OSPF auto-cost reference-bandwidth question

[timm.benkula]

Is there a any recommendations on when to change the default reference bandwidth for OSPF? Our network has WAN links that range from 256K FR to full DS3 point to point links and ethernet connections of 10 mbit, 100 mbit and 1 gigabit.

Also, many of our WAN links are FR connections to our providers MPLS network. If I do change the reference bandwidth, will I need to get them to make changes to the PE routers also?

[pkhatri]

As soon as you go beyond a 100Mbps, it's advisable to change the reference bandwidth. If you don't, OSPF will not be able to distinguish between links greater than 100Mbps.

You don't need to get your provider to make changes to the reference bandwidth on their side. IN fact, they could be using non-Cisco devices that may not have any concept of reference bandwidth at all. As long as they have a consistent mechanism to assign OSPF costs to your links (which I'm sure they would), they do not need to change anything.

Hope that helps - pls rate the post if it does.

Paresh