BGP community attribute taxonomy

Benoit Donnet benoit.donnet at
Thu Nov 15 10:05:55 UTC 2007

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  

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  

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  

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:

You can find the top 100 on the following url: http://  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
Phone: +32 10 47 87 18
Home page:

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