Configuring Mistp Port Instance Cost; Configuring Mistp Port Instance Priority - Cisco WS-C4003 - Catalyst 4000 Chassis Switch Software Configuration Manual

Using MISTP-PVST+ or MISTP
This example shows how to configure the port priority and verify the configuration:
Console> (enable) set spantree portpri 2/12 40
Bridge port
Console> (enable) show spantree mistp-instance 1
Instance 1
Spanning tree mode
Spanning tree type
Spanning tree instance enabled
Designated Root
Designated Root Priority
Designated Root Cost
Designated Root Port
VLANs mapped:
Root Max Age
Bridge ID MAC ADDR
Bridge ID Priority
VLANs mapped:
Bridge Max Age 20 sec
Port
------------------------ ---- ------------- --------- ---- -------- ----------
2/12
Console> (enable)

Configuring MISTP Port Instance Cost

You can configure port instance cost for an instance of MISTP or MISTP-PVST+. Ports with a lower
instance cost are more likely to be chosen to forward frames. You should assign lower numbers to ports
attached to faster media (such as full duplex) and higher numbers to ports attached to slower media. The
default cost differs for different media. The possible value for port instance cost is 1 to 268435456.
To configure the port instance cost for a port, perform this task in privileged mode:
Task
Configure the port instance cost on a
switch port.
This example shows how to configure the port instance priority on a port:
Console> (enable) set spantree portinstancecost 2/12 cost 110110 2
Port 2/12 instances 1,3-16 have path cost 22222222.
Port 2/12 instances 2 have path cost 110110.
Console> (enable)

Configuring MISTP Port Instance Priority

You can set the port priority for an instance of MISTP. The port with the lowest priority value for a
specific MISTP instance forwards frames for that instance. The possible port instance range is 0 to 63.
If all ports have the same priority value for a MISTP instance, the port with the lowest port number
forwards frames for that instance.
Software Configuration Guide—Catalyst 4000 Family, Catalyst 2948G, Catalyst 2980G, Releases 6.3 and 6.4
7-24
2/12 port priority set to 40.
MISTP-PVST+
ieee
00-d0-00-4c-18-00
32769 (root priority: 32768, sys ID ext: 1)
0
none
6
20 sec Hello Time 2
00-d0-00-4c-18-00
32769 (bridge priority: 32768, sys ID ext: 1)
6
Hello Time 2
Inst Port-State
1 forwarding
sec Forward Delay 15 sec
sec Forward Delay 15 sec
Cost Prio Portfast Channel_id
22222222 40 disabled 0
Command
set spantree portinstancecost {mod/port} [cost cost]
[instances]
Chapter 7 Configuring Spanning Tree
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