Assigning a port cost for an MST instance


spanning-tree instance ist | 1..16 port-list path-cost [auto | 1..200000000]

Assigns an individual port cost for the IST or for the specified MST instance.

For a given port, the path cost setting can be different for different MST instances to which the port may belong. The switch uses the path cost to determine which ports are the forwarding ports in the instance; that is, which links to use for the active topology of the instance and which ports to block.

The settings are either auto or in a range from 1 to 200,000,000. With the auto setting, the switch calculates the path cost from the link speed:
10 Mbps


100 Mbps


1 Gbps