Using WPAD

WPAD allows Internet Explorer to automatically detect a server that will supply it with proxy server configuration settings. Clients do not have to configure their browsers to send requests to a proxy server: a single server provides the settings to all clients on the network.


	Note WPAD is incompatible with transparent proxy deployments.

When an Internet Explorer browser starts up, it searches for a WPAD server that will supply it with proxy server configuration settings. It prepends the hostname WPAD to the current fully qualified domain name. For example, a client in x.y.company.com searches for a WPAD server at wpad.x.y.company.com. If unsuccessful, the browser removes the bottommost domain and tries again; for example, it tries wpad.y.company.com. The browser stops searching when it detects a WPAD server or reaches the third-level domain, wpad.company.com. The algorithm stops at the third level so that the browser does not search outside the current network.


	Note By default, Microsoft Internet Explorer are set to automatically detect WPAD servers. However, browser users can disable this setting.

You can configure Content Gateway to be a WPAD server:

If you have an existing wpad.dat file, replace the wpad.dat file located in the Content Gateway config directory with your existing file.

Log on to the Content Gateway manager and go to Configure > Content Routing > Browser Auto-Config > WPAD to display the wpad.dat file.

The WPAD Settings area displays the wpad.dat file:

If you copied an existing wpad.dat file into the Content Gateway config directory, the file contains your proxy configuration settings. Check the settings and make changes if necessary.

If you did not copy an existing wpad.dat file into the Content Gateway config directory (/opt/WCG/config), the WPAD Settings area is empty. Enter a script that will provide the proxy server configuration settings. A sample script is provided in Sample PAC file (a wpad.dat file can contain the same script as a proxy.pac file).

Click Apply.

Navigate to Configure > Networking > ARM.

In the Redirection Rules section, click Edit File to add a special remap rule to the ipnat.conf file.

Enter information in the fields provided, and then click Add:

In the Ethernet Interface field, enter the network interface that receives browser WPAD requests (for example hme0 or eth0).

From the Connection Type drop-down list, select tcp.

In the Destination IP field, enter the IP address of the Content Gateway server that will be resolved to the WPAD server name by the local name servers.

In the Destination CIDR field (optional), enter the CIDR mask value. If the Destination IP is in IPv4 format, enter 32. Enter 128 for an IPv6 Destination IP.

In the Destination Port field, enter 80.

In the Redirected Destination IP field enter the same IP address you entered in the Destination IP field.

In the Redirected Destination Port field, enter 8083.

In the User Protocol field (optional), select dns.

Click Add.

Use the arrow keys on the left side to move the new rule to the first line in the file.

10.

Click Apply, and then click Close.

11.

Click Restart on the Configure > My Proxy > Basic > General.