Configuring The Pvst+ Port Cost - Cisco WS-C6506 Software Manual

Configuring PVST+ on the Switch
Designated Root
Designated Root Priority
Designated Root Cost
Designated Root Port
Root Max Age
Bridge ID MAC ADDR
Bridge ID Priority
Bridge Max Age 20 sec
Port
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1/1
1/2
2/1
2/2

Configuring the PVST+ 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 1–65535
when using the short method for calculating port cost and from 1–200000000 when using the long
method. The default cost differs for different media. For information about calculating the port cost, see
the
To configure the PVST+ port cost for a port, perform this task in privileged mode:
Task
Step 1
Configure the PVST+ port cost for a switch port.
Step 2
Verify the port cost setting.
When you enter the set spantree channelcost command, it does not appear in the configuration file. The
Note
command causes a "set spantree portcost" entry to be created for each port in the channel. See the
"Setting the EtherChannel Port Path Cost"
information on using the set spantree channelcost command.
This example shows how to configure the PVST+ port cost on a port and verify the configuration:
Console> (enable) set spantree portcost 2/3 12
Spantree port 2/3 path cost set to 12.
Console> (enable) show spantree 2/3
VLAN 1
Port
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1/1
1/2
2/1
2/2
2/3
2/4
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
7-28
14 sec Hello Time 2 sec
Hello Time 2 sec
Vlan Port-State
1
1
1
1
"Calculating and Assigning Port Costs" section on page
.
.
.
Vlan Port-State
1
1
1
1
1
1
00-60-70-4c-70-00
16384
19
2/3
Forward Delay 10 sec
00-d0-00-4c-18-00
32769 (bridge priority: 32768, sys ID ext: 1)
Forward Delay 15 sec
Cost
not-connected
not-connected
not-connected
not-connected
Command
set spantree portcost {mod/port} cost
show spantree mod/port
section in Chapter 6, "Configuring EtherChannel,"
Cost
not-connected
not-connected
not-connected
not-connected
forwarding
not-connected
Chapter 7 Configuring Spanning Tree
Prio Portfast Channel_id
4 32 disabled 0
4 32 disabled 0
100 32 disabled 0
100 32 disabled 0
7-4.
Prio Portfast Channel_id
4 32 disabled 0
4 32 disabled 0
100 32 disabled 0
100 32 disabled 0
12 32 disabled 0
100 32 disabled
for
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