ip ospf priority

Much later in the chapter I read, they told me that the higher one is the winner. I guess that confims my suspicion.

Another question, I do have. Does the router automatically assign OSPF cost based upon the speed on the interface or do you have to program either the priority or the bandwidth on the interface?

Regards,

Fred

The numerically highest DR priority wins

Thus ip opsf priority 5 wins over ip ospf priority 2

Cost [1] This is an OSPF metric. Cost is calculated with this formula:

• 10^8 / bandwidth (in bits per second [bps])

In the formula, bandwidth refers to the bandwidth of the interface in bps, and 10^8 is the reference bandwidth.

In the example, the bandwidth of Ethernet0 is 10 Mbps, which is equal to 10^7. The formula yields 10^8 / 10^7, equaling a cost of 10.

Use the ip ospf cost interface cost interface configuration command to explicitly specify the cost on an interface.

Q. How does OSPF calculate its metric or cost? [2]

A. OSPF uses a reference bandwidth of 100 Mbps for cost calculation. The formula to calculate the cost is reference bandwidth divided by interface bandwidth. For example, in the case of Ethernet, it is

Note: If ip ospf cost cost is used on the interface, it overrides this formulated cost.

Sources:

Thanks,

But my *real* question was, 'Does OPSF calculate it based on the bandwidth or does it require the adminstrator to assign the value he calculates manually?'.

You did ultimately answer it. And thanks.

Fred