My I change de bandwidth of my serial interface

[pgarron]

I'd like to change bandwidth of my serial interface, I have this information about the interface.

MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec,

reliability 255/255, txload 41/255, rxload 4/255.

May I change it in <config-if>bandwidth xx ?

[thisisshanky]

Yes, you can use "bandwidth xxx" , where xxx is a number in kilobits per second, under the interface configuration mode.

The bandwidth command, doesnt change the physical bandwidth of the link. It will definitely change the value displayed on the Show interface output....

Protocols such as OSPF and EIGRP which uses bandwidth as a parameter....for calculating costs, will definitely have a change in the cost of a route calculated through that interface, as a result of this bandwidth change. So be careful if you are playing with the bandwidth command, while using it in a EIGRP or OSPF network.

[pgarron]

What is the recomended minimal value for this parameter

[thisisshanky]

I cant say a fixed minimal value for this. I have used values down..to 32k on serial interfaces. but this was used to tweak the cost of EIGRP routes.

So it all really depends on how much u want to tweak the cost of the routes. In case of OSPF, cost of route = 10exp 8/bandwidth in bps. while in EIGRP you can see that cost of route = 256 * (bandwidth + delay ).