Re: [Idr] One week extension to WGLC for draft-ietf-idr-large-community

[Job Snijders <[e-mail]>]

On Tue, Nov 15, 2016 at 03:19:22PM +0100, Robert Raszuk wrote:
> Since I was going to ask the same question let me provide an example:
> 
> AS1 ---- AS2 ---- AS3 ---- peer_X
> 
> AS3 publishes community with action if I receive this community I will
> PREPEND my AS# one time towards my peer X.
> 
> Now AS1 comes with a need for such prepend on PI prefix P. Then AS2 for
> perhaps completely different reason also comes up with idea to hint AS3 to
> execute prepend on the same very prefix P.
> 
> So AS3 is receiving the two communities which both are valid and truely
> intended. Why we would drop it ?
> 
> I admit when the topic came up originally the major concern to me was to
> prevent stuffing community with N identical sets of values by same AS.
> 
> But even this case can be legitimate. Let's consider that said AS2  needs
> prepend by 2 to some prefixes and AS3 offers *only* community of single
> PREPEND. Why not adding it twice to such selected prefixes not be a way to
> signal such requirement ?

You copy+pasted what i described as an "abomination implementation" here
https://mailarchive.ietf.org/arch/msg/idr/0Uv77wdj2U_kAskiz8LOqGUIFKc

- Job