North American Network Operators Group

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Re: Geo location to IP mapping

  • From: Kevin Day
  • Date: Mon May 15 18:42:15 2006

On May 15, 2006, at 4:36 PM, Alain Hebert wrote:


I'm moron. You didn't know it yet?


Come on...

"The way we disperse static IP" ain't imagination, its fact... We spread a /20 on dynamic dialup and dsl over 2 provinces and since most of the residential services is build like this you cannot get a read of where that ip user is located, unless you have also access to our customers db and authentication account db too.

The best you'll get is country. Even then we have some that are LanEx'ed in europe and usa.

(FYI: English is not my first language btw... so dont expect too much)

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

The company we purchased the database from uses a number of sources of data, to produce something pretty accurate:

1) WHOIS records for the IP assignment
2) WHOIS records for domain in the PTR record for the IP
3) Parsing the PTR record for city names and airport codes
4) Purchasing IP/billing and shipping city,state,zip records from sites with accurate records (e-commerce and other sites that people need to enter their local info)
5) All of the above for the hop or two before the end in a traceroute
6) BGP and traceroute comparisons to determine where the boundaries are in how you've internally routed things

Even if you're just allocating from a single /20, you probably have some hierarchy, and that can be picked up through routing or DNS or SWIP.

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.

Never underestimate what can be done through regular expressions and an army of people sitting at terminals in China to verify what can't be automated. :)

For those of you really interested, email me privately and i'll dump what we have on record for a block or two of yours.