BIX Communities

BIX (Budapest Internet Exchange) enables networks connected to the Peering LAN to peer through its route servers (BIX RS1 and RS2). Peers can apply their own routing policies using IRRDB-based filtering and predefined BGP communities. This allows members use the BIX route servers while maintaining full control over their peering policy.

BGP communities are optional attributes that can be attached to BGP routes to apply specific routing policies. They provide a simple and flexible way to influence how routes are handled, propagated, or advertised by BGP speakers.

To use a BGP community, an operator adds the appropriate community value to a route using their BGP configuration. The receiving router (BIX RS1 and RS2) can then match the community and apply a predefined policy, such as accepting, rejecting, or selectively propagating the route. This allows network operators to control route propagation without relying solely on IP prefixes or AS paths.

Recommended Large BGP communities:

5507:1:<peer-as>	Advertise the prefix to AS<peer-as> Peers
5507:101:<peer-as>	Prepend 1x when advertising to AS<peer-as> Peers
5507:102:<peer-as>	Prepend 2x when advertising to AS<peer-as> Peers
5507:103:<peer-as>	Prepend 3x when advertising to AS<peer-as> Peers
5507:0:<peer-as>	Do not advertise to AS<peer-as> Peers

5507:1:0	Advertise the prefix to all Peers (Not needed, this is the default policy)
5507:101:0	Prepend 1x when advertising to all Peers
5507:102:0	Prepend 2x when advertising to all Peers
5507:103:0	Prepend 3x when advertising to all Peers
5507:0:0	Do not advertise to all Peers

Supported Standard BGP communities:
(Only use it if You have problems with large BGP communities)

5507:<peer-as>	Advertise the prefix to AS<peer-as> Peers
0:<peer-as>	Do not advertise to AS<peer-as> Peers
5507:5507	Advertise the prefix to all Peers (Not needed, this is the default policy)
0:5507	Do not advertise to all Peers