Administrator Guide

Layer 2 Switching Commands 781
To change the allocation of spanning-tree instances to VLANs, use the no
spanning-tree vlan command to disassociate a VLAN from a per VLAN
spanning-tree instance and use the spanning-tree vlan command to associate
the spanning-tree instance with the desired VLAN.
Command Modes
Global Configuration mode
User Guidelines
This command can be configured even if the switch is configured for
MST(RSTP) mode. It is only used when the switch is configured for STP-PV
or RSTP-PV modes.
Example
This example configures a switch to use per VLAN spanning tree for VLANS
12, 13 and 24-26
console(config)#spanning-tree vlan 12,13,24-26
spanning-tree vlan forward-time
Use the spanning-tree vlan forward-time command to configure the
spanning tree forward delay time for a specified VLAN or a range of VLANs.
Use the no form of the command to return the forward time to its default
value.
Syntax
spanning-tree vlan vlan-list forward-time 4-30
no spanning-tree vlan vlan-list forward-time
• forward-time — The interval (time spent in listening and learning states)
before transitioning a port to the forwarding state. (Range: 4-30 seconds)
Default Configuration
The default forward delay time is 15.