From: Johnny Dedon (johnny.dedon@xxxxxxxxxx)
Date: Sun May 06 2001 - 13:23:29 GMT-3
Ok, after some sleep, I think I have figured out what was happening. Very
interesting.
On the redistributing router (rip to ospf only), I have a loopback interface
in Area 4 that has address 170.100.64.1/27. I was asked in another question
to redistribute ospf into igrp from area0. Igrp has 24 bit mask. I have two
routes in the ospf domain that are not 24 bit. One in area 0 and the
loopback in area 4. Everything in the network is using the same classful
address 170.100.x.x. I figured that since I call the addresses, that I
would make the loopback in area4 and the other vlsm(non24bit) subnet fit
into the same 24 bit summary and the using an area range command from area 4
advertising into area0 where I redistribute into IGRP. Works fine until Rip
got involved and I filter the connected interface with acl 1 deny
170.100.64.0 0.0.0.31. and then allow any.
Without the summary route the ospf routers see 170.100.64.0/27 as an IA
route.
With the summary route the ospf routers see 170.100.64.0/27 as an E2 route
and they see the summary 170.100.64.0/24 as an IA route.
If I use the summary-address command in area 4 then ospf sees
170.100.64.0/27 as IA and 170.100.64.0/24 as E2. This I understand and
would expect, because OSPF uses the summary-address command to summarize
external routes coming in.
Anyone care to add to this.
I read further and I am being given another classful address that I can use
to get reachability from IGRP.
Johnny Dedon
Senior Staff Consultant
Exodus Professional Services
johnny.dedon@exodus.net
www.exodus.net
----- Original Message -----
From: "Erick B." <erickbe@yahoo.com>
To: "Johnny Dedon" <johnny.dedon@exodus.net>; "Groupstudy"
<ccielab@groupstudy.com>
Sent: Saturday, May 05, 2001 7:32 PM
Subject: Re: blocking connected routes with rip
> Can you post your ACL?
>
> Did you try a prefix-list?
>
> --- Johnny Dedon <johnny.dedon@exodus.net> wrote:
> > Guys,
> > Something simple here is driving me bananas.
> > I am trying to block a connected route with a 27 bit
> > mask from being
> > redistributed into OSPF by RIP. I need the other 24
> > bit mask connected
> > routes. I am using a class B major network. I have
> > tried distribute-list out
> > connected with the access-list denying the 27bit
> > subnet and permiting
> > everything else. This doesn't work. I tried using a
> > route-map with the
> > redistribution statement blocking this subnet and it
> > still doesn't work. I
> > end up either blocking all the rip routes or none of
> > them. When rip is
> > deciding whether or not to put this route in the rip
> > process does it look at
> > the mask configured or just at the classful network?
> >
> > The connected interface is already being advertised
> > by OSPF as an IA route.
> > Rip is causing it to change to and E2 route.
>
>
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