From: Jason Gardiner (gardiner@xxxxxxxxxx)
Date: Thu Oct 25 2001 - 11:07:49 GMT-3
<Sigh> now I remember this from the earlier thread. The addressing
looks like this:
RTR A (Redisting IGRP and OSPF)
172.17.20.48/28 Directly Connected to IGRP only RTR
172.17.20.16/28 IA
172.17.20.32/28 IA
172.17.20.80/29 IA
172.17.20.88/30 IA
172.17.20.92/30 IA
RTR B (IGRP Only)
172.17.20.48/28 Directly Connected
172.16.20.0/24 Directly Connected
I 172.17.20.16/28
I 172.17.20.32/28
Since all the blocks that need to be aggregated are in use, I can't
setup a loopback on RTR A and redist conn. And I've tried to redis conn
on the other OSPF routers, but since the route is being announced
through the network command, that doesn't work, either.
I setup a ip default-network 172.17.0.0 on RTR B, but is assumes that is
is a /28 like the directly connected block. And of course 172.17.0.0/28
is not announced anywhere. Trying a ip default-network of 172.17.48.0
will only result in a static route being injected into the config.
The only solution I could find was to setup a loopback on RTR A with the
172.17.20.0/28 block. Then the default network on RTR B works. Can
anyone think of another way around this?
"Erick B." wrote:
>
> Hi,
>
> If you're doing mutual redist (IGRP into OSPF and vice
> versa) then the networks under IGRP will be put into
> OSPF as external routes also. The summary-address is
> working right.... no tricks or weird things going on.
>
> This is probably biting you: With IOS 12.1 mainline
> and earlier you can redist any route into OSPF if it
> is part of OSPF already. With 12.1T and higher you
> can't redist networks into OSPF as external routes if
> they are already part of OSPF (intra/inter area). If
> you do a debug ip ospf lsa-gen you'll see max-aged
> when it tries. Earlier versions were buggy and they
> fixed it in 12.1T. No sense in having the same network
> in the LSDB twice, etc.
>
> --- Jason Gardiner <gardiner@sprint.net> wrote:
> > That's what I thought. Interesting that you brought
> > this up, as I am
> > having on hell of a problem getting it to work. My
> > scenario:
> >
> > IGRP Segment uses a /28 from 172.17.20.0
> > OSPF network uses mostly /28s from the same class B
> > block. However, it
> > also has a /29 and 2 /30s which, if summarized,
> > would make a /28.
> >
> > These routes are showing up in the ASBR as IA
> > routes. The summary
> > command _APPEARS_ to work, but the summary address
> > never appears in the
> > routing table. I thought it might be because OSPF
> > would not summarize
> > interarea routes to an external protocol, but that
> > doesn't make much
> > sense.
> >
> > I also tried to use ip default-network, but couldn't
> > get that working
> > right, either.
> >
> > Any suggestions?
> >
> >
> > Robert Dubell wrote:
> > >
> > > That is the proper way to redistribute from a OSPF
> > into IGRP. Using the
> > > summary-address command on the ASBR....
> > >
> > > -----Original Message-----
> > > From: Stephen Oliver <stevie_oliver@hotmail.com>
> > > To: ccielab@groupstudy.com
> > <ccielab@groupstudy.com>
> > > Date: Wednesday, October 24, 2001 5:01 AM
> > > Subject: VLSM and IGRP redistribution
> > >
> > > >How many ways can you accomplish VLSM into IGRP
> > redistribution.
> > > >
> > > >I have a router running OSPF on one interface and
> > IGRP on the other. It's
> > > >an ASBR. I have a class B address on both sides
> > but with a /24 mask. The
> > > >OSPF side is all area 0 and from another router
> > in that area some /26 and
> > > >/27 routes are being sent. When redistributing
> > these routes into IGRP what
> > > >are the options.
> > > >
> > > >Every book I read says the ospf command
> > > >
> > > ># summary-address x.x.x.x x.x.x.x
> > > >
> > > >is used when summarizing external routes into
> > OSPF however this is the only
> > > >way I can get the routes accross to IGRP. I put
> > the command
> > > >
> > > ># summary-address x.x.x.x 255.255.255.0
> > > >
> > > >on the ASBR for each of the /26 and /27 routes
> > and they go over to the IGRP
> > > >router. A route to null 0 is created on the ASBR
> > as expected but since
> > > this
> > > >is /24 the more specific route of /26 or /27
> > takes precenence.
> > > >
> > > >Is this the proper way to do this ? I got the
> > problem from a well known
> > > >testing software page and they use the Area Range
> > command which seems
> > > >irrelevant in this case and does not work anyway.
> > > >
> > > >Thanks, Stevie.
> > > >
> > >
> >
This archive was generated by hypermail 2.1.4 : Thu Jun 20 2002 - 22:33:24 GMT-3