Hello,
We are running a small IX fabric (in Mumbai, India) and with multiple
route servers based on a bird. There has been a demand of support of BGP
communities from some of our members and I am trying to find a way to set
it up in the bird. Idea is to provide a community say 0:123 where tagged
routes with 0:123 do not reach AS123. I am new to the bird.
Tried testing with config given here -
https://gitlab.labs.nic.cz/labs/bird/wikis/Route_server_with_community_based_filtering_and_single_RIB
and that results in no announcement peer where the route is going out. (No
specific comms even used. Just applying the export config results in a drop
of the route announcement).
I also tried other config example given over there for putting routes of
each peer in their table
(as per
https://gitlab.labs.nic.cz/labs/bird/wikis/Route_server_with_community_based_filtering_and_multiple_RIBs)
and behaviour is same. No route announcement to peers.
Was wondering if anyone can point to right config to support BGP
communities?
Thanks!
We are running a small IX fabric (in Mumbai, India) and with multiple
route servers based on a bird. There has been a demand of support of BGP
communities from some of our members and I am trying to find a way to set
it up in the bird. Idea is to provide a community say 0:123 where tagged
routes with 0:123 do not reach AS123. I am new to the bird.
I strongly recommend to either use “arouteserver” or “IXP manager” to
generate the BIRD configuration files on your behalf, and no type it by
hand.
Setting up a fully featured secure route server is a lot of work and
research, I’d really recommend to leverage the work others have done in
this problem space. I fear otherwise you may risk repeating mistakes that
others already made.
https://arouteserver.readthedocs.io/en/latest/
https://github.com/pierky/arouteserver
https://www.ixpmanager.org/
And using these automated tools means less work for the IX operator.
Turning up new peers is a breeze with both tools!
Kind regards,
Job
As an operator of large, established IXP I would also recommend this path. A lot of work had gone into the likes of IXPManager and arouteserver and they provide great value in providing secure configurations with added features such as action communities you are after.
Cheers,
Tim
Hi Tim & Job
Thanks a lot for your advice. I was aware of IXP Manager and there were
certain issues we faced due to which we couldn't use it when we tried last
time (which was a few months ago before the latest stable release). I wish
to re-visit and keep on re-visiting it until we can make it work because it
does seem like a package full of everything an IXP needs. 
I checked arouteseerver project which I missed during the previous lookup.
It seems really good and I ended up in building config and getting it live.
For now, we got what we needed (the BGP community support as well as a way
to automatically update config regularly). I will explore IXP manager again
in the very near future.
Thanks again for your help. And oh btw I still do not have an answer to my
question on why route announcement did not go. I do have a well tested and
working config which does the job but the config generated by arouteserver
is like 10x bigger than original config (for 5 peers). Still trying to read
and get a sense from it on what was wrong earlier.
Thanks.
Thanks a lot for your advice. I was aware of IXP Manager and there
were certain issues we faced due to which we couldn't use it when we
tried last time (which was a few months ago before the latest stable
release). I wish to re-visit and keep on re-visiting it until we can
make it work because it does seem like a package full of everything an
IXP needs. 
I checked arouteseerver project which I missed during the previous
lookup. It seems really good and I ended up in building config and
getting it live. For now, we got what we needed (the BGP community
support as well as a way to automatically update config regularly). I
will explore IXP manager again in the very near future.
Note that you can use arouteserver in conjunction with IXP Manager:
arouteserver can plug into IXP Manager so that you use IXP Manager for
the administrative side of things (the portal, statistics, etc), and use
arouteserver for the routeserver configuration generation.
Arouteserver (compared to IXP Manager) offers a bunch of more advanced
features such as "Use RPKI ROAs as route-objects", the "ARIN-WHOIS" data
source, and some extra filters/features. Both are excellent, it is good
to have a choice 
Thanks again for your help. And oh btw I still do not have an answer
to my question on why route announcement did not go.
Feel free to send me your full BIRD configuration off-list and I'll help
you analyse what's wrong in the adoption of that example config.
I do have a well tested and working config which does the job but the
config generated by arouteserver is like 10x bigger than original
config (for 5 peers). Still trying to read and get a sense from it on
what was wrong earlier.
The arouteserver (or ixp manager) configurations are indeed bigger, most
likely due to extensive prefix and as_path filtering! This is a good
thing. Don't worry about size - I've loaded 50 megabyte config files
into BIRD and it handles such large configurations fine.
Kind regards,
Job