Click Start, point to All Programs, point to
Administrative Tools, and then click DHCP.
In the console tree, right-click the applicable DHCP server,
click Set Predefined Options, and then click
Add.
In Name, type WPAD.
In Code, type 252.
In Data type, select String, and then click
OK.
In String, type
http://Computer_Name:Port/wpad.dat where:
Computer_Name is the fully qualified domain name of the
ISA Server computer.
Port is the port number on which automatic discovery
information is published. You can specify any port number. By
default, ISA Server publishes automatic discovery information on
port 8080.
Right-click Server options, and then click Configure
options.
Confirm that Option 252 is selected.
Important
Perform this task on the relevant DHCP server.
When you specify the Option 252 string, be sure to use
lowercase letters when typing wpad.dat. For example, if you type
http://isaserver:8080/Wpad.dat, the request will fail. ISA
Server uses wpad.dat and is case-sensitive.
You do not need to create anything specifically for Wspad.dat.
Wspad.dat uses the same 252 option as wpad.dat, and modifies the
wpad.dat name to Wspad.dat as required.