DDNS substitutes a network identification number for one that's easier for humans to use.

Most ISPs frequently change your computer's IP address, using a technique called DHCP. For Internet users to access your computer, they must know your IP address — for example, when you run your own Web server, or use your router to make a VPN connection. Since the IP address changes, your Internet users will need to keep up with the changes. (As an analogy of this problem, imagine that your telephone number frequently changed without warning. Your friends would always be phoning the wrong number.)

DDNS solves this problem. The DDNS solution comes from companies such as DynDNS.org and TZO.com.

The company creates an account for you that registers an unchanging name, such as myname.dyndns.org. You program your NETGEAR router to recognize that name, and it automatically substitutes the current IP address — no matter what your ISP has changed it to. The configuration is done in the Advanced-Dynamic DNS menu, where you enter your DDNS account login information. Now remote users (and remote routers) can find yours by its Fully Qualified Domain Name (FQDN), myname.dyndns.org.

For remote user access, you must also configure your router for port forwarding — for services you make available on your computer. For port forwarding information, see your router's manual or How is Port Forwarding Configured.

Doc: n101279.asp Feb. 8, 2004