IPv4 OSPF Network statement

Unanswered Question
Jun 22nd, 2007

I had a discussion with a co-worker about OSPF Network statements.

He is going to tweak some of our OSPF configs and one thing he wants to do is to remove the <mask> from the Network statements and use the interface instead.

Now I am asking him not to do that since it's much easier to read the CFG and see the entire Network that is advertized. With just an interface there is ambiguity. BTW, we are not using IPv6, only IPv4.

He says it's more efficient but I don't think so. I've seen large OSPF configs at AT&T and Qualcomm and they use the full Network, not an interface, for readability and possibly other reasons.

Is this just preference or is there a legitimate reason to use an Interface over the Net <mask>? This company I am with now does not follow many of the common standards and practices that I've seen at large companies and I see this as one of them.

Any help would be most appreciated.



I have this problem too.
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deveshkumar Fri, 06/22/2007 - 18:46


OPSF interface configuration was introduced because of IPV6. Howerver IPV4 is also supported with the same command.

The options is urs which way to go with.

both command will remain same.

you can ask ur collegue to use network statements with ip address of your interface you want to participate in ospf with wild card bits of which means run ospf on that praticular interface only.

This will solve both of urporbs.

ryderse69 Sat, 06/23/2007 - 07:24

Thanks for the info.

So there is no difference from the routers perspective???

However, your suggested answer does not help me really. I want to see the true mask in the cfg so as I read the cfg, I know the full Network being advertised from that router. If we use a mask of, there is ambiguity. Using the true mask, one can easily tell the full Network being advertised from the cfg. Of course, there are other ways to tell the full Network but I have always liked to see it in the cfg.

Thanks again,



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