System and method for multiple spanning tree protocol domains in a virtual local area network

A system comprising:

• multiple spanning tree protocol (STP) instances in a virtual local area network (VLAN);
• and
• an access device comprising:
• a network interface;
• a memory;
• and
• an STP module configured to:
• associate each of multiple STP instances with a unique set of ports and an ID for a virtual local area network (VLAN);
• associate each port in the unique sets of ports with its associated STP instance;
• store a representation of the associations in the memory;
• manage each of the multiple STP instances to keep each of the multiple STP instances separate;
• and
• when a topology change is detected in one of the multiple STP instances, transition entries from one state to another that have been learned on the unique set of ports assigned to the STP protocol instance where the topology change is detected.

A system comprising:

• a memory;
• means for associating each of multiple STP instances with a unique set of ports and an ID for a virtual local area network (VLAN);
• means for associating each port in the unique sets of ports with its associated STP instance;
• means for storing a representation of the associations in the memory;
• means for managing each of the multiple STP instances to keep each of the multiple STP instances separate;
• and
• means for transitioning entries from one state to another that have been learned on the unique set of ports assigned to the STP protocol instance where the topology change is detected.

The system of clam 18, wherein the means for managing comprises:

• means for receiving a bridge protocol data unit (BPDU) on a port in the VLAN;
• means for determining which one of the multiple STP instances should process the BPDU;
• and
• means for forwarding the BPDU to the determined STP instance for processing.

A computer implemented method comprising:

• associating, by an access device having a network interface and a memory, a first spanning tree protocol (STP) instance with a first unique set of ports and an ID for a virtual local area network (VLAN);
• associating a second STP instance with a second unique set of ports and an ID for the VLAN;
• associating each port in the unique sets of ports with its associated STP instance;
• storing a representation of the associations in the memory;
• and
• managing the first STP instance and the second STP instance to keep the first and second STP instances separate.

A system comprising:

• a first spanning tree protocol (STP) instance;
• a second STP instance;
• and
• an access device comprising:
• a network interface;
• a memory;
• and
• an STP module configured to:
• associate a first spanning tree protocol (STP) instance with a first unique set of ports and an ID for a virtual local area network (VLAN);
• associate a second STP instance with a second unique set of ports and an ID for the VLAN;
• associate each port in the unique sets of ports with its associated STP instance;
• store a representation of the associations;
• and
• manage each of the first and second STP instances to keep each of the first and second STP instances separate.

A computer readable medium tangibly embodying a computer program to perform a method, the method comprising:

• associating each of multiple STP instances with a unique set of ports and an ID for a virtual local area network (VLAN);
• associating each port in the unique sets of ports with its associated STP instance;
• storing a representation of the associations;
• managing each of the multiple STP instances to keep each of the multiple STP instances separate;
• and
• when a topology change is detected in one of the multiple STP instances, transitioning entries from one state to another that have been learned on the unique set of ports assigned to the STP protocol instance where the topology change is detected.

A computer readable medium tangibly embodying a computer program to perform a method, the method comprising:

• associating a first spanning tree protocol (STP) instance with a first unique set of ports and an ID for a virtual local area network (VLAN);
• associating a second STP instance with a second unique set of ports and an ID for the VLAN;
• associating each port in the unique sets of ports with its associated STP instance;
• storing a representation of the associations;
• and
• managing the first STP instance and the second STP instance to keep the first and second STP instances separate.

A device comprising:

• a memory;
• and
• a spanning tree protocol (STP) module configured to:
• associate each of multiple STP instances with a unique set of ports and an ID for a virtual local area network (VLAN);
• associate each port in the unique sets of ports with its associated STP instance;
• store a representation of the associations;
• manage each of the multiple STP instances to keep each of the multiple STP instances separate;
• and
• when a topology change is detected in one of the multiple STP instances, transition entries from one state to another that have been learned on the unique set of ports assigned to the STP protocol instance where the topology change is detected.