How to setup Windows 2003 as VPN server with one NIC

1. Open Routing and Remote Access from Administrative Tools.

2. Right-click on the servername and click Configure and Enable Routing and Remote Access

3. in the Routing and Remote Access Server Setup Wizard, select Custom configuration.

4. Check the VPN access in Custom Configuration.

5. Click Finish to complete the configuration.

SOURCE: http://www.howtonetworking.com/VPN/2003vpn11.htm

How to configure W2K server as VPN server

To setup a Windows 2000 server for VPN, open Routing and Remote Access console in the Administrative Tools folder, right-click the server and then click Configure and Enable Routing and Remote Access>Virtual private network [VPN] server.

Click Next if TCP/IP is only protocol you will use.

Select a connection you will connect to on the Internet Connection.

You will have two options to assign IP to VPN clients. The default is Automatically. It is recommended to configure the server to assign client addresses from a static address pool, rather than assigning addresses from a DHCP server. If you configure RAS to assign client addresses from a static address pool, clients inherit the DNS and WINS settings from the RAS server.

If your RAS server can browse the network, clients should also be able to browse the network with the same settings.

If you prefer DHCP, verify that DHCP scope option 44 (WINS/NetBIOS name server) points to the WINS server and scope option 6 shows the address of your DNS server. When you don't define these options, you almost guarantee problems with client browsing. Finally, you can select using RADIUS or not.

NOTE: If VPN traffic is traveling through a router or firewall, configure the router or firewall to pass PPTP (TCP Port 1723 and IP Protocol ID 47 [GRE - Generic Routing Encapsulation]) or L2TP over IPSec (UDP Port 500 and IP Protocol ID 50 [Encapsulating Security Payload]) traffic to and from the VPN server.

Which ports need to be opened for running VPN:
A: PPTP VPN uses TCP Port 1723, IP Protocol 47 (GRE); L2TP: UDP Port 1701; IPSec: UDP Port 500, Pass IP protocol 50 and 51. Note: 47 is a protocol number and not TCP port. The protocol name is GRE. It'll make a big difference when configuring your firewall or router.


SOURCE: http://www.chicagotech.net/vpnsetup....20VPN%20server