I am migrating existing ASP sites to a dedicated server which runs Plesk. We have a service site which contains admin pages for the database and server side include file that are accessed using the XMLHTTP object from other sites so that content is centralized and changing one include will change all the sites. At present the service site is accessible by its IP address and is on a different server to the sites which access its include files. The service site will go on the same server as all the other sites. When this happens I want the other sites to access the includes locally without having to go through external name servers. The admin pages need to be accessible from the internet as normal web pages but only to those who are told how to find it. Is a subdomain the way to go about this?