RE: ASR9k - ospf stuck in exchange

Dear Experts,
The IP MTU is set to 9202 at ASR end and 9202 at 7600 end. The problem occurs
when the physical link only supports 1500 not 9202. WHile the same problem is
not observed connecting 7600s, configure mtu-ignore enable on interface and
ospf will come up no matter what mtu is at physical link.

Since this is production network, still will try to get some debug ip ospf adj
and check.

Regards
Akhilesh

> Date: Mon, 23 Apr 2012 23:14:16 -0500
> From: chryan_at_cisco.com
> To: ccielab_at_groupstudy.com
> Subject: Re: ASR9k - ospf stuck in exchange
>
> Not sure if you are able to do this, because it's a production network,
> but "debug ip ospf adj" should give you some clues as to what the
> problem is.
>
> Chuck
>
> On 4/23/12 12:43 PM, AKHILESH THAKUR wrote:
> > Dear Experts,
> > I have migrated my network from 7600 to ASR9k. Before migration if the
link
> > between two router supports max mtu of 1536
> > and interface is configured with mtu9216, the ospf will come up.
> >
> > Now at one end is ASR9k with same configuration it doesnot work. I know
the
> > ASR9k put additional mtu of 14 bytes on ethernet ports and has been
adjusted.
> >
> > so at ASR9k end mtu is 9216 and 7600 end mtu is 9202. The ospf just stuck
in
> > exchange.
> > I have opened the tac case and since the link is max support 1536,
accordingly
> > needs to change the mtu at asr9k. I tired with mtu-ignore but failed.
> >
> > Wanted to know whats the difference between 7600 and asr9k ospf DBD
packet
> > handling ?
> >
> > Any of you guys faced similar issue and the way to deal with it.
> >
> > Regards
> > Akhilesh
> >
> >
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>
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> ------------------------------------
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Received on Tue Apr 24 2012 - 04:56:06 ART