From: Mohamed Heeba (MAHeeba@xxxxxxxxxxx)
Date: Fri May 11 2001 - 18:16:31 GMT-3
ok ;
HOW to summarize 22 subnet in the OSPF domain to be advertise in 24 mask
IGRP one ,
the 22 is directly attached to the redistribution router ,only one area is
there ,area range command didnt work i mean
thx
> -----Original Message-----
> From: Johnny Dedon [SMTP:johnny.dedon@exodus.net]
> Sent: Friday, May 11, 2001 1:54 PM
> To: Johnny Dedon; Mohamed Heeba
> Cc: ccielab@groupstudy.com
> Subject: Re: Fatkid lab 502 ,expert redistribution
>
> Correction on summary route.
> I spoke too soon on the summary route.
> The summary route can be created within OSFP for redistribution into an
> external routing protocol. If you want a summary to appear in ospf then
> it
> must be created from routes external to the OSPF process or it must be
> created using the area range command where it can only be seen by routers
> belonging to areas other than the area it is advertised from.
>
> HTH
> Johnny Dedon
> Senior Staff Consultant
> Exodus Professional Services
> johnny.dedon@exodus.net
> www.exodus.net
> ----- Original Message -----
> From: "Johnny Dedon" <johnny.dedon@exodus.net>
> To: "Mohamed Heeba" <MAHeeba@itqan.co.ae>
> Cc: <ccielab@groupstudy.com>
> Sent: Friday, May 11, 2001 3:37 PM
> Subject: Re: Fatkid lab 502 ,expert redistribution
>
>
> > Mohamed,
> > Responses inline
> > Johnny Dedon
> > Senior Staff Consultant
> > Exodus Professional Services
> > johnny.dedon@exodus.net
> > www.exodus.net
> > ----- Original Message -----
> > From: "Mohamed Heeba" <MAHeeba@itqan.co.ae>
> > To: "'Johnny Dedon'" <johnny.dedon@exodus.net>; "Mohamed Heeba"
> > <MAHeeba@itqan.co.ae>
> > Cc: <ccielab@groupstudy.com>
> > Sent: Friday, May 11, 2001 3:12 PM
> > Subject: RE: Fatkid lab 502 ,expert redistribution
> >
> >
> > > well;
> > > i think things are more difficult than this ..let me share my ideas
> here
> > > i agree that the OSPF summary command is used to summarize the
> external
> > > routes INTO the OSPF domain ,however in some solutions out there ,it
> is
> > used
> > > to summarize the OSPF itself to other protocols like IGRP ,but this
> will
> > > work only if the subnets of the OSPF domain can be summarized at the
> IGRP
> > > subnet boundary ,also the summary route will be propagated into the
> OSPF
> > YOU HAVE TO HAVE A ROUTE TO CREATE THAT SUMMARY WITH AND IT MUST BE
> EXTERNAL
> > TO OSPF
> > > domain as E2 route which i wasnt able to filter it at all(or it will
> aslo
> > > disapear from the IGRP !!)
> > > wat u explained about the route feedback is another problem called
> black
> > > holes ( i hope im right in this ) ]
> > WHAT I TRIED TO EXPLAIN IS THE OSPF ROUTE WITH AN ADMINISTRATIVE
> DISTANCE
> OF
> > 110 GETS DISTRIBUTED INTO IGRP WHERE IT GETS AND ADMINISTRATIVE DISTANCE
> OF
> > 100. IF MUTUAL REDISTRIBUTION IS TAKING PLACE THEN THIS ROUTE WILL BE
> > REDISTRIBUTED BACK TO OSPF WHERE THE ROUTER WILL SEE THAT THIS ROUTE
> COMING
> > FROM IGRP HAS A LOWER ADMIN DISTANCE THAN THAT OF THE OSPF ROUTES AND
> > THEREFORE USE THIS ROUTE IN IT'S TABLE. IF YOU DO A SHOW IP ROUTE, THEN
> ALL
> > OF THE OSPF ROUTES THAT WERE DISTRIBUTED INTO IGRP AND THEN BACK WILL BE
> > LISTED AS E2. ANOTHER NOTE HERE IS THAT IN SOME CASES SPLIT HORIZON
> WILL
> > NOT ALLOW THE ROUTES BACK OUT OF IGRP SO THIS FEEDBACK DOES NOT OCCUR.
> > > where the routes of less admin distance will replace those of higher
> ones
> > > and the routes will stuck in one domain ...this problem will only
> happen
> > if
> > > u have TWO points of redistribution .
> > > AS per doyle , route feedback will happen when u have one point of
> > > redistribution and u do mutual redistribution from two domain one to
> the
> > > other ...doyle required to put filter in each domain to prevent this
> > > ....while without the filter things work fine with me ...that is why
> im
> > > confused ???
