BGP problem

[Ahmede]

BGP was up and suddenley it went down and it doesn't want to come up again.. We removed all the BGP config and it just came down to the neighbor statments but still down.. We ran debug for TCP and BGP and here's the output..

112828: May 9 18:00:20.160: TCP0: Data repacketized, seq 2642756153, sent 56 byte

112829: May 9 18:00:26.024: TCB63A095A0 created

112830: May 9 18:00:26.024: TCP0: state was LISTEN -> SYNRCVD [179 -> 10.133.23

.17(15269)]

112831: May 9 18:00:26.024: TCP0: Connection to 10.133.23.17:15269, received MSS 1460, MSS is 516

112832: May 9 18:00:26.024: TCP: sending SYN, seq 2151872273, ack 2653104385

112833: May 9 18:00:26.024: TCP0: Connection to 10.133.23.17:15269, advertising MSS 1460

112834: May 9 18:00:26.024: TCP0: state was SYNRCVD -> ESTAB [179 -> 10.133.23.17(15269)]

112835: May 9 18:00:26.024: TCB6388CA58 callback, connection queue = 1

112836: May 9 18:00:26.024: TCB6388CA58 accepting 63A095A0 from 10.133.23.17.15269

112837: May 9 18:00:26.024: BGP: 10.133.23.17 passive open

112838: May 9 18:00:26.024: BGP: 10.133.23.17 went from Active to Idle

112839: May 9 18:00:26.024: BGP: 10.133.23.17 went from Idle to Connect

112840: May 9 18:00:26.028: TCP0: RST received, Closing connection

112841: May 9 18:00:26.028: TCP0: state was ESTAB -> CLOSED [179 -> 10.133.23.17(15269)]

112842: May 9 18:00:26.836: BGP: 10.133.23.17 remote close, state CLOSED

112843: May 9 18:00:26.836: BGP: 10.133.23.17 -reset the session

112844: May 9 18:00:27.836: BGP: 10.133.23.17 went from Connect to Idle

112845: May 9 18:00:27.836: BGP: 10.133.23.17 closing

112846: May 9 18:00:27.836: TCB 0x63A095A0 destroyed

112847: May 9 18:00:27.836: BGPNSF state: 10.133.23.17 went from nsf_not_active

to nsf_not_active

112848: May 9 18:00:48.833: BGP: 10.133.23.17 went from Idle to Active

112849: May 9 18:00:48.833: BGP: 10.133.23.17 open active, delay 18155ms

Any help please...

[Ahmede]

My first posting include debug ip bgp and debug ip tcp trans..

[Harold Ritter]

The most important part, which is when the session status gor from idle to connect is missing from the output you provided.

Thanks,

[jrahm]

The initial posting includes the successful TCP handshake, the Idle->Connect msg, then immediately a reset from the far end.

[Harold Ritter]

I was referring to the BGP idle -> connect transition, just like you provided for the other router.

Thanks,

[jrahm]

For whatever reason, the transport connection cannot get to Established. One side appears to get to Active, the other to OpenSent, but neither side can complete the process. The router ID in one of your posts above is showing up as 0.0.0.0, which is odd.

[Ahmede]

I think you see the remote router ID as 0.0.0.0 because BGP did not come up so the router can't detremine the remote router ID..

[Ahmede]

That's all we get from the debug.. It keeps on repeating.. Nothing more..

[Harold Ritter]

This doesn't jive with what we see in the "sh ip bgp nei 10.133.23.17", which show that 859 BGP open messages have been sent to the peer. We see none being received on the other side.

Something else is weird. The sh ip bgp nei shows:

External BGP neighbor may be up to 255 hops away

But ebgp-multihop is not configured on this neighbor.

I would recommend you move to the latest 12.3 mainline before proceeding with the troubleshooting of this issue.

Hope this helps,

[Ahmede]

I did upgarde my router to 12.3.13a and still not coming up.. Also I did remove all BGP config from my router and created new BGP with the wrong AS#, and I was waiting to get this message..

000199: May 11 14:54:12.736: %BGP-3-NOTIFICATION: received from neighbor 172.31.1.89 2/2 (peer in wrong AS) 2 bytes 0001

But I didn't.. I think we are not receiving any BGP updates...

[jrahm]

what type of interface are the neighbor IP's addresses configured on?

Do you have any acl's on the transit interfaces?

[Ahmede]

The inetrfaces are FE and they are connected via switch,,, No access lists any where...

[Sanjeewa Alahakone]

Hi,

Please disregard this post if someone allready suggested the following,

I would get the following information to start with

conf t

no ip domain-lo

end

Router#sh tcp brief

TCB Local Address Foreign Address (state)

01A5C4F8 1.1.1.2.179 1.1.1.1.23905 ESTAB

sh tcp tcb 01A5C4F8

I think if you get the far end router to clear the tcp session session will be comeup.

e.g.

Router#clear tcp tcb 01A5C4F8

[confirm]

[Tanmoy]

Hi all,

What may be the possible cause...kindly explains