From: Padhu (LFG) (padhu@xxxxxxxxxxxx)
Date: Fri Aug 24 2001 - 12:32:21 GMT-3
I concur with your findings and thats what i had mentioned in my previous
email about the solution being IOS dependent.
Not a hack in its true sense however,summary address was designed to
summarize external routes coming in. With the classic VLSM / FLSM we are
doing the other way just fooling ospf that its an external route.
12.1 does a sanity check & doesn't insert native routes as external unlike
its older counterparts.So whats the fix for FLSM / VLSM after 12.1 ?
I am seeing interesting things with my ISIS to igrp redistributions though.
I am getting closer to a working solution however i have dig some more to
find out why its doing what its doing .
Hope cisco comes out with better documentation for ISIS soon.
Cheers,Padhu
"This solution is dependent on ( tempermental on) IOS versions though.Some
work with redistribute connected (if the i/f is already not part of ospf
area)..Some work with redistribute connected (even if the i/f is already
part of ospf area)"
-----Original Message-----
From: Erick B. [mailto:erickbe@yahoo.com]
Sent: Thursday, August 23, 2001 6:22 PM
To: Padhu (LFG); 'Jim Brown'
Cc: 'ccielab@groupstudy.com'
Subject: Re: VLSM - FLSM procedure - One last time
I've been researching this and playing with it
recently and have found a possible bug with the
summary-address not working as expected in 12.1T and
above. I am working with cisco now to confirm it is a
bug as I've searched release notes, etc and haven't
seen anything about the behavior being changed. I will
share the results when we figure it out. I have a
write-up comparing debug outputs of working vs
non-working versions of code as well.
Anyway, this isn't really a hack. If you have a
172.16.2.x interface in OSPF and also IGRP that
doesn't fall on class A/B/C boundaries and
redistribute IGRP into OSPF then 172.16.2.x is being
put into OSPF from an external source also. If a
summary-address is configured that matches it will get
summarized when going into OSPF and a summary route to
null0 will be in the main routing table. Then you can
turn around and redistribute OSPF into IGRP to get the
OSPF summary into IGRP. Nothing wrong or broken here.
--- "Padhu (LFG)" <padhu@steinroe.com> wrote:
> This solution is dependent on ( tempermental on) IOS
> versions though.Some
> work with redistribute connected (if the i/f is
> already not part of ospf
> area)..Some work with redistribute connected (even
> if the i/f is already
> part of ospf area)
>
> Procedure:
> 1.On the ASBR create an ACL for the IGRP nets to be
> redistributed.
> 2. Redistribute mutually between IGRP and OSPF. Code
> summary-address
> 172.16.1.0 255.255.255.0
> 3. Kick off Debug ip ospf lsa-gen & debug ip routing
> 4. Include the directly connected /29 or /28 from
> the ospf side into the
> above IGRP ACL
> 5. show ip ospf summary will show metric of 2^16
> 6. Clear ip ospf redistribution
> 7. show ip ospf summary will now show metric of 20
> 8. The /24 should now get redistributed into IGRP.
> 9. Use area-range elsewhere at the ABR to bring it
> to /24
>
> Hope this helps.
> This is not the way it is supposed to work. Summary
> works on the return path
> in this case.
>
> However this hack doesn't help me when i
> redistribute between ISIS and IGRP.
>
> Cheers,Padhu
>
> -----Original Message-----
> From: Jim Brown [mailto:Jim.Brown@CaseLogic.com]
> Sent: Thursday, August 23, 2001 2:15 PM
> To: 'Padhu (LFG)'
> Cc: 'ccielab@groupstudy.com'
> Subject: RE: How to summarize connected interfaces
> in ISIS ?
>
>
> Padhu,
>
> Could you please expand on the redistribute
> connected + summary-address
> hack. This may be the solution I'm looking for
> regarding VLSM to FLSM
> redistribution.
>
> -----Original Message-----
> From: Padhu (LFG) [mailto:padhu@steinroe.com]
> Sent: Thursday, August 23, 2001 12:02 PM
> To: Ccielab (E-mail)
> Subject: How to summarize connected interfaces in
> ISIS ?
>
>
> My ASBR has /29 on the frame and /28 on the ethernet
> running igrp on another
> subinterface with 24.
> I can summarise all L1 routes to /24 as they enter
> L2, however the directly
> connected interfaces
> on the ASBR do NOT get redistributed into igrp even
> with redistribute
> connected + summary address combo.
> (The ospf summary hack method doesn't work here.)
>
> Any suggestions.
>
> Cheers,Padhu
> **Please
> read:http://www.groupstudy.com/list/posting.html
> **Please
> read:http://www.groupstudy.com/list/posting.html
>
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 10:31:57 GMT-3