From: David Anderson (dma@xxxxxxxxx)
Date: Wed Apr 18 2001 - 17:47:45 GMT-3
How is this:
On R1 take each /24 address that is summarized with the /22 and
permit each one in an extended access list (specifying that each is
a /24 subnet), then configure a distribute list in under IGRP. Any
feedback ?
Thanks,
David
At 03:28 PM 4/18/2001 -0400, Rob Hopkins wrote:
>youre 100% right, but it you could add secondary ip's to r2 to compensate.
>I agree this is getting horrendous, but what other options are avail ?
>
>1> static routes (not allowed)
>2> classless routing protocol (not allowed)
>3> route maps (limited use at best)
>4> tweaking subnet masks and using secondary addresses (very ugly,but
>semi-functional)
>5> worse yet, bridge ip
>6> ducttape and wd40
>
>
>----- Original Message -----
>From: "Walter Chen" <wchen@iloka.com>
>To: "'Alejandro Cadarso'" <a.cadarso@uniway-tec.com>; "Rob Hopkins"
><rshopkins@earthlink.net>
>Cc: <ccielab@groupstudy.com>
>Sent: Wednesday, April 18, 2001 3:01 PM
>Subject: RE: Redistributing OSPF /22 to IGRP /24, same mayor network
>
>
> > Rob,
> >
> > This is a neat solution, however you could not reach .25.0-.27.0 included
>in
> > the .24/22 mask. So you lose 3/4 of your reachability and of course also
> > make .36-.39 unusable as you already pointed out. So while this solution
> > dose not break any rules but also did not fully achieve its primary goal
> > which is to make the .24/22 network reachable from the IGRP side.
> >
> > -----Original Message-----
> > From: Alejandro Cadarso [mailto:a.cadarso@uniway-tec.com]
> > Sent: Wednesday, April 18, 2001 2:19 PM
> > To: Rob Hopkins
> > Cc: ccielab@groupstudy.com
> > Subject: Re: Redistributing OSPF /22 to IGRP /24, same mayor network
> >
> >
> > Rob,
> >
> > It's perfect, that's the solution, or at least one of them ( I cant
> > think in any other ).
> > Of course there is the limitation you posted:
> >
> > 172.16.37.0 thru 172.16.39.0 are not available any more but that doesn't
> > breaks any stated rule.
> > Alejandro
> >
> >
> > Rob Hopkins wrote:
> >
> > > come on guys, dont give up so easy...
> > >
> > > change the subnet mask on r1 to /22, I know we were always taught subnet
> > > masks should
> > > match, but as long as you keep track of what each router "thinks" its
> > > connected to, it will be alright..
> > > If R1 needed to have any routes from 172.16.37.0 thru 172.16.39.0 you're
> > > gonna have bigger problems,
> > > (unless they are hanging out on your serial port..) but since it wasnt
>in
> > > this case..
> > >
> > > output follows:
> > >
> > >
> > > 172.16.0.0/24 is subnetted, 3 subnets
> > > C 172.16.36.0 is directly connected, Serial0
> > > I 172.16.24.0 [100/8976] via 172.16.35.1, 00:01:56, Serial0
> > > [100/8976] via 172.16.36.1, 00:00:07, Serial0
> > > C 172.16.6.0 is directly connected, Loopback100
> > > r2#
> > >
> > >
> > >
> > >
> > > ----- Original Message -----
> > > From: "Alejandro Cadarso" <a.cadarso@uniway-tec.com>
> > > To: "Darren Ward" <dward@pla.net.au>; "Walter Chen" <wchen@iloka.com>;
> > > "ccielab" <ccielab@groupstudy.com>; <lkounkar@uu.net>
> > > Sent: Wednesday, April 18, 2001 12:37 PM
> > > Subject: Re: Redistributing OSPF /22 to IGRP /24, same mayor network
> > >
> > >
> > >> Good idea Darren,
> > >>
> > >> Perhaps your way could work, the problem is that when I try to put any
> > >> IP address from the /24's in a loopback I have:
> > >>
> > >> >r4(config-if)#ip address 172.16.26.1 255.255.255.0
> > >> >172.16.26.0 overlaps with Ethernet0
> > >>
> > >> This sounds logical because in this case we would have two interfaces
>in
> > >> the same /24 network
> > >>
> > >> Louie Answer could be better the problem is that I have another OSPF
> > >> Router in the same mayor network and I'm not allowed to change it.
