A few words about allowing access via ISA Server to a whole plethora of applications.
The nice thing about ISA Server is that, when you first install, you can rest assured that only traffic specifically allowed by the system policy is actually going to pass through to your corporate network.
On the other hand, this implies that you’re going to have to do some configuration work if you want to actually allow additional access. For standard applications--say Web browsers--where you only want to allow access to HTTP, this is fairly straightforward. But when you want to allow access to more complex applications, you may find yourself in that oh-so-tempting predicament: maybe I should just open up all those darn ports in order to finally allow this access?
That, however, is definitely NOT what you want to do. I hope that this post will help you realize how you should actually approach this conundrum...
Let’s consider the following example: some application that runs over HTTPS, using some unidentified (by you, as of yet) protocols.
Here’s what you should do to allow that access:
Nice generic post but to be really useful a real world example would be nice.