[j-nsp] OSPF Debug

Scotty scott at replicenter.com
Sun Feb 22 21:32:17 EST 2004


> I'd suggest doing some 'traceoptions hello detail' and that'd capture
> the hello packets on both routers. Also, I personally like to do
> monitor traffic on the interfaces as it is simpler to see if you
> receives the OSPF packets on the interfaces from the other routers.

Ok I did that on the M160 and I get this (summarized)

# run monitor traffic interface ge-0/0/0.0
verbose output suppressed, use <detail> or <extensive> for full protocol
Listening on ge-0/0/0.0, capture size 96 bytes

21:04:35.454751 Out IP > OSPFv2 Hello length: 44
21:04:41.121834  In IP > P
3886338746:3886338773(27) ack 145002704 win 16384 <nop,nop,timestamp
1665163887 130574421>: BGP, length: 27
21:04:43.285516 Out IP > OSPFv2 Hello length: 44
21:04:51.466302 Out IP > OSPFv2 Hello length: 44
21:04:51.619965  In IP > P 27:111(84) ack 1
win 16384 <nop,nop,timestamp 1665164936 130575218>: BGP, length: 84
94 packets received by filter
0 packets dropped by kernel

The monitored box is the M160 (down state)  As I can see there is
nothing seen on the from .4 ..  yet tcp seems to work fine as you
can see the BGP session is active.
> The "attempt" state is interesting. Does it really say that? The
> M20 is in 'init' state, so it is seeing the hello's from the M160.
> And so, the question is whether the M160 is receiving the hello
> packets and if it is rejecting them for some reasons.

Correction, "Attempt" only happens in un-numbered mode..  dead time counts
down to zero and it goes to "down"  From what I can tell its not getting the
packets.  Why I wonder.

The hello detail stuff on the M20 shows that .4 does indeed send hello
packets to

Feb 22 21:19:46 OSPF sent Hello -> (ge-0/3/0.0, IFL 36)
Feb 22 21:19:46   Version 2, length 48, ID, area
Feb 22 21:19:46   checksum 0xffff, authtype 65535
Feb 22 21:19:46   mask, hello_ivl 10, opts 0x2, prio 128
Feb 22 21:19:46   dead_ivl 40, DR 1010.10.4, BDR

> My guess is that when you tried using ip addresses on the interfaces,
> you can ping between the routers because the bgp session is working.
> Are you using the GE ip addresses for your bgp endpoints? If you are
> using the loopback addresses, they may not go through this GE link.

Correct iBGP peer to the localhost IP (router-id) did not work, makes sense
though there is no IGP on the M160. so this peer is setup direct to the GE
interface IP's

> Let me know what you find! I am quite sure there aren't any changes
> between 5.6 and 6.2 in basic OSPF that may cause this problem but I'll
> set it up myself and verify that. Thanks.

Right, looking at the release notes I don't see anything shocking.


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