Re: [Lsvr] Comments on LSVR with RR peering

[Eric Rosen <[e-mail]>]

This example is based on Section 2.3 of lsvr-bgp-spf-03 ("BGP Peering in 
Route-Reflector or Controller Topology"), which states:

    "In this model, BGP speakers peer solely with one or more Route 
Reflectors [RFC4456] or controllers."

Thus when BC goes down, B cannot tell A of this fact, it can only tell 
the Route Reflector, and A can only learn of this fact from the Route 
Reflector.

Perhaps I took the statement in Section 2.3 too literally? ;-)

On 12/4/2018 6:21 PM, Randy Bush wrote:
> apologies, but i am easily confused.
>
>> RR--1--A--1--B--1--C--1--D--1--E
>>                |                 |
>>                |-----5-----F--1--|
>>
>> The letters represent routers (RR being the Route Reflector), and the
>> numbers are link metrics.
>>
>> Suppose BC goes down, and consider the following sequence of events:
>>
>> 1. B tells RR (via path B-A-RR) that BC is down.
> are you doing some sort of multi-hop or underlay?  if not, then A told
> RR that B told her that B-C was down.
>
>> 2. RR tells A (via path RR-A) that BC is down.
> did A not know B-C was down already?
>
> randy