Example with STARPROXY Return

If these proxies are used for domains and subdomains:

intranet1.com

intranet2.com.proxy.intranet1.com:8080

internetproxy.intranet1.com:80

the corresponding PAC file is:

// Start of the PAC File
function FindProxyForURL(url, host) {
          if (dnsDomainIs(host, ".intranet1.com")) {
              return "DIRECT";
          }
          if (dnsDomainIs(host, ".intranet2.com")) {
              return "PROXY proxy.intranet1.com:8080;" +
                  "PROXY proxy1.intranet1.com:8080";
          }
          return "STARPROXY internetproxy.intranet1.com:80";
}
//End of the PAC File

In this case, if the request is for a host in .intranet2.com domain, the Gateway contacts proxy.intranet1.com:8080. If proxy.intranet1.com:8080 is down, the request fails. The Gateway does not failover and contacts proxy1.intranet1.com:8080.