> > >
> > > DO I HAVE TO PUT FILTERS IF ONLY 1 REDISTRIBUTION ROUTER AND MUTUAL
> REDIST
> > > IS THERE ?? OR I NEED ONLY THIS WHEN I HAVE TWO POINTS OF REDIST.
> >
> > IT IS GOOD PRACTICE TO FILTER ROUTES ANY TIME MUTUAL REDISTRIBUTION
> OCCURS.
> > IT IS ONLY NECESSARY WHEN REDISTRIBUTING FROM A HIGHER ADMIN COST TO A
> LOWER
> > ADMIN COST .
> > > secondly ,i didnt find anyway to summarize the OSPF 22 masks into the
> IGRP
> > > 24 domain without using either static routes or the summary address
> and
> > let
> > > the summary route propagate back to the OSPF domain ...
> > >
> > > any more ideas guys
> > > > -----Original Message-----
> > > > From: Johnny Dedon [SMTP:johnny.dedon@exodus.net]
> > > > Sent: Friday, May 11, 2001 1:01 PM
> > > > To: Mohamed Heeba
> > > > Subject: Re: Fatkid lab 502 ,expert redistribution
> > > >
> > > > Mohamed,
> > > > The summary route is used to summarize routes external to the ospf
> > process
> > > > for reditribution into the OSPF process. Have you looked at
> changing
> > the
> > > > mask on the link between igrp and ospf to a 22 bit mask ? Or have
> you
> > > > looked at sending a default route into igrp. Route feedback occurs
> when
> > > > you
> > > > redistribute ospf routes into igrp and since igrp has a lower admin
> and
> > > > the
> > > > routes are now igrp routes they get advertised back to the
> > redistributing
> > > > router where they get put in the route table as ospf external
> routes.
> > Get
> > > > it, they WERE ospf internal routes until you redistributed them to
> igrp
> > > > and
> > > > they got redistributed back. You should not allow this to happen.
> Use
> > > > route-maps or distribute list to stop this.
> > > > Johnny Dedon
> > > > Senior Staff Consultant
> > > > Exodus Professional Services
> > > > johnny.dedon@exodus.net
> > > > www.exodus.net
> > > > ----- Original Message -----
> > > > From: "Mohamed Heeba" <MAHeeba@itqan.co.ae>
> > > > To: <ccielab@groupstudy.com>
> > > > Sent: Friday, May 11, 2001 1:45 PM
> > > > Subject: Fatkid lab 502 ,expert redistribution
> > > >
> > > >
> > > > > guys ;
> > > > > i have a problem here which is similar to some post was here very
> > > > soon...
> > > > > it is regarding the redist of the OSPF into the IGRP ,here is my
> notes
> > > > and
> > > > > questions
> > > > > the case is :
> > > > > the ospf is having different masks of the network 135.1.x.x ,the
> masks
> > > > are
> > > > > /22
> > > > > ,/24,28 while the IGRP is only 24
> > > > > now i didnt get a clear answer about this question
> > > > > 1-does the summary address of the OSPF used to summarize the OSPF
> > domain
> > > > to
> > > > > other protocols or it is ONLY used to summarize the other
> protocols
> > > > domains
> > > > > into the OSPF ??
> > > > > i noticed that the summary address will NOT work until u redist
> IGRP
> > > > into
> > > > > the ospf process even before u redist the OSPF into the IGRP
> > > > >
> > > > > 2- how to redist the mask 22 in the IGRP ? it is not normal to
> > summarize
> > > > > this mask at the 24 boundary (i know this can be done to solve the
> > lab )
> > > > but
> > > > > the problem is that the OSPF will create a static route to the
> null0
> > in
> > > > the
> > > > > redist router and this will take all the traffic to null0 (since
> 24
> is
> > > > more
> > > > > specific than the 22 in teh routing table
> > > > >
> > > > > 3- is the solution for this problem by using the area range
> command
> > > > > somewhere in teh OSPF domain
> > > > >
> > > > > 4-can someone define how the route feedback can heppen ?? becaue
> when
> > i
> > > > > tried to filter in the ospf domain the routes (to accept those
> only
> > > > coming
> > > > > from OSPF and not IGRP ,)teh summary disappeared from the route
> table
> > as
> > > > if
> > > > > it is coming from the IGRP
> > > > > i want to understand this point "is the route feedback means that
> the
> > > > > routes goes inside the domain to downstream routers and then come
> back
> > > > ,or
> > > > > it is only comes back on the redistribution router "
> > > > >
> > > > >
> > > > > i hope someone is patient to answer all this :)
> > > > > thx
> > > > > **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
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