I am evaluating setting up TMG as a reverse proxy for Lync. Right now we have a SonicWALL as our perimeter firewall and only have OWA setup to external users. I do not want to route all outbound traffic through the TMG and would prefer to keep everything going through are SonicWALL as we have many VPN tunnels set up between ours and our clients SonicWALLS.
My though is to place the TMG between a second interface on our WAN router and then connect it to our switch.
Is this a viable setup? Is it supported? I have been trying to search to find a similar solution but I can't seem to find anything (or at least ask the right question)
I am attaching a picture of how I want to set this up.