I have three separate web servers with three different internal IP addresses on a network with only one public IP address. Each web server has security restrictions such that I cannot just run all of my websites on a single web server. All are running Apache.
I want to setup subdomains that allow me to access each of the different web servers remotely, all on port 80. E.g.,
site1.domain.com
site2.domain.com
site3.domain.com
Where all three of those domains resolve to my single public IP address, but some type of service examines the request to see which subdomain is being requested and pulls the data from the appropriate server.
Is this type of thing (1) possible and (2) easy to implement? I'm running Ubuntu Server 9.04.