Allied Telesis AT-GS950/16 - Manual (Page 337)

AT-GS950/16 Web Interface User Guide
337
Figure 121. Multiple Spanning Tree Region
The AT-GS950/16 switch determines regional boundaries by examining the
MSTP BPDUs received on the ports. A port that receives a MSTP BPDU from
another bridge with regional information different from its own is considered to
be a boundary port and the bridge connected to the port as belonging to
another region.
The same is true for any ports connected to bridges running the single-
instance spanning tree STP. Those ports are also considered as part of
another region.