I am a senior developer working on the System Center Configuration Manager product. I specialize in the client and server framework, and software development kit.
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I was going to save this for last, but there's been a lot of questions lately about this that I've been fielding, including a hot interest at TechReady 6 about ISA bridging. This is not a meant to be a step-by-step guide, and will require a bit of familiarity with ISA, but the information provided here should be adequate to help you get ISA bridging working with ConfigMgr.