From: Mas Kato (loomis_towcar@xxxxxxxxxxxxxx)
Date: Tue Apr 16 2002 - 19:39:10 GMT-3
[demime could not interpret encoding binary - treating as plain text]
<<But I've seen people using it otherwise...>>
You may be thinking of a technique where deliberate route feedback (controlled
mutual redistribution) is used to overcome a subnet mask length mismatch betwee
n VLSM and FLSM routing protocols (typically differing mask lengths within the
same major net).
Basically, summarization commands (area range, summary-address, etc.) are used
to get the router to install a summary route to null0 in the routing table. Onc
e it's there it can be redistributed to other FLSM routing protocols. The trick
is to learn/know when the router will do it and when it will not. Hint: Someth
ing real needs to "prop up" the summary (at least in bug-free code).
Regards,
Mas Kato
https://ecardfile.com/id/mkato
>Date: Tue, 16 Apr 2002 10:10:20 -0500
> Tarek Sabry <tsabry@houston.sns.slb.com> RE: OSPF - IGRP "'Muhamamd Durrani'"
<dan_schaw@yahoo.com>Cc: ccielab@groupstudy.com
>Reply-To: Tarek Sabry <tsabry@houston.sns.slb.com>
>
>Muhammad
>
>Thanks for your reply.
>
>I fully agree that summary-address is for injecting a summary INTO OSPF and
>not to redistribute into another protocol. But I've seen people using it
>otherwise :( Is this IOS-related?
>
>How can I create area-range when the router I'm trying to redistribute at is
>not an ABR? I only have area-1 and IGRP on this router.
>
>Creating statics is also prohibited in the lab. Right?
>
>Thanks again
>Tarek
>
>-----Original Message-----
>From: Muhamamd Durrani [mailto:dan_schaw@yahoo.com]
>Sent: Tuesday, April 16, 2002 8:56 AM
>To: Tarek Sabry
>Cc: ccielab@groupstudy.com
>Subject: Re: OSPF - IGRP
>
>
>Hi Tarek ,
>
>With Summary-Address you cannot re-distribute to other
>routing protocol . Its for the Summary Address for
>Ecternal Routes .
>
>I would rather say create a Summary Address with "Area
>range " commad on the router you want to summarized
>the addresses on, with the mask configured on the
>interfaces running IGRP. If the mask is now same as
>configured on IGRP interfaces than you wil not see the
>route on IGRP router .
>
>Another way that I could see is to create a static
>route on ASBR to NULL 0 and redistribute static into
>IGRP process ..but again the mask SHOULD match with
>interaces configured with IGRP .
>
>
>Let me know id I am wrong .
>
>Regards,
>Muhammad
>
>
>--- Tarek Sabry <tsabry@houston.sns.slb.com> wrote:
>> Hi
>>
>> I understand that there may be more than one way to
>> redistribute VLSM into
>> FLSM. However the only way that seems to work for me
>> when redistributing
>> OSPF into IGRP is the brilliant method suggested by
>> someone a little while
>> back, whereby I need to create an intermediate OSPF
>> process. I don't feel
>> comfortable with just this way though, because the
>> proctors may object to
>> it.
>>
>> So let's say we have a /26 network connected to the
>> OSPF side of the
>> redistributing router. Someone had suggested before
>> that a good way of
>> achieveing what I want would be to redistribute
>> connected into OSPF and
>> create a "summary-address" of a /24, and this route
>> would be redistributed
>> into IGRP with the rest of the OSPF routes.
>>
>> Is that supposed to work??? Well doesn't the
>> "summary-address" inject a
>> route INTO OSPF and not OUT OF it?? Also how come I
>> do not see any routes to
>> "Null 0" after I create my OSPF summary address?
>>
>> What are common gotchas for OSPF summaries??
>>
>> Thanks a lot
>> Tarek
>>
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