Thread: GeoDNS

Originally Posted by burble

I imagine real geodns services use anycast to get routed to the closest nameserver, which then does a lookup on the requesting IP to find their geographical zone, then maps that to the closest IP for that zone. A quick google found a geodns patch for BIND that seems to do just that (skipping anycast), but has anyone here tried it?

ClamAV use it to redirect you to a close signature mirror and I'd guess theres lots of other people using it too. I think PowerDNS can also do it.

Just remember its based off the DNS server that makes the request rather than the client.

ChrisB.

There's a powerdns backend that does a good job of this, and it's free. I've not got a link, but a bit of googling should help you. I think it's on blitzed.org or something

Originally Posted by burble

I imagine real geodns services use anycast to get routed to the closest nameserver, which then does a lookup on the requesting IP to find their geographical zone, then maps that to the closest IP for that zone. A quick google found a geodns patch for BIND that seems to do just that (skipping anycast), but has anyone here tried it?

Can anyone recommend a good geodns solution, either one I can run myself on the cheap, or a third-party service that doesn't cost the earth?

We're running the GeoDNS patch for Bind on a few VPS's for customers. Find a small VPS and a friendly provider and they'll set it up for you free/cheaply and it'll cost you very little time to maintain, and bind requires very little memory so the VPS should be cheap.

Alternatively, at www.domain.com you can have a script which detects the users location and redirects them to us.domain.com or uk.domain.com depending on their IP. This can easily be achieved using many methods such as perl modules or Apache's mod_geoip.

Try something like ip2location.com and have a simple redirect script as mentioned by Cranky. This is simple enough in PHP, here is something for you. Feel free to use it:

PHP Code:

<?
$surfersip = $_SERVER['REMOTE_ADDR'];
if (preg_match("/192.168.0/",$surfersip)) {
      header('Location: http://uk.abc.com/');
} else if (preg_match("/192.168.1/",$surfersip)) {
      header('Location: http://usa.abc.com/');
} else {
      header('Location: http://www.abc.com/i_dont_know_where_you_are.html');
};
?>

This will be more accurate as its not dependant on which DNS server your customer is using, its based on there actual IP and also allows you to geographically load balance.

You can also try some free solutions available but there not as accurate in my experience. Also remember the usual limitations on location determination which are Satellite Internet, VPN and Mobile Broadband (which is backhauled to your home network which is a double edged sword).

Stuart

Bind, why would you if you don't have to? Ewww...

AFAIK TinyDNS AKA DJBDNS will do it.

Originally Posted by Karl

AFAIK TinyDNS AKA DJBDNS will do it.

Shoot me in the head please

ChrisB.

Ahhh, so you'd rather use a bloated, buggy piece of software then? The only reason we use bind anywhere is because that's what the CPs in use make us use, anywhere else we don't. I think of bind as being like Group 4 security in the early days, does the job most of the time, but you know it's only a matter of time before they let another murderer through.