From: Mohamed Heeba (MAHeeba@xxxxxxxxxxx)
Date: Fri May 11 2001 - 19:03:46 GMT-3
well ;
i have given this option a thought to create secondary IP subnet of 22 on
the IGRP domain ..i didnt try it ..but feel that it will work .....i have
also thought that the lab is not prepared welll.....but still it offer a
question ..is there anyway to summarize something like 22 mask of the ospf
domain into higher mask like 24 in IGRP domain (simple static route can
solve the damn problem...but wat if it is not allowed ?)
thx
> -----Original Message-----
> From: Johnny Dedon [SMTP:johnny.dedon@exodus.net]
> Sent: Friday, May 11, 2001 3:02 PM
> To: Mohamed Heeba
> Subject: Re: Fatkid lab 502 ,expert redistribution
>
> Mohamed,
> I took a look at this lab and face value this is what I see.
> You are not given a route to use to create a default to advertise into
> igrp
> so that option is out. You could possibly change the subnet mask on r4's
> ethernet to a 22 bit mask and therefore it will advertise the 22 bit
> subnet.
> The extra routes created here would be lost. Not to change the lab, you
> would need to leave the 24 bit mask on the other end. Downside to this I
> think is you would need to summarize all of the ospf routes to 22 bit
> mask.
> I don't think this lab was very well written.
>
> 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>
> Cc: <ccielab@groupstudy.com>
> Sent: Friday, May 11, 2001 4:16 PM
> Subject: RE: Fatkid lab 502 ,expert redistribution
>
>
> > 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
> > **Please read:http://www.groupstudy.com/list/posting.html
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