NT4 RAS as VPN TCP/IP - Dialin to a network/mainframe

You have a need to connect to your TCP/IP network (for example to access a mainframe), but your TCP/IP-addresses are private and not valid on the Internet ?
VPN offers again the solution:

allowing to 'tunnel' your private IP-address-range through the public Internet.

First, make sure, that your NT RAS system is properly configured for direct dialin via TCP/IP:

Dialup Networking with TCP/IP

Then, install VPN/PPTP:

	Add under Protocols the Point To Point Tunneling Protocol
	you are immediately prompted for the number of VPN-adapters: on an NT4 Workstation, you can ONLY use ONE ! (on an NT4 server, you can configure more for multiple incoming connections).
	You need to configure the new RAS device.
	make sure, that the new VPN-adapter is added to the list of RAS devices.
	Since I use an NT4 workstation, which is already configured for RAS-Modem dialin, I am NOT able to define an additional VPN-dialin (limit on NT WS). If you need both, you will need to install a (slightly more expensive) NT4 server license).
	So, I configure my RAS-Modem ONLY for dialing out
	and the VPN-adapter for dialing in.
	As for the Modem TCP/IP dialin, I need to ensure now the assignment of IP-addresses for the VPN-connection, either using DHCP or a static pool of IP-addresses.
	We are ready for a connection. (in my case, I dial out to the Internet and get my Internet- IP-address assigned).

Lets setup the Windows 95 / 98 for the VPN TCP/IP connection:

	Make sure, that the DUN 1.2 upgrade is installed first (if not, download and install it). VPN is included in 98. Add a SECOND Dialup Adapter.
	Then add the "Microsoft Virtual Private Network adapter"
	Your network setup should now be like this ( "File-and-Print sharing" is optional and only required for access from the LAN back to the remote client).

We are almost ready to connect:

	Define a new Dialup- Networking connection, using as "VPN-adapter".
	define as address the IP-address of the VPN-server
	Configure it for Logon to the Network and for TCP/IP protocol
	While being connected to the Internet, make now the VPN-connection to your VPN-server. Note: the Username and Password have to be valid on the server (I strongly suggest, that you already logon to your Windows Client on boot using this Username and password to avoid access problems on the network)
	we have now different IP-addresses: 1) used to connect to the Internet and assigned to you by your ISP
	2) used to connect to the VPN-server and assigned by the VPN (in this case using an address from the pool of IP-addresses assigned to the RAS-server). This system is also setup with a WINS server, allowing to participate to the workgroup of systems on the LAN by browsing the Network neighborhood. You can now also connect to the mainframe using a TCP/IP connection

	On the VPN-server, you can verify the incoming VPN-connection using the Dialup Networking Monitor.