Sample PAC file

This example PAC file illustrates how to:

• Normalize the requested URL for pattern matching
• Bypass the proxy when the destination is a plain hostname (a hostname that does not include a domain)
• Bypass the proxy for a defined set of local domains
• Bypass the proxy for Windows Update
• Bypass non-routable addresses (RFC 3330)
• Send remaining HTTP, HTTPS, and FTP traffic to a specific proxy

Example:

function FindProxyForURL(url, host)
/* Normalize the URL for pattern matching 
url = url.toLowerCase(); host = host.toLowerCase();

{
/* Don't proxy local hostnames */ 
if (isPlainHostName(host))
{
return 'DIRECT';
}

/* Don't proxy local domains */ 
if (dnsDomainIs(host, ".example1.com") ||
(host == "example1.com") || 
dnsDomainIs(host, ".example2.com") ||
(host == "example2.com") || 
dnsDomainIs(host, ".example3.com") ||
(host == "example3.com"))
{
return 'DIRECT';
}

/* Don't proxy Windows Update */ 
if ((host == "download.microsoft.com") || 
(host == "ntservicepack.microsoft.com") || 
(host == "cdm.microsoft.com") ||
(host == "wustat.windows.com") ||
(host == "windowsupdate.microsoft.com") || 
(dnsDomainIs(host, ".windowsupdate.microsoft.com")) ||
(host == "update.microsoft.com") || 
(dnsDomainIs(host, ".update.microsoft.com")) ||
(dnsDomainIs(host, ".windowsupdate.com")))
{
return 'DIRECT';
}
if (isResolvable(host))
{
var hostIP = dnsResolve(host);

/* Don't proxy non-routable addresses (RFC 3330) */ 
if (isInNet(hostIP, '0.0.0.0', '255.0.0.0') ||
isInNet(hostIP, '10.0.0.0', '255.0.0.0') ||
isInNet(hostIP, '127.0.0.0', '255.0.0.0') ||
isInNet(hostIP, '169.254.0.0', '255.255.0.0') ||
isInNet(hostIP, '172.16.0.0', '255.240.0.0') ||
isInNet(hostIP, '192.0.2.0', '255.255.255.0') ||
isInNet(hostIP, '192.88.99.0', '255.255.255.0') ||
isInNet(hostIP, '192.168.0.0', '255.255.0.0') ||
isInNet(hostIP, '198.18.0.0', '255.254.0.0') ||
isInNet(hostIP, '224.0.0.0', '240.0.0.0') ||
isInNet(hostIP, '240.0.0.0', '240.0.0.0'))
{
return 'DIRECT';
}

/* Don't proxy local addresses.*/ 
if (false)
{
return 'DIRECT';
}
}
if (url.substring(0, 5) == 'http:' || 
url.substring(0, 6) == 'https:' || 
url.substring(0, 4) == 'ftp:')
{
return 'PROXY wcg1.example.com:8080';
}
return 'DIRECT';
}

The following is a simple example of load distribution and failover using DNS. Search the Internet for other methods.

{
if (isInNet(myIpAddress(), "10.1.0.0", "255.255.0.0"))
{ return "PROXY wcg1.example.com:8080; " + 
"PROXY wcg2.example.com:8080";
}

if (isInNet(myIpAddress(), "10.2.0.0", "255.255.0.0"))
{ return "PROXY wcg1.example.com:8080; " + 
"PROXY wcg2.example.com:8080";
}

if (isInNet(myIpAddress(), "10.3.0.0", "255.255.0.0"))
{ return "PROXY wcg2.example.com:8080; " + 
"PROXY wcg1.example.com:8080";
}

if (isInNet(myIpAddress(), "10.4.0.0", "255.255.0.0"))
{ return "PROXY wcg2.example.com:8080; " + "PROXY wcg1.example.com:8080";
}

else return "DIRECT";
}