Configuring Web publishing rules to host multiple Web sites with host headers in ISA Server

You can use host header names with a single static IP address to host multiple sites. Microsoft Internet Information Services (IIS) uses the host name that is passed in the HTTP header to determine which site clients request.

This article describes how to add host headers to a Web site in IIS and configure Web publishing rules in Internet Security and Acceleration (ISA) server to redirect HTTP requests with the original host header from the Internet to the internal Web server.

Note You cannot use host headers when you are using Secure Sockets Layer (SSL) because HTTP requests that use SSL are encrypted. Host headers are part of the encrypted request and cannot be interpreted and routed to the correct site.

Configuring Host Headers in IIS

You can use host header names to host multiple domain names from one IP address. To do this, follow these steps:

1. Start Internet Service Manager (ISM), which loads the IIS snap-in in Microsoft Management Console (MMC).
2. Right-click the Web site that should use a host header name, and then click Properties.
3. On the Web Site tab, click the IP address that the site should use, and then set the TCP port that should be used (typically port 80).
4. Click Advanced.
5. In the Multiple identities for this Web Site box, click the identity that you want to use.
6. Click Edit,, and then add the host header name that you want to use.
   
   NOTE: If you want this site to respond to more than one host header name, use the Add button to add additional identities to the list. Specify a different host header name for each identity, but be sure to use the same IP address and port.
7. Apply the changes, and then start the Web site (if it is not already running).
8. Register the host header name with the appropriate name-resolution system.
   
   If the computer is on an intranet (a private LAN that uses Internet technology), register the host header name with the intranet's name-resolution system, such as Windows Internet Name Service (WINS) or the Domain Name System (DNS).
   
   If the computer is on the Internet, register the host header name with Domain Name System (DNS), which is administered by InterNic.
9. After you register the host header name with the name-resolution system, test it in a Web browser by attempting to browse the host header name. The browser should open the expected Web site.

WARNING: Do not use a host header name with the default Web site. This can cause erratic behavior with add-on packages for IIS.

Creating a Web Publishing Rule in ISA Server

Web publishing rules in ISA Server map incoming HTTP requests to the appropriate Web server on or behind the ISA Server-based server. To create a Web publishing rule:

1. Click Start, point to Programs, point to Microsoft ISA Server, and then click ISA Management.
2. Expand the Publishing item, right-click Web Publishing Rules, and then click New Rule.
3. Type a name for the Web publishing rule, and then click Next.
4. Click All destinations, and then click Next.
5. Click Any request, and then click Next.
6. Click Redirect the request to this internal Web server.
7. Click Browse, and then click the Web server.
8. Click to select the Send the original host header to the publishing server instead of the actual one (specified above) check box, and then click Next.
9. Click Finish.
10. Repeat these steps for each additional Web site.
11. Restart the Microsoft ISA Server Control service.

For additional information, click the article numbers below to view the articles in the Microsoft Knowledge Base: