ospf interface cost value

[wfqk]

Hi Two routers A and B are connected directly with ospf neighbor. The below is routerA config with ospf cost 10000. Do you think the routerB' interface which is connected to routerA also needs to have "ip ospf cost 10000"? Thank you

interface GigabitEthernet0/1/0.1019
encapsulation dot1Q 1019
ip address 10.1.1.16 255.255.255.254
ip ospf network point-to-point
ip ospf cost 10000

[Reza Sharifi · Accepted solution]

Hi,

If the goal is to have the same cost on both sides then yes.

HTH

[wfqk]

Thank you so much for your reply. 

I think the cost is giving the path some priority for traffic. If it is this case, we might not need to configure the cost on both side, right? In addition to this, the cost has some other function?  Thanks

[Reza Sharifi]

If this is production and the cost is configured on one side and not the other, there maybe a reason for that. I would not change that unless you know exactly what you are after. There maybe cases where you don't need it on both side. Overall, you have to know more about the topology before making the change.

HTH

[wfqk]

Thank you!

[Joseph W. Doherty]

Often you would expect symmetrical costs, but there are many reasons why you might have asymmetrical costs too.  On a Cisco device, as Cisco will auto cost based on bandwidth, using an explicit OSPF cost statement is often done for some particular reason.