From: Sanjay Bhakta (sbhakta@xxxxxxxxxxx)
Date: Tue Sep 05 2000 - 22:50:55 GMT-3
Along with this, rtr A must know how to get back to the router sourcing the
pings. In your example, router b,c,d may know about network 1.1.1.0,
however router a does not know about any of the interfaces on c & d. You
can ping from rtr b, because rtr b is directly connected to rtr a, and so
the ping source will be the interface between a & b on rtr b.
In order to test this, you should also create another loopback and advertize
it from AS200. For example, create a loopback interface on rtr d, lo0
4.4.4.4 and advertize this. Now do an extended ping from rtr d using
4.4.4.4 as source.
And remember what Lachlan said, if there is no IGP in the AS200, you should
use next-hop-self.
********
Sanjay Bhakta (RTP 9/24)
----- Original Message -----
From: <Lachlan_Kidd@data3.com.au>
To: "Ola Aiyegbusi" <ola@compath.com>
Cc: <ccielab@groupstudy.com>
Sent: Wednesday, September 06, 2000 7:55 PM
Subject: Re: IBGP, EBGP, AND ROUTE REFLECTORS
>
> Hi Ola,
> I would suggest that you need a next-hop-self on rtB. This will make
> the source of the 1.1.1.0 update appear to be rtrB for C and D. I think
the
> problem lies in the reachability of the update coming from rtrA. Rember
> that with IBGP, the source of the update does not change so C and D will
be
> seeing the update as coming from RtrA's serial port. C and D may not have
a
> route to that network and hence the old rule of 'do not advertise what you
> do not know how to reach' applies. No synch only helps with IBGP. You
could
> try advertising the A-B network with an IGP and see if that fixes the
> problem.
> I may have this completely wrong so feel free to correct me <grin>.
> Regards,
> Lachlan.
>
>
>
> "Ola
> Aiyegbusi" To: <ccielab@groupstudy.com>
> <ola@compath. cc:
> com> Subject: IBGP, EBGP, AND
ROUTE REFLECTORS
> Sent by:
> nobody@groups
> tudy.com
>
>
> 05/09/00
> 05:06 PM
> Please
> respond to
> "Ola
> Aiyegbusi"
>
>
>
>
>
> I have a problem.
>
> I can't ping an external bgp router (AS100) from another AS (AS200) that
> has a route reflector configured with no sync configured on all ibgp
> speakers in the AS (AS200)
>
> a) rtr A (AS100) and rtr B (AS200) are external neighbors connected via
> serial. They can ping each other.
> b) rtr A is advertising it's loopback address via BGP (1.1.1.1/24)
> c) rtr B can ping rtr A's loopback address
> d) In AS200, rtr B is connected to rtr C. rtr C is connected to rtr D e.g.
> (rtrB)--------(rtrC)--------(rtrD)
> e) All 3 routers above are in AS 200. rtr B is neighbored with rtrA
> (external) and rtrC (internal). rtrC is neighbored with B and D (both
> internal. rtr D is neighbored with C (internal)
> f) In AS200, rtr C is configured as the route reflector with B and D as
> clients
> g) The IGP running in AS 200 is OSPF
> h) Synchronization has been disabled in all AS 200 IBGP speakers
> g) Network 1.0.0.0 (see bullet b above) shows up in the bgp table and
> routing table of all IBGP speakers in AS 200
>
> Problem is: I can't ping 1.1.1.1 from rtr C or D, but I can ping it from
> rtr B. HELP!!!!!!!
>
> Ola Aiyegbusi
> ComPath Inc.
> 10201 Lee Hwy Suite 140 Fairfax VA 22030
> Phone: 703-383-9550 Ext. 122
> Pager: 1-888-857-5620
> Cell: 703-395-8808
> Fax: 703-383-1369
> Email: ola@compath.com
> Web: http://www.compath.com
>
>
>
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