Using a transparent mode
 
The “Transparent Mode” option in the proxy server settings becomes enabled if UserGate Server is installed along with a NAT driver. In transparent mode the UserGate NAT driver is listening at the conventional ports in network interfaces: 80 TCP for HTTP, 21 TCP for FTP, 110 and 25 TCP for POP3 and SMTP on the workstation network interfaces and sending requests to the corresponding UserGate proxy. When using this mode in the user network applications, it is not required to specify the proxy server address and port which considerably decreases administrator time when providing LAN-to- Internet access. However, you need to specify UserGate Server as the gateway and enter its DNS server address into each LAN workstation’s settings.