Regarding OSPF auto-cost reference bandwidth

[sudha.chandrashekar]

Hi,

I want information regarding changing of reference bandwidth. According to the formula

for calculating the cost it is 100Mbps/bandwidth of the interface.

My question is what will happen if the bandwidth of the interface changes dynamically,

say I have configured reference bandwidth as 1000 , and due to auto-negotiation if the

bandwidth of the interface changes, (say from 100 Mbps to 10 Mbps). Then will

the cost calcuation take place autmoatically or will I have to configure the reference

bandwidth again.

Thanks in anticipation

[svermill]

The cost will always be calculated using the value inputted using the 'bandwidth' command and is not dynamic. Also, Cisco and most folks (myself included) strongly recommend setting the bandwidth manually. Lots of potential for trouble with autonegotiation.

[thisisshanky]

Autonegotiated bandwidth will not be used for calculation, once this command is used.