[129883] in North American Network Operators' Group
Odd BGP AS Path
daemon@ATHENA.MIT.EDU (Heath Jones)
Wed Sep 22 11:18:25 2010
Date: Wed, 22 Sep 2010 16:18:15 +0100
From: Heath Jones <hj1980@gmail.com>
To: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Hi all,
Probably a silly question, but can anyone explain to me this:
3561 3356 9031 {35821,35821,35821,35821} i
To explain it a bit better, I'm looking at real routing information
from routeviews (#3).
According to RFC 4271 (9.2.2.2 Aggregating Routing Information):
> For the purpose of aggregating AS_PATH attributes, we model
> each AS within the AS_PATH attribute as a tuple <type, value>,
> where "type" identifies a type of the path segment the AS
> belongs to (e.g., AS_SEQUENCE, AS_SET), and "value" identifies
> the AS number.
> ...
> No tuple of type AS_SET with the same value SHALL appear
> more than once in the aggregated AS_PATH.
Am I misreading things, or is this path information out of spec?
Cheers
Heath
