From: Kevin Baumgartner (kbaumgar@xxxxxxxxx)
Date: Thu Sep 21 2000 - 17:49:24 GMT-3
I think you mean a classful route that's what IGRP needs. And you are right
in a real network you will try to get a classful network and advertise this int
o
IGRP. My example won't likely be acceptable in the CCIE lab but it gives
the basic concept. What I would do is use a "OSPF Area range"
command on one of the OSPF ABR routers and summarize to a classful address.
Kevin
At 03:33 PM 9/21/00 -0400, you wrote:
>I had a question similar to that on one of my practice ASET labs. If you
>need a classless route and you are not allowed to use a null statement, look
>for a route that was advertised from somewhere else, for instance I was
>advertising rip routes from the backbone and one of them was a 10.0.0.0
>address. Use that.
>
>
>
>-----Original Message-----
>From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
>Kevin Baumgartner
>Sent: Thursday, September 21, 2000 3:09 PM
>To: Connary, Julie Ann
>Cc: ccielab@groupstudy.com
>Subject: Re: Redistributing OSPF into IGRP
>
>
>The network 172.17.59.0 is not a classful address. Igrp will not use this
>as a default route. For IGRP to use a canidate route it must be
>a classful route and not subnetted.
>Try creating a classful address using a null0 route
>and then defining it on igrp.
>
> So for example
>
>ip route 10.0.0.0 255.0.0.0 null0
>router igrp 100
>network 10.0.0.0
>ip default-network 10.0.0.0
>
> Kevin
>
>
>At 10:20 AM 9/21/00 -0400, you wrote:
> >Hi,
> >
> >Can anyone post configs for the ip default-network method. I cannot seem to
>figure it out. Thanks.
> >
> >I re-read Caslow and he gives two options to solve this problem:
>summarization with a static to null 0 and using ip defulat-network with
>ip-classless. I got the first to work in the lab, no problem. The second
>however is causing me problems.
> >
> >I tried to make an ip default-network to 172.17.59.0 on the router a, but
>what I got in the config was a static route:
> >
> >router igrp 100
> > redistribute ospf 1 metric 64 10 255 1 1500
> > passive-interface Loopback5
> > network 172.17.0.0
> >!
> >ip classless
> >ip route 172.17.0.0 255.255.0.0 172.17.59.0
> >
> >Then I tried to make and ip default-network to 172.17.0.0. now I have a
>candidate default route in my routing table on router a, but
> >router b is not getting the default-route and I can still not get to the
>172.17.59.0 networks in ospf:
> >version 11.2
> >no service udp-small-servers
> >no service tcp-small-servers
> >!
> >hostname r1
> >!
> >!
> >no ip domain-lookup
> >!
> >interface Loopback0
> > ip address 1.1.1.1 255.255.255.0
> >!
> >interface Loopback1
> > ip address 172.17.59.33 255.255.255.240
> >!
> >interface Loopback2
> > ip address 172.17.59.49 255.255.255.240
> >!
> >
> >interface Loopback3
> > ip address 172.17.59.65 255.255.255.192
> >
> >interface Loopback5
> > ip address 172.17.45.1 255.255.255.0
> >!
> >interface Ethernet0
> > no ip address
> > shutdown
> >!
> >interface Serial0
> > ip address 172.17.60.2 255.255.255.0
> >!
> >interface Serial1
> > ip address 193.1.1.1 255.255.255.0
> >!
> >interface BRI0
> > no ip address
> > shutdown
> >!
> >router ospf 1
> > redistribute igrp 100 metric 64 subnets
> > network 172.17.59.32 0.0.0.15 area 0
> > network 172.17.59.48 0.0.0.15 area 2
> > network 172.17.59.64 0.0.0.63 area 3
> >!
> >router igrp 100
> > redistribute ospf 1 metric 64 10 255 1 1500
> > network 172.17.0.0
> >!
> >ip classless
> >ip default-network 172.17.0.0
> >!
> >line con 0
> >line aux 0
> >
> >line vty 0
> >
> >line vty 1 4
> >!
