From: Jason Aarons (jaarons@xxxxxxxxxxx)
Date: Fri Sep 17 1999 - 09:18:12 GMT-3
My ARG Advanced BGP Configuration guide states;
AS not transit:
Use default network into IGP (recommended)(jason-I always redist)
Redistribute BGP into IGP (NOT recommended)
AS IS TRANSIT:
Run BGP on ALL routers and turn off sync (recommended)
Redistribute BGP into IGP, and then IGP into BGP (gotta be nuts)
Seems "Internet Routing Architectures" by Halabi states same thing.
----Original Message Follows----
From: "Peter Van Oene" <vantech@sympatico.ca>
Reply-To: "Peter Van Oene" <vantech@sympatico.ca>
To: <ccielab@groupstudy.com>
Subject: Re: BGP confusion
Date: Fri, 17 Sep 1999 07:40:53 -0700
This is what gets me. All reference material tells me that I should have
Synch on a Transit AS because its crucial to the successful routing of
transit packets. I can certainly see why I need to ensure that my routers
know what to do with the traffic they recieve, however I just can't see
why they need to know about from two sources (IGP/BGP).
Peter Van Oene
Senior Systems Engineer
UNIS LUMIN Inc.
www.unislumin.com
----- Original Message -----
From: Jason Aarons <jaarons@hotmail.com>
To: <vantech@sympatico.ca>; <ccielab@groupstudy.com>
Sent: Thursday, September 16, 1999 5:57 PM
Subject: Re: BGP confusion
> Thing of it in Internet vs intranet terms.
>
> When acting as a transit you should disable sync to pass through 60,000
> routes.
>
> When acting as a stub AS if you had 60,000 routes would you want to
> redistribute them into your internal network ? Most likely not. You
would
> set a default to one/two/three EBGP routers and let them deal with the
> 60,000 routes.
>
> HTH - jason
>
>
> ----Original Message Follows----
> From: "Peter Van Oene" <vantech@sympatico.ca>
> Reply-To: "Peter Van Oene" <vantech@sympatico.ca>
> To: <ccielab@groupstudy.com>
> Subject: BGP confusion
> Date: Thu, 16 Sep 1999 19:11:39 -0700
>
> Ok, I have an IBGP router with a bunch of routes in its BGP table.
Unless
> I disable synch, it does not post them in the main routing table. I
assume
> this is because it does not have an IGP route for the listed networks.
>
> This confuses me somewhat though. If you have a ton of networks learned
> via BGP and you are a transit AS that requires the use of intermediary
> IGBP routers, why do you have to duplicate all of the routes via IGP just
> to do routing? If thats the case why run BGP internally at all? Why no
> just redist into OSPF? Obviously I'm missing something key.
>
> Can anyone tell me where my thinking is awry here?
>
>
> Peter Van Oene
> Senior Systems Engineer
> UNIS LUMIN Inc.
> www.unislumin.com
>
>
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