Quote Originally Posted by Stephen
http://www.dyndns.org/ I believe is the site you are looking for ....
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)

Quote Originally Posted by Stephen
AFAIK you run a client on your machine that goes out and updates the dyndns.org record with your new It when it changes.
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.