Hi Douglas, Just FYI I have tried to capture most common use cases of communities and register them as part of a wide-community effort in IANA. https://tools.ietf.org/html/draft-ietf-idr-registered-wide-bgp-communities-0... That draft is pending standardization of wide-communities itself. You are obviously very welcome to either reuse some of this work or support it :) Kind regards, R. On Tue, Sep 8, 2020 at 5:58 PM Douglas Fischer via NANOG <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