[Xorp-users] OSPF point-to-multipoint issue
Vincent, Michael - 0665 - MITLL
michael.vincent at ll.mit.edu
Fri Jun 18 12:42:21 PDT 2010
> So, in this case, router 1 has Full adjacency to 3, but 3 shows 1 as Down??
> If so, that seems wrong, but maybe I just don't understand point to multi-point OSPF configs...
Agreed. Hence our dilemma.
Cheers.
--
Michael J. Vincent
Group 65 - Advanced Networks and Applications
MIT Lincoln Laboratory
244 Wood Street
Lexington, MA 02420
Office: +1.781.981.3459
-----Original Message-----
From: Ben Greear [mailto:greearb at candelatech.com]
Sent: Friday, June 18, 2010 3:34 PM
To: Vincent, Michael - 0665 - MITLL
Cc: xorp-users at xorp.org; Zuena, John - 0665 - MITLL
Subject: Re: [Xorp-users] OSPF point-to-multipoint issue
On 06/18/2010 12:21 PM, Vincent, Michael - 0665 - MITLL wrote:
>> Ahh, so to get to the original peer, it needs to first remove the routes on the secondary link?
>
> Not necessarily, you can still get there (data path) through the multi-hop path; however, OSPF won't form an adjacency over a multi hop. So to that point, yes, the host route that OSPF added needs to be removed for OSPF to then re-form it's adjacency. Catch-22 sounds appropriate.
>
>
> I've only included the outputs for nodes 1 and 3 as that is what the example is talking about. The actual experiment fails other links also and thus more peering sessions go down and do not re-establish.
>
>
> START:
> root at nlet-89-1> show ospf4 neighbor
> Address Interface State ID Pri Dead
> 172.16.1.2 eth1/eth1 Full 10.10.1.2 128 2
> 172.16.1.3 eth1/eth1 Full 10.10.1.3 128 3
> 172.16.1.4 eth1/eth1 Full 10.10.1.5 128 3
> 172.16.1.5 eth1/eth1 Full 10.10.1.5 128 2
> 172.16.1.6 eth1/eth1 Full 10.10.1.6 128 2
> 172.17.2.1 eth2.1212/eth2.1212 Full 10.10.1.8 1 31
> root at nlet-89-1>
>
> --
>
> [root at nlet-89-3 DISA]# xorpsh -c "show ospf4 neighbor"
> Welcome to XORP on nlet-89-3
> root at nlet-89-3> show ospf4 neighbor
> Address Interface State ID Pri Dead
> 172.16.1.1 eth1/eth1 Full 10.10.1.1 128 2
> 172.16.1.2 eth1/eth1 Full 10.10.1.2 128 3
> 172.16.1.4 eth1/eth1 Full 10.10.1.4 128 2
> 172.16.1.5 eth1/eth1 Full 10.10.1.5 128 3
> 172.16.1.6 eth1/eth1 Full 10.10.1.6 128 3
> root at nlet-89-3> [root at nlet-89-3 DISA]#
>
>
> INTERMEDIATE:
> root at nlet-89-1> show ospf4 neighbor
> Address Interface State ID Pri Dead
> 172.16.1.2 eth1/eth1 Down 10.10.1.2 0 0
> 172.16.1.3 eth1/eth1 Full 10.10.1.3 128 3
> 172.16.1.4 eth1/eth1 Down 10.10.1.5 0 0
> 172.16.1.5 eth1/eth1 Down 10.10.1.5 0 0
> 172.16.1.6 eth1/eth1 Down 10.10.1.6 0 0
> 172.17.2.1 eth2.1212/eth2.1212 Full 10.10.1.8 1 31
> root at nlet-89-1>
>
> --
>
> [root at nlet-89-3 DISA]# xorpsh -c "show ospf4 neighbor"
> Welcome to XORP on nlet-89-3
> root at nlet-89-3> show ospf4 neighbor
> Address Interface State ID Pri Dead
> 172.16.1.1 eth1/eth1 Down 10.10.1.1 0 0
> 172.16.1.2 eth1/eth1 Down 10.10.1.2 0 0
> 172.16.1.4 eth1/eth1 Full 10.10.1.4 128 2
> 172.16.1.5 eth1/eth1 Down 10.10.1.5 0 0
> 172.16.1.6 eth1/eth1 Down 10.10.1.6 0 0
> root at nlet-89-3> [root at nlet-89-3 DISA]#
So, in this case, router 1 has Full adjacency to 3, but 3 shows 1 as Down??
If so, that seems wrong, but maybe I just don't understand point to multi-point
OSPF configs...
>
>
> FINAL:
> root at nlet-89-1> show ospf4 neighbor
> Address Interface State ID Pri Dead
> 172.16.1.2 eth1/eth1 Down 10.10.1.2 0 0
> 172.16.1.3 eth1/eth1 Full 10.10.1.3 128 3
> 172.16.1.4 eth1/eth1 Down 10.10.1.5 0 0
> 172.16.1.5 eth1/eth1 Down 10.10.1.5 0 0
> 172.16.1.6 eth1/eth1 Down 10.10.1.6 0 0
> 172.17.2.1 eth2.1212/eth2.1212 Full 10.10.1.8 1 31
> root at nlet-89-1>
>
> --
>
> [root at nlet-89-3 DISA]# xorpsh -c "show ospf4 neighbor"
> Welcome to XORP on nlet-89-3
> root at nlet-89-3> show ospf4 neighbor
> Address Interface State ID Pri Dead
> 172.16.1.1 eth1/eth1 Down 10.10.1.1 0 0
> 172.16.1.2 eth1/eth1 Down 10.10.1.2 0 0
> 172.16.1.4 eth1/eth1 Full 10.10.1.4 128 2
> 172.16.1.5 eth1/eth1 Down 10.10.1.5 0 0
> 172.16.1.6 eth1/eth1 Down 10.10.1.6 0 0
> root at nlet-89-3> [root at nlet-89-3 DISA]#
3 still shows 1 as Down?
Thanks,
Ben
--
Ben Greear <greearb at candelatech.com>
Candela Technologies Inc http://www.candelatech.com
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