[LINK] RFI: Geolocation based on IP-Address
Roger.Clarke at xamax.com.au
Thu Sep 27 08:44:28 EST 2007
I've finally made time to look at http://www.ip2location.com/free.asp.
It gets me right, at the level of 'ACT' (except for "Net Speed: DIAL").
I'm unclear how the service can narrow it to the ACT.
Is TPG's allocation of IP-addresses to phone-numbers public (enabling
a reverse-lookup on exchange prefixes)??
Here's my amateur's stab at investigating the question.
I understood that APNIC would have allocated a range of addresses to
TPG Internet Pty Ltd.
The table at:
shows the range that my address is in as being allocated as follows:
244.220.in-addr.arpa. IN NS ns1.tpgi.com.au.
244.220.in-addr.arpa. IN NS ns2.tpgi.com.au.
Okay, using Interarchy, the DNS reverse-lookup does show:
And using nslookup:
nslookup 220.127.116.11 ns1.tpgi.com.au
18.104.22.168.in-addr.arpa name = 220-244-240-4-act-pppoe.tpgi.com.au.
So they rely on parsing the DNS entry for odd strings like 'act'?
Roger Clarke http://www.anu.edu.au/people/Roger.Clarke/
Xamax Consultancy Pty Ltd 78 Sidaway St, Chapman ACT 2611 AUSTRALIA
Tel: +61 2 6288 1472, and 6288 6916
mailto:Roger.Clarke at xamax.com.au http://www.xamax.com.au/
Visiting Professor in Info Science & Eng Australian National University
Visiting Professor in the eCommerce Program University of Hong Kong
Visiting Professor in the Cyberspace Law & Policy Centre Uni of NSW
More information about the Link