A question I see a lot has to do with running multiple websites on a single web server. This is a relatively simple topic once you are able to grasp one concept: website bindings. Every website on a server needs to have a unique binding. There are three parts to a website binding, the IP address, the port, and the host name.
IP Address: This is the most obvious thing to make unique on a web server. However, with the depletion of IPv4 IP addresses it continues to get more difficult to get additional IP addresses. Unless each of your sites requires a unique SSL certificate I recommend running as many of your sites as possible on the same IP address.
Port: This is the least favorable setting to make unique. While it is easy to configure multiple sites on the server to use a different port, the HTTP protocol uses port 80 by default. Any other port needs to be explicitly defined in the URL. Unless you want to have your users have to remember to type in http://www.yoursite.com:8080, then you are best served having all of your sites use port 80.
Host name: (Sometimes referred to as Host Headers) This is my recommended way of setting up multiple websites on a single server. You setup each site on the server and have each domain name point to the same IP address in DNS. Then, set the bindings for site #1 to All unassigned for the IP address, 80 for the port, and site1domain.com for the host name, replacing site1domain.com with your actual domain name. Be sure to go back and also add www.site1domain.com as a host name with all unassigned for the IP address if you want your site to respond to both the www. and non www version of your domain. You will need to add any host name to the bindings the same way if you want the site to serve up that domain name.
Using the information I provided above, you should be well on your way to being able to support multiple websites on your web server.
Rick is a Senior Support Lead at OrcsWeb, a hosted server company providing managed hosting solutions.