Allied Telesis AT-GS950/48 - Manual (Page 379)

AT-GS950/48 Web Interface User Guide
379
General Guidelines
Here are the guidelines for MSTIs:
 The AT-GS950/48 switch can support up to 31 spanning
tree instances, including the CIST.
 An MSTI can contain any number of VLANs.
 A VLAN can belong to only one MSTI at a time.
 A switch port can belong to more than one spanning tree
instance at a time by being an untagged and tagged
member of VLANs belonging to different MSTIs. This is
possible because a port can be in different MSTP states
for different MSTIs simultaneously. For example, a port
can be in the MSTP blocking state for one MSTI and the
forwarding state for another spanning tree instance. For
further information, refer to “Ports in Multiple MSTIs” on
page 381.