There are a lot of people out there who want to try to get around Microsoft’s recommended configuration for the OCS Edge Server roles. For whatever reason, they don’t like the thought of have two network interfaces, one on a publicly routable IP network, the other on the private network. I’ve talked in the past about some of the reasons why this configuration is not only recommended, but actually a good idea, but let’s just say it took a lot of talking and thinking before I accepted that notion.
MVP Jeff Schertz has done a fantastic job of walking through the various permutations people have come up with, separating what will work from what won’t, and explaining the pros and cons of each variant. I highly recommend this post.
I also want to amplify a point he makes: having multiple interfaces (whether physical or virtual) on the same subnet will cause interesting and otherwise inexplicable weirdness on a Windows machine. I’ll write up the situation I’m seeing in a bit (not OCS!), but let me be clear: it’s caused me all sorts of problems. Run, do not walk, away from any “solution” that requires this.