IPv6 Address Specific BGP Extended Community

[Ondrej Zajicek]

On Fri, Oct 25, 2024 at 09:39:59PM +0800, Eric Long wrote:
> Hi all,
> 
> BGP flowspec v6 [1] uses IPv6 address specific extended communities [2] for
> traffic actions, which seems to have no signs of support in BIRD (at least
> in BIRD 2). Is this planned to support in the future? Is there a good
> starting point/example where I can refer to to try to implement it in BIRD,
> since it seems to need to touch a lot of parts of the source code (parser,
> data types, protocols, etc.)

Hi

Yes, it is not supported in BIRD, we never registered much interest in
this. The core part is in nest/a-set.c, which contains functions for
manipulations with clists / eclists /lclists (despite its name and name
of functions there, they have nothing in common with set types from
filters). But this code is ripe for rewriting for something more generic.
Besides the a-set.c, you can just git-grep for T_ECLIST (filtering code)
and BA_EXT_COMMUNITY (BGP code) to see what was needed for extended
communities.

Also, such feature would touch a lot of parts of BIRD, including ones
that changed significantly between BIRD 2 and BIRD 3, so i think it
would make sense to implement it directly to BIRD 3.

-- 
Elen sila lumenn' omentielvo

Ondrej 'Santiago' Zajicek (email: santiago at crfreenet.org)
"To err is human -- to blame it on a computer is even more so."