Dear Nanog community, During the past years, we have seen an increasing usage of the BGP community attribute. For instance, in a recent BGP table dump from routeviews, 99% of the routes stored by the router carries BGP communities. In this context, we are currently working on a BGP community taxonomy, i.e., we want to classify and document communities according to their usage. We describe our taxonomy on the following url: http://inl.info.ucl.ac.be/communities Based on this taxonomy, we tried to collect as much as possible information on BGP communities. This was a daunting task as we mainly relied on public database, such as whois server and ISP web sites. Our current database of classified BGP communities currently contains more than 12,000 entries. When running our database and taxonomy on recent BGP table dumps from RouteViews and RIPE (last dump from September 2007), we were only able to classify, on average, 20% of the encountered communities. Based on this result, we ranked the unclassified BGP communities. Here is the top 10 of most seen ASes using uncommented communities: AS19151 AS3549 AS3549 AS2914 AS7473 AS286 AS3292 AS13237 AS6667 AS34225 You can find the top 100 on the following url: http:// www.info.ucl.ac.be/~donnet/communities.html It gives the AS number as well as, for each AS, the various unclassified communities and their total frequency (i.e., the number of times the AS with unrecognized communities is encountered in table dumps). If you have any documentation regarding these communities, it would be very helpful if you can send us back this information. The easiest way for you is probably to reply to this email and attach the information (text, PDF, doc file, ...). When our database will be enough representative of the used BGP communities, we will made it freely available. We will also propose a way for updating (adding or removing) BGP communities information in our database. Thanks in advance. Best regards. Dr. Benoit Donnet & Prof. Olivier Bonaventure -- Dr. Benoit Donnet Université Catholique de Louvain (UCL) Faculté des Sciences Appliquées - Département d'Ingénierie Informatique (INGI) Place Sainte Barbe, 2 1348 Louvain-la-Neuve Belgium Phone: +32 10 47 87 18 Home page: http://inl.info.ucl.ac.be/donnet