BGP peer timing out

wgranada1 · ‎03-16-2007

Good day;

I'm trying to set up a BGP connection but the peers never connect. When I do a sh BGP neighbor I see No active TCP connection. I also ran a debug and get the following:

Mar 16 16:35:02.512 UTC: BGP: 10.128.72.154 open active, local address 10.128.72.156

Mar 16 16:35:02.512 UTC: TCB6769CF90 created

Mar 16 16:35:02.512 UTC: TCB6769CF90 setting property TCP_WINDOW_SIZE (0) C0480020

Mar 16 16:35:02.512 UTC: TCB6769CF90 setting property TCP_MD5KEY (5) 0

Mar 16 16:35:02.512 UTC: TCB6769CF90 setting property TCP_TOS (11) C0480000

Mar 16 16:35:02.512 UTC: TCB6769CF90 setting property TCP_OUT_TTL (24) 6769CAA6

Mar 16 16:35:02.512 UTC: TCP: Random local port generated 21102

Mar 16 16:35:02.512 UTC: TCB6769CF90 bound to 10.128.72.156.21102

Mar 16 16:35:02.512 UTC: TCP: sending SYN, seq 19990871, ack 0

Mar 16 16:35:02.512 UTC: TCP0: Connection to 10.128.72.154:179, advertising MSS 1460

Mar 16 16:35:02.512 UTC: TCP0: state was CLOSED -> SYNSENT [21102 -> 10.128.72.154(179)]

Mar 16 16:35:04.512 UTC: 10.128.72.156:21102 <---> 10.128.72.154:179 congestion window changes

Mar 16 16:35:04.512 UTC: cwnd from 1460 to 1460, ssthresh from 65535 to 2920

Mar 16 16:35:04.512 UTC: TCP0: timeout #1 - timeout is 4000 ms, seq 19990871

Mar 16 16:35:04.512 UTC: TCP: (21102) -> 10.128.72.154(179)

Mar 16 16:35:08.512 UTC: TCP0: timeout #2 - timeout is 8000 ms, seq 19990871

Mar 16 16:35:08.512 UTC: TCP: (21102) -> 10.128.72.154(179)

Mar 16 16:35:12.831 UTC: TCP0: state was SYNSENT -> CLOSED [49992 -> 10.128.72.155(179)]

Mar 16 16:35:12.831 UTC: TCB 0x7089878C destroyed

Mar 16 16:35:12.831 UTC: BGP: 10.128.72.155 open failed: Connection timed out; remote host not responding, open active delayed 27492ms (35000ms max, 28% jitter)

Mar 16 16:35:16.511 UTC: TCP0: timeout #3 - timeout is 16000 ms, seq 19990871

Mar 16 16:35:16.511 UTC: TCP: (21102) -> 10.128.72.154(179)

Mar 16 16:35:32.510 UTC: TCP0: state was SYNSENT -> CLOSED [21102 -> 10.128.72.154(179)]

Mar 16 16:35:32.510 UTC: TCB 0x6769CF90 destroyed

Mar 16 16:35:32.510 UTC: BGP: 10.128.72.154 open failed: Connection timed out; remote host not responding, open active delayed 29168ms (35000ms max, 28% jitter)

Any ides? I've been looking at this for a day now need fresh eyes to point out what I'm missing. Thank you in advance

Richard Burts · ‎03-16-2007

Warren

The debug shows that this router is running BGP and is attempting to open a connection to a neighbor (which is what you described - the debug confirms it). I do not see anything here that indicates that there is a problem on this router. What the debug shows is that this router is not receiving any response from the other router. I suspect that the issue is on the other router. I suggest that you check the configuration of the other router. It is especially important to verify that the other router is configured for BGP, that it has a neighbor statement for this router, and that the router does not have any access list filtering which would not permit the BGP packets.

Check these things and let us know what you find.

HTH

Rick

HTH

Rick

wgranada1 · ‎03-16-2007

Thank you Rick the other router belongs to

a vendor I will have him check is setting again...not that it makes any difference but this is connecting to a Juniper router...will let you know what happens and thanks again!!!

Richard Burts · ‎03-16-2007

Warren

I think it does not matter which vendor router you are connecting to. You are sending the TCP SYN packet in initiate a connection and it looks like they are not responding. So the question is why are they not responding. The mechanics of how you configure it and how you check it are different by vendor but the question of why they do not respond is fairly universal.

HTH

Rick

HTH

Rick

wgranada1 · ‎03-16-2007

no your right Rick BGP or whatever routing protocol is the same just the way you check it may be done differently...that was more of a FYI then anything but thank you for the info!!!!