> >end
> >
> >
> >routing table on router a:
> >Gateway of last resort is not set
> >
> > 1.0.0.0/24 is subnetted, 1 subnets
> >C 1.1.1.0 is directly connected, Loopback0
> > * 172.17.0.0/16 is variably subnetted, 5 subnets, 3 masks
> >C 172.17.60.0/24 is directly connected, Serial0
> >C 172.17.45.0/24 is directly connected, Loopback5
> >C 172.17.59.32/28 is directly connected, Loopback1
> >C 172.17.59.48/28 is directly connected, Loopback2
> >C 172.17.59.64/26 is directly connected, Loopback3
> >C 193.1.1.0/24 is directly connected, Serial1
> >
> >routing table on router b:
> >
> >
> >Gateway of last resort is not set
> >
> > 172.17.0.0/24 is subnetted, 2 subnets
> >C 172.17.60.0 is directly connected, Serial0
> >I 172.17.45.0 [100/8976] via 172.17.60.2, 00:00:12, Serial0
> >
> >I put the 172.17.45.0 loopback interface on router a, just to make sure I
>was getting routes distributed via IGRP.
> >
> >Can anyone post configs that work for the ip default-network method.
> >
> >Thanks Julie Ann
> >
> >
> >At 04:52 PM 9/20/2000 -0700, mark salmon wrote:
> >>I still disagree with the blanket statement about static routes. If you
> >>want to summarize OSPF you have to use static routes (null 0). I still
> >>believe that you can do so as long as you are using summarization.
> >>
> >>One method that is recommended by Caslow is to use a static route to
> >>null 0 with the same mask as the IGRP net.
> >>
> >>For example, suppose the masks on the IGRP networks is /24, but it
> >>varies on the OSPF net.
> >>
> >>On the ASBR, you can do 172.17.x.0 255.255.255.0 null 0 (be careful
> >>here, if you have a dynamic route for x you will pass packets into a
> >>black hole, the key is to have good network design to prevent this). If
> >>you already have a 172.17.x.0/24 network, then I would create a class c
> >>subnet (e.g. 198.135.244.1/24) on a loopback interface, either
> >>redistribute it into IGRP or advertise it in IGRP. Then make it the
> >>default network for IGRP.
> >>
> >>Comments group (Flame jacket on for this).
> >>Mary Weidner wrote:
> >> >
> >> > All,
> >> >
> >> > I am working on a practice lab on one of the midwest channels racks and
>am having a problem with redistribution. Here's a sample config:
> >> >
> >> > Router A
> >> > !
> >> > router ospf 100
> >> > network 172.17.59.32 0.0.0.15 area 0
> >> > network 172.17.59.48 0.0.0.15 area 2
> >> > network 172.17.59.64 0.0.0.63 area 3
> >> > redistribute igrp 100 metric 64 subnets
> >> > !
> >> > router igrp 100
> >> > network 172.17.0.0
> >> > redistribute ospf 100 metric 64 10 255 1 1500
> >> >
> >> > Router B
> >> > !
> >> > router igrp 100
> >> > network 172.17.0.0
> >> > !
> >> >
> >> > Here's the deal, IGRP does not understand VLSM which is what is being
>used on router A with OSPF. From all the docs I've read, you would have to
>put in static routes on Router B to tell it how to get to those other
>subnets, except I'm not allowed to use static routes. The subnets in OSPF on
>Router A are not redistributing into IGRP. They come out as 172.17.0.0
>instead of whatever the real network number is.
> >> >
> >> > Here's the other thing I tried; I added these lines:
> >> >
> >> > Router A
> >> > !
> >> > router ospf 100
> >> > default-information originate always
> >> > !
> >> > router igrp 100
> >> > default-information allowed in 1
> >> > default-information allowed out 1
> >> > !
> >> > access-list 1 permit any
> >> >
> >> > Router B
> >> > !
> >> > router igrp 100
> >> > default-information allowed in 1
> >> > !
> >> > access-list 1 permit any
> >> >
> >> > The thinking here was to originate a default route (0.0.0.0) from
>Router A in OSPF and try to redistribute this into IGRP..... it didn't work.
>Maybe I just configured it wrong or maybe it's just not possible. I don't
>know. This is the second time I've attempted to get this working to no
>avail. Let me know if you have any ideas.
> >> >
> >> > Thanks,
> >> >
> >> > Tony Olzak
> >> >
> >> > BTW-I've just joined the list. I'm scheduled to take the test on Nov
>19-20 in RTP.
> >> >
> >> >
> >> >
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