Follow the bouncing IP
In a nutshell, dynamic DNS services (also called DNS Providers) provide a way to keep a domain name tied to a changing IP address. They usually do this by having you run a small program on one of your computers that is tied to the Internet. Each time your ISP changes the IP address that they issue to you, the program contacts the service’s computer and updates your DNS entry, keeping your domain name tied to your new IP address.
With this service, the only data that changes when your IP address changes is the DNS database at the dynamic DNS provider. Since the rest of the DNS servers across the Internet point your domain to the static IP address that the dynamic DNS service gave you when you signed up for the service, the change occurs very quickly. Instead of taking days for the world to know that your IP address changed, the dynamic DNS service reduces the process to minutes. This makes hosting with a changing IP address now a viable solution.
Easy to reach
Even if you don’t want to run your own webserver, using a dynamic DNS provider can make life with a dynamic IP simpler, since there are a growing number of applications that require your computer to be contacted from the Internet:
PCAnywhere or other remote access
Internet telephony or videoconferencing
With a domain or subdomain name and a dynamic DNS service, all you need to do is type in your domain (or subdomain) name and you’re in business! Your servers will now always be reachable, no matter how often your IP address changes.
– Running any sort of Internet accessible service from your computer can greatly increase your chances of getting “uninvited visitors” to your LAN. Be sure to read Securing your Servers.
– If you need help configuring your firewall or proxy server to allow access to your servers, read Configure your Firewall.
– Some Dynamic DNS services have problems when used with a hardware router. Make sure you check with the service before you sign up to be sure that their client software will handle updating your IP address with a hardware router. Also check Linksys Router Help for some software that may help if you use a Linksys router and dyndns.org.
Sign me up!
Dynamic DNS providers are relatively new and their dependability, services, and costs vary. So do a little homework before you buy. Making the wrong decision isn’t the end of the world, but changing to a new dynamic DNS provider will have the same delays as changing your DNS information with your domain registration company (see What Takes So Long? for more info).
highSynth has a page that you might want to check out that ranks DNS providers. They also have a useful background article that’s worth checking out if you’re not clear on how all this works. You can also check this page for links to a few top-ranked Dynamic DNS services.