How does circumventing IP restrictions through DNS work in the case of hulu.com?

It sounds like the service he's using might be UnoTelly

Their FAQ has an entry for how it works, but it's not very enlightenning:

UnoTelly DirectDNS, like its name implies, utilizes properitory DirectDNS technology to give you access to blocked websites. Unlike VPN or Proxy, UnoTelly DirectDNS only shields the relevant traffic so you can access blocked websites.

VPN or Proxy is like a big-net that catches every fish in the water but sometimes it is not desirable because you might not want some of the fishes ! On the other hand, UnoTelly DirectDNS functions like a laser-guided net that only catches the relevant fish you want and let other non-essential fish pass.

More instructive is actually looking to see what their DNS returns as the address for hulu.com:

• Using my regular DNS, nslookup reports that hulu.com is 24.143.196.24, which is an Akamai CDN - makes sense

• Using their DNS (http://currentdns.unotelly.com reports 23.21.182.24, I get :

  > server 23.21.182.24
  Default server: 23.21.182.24
  Address: 23.21.182.24#53
  > hulu.com
  Server:         23.21.182.24
  Address:        23.21.182.24#53
  
  hulu.com        canonical name = www.hulu.com.
  www.hulu.com    canonical name = ec2-usa.unostructure.com.
  

So yes: you can see that when you use their DNS, hulu.com becomes a UnoTelly server, that is proxying the connection through a server that's probably stateside.

You can use my service ProxyDNS wich I created exactly because had the need to access my favorite (but otherwise blocked) websites from outside the US.

All you have to do is configure your DNS to the ip specified in http://www.proxydns.co/

This is how it works:

It's just like any other DNS, but when you go to a website that you wouldn't be allowed to access because of your location, the DNS takes care of that using a Cloud-based Proxy (a proxy is like a "tunnel" that bypasses any restrictions) in a way that you don't even notice it.

ProxyDNS works mostly like a normal DNS, not altering your normal browsing in any way, but only for those sites that are blocked for you. It all happens so transparently that you just notice the fact that there is no blocking anymore.

Being a Cloud Based Proxy has many advantages:

If you need help to configure it on Linux, Windows, Mac, Roku, Xbox, can get it here.

If you cant to contact me or request a new site to unblock, you can do it on the support section.