Most DSL broadband internet service providers and many cable companies change the IP addresses of their customers frequently. In the case of DSL, the change generally occurs each time the customer connects to the Internet, while with cable, the changes can occur at any point.

It might seem impossible to host a web site from an IP address that potentially changes every day, but it can actually be done quite easily through the magic of dynamic DNS.

What is Dynamic DNS?

Dynamic DNS services provide their clients with a DNS address (as covered above) and install a small application on the client's computer which monitors its current ISP-designated IP address. When that IP address changes, the application alerts the dynamic DNS provider who then updates the client's DNS records with the new IP. In this way, visitors who try to access the client's web site using his DNS address will always be directed to the right IP address, no matter how many times a day it changes.

Several companies offer free dynamic DNS service over the Internet. Generally speaking, you sign on for a free membership and pick a DNS name from the ones the company has on offer. This does provide you with limited options for personalizing the address of your website, since most dynamic DNS companies will only allow you to customize the 'server' part of the address they give you. For example, you might be presented with '*****.sytes.net' and be allowed to customize the asterisked portion.

Fortunately, most domain registration services allow you to redirect your registered DNS name to another DNS name. This means you can register the domain name of your choice then redirect it to your yourwebsite.sytes.net dynamic DNS address, which then redirects visitors to your constantly updated IP address. Neat.

To set this up, you'll first have to register with a dynamic DNS provider. Some of the more popular free dynamic DNS sites are DynDNS.org and No-IP.com, but there are many, many more. Here's a list to get you started.

In most cases, the dynamic DNS provider will lead you through the process of setting up dynamic DNS, which includes choosing a domain name from the provider and downloading and installing their client software. There are several other options that dynamic DNS providers may offer, such as aliases (which allow you to map multiple domain names to your computer's IP address) and MX records for email, but we're not going to cover these in detail in this guide.

Once the dynamic DNS is all set up, test it by opening up a web browser and entering the domain name you got from the dynamic DNS provider. Provided your web site is up and running in IIS, you will now be seeing your website from across the Internet.

Now all you have to do is ensure that the dynamic DNS update program you downloaded from the provider is running at all times, and anyone will be able to access your website from the Internet.