OSPF cost setting

Unanswered Question
Oct 22nd, 2008

I have a site that is sending traffic out the FW instead of the DS3 link. I think it's because OSPF thinks that the firewall has a 100mb link while the DS3 will just have 45mb. If there a way for me to adjust the cost so that the DS3 link is preferred?

Thanks in advance.

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Giuseppe Larosa Wed, 10/22/2008 - 11:18

Hello Brent,

on the FE to the firewall use:

int f0/0

ip ospf cost 10

this should be enough with default settings FE cost is 1 and DS3 is 2.

to check the ip ospf costs


sh ip ospf int typex/y

Hope to help


Joseph W. Doherty Wed, 10/22/2008 - 16:38

You might also try defining the bandwidth, with the bandwidth statement, to either be less than 45 Mbps (e.g. 40 Mbps) or whatever the bandwidth is on the other side of the firewall (assuming it's less than 45 Mbps). An advantage of using bandwidth, if you change the default Cisco OSPF costing, bandwidth will generate the correct proportion for the base bandwidth being used.


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