It assumes that Extended Length bit of Attribute Type is properly implemented so community attribute can use attribute length field as 2 octet field, right?
How situation changes with RFC 8654<http://www.rfc-editor.org/info/rfc8654> - Extended Message Support for BGP? Regards, Grzegorz From: Ondrej Zajicek <santi...@crfreenet.org> Date: Friday, 12 July 2024 at 05:40 To: "Ponikierski, Grzegorz" <gponi...@akamai.com> Cc: "bird-users@network.cz" <bird-users@network.cz> Subject: Re: Limit of numbers of BGP communities On Fri, Jul 12, 2024 at 02:30:10AM +0000, Ponikierski, Grzegorz via Bird-users 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. Hello There is no specific limit on communities, just a limit on overall BGP attribute length on export, which is 1 kB less than BGP message size (there is 1 kB reserved for prefixes). So with regular BGP messages, there can be at most 3 kB of attributes, which is ~768 standard, ~384 extended, or ~256 large communities. In fact, it is a slightly less due to attribute framing and presence of other attributes than communities. -- Elen sila lumenn' omentielvo Ondrej 'Santiago' Zajicek (email: santi...@crfreenet.org<mailto:santi...@crfreenet.org>) "To err is human -- to blame it on a computer is even more so."
