I have 5 mac clients and a mac server (running latest the version on Mountain Lion) in a remote office from me. I used to be able to access them all easily over VPN using ARD but over the past year I started having issues with some of the macs (I believe that it was after an OS upgrade). I am using a SonicWall TZ210 router and the built in L2TP VPN to connect to the remote network. The VPN seems to work great and I can access all remote network resources. I also setup a port forward in the router and am able to access my server using ARD and the external IP address (no VPN needed). The problem I have is when connecting through the VPN, I am only able to see one of the computers and connect to it. All of the computers are on the same subnet and it is different from my home subnet. I have tried turning remote management off and back on and even reinstalled ARD and nothing seems to work. I installed ARD on the local server and all of the computers show up fine.
So to summarize:
1.) ARD works great locally
2.) ARD is only able to see and connect to 1 of my 5 computers over the VPN
I would normally say that this is a VPN issue but one of my computers (not the server with the port forward) is working fine. And then I would say that it was an ARD client issue but they all work great locally.
Any help would be greatly appreciated.