The reason why I’m saying “demystifying” is because many people are still having wrong concepts and therefore making wrong assumptions about how networks are configured on ISA Server/TMG. Although this is well documented at TechNet (since it is a core concept), sometimes due the massive amount of information you feel like: ah…I already know all this, I don’t need to read it.

 

Wrong assumption and this makes me go back in the day that I was Professor in a university in Brazil. I was teaching Operating System using the classic Tanenbaum’s book about OS and I remember that there was a student that clearly thought he knew all that stuff. He didn’t attend that much and when he did attend he didn’t pay attention. Well, that’s fine, let’s give the benefit of the doubt and assume that he knows what he is doing. Six months later he comes to me saying that he needs help to better understand preemptive multitasking and confessed that he missed that class because he thought he knew and preferred to do other stuff on that day. Moral of the story: never think that you know everything, even if the subject is the same that you read or heard many times. The person that is writing or telling you something usually have a different perspective and insight of the same subject that can show you things that you didn’t realize before.

 

Sorry, off topic, but I couldn’t resist. Anyway, since I’m a lover of self explanatory pictures combined with a decent walkthrough I think that this is probably one of the most intuitive explanations about networks concept on ISA/TMG. I’m talking about the series of two articles written by my friend Tom Shinder that will make you digest all you need to know about networks on ISA.

 

Check it out at here:

 

http://www.isaserver.org/tutorials/Overview-ISA-TMG-Networking-ISA-Networking-Case-Study-Part1.html

 

http://www.isaserver.org/tutorials/Overview-ISA-TMG-Networking-ISA-Networking-Case-Study-Part2.html