Thanks for your response.
With this config I get problem. My authenticated users need access through a firewall on DMZ to they VDI machines (VMWare Windows 7 machines). This is on a part of our internal network. They need access to machines on DMZ.
My only problem is how to limit DNS to current Zeroshell server to avoid creating a DNS tunneling relevate by auditor.
So how delete “Free service DNS” and remplace it with firewall rules to limit DNS request to Zeroshell and limit it at this server.
This is the only point they found on Zeroshell.
Thanks for your help.