Re: Redistributing OSPF into IGRP

From: Connary, Julie Ann (jconnary@xxxxxxxxx)
Date: Thu Sep 21 2000 - 11:20:27 GMT-3


   
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.
> >
> >
> >



This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 08:24:59 GMT-3