geo-targeted dns

[Tim Peiffer]

Jason - Your scheme sounds like you are looking for ways to vary IP 
response to name requests. Correct me if I misunderstand the the 
problem.  Most of the controls you need are part of the DNS server, not 
the client and not under your control.

Can I suggest that you research IP anycast - RFC 1545 and 2101..  Use 
exactly the same public IP address and have the routing table (closest 
hop count wins) decide the best path to your public IP address.  The 
root nameservers have been doing this for years to deliver 'N' servers 
in 'N' countries all with the same name and address.

Reference:
http://www.google.com/url?sa=t&ct=res&cd=1&url=http%3A//www.net.cmu.edu/pres/anycast/&ei=qsjzQuGEL6j2RdXCqKoC
http://www.google.com/url?sa=t&ct=res&cd=4&url=http%3A//nms.lcs.mit.edu/%7Edina/pub/Katabi-350.pdf&ei=qsjzQuGEL6j2RdXCqKoC
http://www.google.com/url?sa=t&ct=res&cd=1&url=http%3A//www.zurich.ibm.com/%7Erha/papers/anycast-gi98.pdf&ei=WcjzQqVSyNZFtdullgI

Geo-targeted services instead of using DNS to band-aid the problem:
Alternatively, you might be best served using a content switch; use your 
first webserver to redirect to a more local web server for local 
content.  You could use the query source coming from your web logs, 
dereference the page query source to a given country and then format a 
reference to desired content.  Tables are available from each of the 
routing registries..

Examples from ARIN delegations for August 2005.
ftp://ftp.arin.net/pub/stats/arin/delegated-arin-20050805

[...]
arin|US|ipv4|3.0.0.0|16777216|19880223|assigned
arin|US|ipv4|4.0.0.0|16777216|00000000|allocated
arin|US|ipv4|6.0.0.0|16777216|00000000|allocated
arin|US|ipv4|7.0.0.0|16777216|19971124|allocated
arin|US|ipv4|8.0.0.0|16777216|00000000|allocated
arin|US|ipv4|9.0.0.0|16777216|19881216|assigned
[...]


  

Current data from all the registries:
ftp://ftp.apnic.net/pub/apnic/stats/apnic/delegated-apnic-latest
ftp://ftp.arin.net/pub/stats/arin/delegated-arin-latest
ftp://ftp.lacnic.net/pub/stats/lacnic/delegated-lacnic-latest
ftp://ftp.ripe.net/ripe/stats/delegated-ripencc-latest

Tim Peiffer
University of Minnesota
Networking and Telecommunications Services.