Internal Program Version: Geo::IP  1.510.0.5.42.0

This module a simple file-based database. This database 
simply contains IP blocks as keys, and countries as values. 
The data contains all public IP addresses and should be 
more complete and accurate than reverse DNS lookups.

This module can be used to automatically select the 
geographically closest mirror, or to analyze your web 
server logs to determine the countries of your visiters.

https://github.com/maxmind/geoip-api-perl