For delivering updates and support on software I've been working on I have been thinking about setting up a VPN server. The idea would be that the clients are constantly connected but only the traffic that has to go through the vpn would go through the VPN. I know this can be achieved client side but I would like to enforce this server side as well.
For security reasons I would like to make sure that on the vpn the customers can only connect with me (Remote desktop/FTP/Windows shares) and not with eachother.
Is there anyone who can confirm that this is a viable option and with what software this could be achieved?