From: Cecil Wilson (Cecil.Wilson@flextronics.com)
Date: Thu Sep 27 2007 - 12:44:19 ART
Seems a little confusing
1. locally origin routes will be select oover ebgp however in terms
of AD
EBGP 20
IBGP 200
RIP 120
So in terms of AD external BGP routes should be selected over IBGP?
Im I looking at it wrong?
Cecil G. Wilson
IT Network Services
Office: (901) 215-2710
Cell: (901) 601-6201
cecil.wilson@flextronics.com
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Ben
Sent: Thursday, September 27, 2007 10:23 AM
To: Gregory Gombas
Cc: Cisco certification
Subject: Re: RIP is preferred over eBGP!
Gregory,
Step 1: Router B is faced with two BGP sources, ebgp and locally
originated (redistributed from RIP).
BGP decision process will pick the locally originated over the ebgp
route (Wendel Odom)
W - weight
L - local preference
L - locally originated
A - AS path
O - Origin
M - MED
N - Neighbor Type
I - cannot remember :)
Step 2: BGP administrative distance for locally originated is 200, for
RIP 120. RIP therefore wins.
In case I've got the sequence figured out wrongly, comments are welcome.
Ben
On 9/26/07, Gregory Gombas <ggombas@gmail.com> wrote:
>
> I'm seeing the following quirk in a production network:
>
> BGP-->
> RIP-->
> RTRA----------RTRB
>
> Router A is directly connected to router B and is sending the same
> routes via RIP and eBGP.
> Router B is also redistributing the RIP routes into BGP (but filtered
> from sending back to A)
>
> When you look at the route table on RouterB, it shows the routes as
> RIP routes!
> You would think the eBGP learned routes would be preferred because of
> lower AD.
> But when I look at BGP table it shows the route originated locally and
> thus preferred over eBGP learned route.
> When I clear ip route the route is then shown as a eBGP route in the
> routing table and BGP route table does not show the locally originated
> route!
>
> Just wondering if anyone else has seen this...
>
> ______________________________________________________________________
> _ Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Sat Oct 06 2007 - 12:01:16 ART