From: Brian McGahan (brian@xxxxxxxxxxxxxxx)
Date: Mon May 06 2002 - 15:56:02 GMT-3
Jason,
This is most likely due to the BGP session being in 'race'
state, synchronization, or both. I'd have to see your exact configs to
be sure.
On synchronization:
http://www.cisco.com/univercd/cc/td/doc/cisintwk/ics/icsbgp4.htm#xtocid2
04397
On race state:
"The neighbor negotiation process is mainly the same for internal and
external neighbors as far as building the TCP connection at the
transport level. It is essential to have IP connectivity between the two
neighbors for the transport session to take place. IP connectivity has
to be achieved via a protocol different from BGP; otherwise, the session
will be in a race condition. An example of a race condition follows:
neighbors can reach one another via some IGP, the BGP session gets
established, and the BGP updates get exchanged. The IGP connection goes
away for some reason, but still the BGP TCP session is up because
neighbors can still reach each other via BGP. Eventually the session
will go down because the BGP session cannot depend on BGP itself for
neighbor reachability."
- Halabi, Basaam. "Internet Routing Architectures"
Paste your configs if you're still having trouble.
HTH
Brian McGahan
CCIE #8593
brian@cyscoexpert.com
CyscoExpert Corporation
Internetwork Consulting & Training
http://www.cyscoexpert.com
Voice: 847.674.3392
Fax: 847.674.2625
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Jason Wydra
Sent: Monday, May 06, 2002 1:26 PM
To: ccielab@groupstudy.com
Subject: IBGP HELP??
I have AS 3127 with 3 routers. R1 is connected to R2 via Token ring. R2
is connected to R3 via Ethernet. R1 and R3 do not have a direct
connection. They are attempting to peer through R2. R1 and R2 neighbor
states are active. R2 and R3 neighbor state is active. R1 and R3
neighbor state will NOT come up. The network on link between R1 and R2
is 204.156.20.0/30 and network between R2 and R3 is 165.40.22.0/23. From
R1 I CANNOT ping R3. R1 has learned a route from BGP to R3. Looking on
R3 it has not learned a route to R1 (From R2). This is obviously why I
cannot ping from R1 to R3 and this is also why the BGP peer won't come
up. Simply adding a static route on R3 pointing to R1 solves the problem
and my BGP peers comes up. My question is why does R2 tell R1 about the
165 network but R2 does not tell R3 about the 204 network? Why do I have
to add a static to R3? Please help!!
Jason Wydra
CCNP,CCDP
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