Cisco NM-8B-U - HW ROUTERS L-M User Manual page 128

Configuration Tasks
Changing the Maximum-Idle Interval
If a switch does not hear BPDUs from the root switch within a specified interval, it recomputes the
spanning-tree topology.
Beginning in privileged EXEC mode, follow these steps to change the maximum-idle interval (maximum
aging time):
Command
Step 1 configure terminal
Step 2
bridge bridge-group max-age seconds
Step 3
end
Step 4
show running-config
Step 5
copy running-config startup-config
To return to the default setting, use the no bridge bridge-group max-age global configuration command.
Disabling the Spanning Tree on an Interface
When a loop-free path exists between any two switched subnetworks, you can prevent BPDUs generated
in one switching subnetwork from impacting devices in the other switching subnetwork, yet still permit
switching throughout the network as a whole. For example, when switched LAN subnetworks are
separated by a WAN, BPDUs can be prevented from traveling across the WAN link.
Beginning in privileged EXEC mode, follow these steps to disable spanning tree on an interface:
Command
Step 1
configure terminal
Step 2
interface interface-id
Step 3 bridge-group bridge-group
spanning-disabled
Step 4 end
Step 5
show running-config
Step 6
copy running-config startup-config
To reenable spanning tree on the interface, use the no bridge-group bridge-group spanning-disabled
interface configuration command.
Cisco IOS Release 12.2(2)XT, 12.2(8)T, and 12.2(15)ZJ
128
16- and 36-Port Ethernet Switch Module for Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series
Purpose
Enters global configuration mode.
Specifies the interval the switch waits to hear BPDUs from the root
switch.
• For bridge-group, specify the bridge group number. The range is 1
to 255.
For seconds, enter a number from 10 to 200. The default is 30
•
seconds.
Returns to privileged EXEC mode.
Verifies your entry.
(Optional) Saves your entry in the configuration file.
Purpose
Enters global configuration mode.
Enters interface configuration mode, and specify the interface ID.
Disables spanning tree on the interface.
For bridge-group, specify the bridge group number. The range is 1
to 255.
Returns to privileged EXEC mode.
Verifies your entry.
(Optional) Saves your entry in the configuration file.