Hello there,
First of all, what is wpad ?
WPAD is acronym to Web Proxy Autodiscovey Protocol, it is reponsible for automatic detecting of proxy under web browsers.
I will assume that you know OpenBSD, know configure a basic DHCP Server, and know configure Apache.
First step:
create a file named “wpad.pac” with this content:
function FindProxyForURL(url, host)
{
if( shExpMatch(url, “!ftp:*”) || isPlainHostName(host) || dnsDomainIs(host, “.example.com”) isInNet(host, “127.0.0.1”, “255.255.255.255”))
{
return “DIRECT”;
} else {
return “PROXY proxy.example.com:3128; DIRECT”;
}
}
Put this file under your DocumentROOT of your Apache
example : /var/www/htdocs/wpad.pac
Understanding the javascript :
If these conditions are true, so You will access directly without proxy, else you will use proxy.
Now, the configuration of Apache.
Virtual Host Configuration:
ServerAdmin postmaster@example.com
DocumentRoot /var/www/htdocs
Servername www.example.com
ErrorLog logs/default_error
CustomLog logs/default_access common
AddType application/x-ns-proxy-autoconfig .pac
Reload your apache doing:
# apachectl restart
Now it’s time to configure DHCP
Put this into your dhcpd.conf
option autoproxy-script “http://www.example.com/wpad.pac”;
Kill you dhcp server:
# pkill dhcpd && sleep 3 && dhcpd
Ok, All configuration are done 🙂
Internet Browsers, must have AutoDetection Proxy option enabled:
Internet explorer -> Internet Options/Conections TAB/Lan Settings : “Automatically detect settings” check box. must be checked
Troubleshoting:
Internet Explorer -> Internet Options/Advanced TAB/Reset
Mozilla Firefox -> Set manually address of pac file, in case of us, http://www.example.com/wpad.pac
Google Chrome: Same of Firefox
On Microsoft OS, Skype, Messenger etc will catch configuration very fine 🙂
Now block at your firewall the rule to port { www https }
References:
http://www.wlug.org.nz/WPAD
http://www.sxlist.com/techref/app/inet/wpad_dat.htm
http://wiki.squid-cache.org/Technology/WPAD
http://en.wikipedia.org/wiki/Web_Proxy_Autodiscovery_Protocol
http://homepage.ntlworld.com./jonathan.deboynepollard/FGA/web-browser-auto-proxy-configuration.html
Until next time 🙂
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