Perceptive Enterprise Search supports hosting multiple websites on a single server. For example, rather than using three different servers to host www.lexmark.com, search.lexmark.com and download.lexmark.com, you can install all three websites on the same server.
To ensure user requests reach the correct Web site, you must configure a unique identity for each site on the server. To do so, you must distinguish each Web site with at least one of three unique identifiers: a host header name, an IP address, or a unique TCP port number.
By changing one of these three identifiers, you can create unique identities for multiple websites without installing a dedicated server for each site. You can also create a unique home directory for each site and store the content on the local server or on remote network shares. Thus, each Web site acts as a separate entity, or virtual server.
Every Web site has a descriptive name, and can support one or more host header names. Organizations that host multiple websites on a single server often use host headers because this method enables them to create multiple Web site identities without using a unique IP address for each site.
When a client request reaches the server, Perceptive Enterprise Search uses the host name, which is passed in the HTTP header, to determine which site clients are requesting. If the site is used on a private network, the host header can be an intranet site name, such as SupIntranet. If the site is used on the Internet, the host header must be a publicly available Domain Name System (DNS) name, such as search.lexmark.com, and you must register the name with an authorized Internet name authority.
Using host headers to distinguish multiple websites on the same server is recommended for most situations. When using this method, carefully consider what the default Web site displays. If a user attempts to contact your site with an old browser that does not support HTTP 1.1, and the default Web site is enabled on the server but does not include programming to overcome the limitations of old browsers, the user is directed to the default Web site assigned to the IP address. This might not be the site the user is expecting to see. The default Web site might include a script that supports the use of host header names in browsers that do not support HTTP 1.1.