Spanning Tree Commands 755User GuidelinesFor two or more switches to be in the same MST region, they must have thesame VLAN mapping, the same configuration revision number and the samename.ExampleThe following example configures an MST region.console (config)#spanning-tree mst configurationconsole (config-mst)#instance 1 add vlan 10-20console (config-mst)#name region1console (config-mst)#revision 1spanning-tree mst costUse the spanning-tree mst cost command in Interface Configuration modeto configure the internal path cost for multiple spanning tree (MST)calculations. If a loop occurs, the spanning tree considers path cost whenselecting an interface to put in the forwarding state. To return to the defaultport path cost, use the no form of this command.Syntaxspanning-tree mstinstance-id costcostno spanning-tree mstinstance-id cost•instance-ID — ID of the spanning -tree instance. (Range: 1-4094)•cost — The port path cost. (Range: 0–200,000,000)Default ConfigurationThe default value is 0, which signifies that the cost will be automaticallycalculated based on port speed.The default configuration is:• Ethernet (10 Mbps)— 2,000,000• Fast Ethernet (100 Mbps)— 200,000• Gigabit Ethernet (1000 Mbps)— 20,000• Port-Channel— 20,000
