From: Gary Woodward (aoqo89@dsl.pipex.com)
Date: Mon May 03 2004 - 10:53:28 GMT-3
I had the Bad LSA message occuring all the time on our network in the logs.
After much investigation, it turned out to be a "native vlan mismatch" on a
cataylst switch was the root cause. The OSPF Hello multicasts from one VLAN
were being seen in another seperate VLAN.
This occured because one end of the switch to switch connection were in a
different VLANs. This meant that broadcasts/multicats from one VLAN were
being propogated into the other.
The router seeing these multicasts generated a Bad LSA message in the logs
once the native vlan mismatch was removed the error ceased.
Might be worth having a trawl through your catalysts to see if you can see
any native vlan mismatch messages and fixing those to see if it removes your
problem.
Regards
Gary Woodward
----- Original Message -----
From: "Peter van Oene" <pvo@usermail.com>
To: <ccielab@groupstudy.com>
Sent: Monday, May 03, 2004 12:41 AM
Subject: Re: BAD LSA in OSPF Database - How to determine originator
> At 04:36 PM 5/2/2004, Bob Sinclair wrote:
> >Remember that when you issue the command "show ospf database" you see one
> >line per LSA. Each Router LSA may report multiple links. Try issuing
the
> >command:
> >
> >show ip ospf database router
> >
> >This will give you a more comprehensive list of actual links in that
area.
> >If you have a lot of links, try issuing the above with a "pipe include"
on
> >the end, e.g.
> >
> >sh ip ospf database router | include 1.1.1.0
> >
> >Are you running multiple protocols? You could be seeing this LSA from
> >multiple ABRs if you are doing mutual redistribution at multiple points
with
> >another protocol.
>
> Type 3's are IA routes. Redistribution shouldn't come into play. You
> should only see these three's in areas where they don't live in
> 1/2's. All one needs to do is look at the ospf database and see who
> advertised the three.
>
> >HTH,
> >
> >Bob Sinclair
> >CCIE #10427, CISSP, MCSE
> >www.netmasterclass.net
> >
> >----- Original Message -----
> >From: "CCIE 2004" <ccie2004@excite.com>
> >To: <ccielab@groupstudy.com>
> >Sent: Sunday, May 02, 2004 3:21 PM
> >Subject: BAD LSA in OSPF Database - How to determine originator
> >
> >
> > > Hi, I am trying to figure out if you have a Bad LSA being generated by
> >ABR's how do you find out who is the originator. I have looked around and
am
> >going in circles because all I have are summary LSA's pointing to the
other
> >ABRs. My thinking is that the LSA has to be originated somewhere. I have
> >checked all ABR's and do not find anything except Type 3 LSA's. This is
> >causing a subnet to be blackholed because the routers are seeing a /26
> >coming from somewhere. Can someone please lay out the steps to follow to
> >troubleshoot this. Thanks
> > >
> > > _______________________________________________
> > > Join Excite! - http://www.excite.com
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> > >
> > >
This archive was generated by hypermail 2.1.4 : Wed Jun 02 2004 - 11:12:03 GMT-3