Cisco WS-X6066-SLB-APC - Content Switching Module Software Manual page 138

Using MISTP-PVST+ or MISTP
Configuring the MISTP Port Cost
You can configure the port cost of switch ports. The ports with lower port costs are more likely to be
chosen to forward frames. Assign lower numbers to ports that are attached to faster media (such as full
duplex) and higher numbers to ports that are attached to slower media. The possible cost is from 1 to
65535 when using the short method for calculating port cost and from 1 to 200000000 when using the
long method. The default cost differs for different media. For information about calculating port cost,
see the
To configure the port cost for a port, perform this task in privileged mode:
Task
Step 1 Configure the MISTP port cost for a switch port. set spantree portcost mod/port cost
Step 2 Verify the port cost setting.
This example shows how to configure the port cost on a MISTP instance and verify the configuration:
Console> (enable) set spantree portcost 2/12 22222222
Spantree port 2/12 path cost set to 22222222.
Console> (enable) show spantree mistp-instance active
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 the MISTP Port Priority
You can configure the port priority of ports. The port with the lowest priority value forwards frames for
all VLANs. The possible port priority value is 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:
Task
Step 1 Configure the MISTP port priority for a port. set spantree portpri mod/port priority [instance]
Step 2
Verify the port priority setting.
Catalyst 6000 Family Software Configuration Guide—Releases 6.3 and 6.4
8-26
"Calculating and Assigning Port Costs" section on page
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 sec
00-d0-00-4c-18-00
32769 (bridge priority: 32768, sys ID ext: 1)
6
Hello Time 2 sec
Inst Port-State
1
Command
show spantree mistp-instance instance
[mod/port] active
Forward Delay 15 sec
Forward Delay 15 sec
Cost
forwarding 22222222
Command
show spantree mistp-instance instance [mod/port]
active
Chapter 8 Configuring Spanning Tree
8-4.
Prio Portfast Channel_id
40 disabled 0
78-13315-02