From: John Matus (jmatus@pacbell.net)
Date: Thu Nov 17 2005 - 00:13:02 GMT-3
|--4.4.4.4---rip------R1-----ospf------R2------eigrp-----|
i'm not sure, but i recall scott morris telling me this was possible, but
let's take a closer look.
the route 4.4.4.4 is redistributed from rip into ospf (with an AD of 110),
so R2 learns how to get to 4.4.4.4 via R1
then route 4.4.4.4 is redistributed into eigrp (with an AD of 170).. R2
would install the route via ospf over eigrp because of it's lower AD and
that would be it..... but let me try something else
|--4.4.4.4---eigrp------R1-----rip------R2------ospf-----|
let's look at this one. R1 learn the route to 4.4.4.4 via eigrp.
R2 learns the route via rip and installs it in the rip database
R2 redistributes 4.4.4.4 into ospf with an AD 110..........but i don't see
how it could install this route into the routing table when it is a stub
network, so again, it looks kosher.....
i think scott morris needs to chime in and explain, because i'm 99.982% sure
he said that a routing loop could happen in a linear topology.
scott??
Regards,
John D. Matus
MCSE, CCNP
Office: 818-782-2061
Cell: 818-430-8372
jmatus@pacbell.net
----- Original Message -----
From: "Bob Sinclair" <bob@bobsinclair.net>
To: "John Matus" <John.Matus@tokiom.com>; <ccielab@groupstudy.com>
Sent: Wednesday, November 16, 2005 6:36 PM
Subject: Re: understading multiple points of redistribution
> John,
>
> As a starting point, look for physical loops that cross routing domains.
> I
> have not seen a scenario that risks routing loops in the linear topology
> you
> show, copied below. How would a loop form?
>
> |-----rip------R1-------ospf------------R2------eigrp------|
>
>
> Bob Sinclair
> CCIE #10427, CCSI 30427
> www.netmasterclass.net
>
> ----- Original Message -----
> From: John Matus
> To: ccielab@groupstudy.com
> Sent: Wednesday, November 16, 2005 8:43 PM
> Subject: understading multiple points of redistribution
>
>
> i'm not sure i'm understanding the whole concept of multile points of
> redisribution.
>
> i used to think that this was when there was 2 routers on the same subnet
> that were redisributing the same routing protocol to 2 other subnets
>
> |-------eigrp-------R1----------rip---------|
> | |
> | |
> |------eigrp--------R2----------rip---------|
>
> but then i found out that this was not the case and that the following
> diagram woujld also clasify as multiple points and that a routing loop
> could occur here as well.
>
> |-----rip------R1-------ospf------------R2------eigrp------|
>
> so, technically, does "multiple points of redistribution" just mean that
> there are at least 2 routers that are redistributing between 2 protocols
> (not necessarily the same 2)?
>
> in that case, i've just done IE's lab 1 and 2, and they don't use any
> filters when redistributing, but there are multiple points of
> redistribution. should there be filters in place?? were the brains'
> just
> hoping there would be no routing loop, or did they know absolutly that
> there was no routing loop by looking at the topology?
> what should i be looking for in identifying where a routing loop might
> occur? i sure thought i knew, but alas this seems not to be the case.
> does it make any difference "where and which" protocols are being
> redistributed?........
>
> |--------eigrp---------R1--------ospf------------R2-------------eigrp--|
>
>
> |--------eigrp---------r1----------ospf-----------R2----------------rip---|
>
> do either of these topologies have any more or less chance of having a
> routing loop than the other?
>
> TIA!!!
>
> Regards,
>
> John D. Matus
> Technical Support / PAS
> Fujitsu Consulting
> 626-568-7716
> John.Matus@tokiom.com
>
> ===========================================================================
> =============================
> This e-mail is intended solely for the individual to whom it
> is
> addressed. The information contained in this transmission
> contains
> confidential and/or proprietary information or is otherwise privileged.
> If
> the reader of this message is not the intended recipient, please be
> advised
> that any dissemination, distribution or copying of this transmission
> is
> strictly prohibited. If you have received this e-mail in error,
> please
> notify us immediately by returning it to the sender and deleting this
> copy
> from your system. Thank you for your
> cooperation.
>
> ===========================================================================
> =============================
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Thu Dec 01 2005 - 09:12:07 GMT-3