Quote Originally Posted by Harry Kuhman
Thanks. Having the right URL seems to help
Strangely, the other did do a good DNS lookup, just never got an answer from it's server, so I didn't guess the URL was wrong (maybe it's also valid, but it's not answering)
I got the same thing when I checked the same url just a time out on the server port 80 for the original but I knew it did not look like the right url from seeing people on Debian user who use the same service so I checked a couple of post and there was the correct one.
Yea, I get that you run a client. My question is that, when I'm behind a NAT router I'll be on a box who's IP address never changes. It's the IP address of my router that changes, and I'm wondering how the client knows when that happens (since there seems to be no common way to talk to the many different routers out there to determine it). The only way I could come up with that the clients might work is to send frequent update packets to the server and let the server decide if the IP address that are coming from has changed or not, but there certainly could be some other way this happens and I would like to know if I'm overlooking something.
I believe the idea is the same as something like grc.com does when you probe your ports the client goes out to a site (dyndns.org itself I'm thinking) and uses a lookup to determine the IP you currently have (which would be the IP of the router) and compares to the record it already has if it differs then it changes the record and then your router handles the port forwarding to the IP you choose for the service you will open up.