Patent ID: 8565123

Claim:
In an intermediate network device having a plurality of ports for forwarding network messages within a bridged network, a method for establishing a plurality of active topologies within the bridged network, each active topology associated with a corresponding Multiple Spanning Tree Instance (MSTI), the method comprising: defining a plurality of bridge domains within the intermediate network device, each bridge domain corresponding to a different broadcast domain, and defined by one Virtual Local Area Network (VLAN) Identifier (ID) and at least one port of the intermediate network device; for each port of the intermediate network device at which a bridge domain has been defined, providing a separate mapping of VLAN IDs to MSTIs at the respective port, wherein a first port having a first mapping of VLAN IDs to MSTIs maps a first VLAN ID to a first MSTI and a second port having a second mapping of VLAN IDs to MSTIs maps the first VLAN ID to a second MSTI that is different than the first MSTI; deriving a value from the mapping of VLAN IDs to MSTIs for a selected port; and loading the deriving value into Spanning Tree Protocol (STP) control messages transmitted from the selected port, wherein the STP control messages transmitted from the selected port include different derived values than STP control messages transmitted from one or more other ports of the intermediate network device.