HowTo: Securely get into your office network using WindowsXP over the Internet

Requirements: network permissions and an Internet connection (dial-up, xDSL, Cable Modem or dedicated line)
Author: Randall Perry
Date: 06-23-2003
Synopsis: This procedure will guide you through setting up your PC so that you can get into network resources like files servers and printers to a remote server that runs the PPTP VPN server software.
NOTE: Running personal firewall software like ZoneAlarm or Sygate's Fire may cause issues. Either reconfigure these programs or disable them.
Some ISPs (Internet Service Providers) may block services that would prevent you from getting into our system.

Configuring a Windows XP VPN Client

Configuring Windows XP to establish a VPN tunnel (Point to Point Tunneling Protocol) connection to your office network is a straight forward process.

Initial Configuration

The following procedure for configuring Windows XP assumes that a dial up connection to an ISP has already been configured on the client computer. (or other type of Internet connection)

Follow the steps below to configure a PPTP connection:

  1. Go to Start -> Settings ->Network and Dial-up Connections then select the New Connection Wizard icon. After the intial Welcome Dialog box appears, Click Next.
  2. The Network Connection type dialog box opens as shown below. Select Connect to the network at my workplace. Click Next .

    New Connection Wizard Picture

  3. Next select the VPN option

  4. The Connection Name Dialog Box opens. This dialogue allows the user to provide a name for the connection, so type in My Secure Office Connection.
  5. The next dialog is Public Network. Here you can tell the connection to automatically dial-out to the Internet when it needs to. You can choose Do not dial the initial connection if you are always connected to the Internet, or you want to establish the connection at your liesure.
  6. VPN Server Selection is where you specify the name or address of the VPN server. The preferred method is to enter the number like in the picture. You can also just type in secure.yourdomain.com (where you substitute the host name for your Linux PPTP server)

    123.45.67.89

  7. Connection Availability allows you to permit or disallow others that use your PC to be able to use this connection.
  8. You are almost finished! If you want to place a shortcut on the Desktop, select the checkbox as follows:

  9. After selecting Finish, a logon box will appear. Do NOT log in at this time. Press Cancel.

Configuring the Network Connection

Initially, the settings for your connection to the Internet need to be checked to ensure the PPTP VPN connection to your network behaves as expected. Follow the steps below:

  1. Click on Start -> Settings -> Network and Dial-up Connections then right click the recently configured PPTP connection and select Properties.
    Note: You can also get here by just double-clicking on the connection and then clicking on the Properties button.

    You can reconfigure or view all of the parameters from this window.

  2. Click the Security tag then select Advanced (custom settings) and click on the Settings button to the right of the screen.

  3. Be sure to select Maximum Strength Encryption
  4. Click on the radio button next to Allow these protocols and ensure that MS-CHAP and MS-CHAP v2 are selected by ticking the box next to them. These are required to encrypt data over the secure VPN. When the above steps have been completed, click OK.
  5. Next click on the Networking tag.

    Verify that Internet Protocol (TCP/IP) is present and that the checkbox is checked. Select Internet Protocol (TCP/IP) and click Properties. Click on the Advanced button. You will see the following image:

  6. Click on the WINS tab. The WINS Server IP is important to know. Without it, you won't see resources in Network Neighborhood

DNS is an acronym for Domain Name System. DNS converts IP host names to IP addresses. WINS (Windows Internet Name Service) converts Windows computer names (NetBIOS names) to IP addresses. WINS or manual NetBIOS name resolution (using LMHOSTS) is required for Windows network logon and browsing to function correctly.

Starting the PPTP Tunnel

To start your PPTP tunnel connection and connect to your secure network, simply click the previously configured network connection (icon) under Settings -> Network and Dial-up Connections. Depending on the way in which the VPN was setup, you may need to connect to your ISP before starting the tunnel.