On Clients behind ISA Server, Java Applets Fail to Start/Communicate When IE has “Automatically Detect Settings” Selected

A typical problem we usually meet is:

We have java applets installed on client computers. When “Automatically Detect Settings” option is checked in IE, these applets won’t work. They will either fail to start or can’t communicate.

Actually this is not an ISA issue. Java applets run in Java VM, thus, “sandbox”. Inside the sandbox, everything is independent from IE, including Internet access.

In implementation of Sun’s JRE, the VM will adopt IE’s proxy settings. So if “automatically detect settings” is selected, the VM has to detect the proxy server itself, through the WPAD mechanism.

Per our test result, current JRE versions will behave abnormally when “automatically detect settings” and can’t fetch the correct proxy address.

If you or your customer met this issue, please contact the Java applet vendor or Sun Microsystems directly about the new version.