[LINK] RFI: Geolocation based on IP-Address

[Roger Clarke]

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:
http://ftp.apnic.net/stats/apnic/delegated-apnic-latest
shows the range that my address is in as being allocated as follows:
apnic|AU|ipv4|220.244.0.0|65536|20030618|allocated

This one:
http://ftp.apnic.net/zones/220-APNIC
shows:
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:
220-244-240-4-act-pppoe.tpgi.com.au (220.244.240.4)

And using nslookup:
nslookup 220.244.240.4 ns1.tpgi.com.au
Server:         ns1.tpgi.com.au
Address:        203.12.160.40#53

4.240.244.220.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