August 2005
Intermediate to advanced
798 pages
31h 12m
English
ospf auto-cost reference-bandwidth — router
ospf auto-cost reference-bandwidthvalueno ospf auto-cost reference-bandwidthvalue
How OSPF calculates default metrics
100 Mb
The default OSPF metric is calculated by dividing the reference bandwidth by the bandwidth of the interface. The default value of the reference bandwidth is 10^8 or 100,000,000. Using this formula, the OSPF cost for a T1 is 65 (100,000,000/1,544,000). This number is also convenient because it causes the cost of an FDDI link or Fast Ethernet to be 1. This command allows you to modify the reference bandwidth to support interfaces that are faster than 100 Mbps.