An OSPF interface on the Branch Gateway can dynamically set a Cost. The Cost represents the price assigned to each interface for purposes of determining the shortest path.

By default the OSPF interface Cost is calculated based on the interface bandwidth, according to the following formula: Cost = 100,000 / bandwidth (in kbps)

The result is that the higher the bandwidth, the lower the Cost.

When manually configuring the Cost of an OSPF interface (ip ospf cost command), dynamic bandwidth updates do not change the Cost.

When manually adjusting the interface’s bandwidth, (bandwidth command), if Cost is being determined dynamically, it is this configured bandwidth and not the actual interface bandwidth that is used to calculate Cost.