Re: BGP Community - AS0 is de-facto "no-export-to" marker - Any ASN reserved to "export-only-to"?'

[Owen DeLong <owen () delong com>]

Yes, but with large communities, that’s called RFC-8092 and in general, RFC-8642 has some good data.

There’s also BGP extended communities (RFC-7153 and the IANA registry it creates).

Creating an ad hoc BCP vs. using the existing RFC process seems ill-advised.

Owen

> On Sep 8, 2020, at 11:35 AM, Mike Hammett via NANOG <nanog () nanog org> wrote:
>
> How I see the OP's intent is to create a BCP of what defined communities have what effect instead of everyone just 
> making up whatever they draw out of a hat, simplifying this process for everyone.
>
>
>
> -----
> Mike Hammett
> Intelligent Computing Solutions
> http://www.ics-il.com
>
> Midwest-IX
> http://www.midwest-ix.com
>
> From: "Tom Beecher via NANOG" <nanog () nanog org>
> To: "Douglas Fischer" <fischerdouglas () gmail com>
> Cc: "NANOG" <nanog () nanog org>
> Sent: Tuesday, September 8, 2020 1:30:19 PM
> Subject: Re: BGP Community - AS0 is de-facto "no-export-to" marker - Any ASN reserved to "export-only-to"?'
>
> BGP Large Communities ( https://tools.ietf.org/html/rfc8195 <https://tools.ietf.org/html/rfc8195> ) already provides 
> for anyone to define the exact handling you wish. 
>
>
>
> On Tue, Sep 8, 2020 at 11:57 AM Douglas Fischer via NANOG <nanog () nanog org <mailto:nanog () nanog org>> wrote:
> Most of us have already used some BGP community policy to no-export some routes to some where.
>
> On the majority of IXPs, and most of the Transit Providers, the very common community tell to route-servers and 
> routers "Please do no-export these routes to that ASN" is:
>
>  -> 0:<TargetASN>
>
> So we could say that this is a de-facto standard.
>
>
> But the Policy equivalent to "Please, export these routes only to that ASN" is very varied on all the IXPs or Transit 
> Providers.
>
>
> With that said, now comes some questions:
>
> 1 - Beyond being a de-facto standard, there is any RFC, Public Policy, or something like that, that would define 
> 0:<TargetASN> as "no-export-to" standard?
>
> 2 - What about reserving some 16-bits ASN to use <ExpOnlyTo>:<TargetASN> as "export-only-to" standard?
> 2.1 - Is important to be 16 bits, because with (RT) extended communities, any ASN on the planet could be the target 
> of that policy.
> 2.2 - Would be interesting some mnemonic number like 1000 / 10000 or so.
>
> -- 
> Douglas Fernando Fischer
> Engº de Controle e Automação