Best Practices

[djohnson]

I am in a debate with a customer, when configuring a Serial interface what is the best practice to put a bandwidth statement or not ?

[Edison Ortiz · Accepted solution]

The bandwidth statement influences dynamic routing protocol and to some extend QoS.

By default, routing protocols will get their routing decisions based on the default bandwidth value on an interface (show interface will display this value).

If you have a link where the value is greater or lesser than what's presented under the show interface command, then entering the bandwidth statement is considered Best Practice.

[bvsnarayana03]

The bandwidth command is used only for metric calculations by routing protocols. It does not change interface performance.

[royalblues]

The best practice would be put the correct line speed as the bandwidth of the interface. Parameters like the metric calculation for dynamic protocols, QoS policies look at the configured bandwidth on the interface.

Some NMS tools too refer to the configured bandwidth on the interface.

HTH

Narayan