Upstream BGP community support

Daniel Roesen dr at
Thu Nov 5 23:04:18 UTC 2009

On Mon, Nov 02, 2009 at 02:13:38PM -0600, Richard A Steenbergen wrote:
> Rather than simply double the size and break it
> up into 32:32, the designers reserved the top 16 bits for "type" and
> "subtype" attributes, leaving you only 48 bits to work with. Clearly the
> only suitable mapping for support of 32-bit ASNs on the Internet is
> 32:16, leaving us with exactly the same range of "data" values that we
> have today.

... which breaks schemes such as


where 45678 is the neighboring AS to apply the action defined by
65123 to. Seen those multiple times.

Of course using anything else then your own ASN in the "AS part" of
TE communities is certainly debatable.

Best regards,

CLUE-RIPE -- Jabber: dr at -- dr at IRCnet -- PGP: 0xA85C8AA0

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