From: Stephen Sprunk (no email)
Date: Sun Nov 23 2008 - 21:17:32 EST
Joe Abley wrote:
> On 19 Nov 2008, at 19:16, Heather Schiller wrote:
>> ARIN makes available a list of prefixes with OriginAS. I don't know
>> if other RIR's do.
> How is that list generated?
> I'm not aware of any tight coupling between address assignment and AS
> assignment that binds anybody to advertise particular routes with
> particular origins, at least at the time that either is
> assigned/allocated by an RIR/LIR.
Presumably it's from the "Origin AS" field in WHOIS:
** As of February 2007
** Detailed instructions are located below the template.
01. Registration Action (M or R):
02. IP Address and Prefix or Range:
03. Network Name:
04. Origin AS:
04. List all AS numbers from which the network may originate.
You can list as many AS numbers as necessary. You must
separate multiple AS numbers with a comma. You may not list
AS number ranges; only list individual AS numbers.
Interesting is how accurate the field actually is. Slide 6 at:
says that 91% of the routes they checked had a correct Origin AS in
WHOIS, compared to 64% in the ARIN IRR database.