Subject: Re: Router link origination when interface is up

From: Rajesh G <[email-masked]>
Date: Fri, 13 Dec 2002 17:17:14 -0000

Thanks Acee, but I am not able to appreciate the need
of advertising a network as stub and let all other routers
flood that info and then after a small period again advertise
the network as transit.
    what exactly are we gaining by advertising immediately when
the interface is up instead of delaying till we come out of the
waiting state?

On Thu, 12 Dec 2002 Acee Lindem wrote :
>Rajesh G wrote:
>>Hi,
>>
>>       When ospf is enabled on an interface in which we
>>already
>>have valid DR and BDR for the network, we face the following
>>problem. As soon as the interface comes up a router LSA is
>>generated stating the network as stub (as we don't have
>>knowledge
>>about other routers in the n/w). After some time we get a
>>hello
>>packet from a neighbor giving us the DR and BDR for the n/w
>>which
>>we accept. Here we do not re-build our own router LSA. Even if
>>we
>>run the DR election and dont find any change in the DR status,
>>we
>>still don't rebuild our router LSA. So we advertise the n/w as
>>stub link, till the refresh interval.
>>
>>      What could be the possible solution to avoid this
>>problem.
>>My guess is that we should not originate our router LSA till
>>we
>>are sure about the nature of the network (either our wait
>>timer
>>expires or we get a Hello with a valid DR and BDR on the n/w).
>>Is
>>this correct? please give your inputs.
>
>Rajesh - don't delay origination. You should re-originate your
>router LSA when you go to FULL state with the DR. Look at
>section
>12.4 in RFC 2328.
>
>>
>>TIA,
>>
>>Rajesh
>>
>
>
>--
>Acee

---

From: Acee Lindem <[email-masked]>
Date: Fri, 13 Dec 2002 12:31:32 -0500

> the interface is up instead of delaying till we come out of the

The wait interval (in terms of connectivity) is not a small
period. It is better just to re-originate your router LSA as
changes occur and only delay MinLSInterval seconds between
sucessive originations of the same LSA.

--
Acee