From: Narbik Kocharians (narbikk@gmail.com)
Date: Wed Jul 11 2007 - 13:57:58 ART
This is the normal behavior, especially when the three routers are in the
same multi-access networks. EBGP speakers WILL NOT change the next hop
attribute in these networks. Your solution (Next-hop-self on R2 for the R3
neighbor) should have worked, and it does, but I think may be what you
should do is to try the "clear ip bgp *" command and if that does not work,
perform a Microsoft (Reload). But understand that you do not need to do any
of these for the next-hop-self command and it should take effect
immediately.
One thing that I noticed in your frame-relay configuration (BY THE WAY THAT
IS NOT THE PROBLEM HERE) is the following:
Looking at your configuration one thing that I keep seeing is the
"broadcast" keyword at end of the frame-relay map command, there is no need
for that when configuring BGP.
On 7/11/07, CCIE W <wan2bccie@gmail.com> wrote:
>
> Hi Sadiq,
>
> I am using main interface on all routers with same ip subnet.but not full
> mesh
>
> R1 ;-
>
> interface Loopback0
> ip address 100.1.1.1 255.255.255.0
> !
> interface Serial1/0
> ip address 10.1.1.1 255.255.255.0
> encapsulation frame-relay
> serial restart-delay 0
> no dce-terminal-timing-enable
> frame-relay map ip 10.1.1.2 102 broadcast
> no frame-relay inverse-arp
>
> router bgp 65101
> no synchronization
> bgp log-neighbor-changes
> network 100.1.1.0 mask 255.255.255.0
> neighbor 10.1.1.2 remote-as 65102
> no auto-summary
>
> SH IP BGP :-
>
> BGP table version is 9, local router ID is 10.1.1.1
> Status codes: s suppressed, d damped, h history, * valid, > best, i -
> internal,
> r RIB-failure, S Stale
> Origin codes: i - IGP, e - EGP, ? - incomplete
>
> Network Next Hop Metric LocPrf Weight Path
> *> 100.1.1.0/24 0.0.0.0 0 32768 i
> *> 200.1.1.0 10.1.1.2 0 0 65102 i
> R2 :-
>
> interface Loopback0
> ip address 200.1.1.1 255.255.255.0
> !
> interface Serial1/0
> ip address 10.1.1.2 255.255.255.0
> encapsulation frame-relay
> serial restart-delay 0
> no dce-terminal-timing-enable
> frame-relay map ip 10.1.1.1 201 broadcast
> frame-relay map ip 10.1.1.3 203 broadcast
> no frame-relay inverse-arp
> !
> router bgp 65102
> no synchronization
> bgp log-neighbor-changes
> network 200.1.1.0
> neighbor 10.1.1.1 remote-as 65101
> neighbor 10.1.1.3 remote-as 65103
> no auto-summary
> !
>
> SH IP BGP :-
>
> BGP table version is 11, local router ID is 10.1.1.2
> Status codes: s suppressed, d damped, h history, * valid, > best, i -
> internal,
> r RIB-failure, S Stale
> Origin codes: i - IGP, e - EGP, ? - incomplete
>
> Network Next Hop Metric LocPrf Weight Path
> *> 100.1.1.0/24 10.1.1.1 0 0 65101 i
> *> 200.1.1.0 0.0.0.0 0 32768 i
>
> R3:--
>
> interface Serial1/0
> ip address 10.1.1.3 255.255.255.0
> encapsulation frame-relay
> serial restart-delay 0
> no dce-terminal-timing-enable
> frame-relay map ip 10.1.1.2 302 broadcast
> no frame-relay inverse-arp
> !
> router bgp 65103
> no synchronization
> bgp log-neighbor-changes
> neighbor 10.1.1.2 remote-as 65102
> no auto-summary
>
> SH IP BGP
>
> BGP table version is 13, local router ID is 10.1.1.3
> Status codes: s suppressed, d damped, h history, * valid, > best, i -
> internal,
> r RIB-failure, S Stale
> Origin codes: i - IGP, e - EGP, ? - incomplete
>
> Network Next Hop Metric LocPrf Weight Path
> **> 100.1.1.0/24 10.1.1.1 0 65102 65101
> i*
> *> 200.1.1.0 10.1.1.2 0 0 65102 i
>
> Problem is here bold and underline
>
> HTH
>
> Thanks Mark
> -----Original Message-----
>
> From: nobody@groupstudy.com
> [*mailto:nobody@groupstudy.com*<nobody@groupstudy.com>]
> On Behalf Of Sadiq Yakasai
>
> Sent: Wednesday, July 11, 2007 21:17
>
> To: CCIE W
>
> Cc: Cisco certification
>
> Subject: Re: BGP Doubt
>
> hey Mark,
>
> So are you doing a Hub and Spoke setup? If yes, are you using a multipoint
> sub interface on the hub or point-to-point sub interfaces?
>
> Is possible, can u sketch something out? - Always helps ppl understand the
> topology..
>
> On 7/11/07, CCIE W <wan2bccie@gmail.com> wrote:
>
> > Dear All,
>
> >
>
> >
>
> > Could someone please help me, in following issue,
>
> >
>
> > Scenario: I have configured 3 dynamips routers connected via FR switch.
>
> > Inverse-ARP is disabled. 2 PVCs are configured Rtr A to Rtr B, & Rtr B
>
> > to Rtr C All 3 routers are in different BGP AS & are ebgp peers.
>
> >
>
> > Problem : Routes advertised on Rtr B (by Rtr A) are advertised to Rtr
>
> > C with next hop IP of Rtr A. (Normally due to EBGP relation, the next
>
> > hop should have been Rtr B). I think this is happening due to
>
> > Multi-access environment, But when I try setting the next-hop-self on
>
> > Rtr B for neighbor C, it gives following error
>
> >
>
> > %BGP: next-hop-self is implied for an eBGP peer, there is no need to
>
> > configure it
>
> >
>
> >
>
> >
>
> > Thanks
>
> > Mark.
>
> >
>
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>
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-- Narbik Kocharians CCIE# 12410 (R&S, SP, Security) CCSI# 30832
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