From: tom cheung (tkc9789@xxxxxxxxxxx)
Date: Wed Dec 26 2001 - 12:08:50 GMT-3
Dan,
If you don't have another major net other than the 172.100.x.x injected into
igrp, then defining a LB the way you described is a workaround. I remember
seeing couple of threads regarding similar issues in the archives.
Tom
>From: "DAN DORTON" <DHSTS68@dhs.state.il.us>
>To: <Ron.Kirby@getronics.com>,<ccielab@groupstudy.com>,
><tkc9789@hotmail.com>, <tlarus@mwc.edu>
>Subject: RE: OSPF to IGRP redistrib - How to summarize area 0 routes?
>Date: Wed, 26 Dec 2001 08:33:56 -0600
>
>I had a situation with OSPF to IGRP redistribution to which I had an
>ISDN backup link that was in area 0 & was a different mask than the rest
>of the network.
>
>The IGRP router interface was a /24 & it reconized all the /24 routes &
>the routes within the OSPF network at ABRs with a different mask I used
>the area range command to summarize to a /24. I still could not get this
>to work due to the fact that when the ISDN came up the /28 route for it
>did not get to the IGRP network. Therefore all the routes that were in
>the table that had to transit the ISDN link were inaccessable.
>
>After trying many scenarios I came up with an idea. I could not see
>this as being a problem in the lab since there was no static, or default
>routes, but I thought I would get your opinion.
>
>The network was 172.100.10.0/28. I need to get this into the IGRP
>network which was a 172.100.100.0/24 network. I created a loopback with
>the address of 172.100.10.17/28 & then created a summary address within
>OSPF of 172.100.10.0/24. Then I redistributed connected & only allowed
>this network with route-maps. Once the redistribution occured & the
>loopback interface was not already in the OSPF process it injected the
>172.100.10.0/24 summary route into the IGRP AS. Everything worked just
>fine & dandy.
>
>Anyone else used this method?
>I kept seeing thing through this mailing list about using secondaries
>to fix this issue, but I must not have understood correctly since I
>could never make it work that way.
>
>Thanks,
>Dan
>
> >>> "tom cheung" <tkc9789@hotmail.com> 12/21/01 01:20PM >>>
>Ron,
>The area range for area 0 only works on older IOS. I don't that works
>on
>12.1, which is IOS in the lab now.
>
>Tom
>
>
> >From: "Kirby, Ron" <Ron.Kirby@getronics.com>
> >Reply-To: "Kirby, Ron" <Ron.Kirby@getronics.com>
> >To: "'Thomas Larus'" <tlarus@mwc.edu>, ccielab@groupstudy.com
> >Subject: RE: OSPF to IGRP redistrib - How to summarize area 0 routes?
> >Date: Fri, 21 Dec 2001 12:33:30 -0500
> >
> >The "area range" command will summarize a backbone net into an IGRP
>AS. I
> >did a lab similar to this 2 days ago. The IGRP AS was a /24 and the
>frame
> >network, which was the ospf area 0 was a /28. I also had /32's from
>some
> >loopbacks that had to go into the IGRP AS as well. I played with
>various
> >ways to do it. First, I had a Class C network hanging off another
>router,
> >so I created a default route to that classful network on the
>IGRP-only
> >router and I could ping everything in the OSPF system, even though the
>
> >frame
> >and loopback addresses were not in the routing table. I suspect this
>would
> >not be acceptable though, as this is a "default-route", it just
>doesn't use
> >the quad-zero entry in the routing table, but it does work. Next I
>added
> >the "ip ospf network type" command to the loopbacks and used the
>"area
> >range" command at the redistribution point, summarizing the /28 to a
>/24.
> >The loopbacks appeared at the IGRP router as /24s, but not the /28s.
>I had
> >to add the null route to the config on the redistribution router (as
> >explained by Doyle in V1) and then it worked fine, both the loopbacks
>and
> >the frame network (as a /24) was in the IGRP routing table. But is
>that a
> >technical no-no, as it involves a "static route"? If this is a no-no,
>what
> >else can you do to get /28s into an IGRP AS using a /24??
> >
> >Ron Kirby
> >CCNP, MCSE, CNA
> >Network Engineer
> >Getronics, Houston ESC
> >713-852-5567 / 832-256-5403
> >ron.kirby@getronics.com
> >
> >This e-mail message and any attachments are confidential and may be
> >privileged. If you are not the intended recipient, please notify me
> >immediately by replying to this message and please destroy all copies
>of
> >this message and attachments. Thank you.
> >
> >
> >
> >
> >
> >-----Original Message-----
> >From: Thomas Larus [mailto:tlarus@mwc.edu]
> >Sent: Friday, December 21, 2001 11:10 AM
> >To: ccielab@groupstudy.com
> >Subject: OSPF to IGRP redistrib - How to summarize area 0 routes?
> >
> >
> >I am working on basic everyday OSPF to IGRP redistribution. I was
>able
> >to use area range for the routes I needed to get down to /24 to match
> >the IGRP domain s mask. But what if the scenario had been set up
> >differently, and I had had routes within area 0 that had to be
> >summarized to /24 to be redist ed into IGRP? Area range summarizes
> >non-backbone areas INTO area 0. Summary-address only works on routes
> >redistributed INTO the OSPF domain. The experts all say that there
>are
> >two way to deal with the classless to classful redist problem
>static
> >routes and summarization. If it is stated that I cannot use static
> >routes, and the routes I need to summarize are within area 0, what do
>I
> >do?
> >
> >I can design the network to make sure all the routes that need to be
> >redistributed from OSPF to a classfull routing protocol are in an
>area
> >other than 0, but what if I am given the situation I have set out?
> >
> >A route-map comes to mind, but I don t see how I can summarize using
>a
> >route-map, although I can make it so that only routes with a certain
> >mask get redistributed.
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