From: Peng Li (lipeng@xxxxxxxxxx)
Date: Fri Aug 31 2001 - 08:03:55 GMT-3
Hi,
I think there's several examples in the book either Jeff overlooked or doesn't
elaborate in much detail or maybe some misunderstanding If I dare to challenge.
One of the AM example is what you discovered. According to my understanding and
lab results, the "network xxx backdoor" does't change the Ebgp into IBGP with
changing AD from 20-200. This is not the way it works. When you finish you conf
ig of AM command, you should shut down the EBGP neibor and see the difference.
It works now. The reason is that it takes time for EBGP tcp connection to setup
and get routes with AD20, approximately 40-50 seconds. By this time, the rip a
lready got the route and by using "network" command . The rip learned route is
already entered in Local BGP table with Weitht 32768 much hiher than the later
learned EBGP with Weight of 100, this cause the Router deny EBGP routes and pre
fer IBGP one. at the same time, he keeps the RIP one in RT.
Hope it helps and correct me if I'm wrong.
Take care.
My lab is Oct.10 in Beijing.
----- Original Message -----
From: "Michael Wong" <Michael.Wong@nec.com.au>
To: "Groupstudy - CCIELAB (E-mail)" <>
Sent: Friday, August 31, 2001 1:40 AM
Subject: BGP Backdoor (Doyle Vol II page 240)
> BGP gurus .....
>
> Has anyone managed to get BGP backdoor to work properly ??? I'm going through
Doyle's example on page 240 and I can't seem to get the BGP backdoor command t
o work properly.
>
> The funny thing is that I am able to get the correct results and change the E
BGP route to a local BGP route and make RIP take precedence over the local BGP
route with the "network 172.18.0.0" command, however when I use the same networ
k command and just add "backdoor" to it, the RIP routes do not appear .... stra
nge I thought ????
>
> The RIP routes are definitely getting through as when I close the BGP session
s, the RIP routes appear in the routing table. It seems that when the "backdoor
" command is added to the network command, BGP does not modify the EBGP to a lo
cal BGP route and the route table still has an AD of 20.
>
> Any thoughts ????
>
> Thanks peoples ..... MW
> **Please read:http://www.groupstudy.com/list/posting.html
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