From: Alexander Arsenyev (GU/ETL) (alexander.arsenyev@ericsson.com)
Date: Thu Apr 29 2004 - 07:56:18 GMT-3
Hello,
I believe there is a better solution:
make R1 (route-reflector-client) an NSSA ASBR and R2 (route-reflector) an NSSA ABR. R3 could be in the same area as R2 or not but it should not be in stub or NSSA area.
Then external-to-OSPF routes redistributed into OSPF on R1 will be Type-7 and will be tagged with R1' router-id. When these routes get to R2 it will convert them to Type-5 and tag them with own router-id. When BGP routes from R1 will get to R3 they will be synced with Type-5 OSPF ones because a) OSPF routes will bear R2 OSPF router-id b) BGP routes will bear R2 BGP router-id.
Now You have to watch that R2 OSPF router-id and BGP router-id are the same which is trivial.
HTH,
Cheers
Alex
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
Richard Davidson
Sent: 28 April 2004 21:02
To: Peter van Oene; ccielab@groupstudy.com
Subject: Re: Another burning question on BGP
I agree with Peter. However, if my memory serves me
this is what to do.
At the ASBR (R1) you are redistributing the BGP routes
into ospf and they are comming from the ASBR ospf
Router ID R1. Those routes get to R3 and they are
from ,,, you guessed it R1. Well stop there and
switch to BGP.
R1 & R3 both peers with R2 which is a RR. When the
BGP route gets to R3 it is from R2 "not R1". Sync
will fail.
Solution: swap BGP router IDs with R2 and R1. Now R1
sends a BGP route as if he is R2. R2 gets it and it
sends it as if it is R1 to R3. When R3 sees the BGP
route is from the R1 BGP Router ID and the OSPF route
is from the R1 ospf Router ID it will sync.
---------------------
{R1}---{R2}----{R3} |
|
AS1 |
---------------------
--- Peter van Oene <pvo@usermail.com> wrote:
> The short answer is that this is an @#$@'ing
> ridiulous scenario that is a
> complete waste of your time. If Cisco wants to test
> on it, then shame on
> them for forcing you to study such a moronic topic.
> There is nothing
> anywhere near a practical requirement for such a
> topology and
> synchronization is years more outdated than many of
> the already deprecated
> items that have found space on the CCIE lab.
>
>
>
> At 12:39 PM 4/28/2004, Edwards, Andrew M wrote:
> >I'm trying to understand methods to keep
> synchronization on in BGP and
> >provide BGP to OSPF redistribution with route
> reflectors.
> >
> >You know the problem where the route reflector
> server receives an update
> >from a route reflector client that is
> redistributing BGP to OSPF.
> >
> >When the route reflector server gets the update, it
> reflects that update
> >to all other RR clients but changes the BGP ID to
> itself.
> >
> >Obviously the other BGP RR clients get the BGP
> update but the OSPF
> >router ID and BGP ID do not match on the clients so
> the BGP route is not
> >marked
> >As a best path ">"
> >
> >So the question I have is what methods are
> available to make this work
> >with synchronization on and using route reflectors?
> >
> >Is the answer go to full mesh or transfer to
> confederations?
> >
> >I'm stumped on how to change the BGP router-id to
> the originators BGP
> >router ID on the RR server.
> >
> >Thanks for the input... or clearing up my
> confusion.
> >
> >Andy
> >
>
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