From: WorkerBee (ciscobee@gmail.com)
Date: Tue May 22 2007 - 18:39:15 ART
How about this ->
- debug ip tcp packet port 179
- clear ip bgp A.B.C.D (BGP neighbor address to clear)
You can see that R1 is using 1.1.17.1 to peer to 1.1.17.7. However, the remote
end is using 1.1.7.7 and trying to connect back. Since R1 defined the remote
end as 1.1.17.7 as remote peer, it sends a TCP RST packet to it and refuse
the BGP connection.
HTH
*May 22 22:05:13.955: tcp0: I LISTEN 1.1.7.7:11013 1.1.17.1:179 seq 3135701452
OPTS 4 SYN WIN 16384
*May 22 22:05:13.955: TCP: sent RST to 1.1.7.7:11013 from 1.1.17.1:179
*May 22 22:05:30.003: tcp0: O CLOSED 1.1.17.7:179 1.1.17.1:15759 seq 1737117660
OPTS 4 SYN WIN 16384
*May 22 22:05:30.003: tcp0: I SYNSENT 1.1.17.7:179 1.1.17.1:15759 seq 3676273756
OPTS 4 ACK 1737117661 SYN WIN 16384
*May 22 22:05:30.003: tcp0: O ESTAB 1.1.17.7:179 1.1.17.1:15759 seq 1737117661
ACK 3676273757 WIN 16384
*May 22 22:05:30.007: tcp0: I ESTAB 1.1.17.7:179 1.1.17.1:15759 seq 3676273757
RST WIN 16384
*May 22 22:05:30.007: tcp0: O CLOSED 1.1.17.7:179 1.1.17.1:15759 seq 1737117661
DATA 45 ACK 3676273757 PSH WIN 16384
On 5/23/07, Rocco R21 <roccor21@hotmail.com> wrote:
> Hi,
>
> Does anybody know a way to see what a potential BGP neighbor router is using
> as a destination IP address when trying to establish a TCP session on 179
> without going into the router's configuration to check? I've tried using
> 'debug ip packet detail' but this doesn't show what remote EBGP peer is
> trying to connect to my router, and with what destination IP they are trying
> to connect?
>
> For example R1 and R2 are to EBGP peers. If I'm telneted into R1 and running
> 'debug ip packet detail' I can only see R1's source IP and the destination
> it's trying to connect to. I don't see the inbound TCP connection from R2.
> I've tried this both ways where R1/R2 have been the server and client
> speakers.
>
> What I'm basically trying to do is troubleshoot if I were using the wrong IP
> address as a destination in my BGP configuration and did not have access to
> the BGP router I was tring to connect to. There may be a simple answer or
> trick for this I'm hoping. Any suggestions are appreciated. Thanks
>
> Rocco
>
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This archive was generated by hypermail 2.1.4 : Fri Jun 01 2007 - 06:55:21 ART