Specifications

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Cisco ME 3400 Ethernet Access Switch Command Reference
OL-9640-07
Chapter 2 Cisco ME 3400 Ethernet Access Switch Cisco IOS Commands
spanning-tree mst cost
spanning-tree mst cost
Use the spanning-tree mst cost interface configuration command on a network node interface (NNI) or
an enhanced network interface (ENI) with STP enabled to set the path cost for multiple spanning-tree
(MST) calculations. If a loop occurs, spanning tree considers the path cost when selecting an interface
to put in the forwarding state. Use the no form of this command to return to the default setting.
spanning-tree mst instance-id cost cost
no spanning-tree mst instance-id cost
Syntax Description
Defaults The default path cost is computed from the interface bandwidth setting. These are the IEEE default path
cost values:
• 1000 Mbps—20000
• 100 Mbps—200000
• 10 Mbps—2000000
Command Modes Interface configuration
Command History
Usage Guidelines Spanning Tree Protocol (STP) is not supported on user network interfaces (UNIs). You can configure
path cost only on NNIs or on ENIs on which STP has been enabled. To set a port as an NNI or ENI, enter
the port-type {eni | nni} interface configuration command. To enable STP on an ENI, enter the
spanning-tree interface configuration command.
When you configure the cost, higher values represent higher costs.
Examples This example shows how to set a path cost of 250 on a port associated with instances 2 and 4:
Switch(config)# interface gigabitethernet0/2
Switch(config-if)# spanning-tree mst 2,4 cost 250
You can verify your settings by entering the show spanning-tree mst interface interface-id privileged
EXEC command.
instance-id Range of spanning-tree instances. You can specify a single instance, a range of
instances separated by a hyphen, or a series of instances separated by a comma. The
range is 0 to 4094.
cost Path cost is 1 to 200000000, with higher values meaning higher costs.
Release Modification
12.2(25)EX This command was introduced.
12.2(25)SEG The instance-id range changed to 0 to 4094.