From owner-nanog@merit.edu Mon May 15 17:42:13 2006 From: Kevin Day <toasty@dragondata.com> Subject: Re: Geo location to IP mapping Date: Mon, 15 May 2006 17:40:23 -0500

We use a Geo/IP location database. It's surprisingly accurate, with a few exceptions.

[[ sneck ]]

Comparing the database to the IP that our customers used to make purchases we exceed 95% accuracy in identifying the country, and 75-85% in city/state. The big exception is AOL, since their IP assignments are pretty well randomized with respect to geography.

*dynamically* randomized, no less, or so I've been told. As in: _all_ the customer session addresses are assigned out of *one* DHCP pool. I thought that 'unlikely', considering the mayhem on internal routing tables, but the AOL rep was rather insistant that that _was_ the case. They also have 'virtual' POPs, where they just backhaul ('tens if not hundreds' of miles, in same cases) voice, rather than having any physical equipment present.