From: Mannan Venkatesan (venkat_m@xxxxxxx)
Date: Mon May 14 2001 - 15:38:38 GMT-3
I have done this before. I used policy routing to bypass /24 null0. And I
used 'not-advertise' option with summary-address to prevent the EX route
propagated to the OSPF domain. I found, with 'not-advertise' command, OSPF
domain routers will have the EX route in their OSPF database but not in
their routing table.
HTHs
Mannan
----- Original Message -----
From: "Mohamed Heeba" <MAHeeba@itqan.co.ae>
To: <lkouncar@UU.NET>
Cc: <ccielab@groupstudy.com>
Sent: Friday, May 11, 2001 5:59 PM
Subject: RE: Fatkid lab 502 ,expert redistribution
> let me understand this please ,i have read the post and the guys was
talking
> about the same thing
> let me explain wat is in that damn lab
>
> ----IGRP/24--------R4---------OSPF/22-------R2------OSPF/24
> the redistribution should be done on R4 in both direction
> on the ospf process ,i created the summary address of the 22 mask to be as
> 24 (which is weird ..but ok )
> the OSPF process created a static route to the null0 into the routing
table
> (not appeared in the configuration )
> the route (/24) propagated to the IGRP as well as to the OSPF domain
without
> problems
> when the IGRP internal routes tried to ping the OSPF 22 network , it didnt
> work ???? because R4 null0 take the traffic ....i have tried to change the
> 22 to 26 mask and in that case it worked fine .
>
> so ,now u can tell me wat redistribute connected can do in this case and
> where do u want to put it ?
> another thing when i tried it with 26 mask ,the summary propagated to the
> OSPF domain ,i didnt find anyway to filter it ,if i do it will NOT go the
> IGRP domain as well.........
>
> any suggestion ?
>
>
>
>
>
>
> > -----Original Message-----
> > From: louie kouncar [SMTP:lkouncar@UU.NET]
> > Sent: Friday, May 11, 2001 2:48 PM
> > To: 'Mohamed Heeba'; 'Johnny Dedon'
> > Cc: ccielab@groupstudy.com
> > Subject: RE: Fatkid lab 502 ,expert redistribution
> >
> > Mohamed,
> >
> > If the network you want to summarize is connected to the router, then
> > redistribute connected with an access list that will allow only that
> > network
> > to be redistributed, at this time, you will have an LSA 5 to that
network
> > and you can then use the summary-address command to advertise it to your
> > IGRP neighbor which will accept it......
> >
> >
> >
> >
> > Louie J. Kouncar
> > TCO3 Senior Data Center Engineer
> > UUNET
> > W-703-343-6645
> > C-703-304-2460
> >
> >
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> > Mohamed Heeba
> > Sent: Friday, May 11, 2001 5:17 PM
> > To: 'Johnny Dedon'
> > Cc: ccielab@groupstudy.com
> > 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
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