From: Wayne Lewis (lewisway@xxxxxxxxxxxxxx)
Date: Tue Nov 27 2001 - 04:55:06 GMT-3
Sorry for the confusion. Hansang, I agree with your statement about us
ing
route-maps with redistribution. But my question wasn't whether or not to
use them, but if a prescriptive route-map for IGRP to OSPF redistribution is
acceptable on the exam. What I like to do is create a route-map specifying
the exact IGRP routes I want to redistribute into OSPF. But I'm wondering
if the powers that be might prefer that the redistribution is more dynamic
in that it would be designed to allow for 'other' IGRP routes to be
redistributed should more be added later - it's really a design question.
Considering that the scenarios in the lab exam are typically far from
practical/real-life, I'm assuming that we don't need to be especially
concerned with following design principles, as long as our method is
functional. I'd like to hear one or two people say, yeah, that's right,
you're OK with just redistributing a list of routes and denying all others.
Thanks,
Wayne
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
Hansang Bae
Sent: Monday, November 26, 2001 9:08 PM
To: ccielab@groupstudy.com
Subject: RE: flsm to vlsm
At 02:26 PM 11/27/2001 +1100, Albert Lu wrote:
>[snip]
>I'm pondering this question as well, as I see from examples in Doyle that
>redistribution between IGPs should be done carefully, so filtering via
>route-maps or distribute-list is required. That means you have to use
>route-maps and distribute-lists for all routers that are doing
>redistribution between two protocols. But Heck!!! I've seen examples that
>don't use filtering, and it still works!!
>My thoughts are that the filtering is there for precautionary measures,
just
>in case routes do feed back into the routing protocol it originated from.
>There's also the admin distance that has to be taken into account of.
>If anyone has any suggestions of the proper way of doing this, please let
me
>know
Folks,
While I understand that people are fretting about the smallest detail of
the lab (e.g. what's consider superfluous command...) there are some
definite engineering standards that should be used in the real world. One
of these is "if you redistribute, you need to route-map/distribute-list
what your redistributing." If you don't... sooner or later, you'll
experience rolling blackouts. Just about every book on IGP has examples
of route feedback causing temporary/rolling blackouts. This won't happen
every single time as it's a function of topology and routing protocols in
use. But sooner or later, you will be bitten by this.
So you should ALWAYS use route-maps (I prefer them to distribute-lists) to
control redistribution.
hsb
This archive was generated by hypermail 2.1.4 : Fri Jun 21 2002 - 06:45:23 GMT-3