In a system comprising a first fabric and a plurality of devices coupled
to the fabric by Fibre Channel connections, the devices are logically
grouped to form configurations and zones. A configuration includes at
least one zone, and each zone includes at least one device as a member of
the zone. Communications between the devices is restricted according to
the configuration currently in effect. For example, one device may be
permitted to communicate with another device only if they are members of
a common zone.