So Sophos UTM (Astaro Gateway UTM) can be virtualized in Hyper-V, VMWare, vSphere etc. Now I'm new to virtualization, so am wondering how the networking would be configured in this situation.

Imagine the following (a very simple setup). A Zyxel router acting as the default gateway, standard ADSL line. This is connected directly via Ethernet to my VHost, Hyper-V in my case. Now I assume I need two virtual network adapters, one which is the "External" interface to the firewall, and the other being the "Internal" interface.

But where does my switch go, since I have 5 machines (or X number of machines). Where is the switch connected, to the internal interface on the VHost? What default gateway do my clients use etc? How would the routing work if these two interfaces weren't bridged since they are virtual networks anyway.

I'm a little confused! Any advice is much appreciated!

Cheers