From: Howard C. Berkowitz (hcb@xxxxxxxxxxxx)
Date: Tue Aug 27 2002 - 00:57:25 GMT-3
At 10:49 PM -0400 8/26/02, Peter van Oene wrote:
>Synchronization has been obsolete for almost a decade. It is not
>supposed, nor was ever supposed to work with route reflection.
>These are orthogonal topics. How it does perform is likely more a
>matter a coding fortune/misfortune rather than desired effect.
>
>This has got to be my number one pet peeve topic and really goes to
>the negative side of any cert program. People get way to focused on
>arcane, core case issues and completely lose site of the real world
>implication. For example, when trying to figure this out, have you
>stopped and wondered exactly what problem using the two techniques
>together would solve? Even one step back you'd realize that
>synchronization attempts to prevent blackholing in non IBGP meshed
>networks whereas route reflection ameliorates scaling issues in full
>mesh IBGP networks. That is to say they are designed for use in
>completely different networks. Furthermore, IGPs cannot handle
>transit style Internet feeds anyway, nor have they been able to for
>quite some time so the use or otherwise of synchronization is a moot
>point anyway.
>
>I expect you are just prepping for a test and trying to cover all
>the angles and I've had a rather challenging day and should likely
>just drink some beer and ignore these threads :-)
Yeah right. You're one of those BGP expert that believe it should
beer, not peer.
Seriously, I agree completely with Peter that synchronization is
completely obsolete, and thoroughly confusing.
>
>
>
>At 07:55 PM 8/26/2002 -0400, George Spahl wrote:
>>Greetings,
>>
>>This is similar to Dmitry's thread, but more general since it doesn't
>>involve the OSPF vs. BGP router id (I don't think!), however I think it
>>may be the same problem. I don't know why I haven't noticed this
>>before, but when a prefix is being reflected by a RR from one RR client
>>to the next RR client and the prefix isn't synchronized on the RR is it
>>forbidden for it to reflect it?
>>
>>For example, R1 is the RR, R2 and R3 are the RR clients. A prefix is
>>added to R2 with a "network" statement (and no other routing protocol
>>carries this route). R2 sends it to the route reflector who refuses to
>>reflect it to R3 since it's not "synchronized" on the RR. Is this
>>normal or is there something else going on here?
>>
>>It seems like that since Route Reflection in general is supposed to
>>substitute for an IBGP full mesh that even though it may not be
>>"synchronized" on the RR, the RR should still reflect it to other RR
>>clients, even if he doesn't enter it into his own ip routing table,
>>since this is what would happen if it were an IBGP full mesh anyway. At
>>least, I would think that's how you would want it to work. If this is
>>really the way it works does anyone have an idea why they would want to
>>work this way?
>>
>>By the way, this is from the interesting lab that Brian McGahan put out
>>on the list for us. It's the basic BGP setup, section F.1 and F.2.
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