A system and method that modifies the behavior of the IEEE 802.1D STP
standard to thereby decouple the one data domain from the one control
domain involves managing multiple spanning tree protocol (STP) instances
in a virtual local area network (VLAN). The method includes the step of
assigning a unique set of ports within the VLAN to each of the multiple
STP instances. Then, each of the multiple STP instances are managed to
keep each of the multiple STP instances separate. Finally, when a
topology change is detected in one of the multiple STP instances, entries
that have been learned on the unique set of ports assigned to the STP
protocol instance where the topology change is detected are fast-aged or
transitioned from one state to another.