The show spanning-tree interface interface-id privileged EXEC command displays information only for ports that are in a link-up operative state. Otherwise, you can use the show running-config privileged EXEC command to confirm the configuration. (Optional) Configuring the Device Priority of a VLAN You can configure the switch priority and make it more likely that a standalone switch or a switch in the stack will be chosen as the root switch. Note Exercise care when using this command. For most situations, we recommend that you use the spanning-tree vlan vlan-id root primary and the spanning-tree vlan vlan-id root secondary global configuration commands to modify the switch priority.
To configure device priority of a VLAN, perform this procedure: Procedure Configuring Spanning Tree Protocol (Optional) Configuring the Device Priority of a VLAN Command or Action Purpose Step 1 enable Example: Device> enable Enables privileged EXEC mode. Enter your password if prompted. Step 2 configure terminal Example: Device# configure terminal Enters global configuration mode. Step 3 spanning-tree vlan vlan-id priority priority Example: Device(config)# spanning-tree vlan 20 priority 8192 Configures the device priority of a VLAN. • For vlan-id, 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. • For priority, the range is 0 to 61440 in increments of 4096; the default is 32768. The lower the number, the more likely the switch will be chosen as the root switch. Valid priority values are 4096, 8192, 12288, 16384, 20480, 24576, 28672, 32768, 36864, 40960, 45056, 49152, 53248, 57344, and 61440. All other values are rejected. Step 4 end Example: Returns to privileged EXEC mode. Configuring Spanning Tree Protocol 18