Zero configuration proxy is advanced version of Auto PAC. It uses some additional techniques. As you know in proxy auto config system, you have to enter the pac url (the url directed to proxy autoconfig file) in the browser settings. So its a bit lengthy to configure all the clients PC (Although you can instruct the users with a splash/proxy welcome page).
So the next technology comes in is WPAD (Web Proxy Auto Discovery Protocol), this makes you free from the above task, this WPAD will publish the pac file which will be automatically configured at the browser.
How To Configure
WPAD can be configured in two ways, it can be published on DHCP server or the DNS server, All the DHCP server has priority this is not used because firefox and non-window chrome does not support WPAD -DHCP.
ok if u want to use the DHCP then just install a web server on the same machine where DHCP server is running, if you are using windows ICS (Internet connection Sharing) then its a DHCP server also so you can host the pac file in that pc. But you should use the DNS for better support.
ok if you choosed the DNS then you have to place the pac file on a server adress on any of its parent level adresses.
For example the address of the DNS is
then you can use a location wpad.dept.physics.com
MIME Type Settings on the webserver
open the Apache configuration file, search for
any of these lines
AddType application/x-compress .Z
AddType application/x-gzip .gz .tgz
AddType application/x-tar .tgz
AddType image/x-icon .ico
AddType application/vnd.wap.wmlc .wmlc
AddType application/x-httpd-php .phtml .pwml .php5 .php4 .php3 .php2 .php .inc
AddType text/vnd.wap.wml .wml
AddType text/vnd.wap.wmlscript .wmls
AddType text/vnd.wap.wmlscriptc .wmlsc
AddType image/vnd.wap.wbmp .wbmp
add this line
AddType application/x-ns-proxy-autoconfig .pac