Subject: OAPFv3: what is the use of prefixes in Link LSA

From: "Goyal, Manoj" <[email-masked]>
Date: Wed, 8 Mar 2006 16:37:50 -0800

HI,

In ospfv3 the intra-area-prefix LSAs have all the prefixes and routing
table

should be calculated using them. Then what is really the use of having

the prefixes of the link in its link-LSA.

Is there a case where the router will not include some prefixes in
intra-area-prefix LSA

but advertise in the link-LSA? I don't see any such case.

Thanks,

Manoj

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From: Paul Wells <[email-masked]>
Date: Wed, 8 Mar 2006 20:00:53 -0600

Hi Manoj,

Goyal, Manoj wrote:
> HI,
> 
> In ospfv3 the intra-area-prefix LSAs have all the prefixes and routing table
> 

For broadcast and nbma links, the prefixes in the link lsas are used by 
the DR to construct the intra-area prefix lsa associated with the 
network lsa.

> but advertise in the link-LSA? I don’t see any such case.

Prefixes for broadcast/nbma transit links are advertised by the DR on 
behalf of the attached routers, and not by the non-DR routers 
themselves.  But if you are asking if some of the prefixes won't appear 
in _any_ intra-area prefix lsa, then no, I don't think so.

Regards,
Paul