each CP
generally has the same software load including a fabric state
synchronization ("FSS") facility. The FSSs of each CP communicate with
each other. The state information pertaining to an active "image" is
continuously provided to a standby copy of the image ("standby image").
The CPs' FSSs perform the function of synchronizing the standby image to
the active image. The state information generally includes configuration
and operational parameters and other information regarding the active
image. By keeping the standby image synchronized to the active image, the
standby image can be rapidly transitioned to the active mode if the
active image experiences a fault and continue where the previous active
image left off.