Configuring Mst Instance Parameters - Cisco 4500M Software Manual

Chapter 16 Understanding and Configuring Multiple Spanning Trees

Configuring MST Instance Parameters

To configure MST instance parameters, perform this task:
Command
Step 1
Switch(config)# spanning-tree mst X priority Y
Step 2
Switch(config)# spanning-tree mst X root [primary |
secondary]
Step 3
Switch(config)# Ctrl-Z
Step 4
Switch# show spanning-tree mst
This example shows how to configure MST instance parameters:
Switch(config)# spanning-tree mst 1 priority ?
<0-61440>
Switch(config)# spanning-tree mst 1 priority 1
% Bridge Priority must be in increments of 4096.
% Allowed values are:
0
32768 36864 40960 45056 49152 53248 57344 61440
Switch(config)# spanning-tree mst 1 priority 49152
Switch(config)#
Switch(config)# spanning-tree mst 0 root primary
mst 0 bridge priority set to 24576
mst bridge max aging time unchanged at 20
mst bridge hello time unchanged at 2
mst bridge forward delay unchanged at 15
Switch(config)# ^Z
Switch#
Switch# show spanning-tree mst
###### MST00
Bridge
Root
Configured
Interface
---------------- ---- --- --------- -------- --------------------------------
Fa4/4
Fa4/5
Fa4/48
###### MST01
Bridge
Root
Interface
---------------- ---- --- --------- -------- --------------------------------
Fa4/4
Fa4/5
Fa4/48
Switch#
OL-6696-01
bridge priority in increments of 4096
4096 8192 12288 16384 20480 24576 28672
vlans mapped:
address 00d0.00b8.1400
this switch for CST and IST
hello time 2, forward delay 15, max age 20, max hops 20
Role Sts Cost
Back BLK 1000
Desg FWD 200000
Desg FWD 200000
vlans mapped:
address 00d0.00b8.1400
this switch for MST01
Role Sts Cost
Back BLK 1000
Desg FWD 200000
Boun FWD 200000
Purpose
Configures the priority for an MST instance.
Configures the bridge as root for an MST instance.
Exits configuration mode.
Verifies the configuration.
11-4094
priority 24576 (24576 sysid 0)
Prio.Nbr Status
240.196 P2p
128.197 P2p
128.240 P2p Bound(STP)
1-10
priority 49153 (49152 sysid 1)
Prio.Nbr Status
160.196 P2p
128.197 P2p
128.240 P2p Bound(STP)
Software Configuration Guide—Release 12.2(25)EW
Configuring MST
16-11