OVH Systems’ AS 16276 is #1 in the April 2013 worldwide from CBL data with 631,539,742 spam message seen according to the new Version 2 of SpamRankings.net, while the same ASN is #3 in the old version 1 rankings with 363,884,989 spam messages seen. Why the difference?
The difference is because Version 2 finds more netblocks assigned to AS 16276. Specifically:
|72||netblocks currently assigned|
|27||netblocks previously assigned|
|14||netblocks are persistant|
|58||netblocks have been added|
|13||netblocks have been removed|
Many more netblocks were found for AS 16276 only by Version 2 than were found only by Version. So the difference in the amount of spam presumably comes from those added netblocks. Yes, we can drill down and see, and we may do that later.