If the internal network computer to go out required a NAT router can help them to send out packets.Not only out to the Internet, if you want two different network segments connected in fact, we can rely on Windows RASS help.Windows Server 2012 RASS NAT Routing setting is simple, basically is the same as with the old Windows version.
With the installation of other roles, Add Roles and Features
Confirm RAS Connection Manager Administrator Kit is checked in the Features page .
Again we have to choose to install RASS two functions, the first is we need make NAT router Routing
Though the DirectAccess and VPN (RAS) do not need here, but I have still installed them there.
Need to reboot the computer after the installation is complete.Then open the Routing and Remote Access (RASS) tools.
Right-click the name of the computer to open the menu, select Configure and Enable Routing and Remote Access
Setting function selected Network address translation (NAT).
To point out which NIC can come to the Internet,You can see the IP address, and also changing the NIC Adapter name first.
Simple and easy to complete the setting.
Now the intranet computers can connect Internet via the Windows 2012 Gate NAT Router.
If not immediately online, Disable the NIC first on Client then enable ,and try to get a new settle.
This address is http://www.computerites.com/computer-skills/2013/03/install-rass-sevice-as-nat-router-in-windows-server-2012-692.html