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 cost
spanning-tree cost
Use the spanning-tree cost interface configuration command on a network node interface (NNI) or
enhanced network interface (ENI) with STP enabled to set the path cost for spanning-tree calculations.
If a loop occurs, spanning tree considers the path cost when selecting an interface to place in the
forwarding state. Use the no form of this command to return to the default setting.
spanning-tree [vlan vlan-id] cost cost
no spanning-tree [vlan vlan-id] cost
Syntax Description
Defaults The default path cost is computed from the STP port bandwidth setting. These are the IEEE default path
cost values:
• 1000 Mbps—4
• 100 Mbps—19
• 10 Mbps—100
Command Modes Interface configuration
Command History
Usage Guidelines Spanning Tree Protocol (STP) is not supported on user network interfaces (UNIs). You can configure
spanning-tree cost only on NNIs or on enhanced network interfaces (ENIs) on which STP has been
enabled. To set a port as an NNI or ENI, enter the port-type {nni | eni} 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.
If you configure an STP port with both the spanning-tree vlan vlan-id cost cost command and the
spanning-tree cost cost command, the spanning-tree vlan vlan-id cost cost command takes effect.
Examples This example shows how to set the path cost to 250 on a port:
Switch(config)# interface gigabitethernet0/1
Switch(config-if)# spanning-tree cost 250
vlan vlan-id (Optional) VLAN range associated with a spanning-tree instance. You can specify
a single VLAN identified by VLAN ID number, a range of VLANs separated by a
hyphen, or a series of VLANs separated by a comma. The range is 1 to 4094.
cost Path cost. The range is 1 to 200000000, with higher values meaning higher costs.
Release Modification
12.2(25)EX This command was introduced.