Cisco HWIC-4ESW - EtherSwitch HWIC Switch User Manual page 36

How to Configure EtherSwitch HWICs
Configuring the Maximum Aging Time for a VLAN
Follow the steps below to configure the maximum age interval for the spanning tree.
SUMMARY STEPS
1.
2.
3.
DETAILED STEPS
Command or Action
Step 1
enable
Example:
Router> enable
Step 2
configure terminal
Example:
Router# configure terminal
Step 3
spanning-tree vlan vlan-id max-age max-age
Example:
Router(config)# spanning-tree vlan 200 max-age
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Configuring the Root Bridge
The EtherSwitch HWIC maintains a separate instance of spanning tree for each active VLAN configured
on the switch. A bridge ID, consisting of the bridge priority and the bridge MAC address, is associated
with each instance. For each VLAN, the switch with the lowest bridge ID will become the root bridge
for that VLAN.
To configure a VLAN instance to become the root bridge, the bridge priority can be modified from the
default value (32768) to a significantly lower value so that the bridge becomes the root bridge for the
specified VLAN. Use the spanning-tree vlan root command to alter the bridge priority.
The switch checks the bridge priority of the current root bridges for each VLAN. The bridge priority for
the specified VLANs is set to 8192 if this value will cause the switch to become the root for the specified
VLANs.
If any root switch for the specified VLANs has a bridge priority lower than 8192, the switch sets the
bridge priority for the specified VLANs to 1 less than the lowest bridge priority.
For example, if all switches in the network have the bridge priority for VLAN 100 set to the default value
of 32768, entering the spanning-tree vlan 100 root primary command on a switch will set the bridge
priority for VLAN 100 to 8192, causing the switch to become the root bridge for VLAN 100.
36
enable
configure terminal
spanning-tree vlan vlan-id max-age max-age
Cisco HWIC-4ESW and HWIC-D-9ESW EtherSwitch Interface Cards
Purpose
Enables privileged EXEC mode.
Enter your password if prompted.
•
Enters global configuration mode.
Configures the maximum aging time of a VLAN.
Enter the VLAN number.
•
The value of max-age can be from 6 to 40 seconds.
•
Use the no form of this command to restore the
•
defaults.