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Catalyst 4500 Series, Catalyst 2948G, Catalyst 2948G-GE-TX, and Catalyst 2980G Switches Software Configuration Guide—Release 8.2GLX
78-15908-01
Chapter 7 Configuring Spanning Tree
Using MISTP-PVST+ or MISTP
Bridge ID Priority 32769 (bridge priority:32768, sys ID ext:1)
VLANs mapped: 1,74
Bridge Max Age 20 sec Hello Time 2 sec Forward Delay 15 sec
Port Inst Port-State Cost Prio Portfast Channel_id
------------------------ ---- ------------- --------- ---- -------- ----------
1/1 1 forwarding 20000 32 disabled 0
3/1 1 forwarding 200000 32 disabled 0
3/25 1 forwarding 200000 32 disabled 0
3/26 1 forwarding 200000 32 disabled 0
3/27 1 forwarding 200000 32 disabled 0
3/28 1 forwarding 200000 32 disabled 0
3/29 1 forwarding 200000 32 disabled 0
3/30 1 forwarding 200000 32 disabled 0
7/1-4 1 blocking 5000 32 disabled 833
7/5 1 forwarding 20000 32 disabled 0
7/6 1 forwarding 20000 32 disabled 0
8/37 1 blocking 200000 32 disabled 0
8/38 1 blocking 200000 32 disabled 0
15/1 1 forwarding 20000 32 enabled 0
16/1 1 forwarding 20000 32 enabled 0
Console> (enable)
Configuring the MISTP Port Priority
You can configure the port priority of switch ports. The port with the lowest priority value forwards
frames for all VLANs. The possible port priority value is from 0–63; the default is 32. If all ports have
the same priority value, the port with the lowest port number forwards frames.
To configure the port priority for a port, perform this task in privileged mode:
This example shows how to configure the port priority and verify the configuration:
Console> (enable) set spantree portpri 1/1 32
Bridge port 1/1 port priority set to 32.
Console> (enable) show spantree mistp-instance 1
Instance 1
Spanning tree mode MISTP
Spanning tree type ieee
Spanning tree instance enabled
Designated Root 00-05-31-40-64-00
Designated Root Priority 32769 (root priority:32768, sys ID ext:1)
Designated Root Cost 20000
Designated Root Port 1/1
VLANs mapped: 1,74
Root Max Age 20 sec Hello Time 2 sec Forward Delay 15 sec
Bridge ID MAC ADDR 00-d0-02-27-9c-00
Bridge ID Priority 32769 (bridge priority:32768, sys ID ext:1)
VLANs mapped: 1,74
Bridge Max Age 20 sec Hello Time 2 sec Forward Delay 15 sec
Task
Command
Step 1
Configure the port priority for a switch port.
set spantree portpri mod_num/port_num priority
[instance]
Step 2
Verify the port priority setting.
show spantree mistp-instance instance
[mod_num/port_num] active