[Coral-dev] Incorrect masklen.

[Ryan Koga]

On 2/7/11 2:35 AM, Sharad Chandra wrote:

> I am also trying to understand why is there a list of "origin AS" for some
> network instead of just one AS number. eg
>
> 8.27.160.0      21      {6298,11588,12989,22773}
>
> I understand it is the last in bgp routing table dump.
> *  8.27.160.0/21    85.114.0.217             0      0      0 8492 9002 3356
> 13550 {6298,11588,12989,22773} i
>
> 'whois' gives another number as AS, appeared before in the above line but not
> the curly bracket.
>
> [~]$ whois -h whois.cymru.com " -w 8.27.160.0/21"
> AS      | IP               | AS Name
> 3356    | 8.27.160.0       | LEVEL3 Level 3 Communications

That origin AS is an AS set.  We try our best to reduce sets to a single 
AS, but don't always have enough information to do so.  We do not 
incorporate WHOIS data, since parse_bgp_dump only parses the BGP dump, 
so I cannot speak to differences with WHOIS results.
-- 
rkoga at caida.org (Ryan Koga)