How to override DNS resolution during auto-install
The auto-installer allows you to override DNS resolution for one hostname during the install. The option is useful only in one very special case, where:
You are installing to a new web hosting account, which is accessible only via a known IP address,
and, where your DNS name www.mysite.tld has not yet been mapped to the new IP address,
and, where your new web server requires the DNS name to be present in the HOST header when serving requests.
When all of these conditions are true, use the following settings on Step 4 of the auto-installer. Assume that "www.mysite.tld" is your DNS name, and "184.108.40.206" is the IP address of the new server where you want to install the script.
With those settings present, the auto-installer will make all requests to your new server at IP 220.127.116.11. However, for HTTP requests, the auto-installer will pretend that the hostname is "www.mysite.tld", which many web server will require.
"How to override DNS resolution during auto-install" http://www.xav.com/scripts/installer/1000.html