Microsoft 2004 User Manual

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ISA Server 2004 Configuration Guide 40 
Introduction 
The Web Proxy Autodiscovery Protocol (WPAD) can be used to allow Web browsers and the 
Firewall client application to automatically discover the address of the ISA Server 2004 
firewall. The client can then download autoconfiguration information from the firewall after the 
Web Proxy or Firewall client discovers the address. 
WPAD solves the problem of automatically provisioning Web browsers. The default setting on 
Internet Explorer 6.0 is to autodiscover Web proxy client settings. When this setting is 
enabled, the browser can issue a DHCPINFORM message or a DNS query to find the 
address of the ISA Server 2004 from which it can download autoconfiguration information. 
This greatly simplifies Web browser setup so that it automatically uses the firewall to connect 
to the Internet. 
The ISA Server 2004 Firewall client can also use the wpad entry to find the ISA Server 2004 
firewall and download Firewall client configuration information. 
In this ISA Server 2004 Configuration Guide document, we discuss how to: 
•  Configure DHCP WPAD support, and 
•  Configure DNS WPAD support 
After the wpad information is entered into DHCP and DNS, Web Proxy and Firewall clients 
will not require manual configuration to connect to the Internet through the ISA Server 2004 
firewall machine.