From: Howard C. Berkowitz (hcb@gettcomm.com)
Date: Thu Apr 29 2004 - 08:23:27 GMT-3
At 12:56 PM +0200 4/29/04, Alexander Arsenyev (GU/ETL) wrote:
>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.
Just for reference, that requirement for the router IDs is from
now-historic RFC 1403. "Historic", in IETF-speak, means "obsolete and
don't use it".
>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 synchronization is years more outdated than many of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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>
>=====
>Richard Davidson
>Yahoo IM: r1davidson
>e-mail rich@myhomemail.net
>
>_______________________________________________________________________
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