From: Gregory W. Posey Jr. (gposey@xxxxxxxxxxx)
Date: Mon Sep 10 2001 - 09:09:45 GMT-3
I've never heard of the AS# purpose outlined below, but I do know that "set
tag" helps give more granular control over routing information.
For example, you can set a tag on routes learned on E0 to be one thing, and
those learned on S0 to be something else. As those routes pass through the
network, a downstream router can allow routes with the 1st tag, but deny the
others (or set a different metric depending on the tag, or redistribute
based on tag, etc.).
I hope this helps.
I think Doyle Vol. I (or Advanced IP Routing) may have some examples, if I
find one then I'll post it.
Thank you,
Greg Posey Jr.
CCIE #7981
CCDA/CCNP - Security Specialist
Cisco Voice Access Specialist
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
jonatale@earthlink.net
Sent: Monday, September 10, 2001 2:42 AM
To: kenairs
Cc: ccielab@groupstudy.com
Subject: Re: set tag in route map
Check RFC1771 (BGP) and/or the ~= "OSPF to BGP Interaction" RFC (I don't
know
the number).
I remember something about setting the tag to the neighbor AS#. I think
newer
Cisco IOS does this by default.
The intent was if you redistribute BGP into the IGP and then back into BGP
on
the other side of your AS then BGP path info could be maintained. I think in
practice this proved to be impractical. The problem is that the tag field is
not big enough to hold the entire AS path - so BGP AS path loops can not be
totally eleminated with this method.
kenairs wrote:
> Hi ,
> Can i ask how is the set tag < value > in route-map used for ?
>
> Or
> can point me to some sample config regarding this ?
> Tks
> **Please read:http://www.groupstudy.com/list/posting.html
**Please read:http://www.groupstudy.com/list/posting.html
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