I didn't know this could be done. I am using powerdns on my own server at home, and it displays correctly my ip address.
Can you give me some pointers to understand how this works?
Disclaimer: I don't know with absolute certainly that this is correct but based on a quick look at the page and what I already know I think it's probably correct.
Look at the the source for that page and you'll see:
When your browser loads that, it'll return a reference to a resource with a unique hostname. Open that URL in your browser, for example, and you'll likely see something like the following in the address bar (this is what I received, with a few characters changed):
Thus, your browser will do a DNS lookup for that hostname. Because that URL is unique to you, the DNS server knows that it is you making the DNS request. It makes a note of what IP address the request came from and returns that to you as the IP of your resolver.
Similar to you, I have a pair of resolvers running here at home and I am returned the IP address of one of them.
I didn't know this could be done. I am using powerdns on my own server at home, and it displays correctly my ip address. Can you give me some pointers to understand how this works?