Limit of numbers of BGP communities

Douglas Fischer fischerdouglas at gmail.com
Fri Jul 12 14:57:09 CEST 2024


Unfortunately, this number of 100 BGP communities has no basis, at least
not yet, in the RFC.
It is just a recommendation (a very healthy one, by the way) from the NLNOG
team.

As far as I remember, neither the maximum mask limit of /24 for IPv4 nor
/48 for IPv6 in a BGP session are defined in RFC as either must or should.

It would be good if it were in the RFCs, but it is not.

Em sex., 12 de jul. de 2024 às 06:43, Jeroen Massar via Bird-users <
bird-users at network.cz> escreveu:

>
>
> > On 12 Jul 2024, at 04:30, Ponikierski, Grzegorz via Bird-users <
> bird-users at network.cz> wrote:
> >
> > Hello all!
> >  How many standard communities, extended communities and large
> communities, user can apply on a route using Bird? BGP UPDATE message has
> finite size so I guess that there must be a limit somewhere.
>
> The limit is that ISPs are limiting it to a 100:
>
>  https://bgpfilterguide.nlnog.net/guides/many_communities/
>
> Above that, it will be emptied completely in many networks.
>
> Greets,
>  Jeroen
>
>
>
>

-- 
Douglas Fernando Fischer
Engº de Controle e Automação
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://trubka.network.cz/pipermail/bird-users/attachments/20240712/df6e9580/attachment.htm>


More information about the Bird-users mailing list