From: Michael Snyder (msnyder@xxxxxxx)
Date: Sat Jun 08 2002 - 23:31:44 GMT-3
I haven't tried tagging with rip. I know that rip version 1 would have
a big problem with it.
But, why tag in the rip? Unless I was doing three way redistribution,
with rip v2 as transit in the middle (there's a poor design). I would
do everything on the ospf side.
Remember to block route feedback, you only have to block route return on
one side.
Tag the rip as it enters the ospf, and don't let those tags return back
into rip via route-map.
route-map stopimport deny 10
match tag 111
!
route-map stopimport permit 20
That's what I would do. Same with rip and eigrp. Do everything on the
eigrp side.
Now, the nightmare would be rip v1 and igrp. Hello distribute list.
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Treptow, Georg
Sent: Saturday, June 08, 2002 8:42 PM
To: 'Tom Larus'; Anthony Pace; Dennis Laganiere; 'Paul Connelly';
ccielab@groupstudy.com
Subject: RE: OSPF tags as a way to stop route feedback from
redistribution -- what is the downside?
This unfortunatly is not an answer but more of an extension to Tom's
question.....
I have recently done a lot of work on tagging, one of my scenarios that
I
tried did not work out that great..
R1--------------R6----
RIP v.1 |
| OSPF
R10--|
|
R4--------------R13---
R1,R4 are redistribution routers between RIP v.1 and OSPF, R10 runs
RIPv.1
only. R6 and R10 OSPF only.
I thought to myself that there has to be a better way of redistribution
from
RIP to OSPF and vice versa.
Instead of doing distribute/prefix lists I tagged all routes going into
the
RIP domain (from OSPF) at R1 with 1111 and R4 I used 4444.
At R1 I declared all routes with a tag of 4444 to be dismissed from
redistribution back into OPSF and at R4 i did the same blocking all
routes
with a tag of 1111 but allowing all others. For whatever reason all
routes
from the RIP domain were blocked.
Is it possible that RIP gets rid of tag information? Am I missing
something
here?
Thanks,
Georg Treptow
-----Original Message-----
From: Tom Larus [mailto:tlarus@novacoxmail.com]
Sent: Saturday, June 08, 2002 8:21 PM
To: Anthony Pace; Dennis Laganiere; 'Paul Connelly';
ccielab@groupstudy.com
Subject: OSPF tags as a way to stop route feedback from redistribution--
what is the downside?
I'd like to ask about the downside of another approach that seems too
good
to be true. In doing practice labs, I like to tag routes from other
protocols as they are redistributed into OSPF (for example, tag routes
from
IGRP 120 with tag 120), then have a route-map that stops those routes
from
going back into the other protocol. The problem is that one does not
see
this in case studies or in practice lab solutions very often, and that
makes
me nervous. Doyle I contains a reference to this use of tags in the
chapter
on route-maps, and that makes me feel a little better.
This has the feel of something that seems neat but is very dangerous.
Basically, anything that does involve manually typing in half the routes
in
my network feels wrong, because it is not the tedious method that
involves
as much typing of routes as possible and nailing things down manually.
--- Original Message -----
From: "Anthony Pace" <anthonypace@fastmail.fm>
To: "Tom Larus" <tlarus@novacoxmail.com>; "Dennis Laganiere"
<dennisl@advancedbionics.com>; "'Paul Connelly'" <chewy7700@yahoo.com>;
<ccielab@groupstudy.com>
Sent: Saturday, June 08, 2002 8:01 PM
Subject: OSPF into IGRP and summarizing into FLSM
> Tom Larus said "Let's say you have loopback addresses on OSPF enabled
> routers that you will need to summarize so that an IGRP /24 network
> will be able to see them and reach them. You redistribute them into
> OSPF, and use summary-address ip mask to summarize them right there on
> the same router, which is by definition an ASBR because redistribution
> is happening on it. Works like a charm."
>
> In other words you are using IP SUMMARY under OSPF even though you
want
> to shoot the /24 into IGRP? Then, a /24 is created right there on that
> router and puhed into the IGRP world? Is that correct?
>
> I have been looking at this list for a definitive answer on this for a
> while (not wanting to repost a question if it has allready been
> answered) This seems like a solution. The quesion has been asked many
> times and interpreted or missinterpreted differently in different
posts
> but essentially this is the problem as I see it: All of the protocoles
> on the LABS we have all been doing have a mechanism for redistributing
> and controlling summarization except IGRP. The LABS almost always give
> you the ability to summarize almost all your networks via these other
> mechanisms long before they reach the OSPF/IGRP redistribution point
> with the exeption of a loopback or directly connected network on that
> router which does not conform to the IGRP FLSM. It has been suggested
> that a "ip default-network" be shot into IGRP and this works but it is
> questionable as to weather this constitutes an ILLEGAL STATIC ROUTE.
> The Solie labs pose this scenario but the soltions do not address it.
>
> Are there any other tools that can be used?
>
> Anthony Pace
>
>
>
> On Tue, 4 Jun 2002 13:35:53 -0400, "Tom Larus"
<tlarus@novacoxmail.com>
> said:
> > I have never taken the lab, so I could not speak to that aspect of
the
> > question, but I did learn something recently I thought was neat, but
> > that
> > many others here have probably known for years.
> >
> > Let's say you have loopback addresses on OSPF enabled routers that
you
> > will
> > need to summarize so that an IGRP /24 network will be able to see
them
> > and
> > reach them. You redistribute them into OSPF, and use
summary-address
> > ip
> > mask to summarize them right there on the same router, which is by
> > definition an ASBR because redistribution is happening on it. Works
> > like a
> > charm.
> >
> > Okay, it's old hat for a lot of you old hands, but I still think it
is
> > pretty neat.
> >
> >
> > ----- Original Message -----
> > From: "Dennis Laganiere" <dennisl@advancedbionics.com>
> > To: "'Paul Connelly'" <chewy7700@yahoo.com>;
<ccielab@groupstudy.com>
> > Sent: Tuesday, June 04, 2002 12:40 PM
> > Subject: RE: Connected routes vs network statement
> >
> >
> > > Some routing protocols will interpret the two differently. EIGRP,
or
> > > instance, will see the redistributed route as external, which has
a
much
> > > higher AD.
> > >
> > > --- Dennis
> > >
> > >
> > > -----Original Message-----
> > > From: Paul Connelly [mailto:chewy7700@yahoo.com]
> > > Sent: Tuesday, June 04, 2002 9:03 AM
> > > To: ccielab@groupstudy.com
> > > Subject: Connected routes vs network statement
> > >
> > > Is there a preference in the lab when to use "redistribute
connected"
vs.
> > > network statements? I know the redistribute connected will not
turn on
the
> > > routing protocol on the interface but you can easily turn it off
with
> > > passive-interface. Just want to check if the exam wants you to do
it a
> > > certain way.
> > >
> > >
> > >
> > > Thanks
> > >
> > >
> > >
> > > ---------------------------------
> > > Do You Yahoo!?
> > > Sign-up for Video Highlights of 2002 FIFA World Cup
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