> > >>
> > >> Thanks very much for your help, but I think there is no answer.
> > >>
> > >> Alejandro.
> > >>
> > >>
> > >> Darren Ward wrote:
> > >>
> > >>> Hows this sound for a silly idea:
> > >>>
> > >>> The requirement is to get a /20 into a /24 IGRP domain.
> > >>> The second requirement is that no static's can be used at all.
> > >>>
> > >>> Create a second OSPF process on the redistributing router (ospf 2 for
> > >>
> > > arguments
> > >
> > >>> sake)
> > >>> Create one or more loopbacks and put the 4 /24's on it.
> > >>> Redistribute the ospf 2 into IGRP and IGRP into ospf 1.
> > >>>
> > >>> You may need to do some tweaking on the border router, maybe policy
> > >>
> > > routing at
> > >
> > >>> worst.
> > >>>
> > >>> Darren
> > >>>
> > >>>
> > >>> Walter Chen wrote:
> > >>>
> > >>>> The "area x range" command won't work in this case because it won't
> > >>>
> > > change
> > >
> > >>>> the way directly connected networks are redistributed to IGRP. Using
> > >>>
> > > static
> > >
> > >>>> routes in this case is preferred because you only need four of them.
> > >>>>
> > >>>> However, if you were asked to redistribute /20 OSPF into /28 IGRP (in
> > >>>
> > > this
> > >
> > >>>> case you have to configure 256 static routes!) or you were not
>allowed
> > >>>
> > > to
> > >
> > >>>> use static routes, then you could configure a separate major network
> > >>>
> > > with a
> > >
> > >>>> /24 mask in OSPF domain, say, 192.168.1.0/24 and redistribute it into
> > >>>
> > > IGRP.
> > >
> > >>>> >From the IGRP router, configure this network to be your
> > >>>
> > > default-network to
> > >
> > >>>> let you reach the OSPF 172.16.x.x/20 networks.
> > >>>>
> > >>>> If you are now allowed to use either static or IGRP default-network,
> > >>>
> > > then
> > >
> > >>>> you're stuck.
> > >>>>
> > >>>> Walter
> > >>>>
> > >>>> -----Original Message-----
> > >>>> From: Michel GASPARD [mailto:mgaspard@cisco.com]
> > >>>> Sent: Wednesday, April 18, 2001 8:12 AM
> > >>>> To: Alejandro Cadarso
> > >>>> Cc: ccielab
> > >>>> Subject: Re: Redistributing OSPF /22 to IGRP /24, same mayor network
> > >>>>
> > >>>> Alejandro,
> > >>>>
> > >>>> Did you already tried the "area x range" command?
> > >>>>
> > >>>> Regards,
> > >>>>
> > >>>> Michel
> > >>>>
> > >>>> Alejandro Cadarso wrote:
> > >>>>
> > >>>>> I'm playing with the following scenario and was unable to imagine
>how
> > >>>>> can I get 172.16.24.0/22 redistributed from ospf to igrp for r2
> > >>>>> inserting it in its routing table.
> > >>>>>
> > >>>>> Any suggestions will be appreciated. Of course neither Default
>routing
> > >>>>> nor static are allowed.
> > >>>>>
> > >>>>> ospf igrp loop0
> > >>>>> -------------r1------------------r2----172.16.6.0/24
> > >>>>>
> > >>>>> 172.16.24.0/22 172.16.36.0/24
> > >>>>> **Please read:http://www.groupstudy.com/list/posting.html
> > >>>>
> > >>>> **Please read:http://www.groupstudy.com/list/posting.html
> > >>>> **Please read:http://www.groupstudy.com/list/posting.html
> > >>>
> > >>> **Please read:http://www.groupstudy.com/list/posting.html
> > >>
> > >> **Please read:http://www.groupstudy.com/list/posting.html
> > **Please read:http://www.groupstudy.com/list/posting.html
> > **Please read:http://www.groupstudy.com/list/posting.html
>**Please read:http://www.groupstudy.com/list/posting.html
David Anderson
Network Design Engineer
Enterprise Solutions Architecture & Design
(408) 853-5515
dma@cisco.com
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