nanog mailing list archives

Re: AS0 in AS path


From: Mikhail Strizhov <strizhov () cs colostate edu>
Date: Fri, 06 Aug 2010 16:10:36 -0600

 Thanks everyone.

Answer is simple - 4byte ASN's.
I was parsing Route Views RIB-IN tables, and found that, by default, Quagga is using 4byte AS length field to store 2-byte and 4-byte AS Numbers. So, using 2 bytes length in parser, I had wierd output like "0 3549 0 1239" and so on.



--
Sincerely,
Mikhail Strizhov
Email: strizhov () cs colostate edu <mailto:strizhov () cs colostate edu>


On 08/06/2010 03:47 PM, Kameron Gasso wrote:
On 08/06/2010 02:15 PM, Mikhail Strizhov wrote:
Does anybody have\had experience with BGP announces containing AS 0 in
AS path?
I know that AS 0 is reserved by IANA, but  still, is it possible to
receive such announce messages?
eBGP or iBGP?  What type of device and/or software are you using to
speak BGP?

As far as I know, most devices should NOT let you set your ASN to 0 or
let you add it to the AS path.

My guess is it's probably going to be filtered by the BGP scanner, but I
don't have any gear laying around that I can play with at the moment to
confirm. :)


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