From: Hai Phung (harryuts@yahoo.com)
Date: Mon Feb 17 2003 - 04:59:54 GMT-3
In BGP, you can ping does not mean that peers can establish BGP session.
In order to get two eBGP peers which are more than 1 hop away from each
other to form session, you need this command "neighbor x.x.x.x
ebgp-multihop 255"
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Teisberg, Evan
Sent: Saturday, February 15, 2003 12:05 AM
To: 'Janto Cin'; sascha.lemberg@degussa.com
Cc: ccielab@groupstudy.com
Subject: RE: Antwort: Re: Antwort: BGP neighbor
I ran into this same issue in a test lab I set-up a while back. I have
read
documents that say that as long as you can ping, you can form a BGP
session.
I found that if you have a default route pointing both ways (ip route
0.0.0.0 0.0.0.0 x.x.x.x)and are not using a directly connected peer
address
(instead your using loopbacks and update source) on either side that BGP
will NOT establish. But you can of course ping.
I had to put a more specific route on at least one side.
If you put in at least:
"ip route 44.0.0.0 255.0.0.0 173.168.40.1" on R1
OR
"ip route 10.0.0.0 255.0.0.0 173.168.40.2" on R2
I think it was enough to get BGP to establish.
I believe I only needed a more specific route on one side (more specific
than default).
BGP apparently can't rely solely on default routes to establish a
connection
if your peer addresses are not a directly connected subnet (loopbacks on
both sides and update source).
Maybe someone else can explain why that is.
-Evan
-----Original Message-----
From: Janto Cin [mailto:jantocin@datacomm.co.id]
Sent: Friday, February 14, 2003 6:38 AM
To: sascha.lemberg@degussa.com
Cc: ccielab@groupstudy.com
Subject: Re: Antwort: Re: Antwort: BGP neighbor
still doesn't solve the problem.
i try this config below and it works:
r1
--- router bgp 1 neigh 173.168.40.2 remote 1 neigh 173.168.40.2 update lo0r2 ---- router bgp 1 neigh 10.33.1.1 remote 1
but why? please if somebody can give explanation about this? TIA. Janto ----- Original Message ----- From: <sascha.lemberg@degussa.com> To: <jantocin@datacomm.co.id> Sent: Friday, February 14, 2003 7:28 PM Subject: Antwort: Re: Antwort: BGP neighbor
after that do a "clear ip bgp *" .
Mit freundlichen Gr|_en / Best regards
Sascha Lemberg
its.on Global Network Services T +49.(0)69 218 5663 E-Mail: sascha.lemberg@degussa.com
"Janto Cin" <jantocin@datac An: <sascha.lemberg@degussa.com> omm.co.id> Kopie: <ccielab@groupstudy.com>, <nobody@groupstudy.com> Thema: Re: Antwort: BGP neighbor 14.02.2003 13:24
still doesn't solve the problem. any idea? btw thanks for your reply.
janto ----- Original Message ----- From: <sascha.lemberg@degussa.com> To: "Janto Cin" <jantocin@datacomm.co.id> Cc: <ccielab@groupstudy.com>; <nobody@groupstudy.com> Sent: Friday, February 14, 2003 7:17 PM Subject: Antwort: BGP neighbor
add an next-hop-self entry.
router bgp 1 neighbor 44.1.1.1 remote 1 neighbor 44.1.1.1 update lo0 neighbor 44.1.1.1 next-hop-self
router bgp 1 neighbor 10.33.1.1 remote 1 neighbor 10.33.1.1 update lo0 neighbor 10.33.1.1 next-hop-self
Mit freundlichen Gr|_en / Best regards
Sascha Lemberg
its.on Global Network Services T +49.(0)69 218 5663 E-Mail: sascha.lemberg@degussa.com
"Janto Cin" <jantocin@datac An: <ccielab@groupstudy.com> omm.co.id> Kopie: Gesendet von: Thema: BGP neighbor nobody@groupstu dy.com
14.02.2003 13:04
Bitte antworten an "Janto Cin"
Dear All,
Please help on my problem below:
(lo0)R1(s0)-------------(s0)R2(lo0)
R1(lo0): 10.33.1.1/24 R1(s0): 173.168.40.1/24 R2(s0): 173.168.40.2/24 R2(lo0): 44.1.1.1/24
R1 ---- ip route 0.0.0.0 0.0.0.0 173.168.40.2
router bgp 1 neighbor 44.1.1.1 remote 1 neighbor 44.1.1.1 update lo0
R2 ---- ip route 0.0.0.0 0.0.0.0 173.168.40.1
router bgp 1 neighbor 10.33.1.1 remote 1 neighbor 10.33.1.1 update lo0
I can ping R1 lo0 from R2 and vice-versa, but why the bgp connection still not established? I turn on debug ip bgp on both routers and get this: on R1 -------- 01:45:46: BGP: 44.1.1.1 multihop open delayed 17789ms (no route)
on R2 -------- 01:35:20: BGP: 10.33.1.1 multihop open delayed 11888ms (no route)
TIA, Janto
This archive was generated by hypermail 2.1.4 : Sat Mar 01 2003 - 11:06:26 GMT-3