WEB TRAFFIC WITH HOST HEADERS
When a Web client such as Internet Explorer or Netscape sends a request
to a server for a Web page, the client typically does so using the
fully qualified host name of the server, such as www.microsoft.com.
When Internet Information Services (IIS) receives the request, it
examines the host header in the request to determine how it should
respond. For example, in the request for
the host header is www.microsoft.com.
IIS looks in the properties for the sites it maintains and serves
the one that matches.
Each Web site in IIS has three identifying properties: IP address,
port, and host header. At least one of these properties must be unique
for each site. For example, multiple sites on the same server can
use the same IP address and port, but each must have a unique host
header. To direct traffic to a specific Web site, specify the appropriate
host header in the site's properties.
For example, perhaps local clients can't access an internal Web site
because of the way the firewall handles in-network requests for the
server's public IP address. Rather than change the firewall configuration,
add a DNS host record named local that points to the local IP address
of the server.
Then, modify the properties of the site to add local.yourdomain.tld
to the site, specifying your own public Internet domain in place of
yourdomain.tld. Local clients can then connect to http://local.yourdomain.tld/ to
access the site from behind the firewall.