User guide

Chapter 19: Multiple Spanning Tree Protocol
306 Section IV: Spanning Tree Protocols
MSTI List
The MSTIs defined on the switch. You can use this list when setting
the port priority and port internal path cost parameters to assign
different values to a port for each MSTI when the port is a member.
Before setting priority or internal path cost, select the appropriate MSTI
where you want the new setting to be applied on the port. The default
is all MSTIs on the switch.
The MSTI List shows all of the spanning tree instances on the switch,
and not just those where the selected port is currently a member. If you
select an MSTI where the port is not a member, you can pre-configure
the parameter in the event you later add the port as a member of the
MSTI through a VLAN assignment.
Enable Migration Check
This parameter is displayed only when MSTP is enabled. This
parameter resets a port, allowing it to send RSTP BPDUs. When an
MSTP bridge receives STP BPDUs on an MSTP port, the port
transmits STP BPDUs. The port continues to transmit STP BPDUs
indefinitely.
Point-to-Point
This parameter defines whether the port is functioning as a point-to-
point port. The possible settings are Yes, No, and Auto-Detect. For an
explanation of this parameter, refer to “Point-to-Point and Edge Ports”
in Chapter 22, “Spanning Tree and Rapid Spanning Tree Protocols” in
the AT-S63 Management Software Features Guide.
Port External Path Cost
The port cost of the port if the port is connected to a bridge which is a
member of another MSTP region or is running STP or RSTP. The
range is 0 to 200,000,000. Table 9 on page 306 lists the MSTP port
costs with the Auto setting when the port is not a member of a trunk.
1000 Mbps 2,000
Table 9. MSTP Auto External Path Costs
Port Speed Port Cost
10 Mbps 2,000,000
100 Mbps 200,000
1000 Mbps 20,000
Table 8. MSTP Auto Update Port Trunk Internal Path Costs
Port Speed Port Cost