Re: Route Selection in BGP

One of my students gave me the following formula to remember the order:

*W*ho *L*ikes *N*arbik's *A*nswer *O*ver *M*ine *E*veryone.

On Mon, May 3, 2010 at 4:34 PM, Kambiz Agahian <kagahian_at_ccbootcamp.com>wrote:

> Hi there,
>
> It's only 75F now so not a real "hell" YET!
>
> Anyway, there is big difference between these 2 attributes. Actually I
> can't think of many real world/CCIE examples that you've got both
> options available to you. The local-pref feature does get propagated
> across your BGP peers in your AS and it influences the decision of how
> my BGP nodes go out. The Weight attribute on the other hand, is a local
> feature only so can be configured on your BGP boxes that have 2
> (logical/physical) connections. This attribute affects your local
> decision only (local on that particular box).
>
> For instance, you have a router with 2 connections one goes to ATT and
> the other one goes to SPIRINT you want to use ATT as long as it's
> available; in this case I'd configure the Weight (if do I have Cisco
> gear). But let's say you have 5 BGP routers with various connections and
> you'd like to let your BGP peers in your AS know that in order to get to
> any IP ranges within MSN they're better off taking the path offered by
> RTR101 which is connected to SPIRINT as long as it's up. But for the
> rest of the prefixes you don't really care. In this case I'd configure
> the local-pref for the customer.
>
> Please read through the volume 2 of TCP/IP by Jeff Doyle for more
> information on this.
>
>
> HTH
>
> --------------------------
> Kambiz Agahian
> CCIE (R&S), CCSI, WAASSE, RSSSE
> Technical Instructor
> CCBOOTCAMP - Cisco Learning Solutions Partner (CLSP)
> Email: kagahian_at_ccbootcamp.com
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>
>
>
>
> -----Original Message-----
> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
> oluwaseyi ojo
> Sent: Monday, May 03, 2010 4:04 PM
> To: Cisco certification
> Subject: Route Selection in BGP
>
> Hell,
>
>
> In the lab if you are given a task to influence route selection based on
> weight and local pref.
>
> Can you use both weight and local pref attributes to influence route
> selection or use either?
>
> Comments will be deeply appreciated.
>
> Thanks in advance.
>
> Ojo Oluwaseyi O.
>
>
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-- 
Narbik Kocharians
CCSI#30832, CCIE# 12410 (R&S, SP, Security)
www.MicronicsTraining.com
Sr. Technical Instructor
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