Adjusting Bpdu Intervals - Cisco Catalyst 3550 series Software Configuration Manual

Configuring Fallback Bridging

Adjusting BPDU Intervals

You can adjust BPDU intervals as described in these sections:
•
•
•
Note Each switch in a spanning tree adopts the interval between hello BPDUs, the forward delay interval, and
the maximum idle interval parameters of the root switch, regardless of what its individual configuration
might be.
Adjusting the Interval between Hello BPDUs
Beginning in privileged EXEC mode, follow these step to adjust the interval between hello BPDUs:
Command
Step 1
configure terminal
Step 2
bridge bridge-group hello-time 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 hello-time global configuration
command.
This example shows how to change the hello interval to 5 seconds in bridge group 10:
Switch(config)# bridge 10 hello-time 5
Changing the Forward-Delay Interval
The forward-delay interval is the amount of time spent listening for topology change information after
an interface has been activated for switching and before forwarding actually begins.
Beginning in privileged EXEC mode, follow these steps to change the forward-delay interval:
Command
Step 1 configure terminal
Step 2 bridge bridge-group forward-time
seconds
Catalyst 3550 Multilayer Switch Software Configuration Guide
36-10
Adjusting the Interval between Hello BPDUs, page 36-10
Changing the Forward-Delay Interval, page 36-10
Changing the Maximum-Idle Interval, page 36-11
Purpose
Enter global configuration mode.
Specify the interval between hello BPDUs.
• For bridge-group, specify the bridge group number. The range is 1
to 255.
For seconds, enter a number from 1 to 10. The default is 2 seconds.
•
Return to privileged EXEC mode.
Verify your entry.
(Optional) Save your entry in the configuration file.
Purpose
Enter global configuration mode.
Specify the forward-delay interval.
• 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 20
•
seconds.
Chapter 36 Configuring Fallback Bridging
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