34. Configure a Secure Tunnel (VPN) BEFORE YOU BEGIN 30 Configure Networking Manually 33 Share Your Internet Connection SEE ALSO 35 Share Another Mac's Files One major problem with using the Internet for mission-critical business is that data transmitted over the Internet is subject to being intercepted by malicious eavesdroppers. A confidential document being sent from San Francisco to New York might be captured in transit by someone in Chicago or China; clearly this isn't something that will fill stockholders with confidence. 34. Configure a Secure Tunnel (VPN) Fortunately, there's a way of transmitting data so that it can't be usefully intercepted: a Virtual Private Network ( VPN ) . A VPN is a kind of "tunnel" on the Internet, a method for encrypting ( scrambling ) your transmitted data and sending it to a server at the other end of the tunnel that descrambles it so that it can be read by the intended recipients. If your computer is part of a VPN, it uses a different set of TCP/IP settings from the ones it normally uses on the open , "clear-text" Internet. Other computers in the VPN are also configured as though part of the same virtual network, hence the name . KEY TERMS Virtual Private Network (VPN) A virtual "tunnel" that allows you to send and receive scrambled (private) traffic to a secure remote location, such as to your corporate network from home. PPTP protocol Point-to-Point Tunnel Protocol, a popular type of VPN architecture. L2TP/IPSec protocol Secure IP, a newer and more versatile form of VPN architecture. Many companies use VPNs to connect one office to another, or for employees to gain access to the private internal network protected by a NAT gateway. Your Mac can use the PPTP or L2TP/IPSec protocols to create a VPN tunnel to an appropriate server and join its virtual network, provided that you have a valid username and password for the VPN. | 1. | Open Internet Connect To create a VPN, you must use the Internet Connect application. This utility can be launched a number of ways, the simplest of which is to simply navigate to the Applications folder and double-click its icon. You can also open Internet Connect from the AirPort or Modem System Menus (if you have enabled them, these menus appear at the far right of the Mac's menu bar), or by clicking the Connect button on the Network Status page of the Network Preferences pane. | | 2. | Create a New VPN Connection Choose File, New VPN Connection . A sheet appears that prompts you for the type of VPN connection to make. | | 3. | Select the VPN Type Enable the radio button for either L2TP/IPSec or PPTP , depending on the kind of VPN you're using to connect. Consult your network administrator if you're not sure which kind of VPN it is. Click Continue . | | 4. | Enter Server Information The menu bar at the top of the Internet Connect window now has an icon for the new VPN connection, named either VPN (L2TP/IPSec) or VPN (PPTP) depending on the type you chose. Enter the VPN server's IP address, and your username and password for the account on the remote network in the fields provided. | | 5. | Create a New VPN Configuration You can create more than one VPN configuration and switch from one to another each time you connect. Having multiple VPNs can be useful if you regularly use more than one VPN. Select Edit Configurations from the Configuration drop-down menu. Click the + icon to create a new configuration and fill in the server details. Click OK when you're done; this newly defined configuration now appears as the active configuration. From now on, if you open Internet Connect and click the VPN icon in the toolbar, this configuration will automatically appear. TIP You can always manually define a new VPN configuration without saving it by selecting Other from the Configuration menu and filling in the server information yourself. | | 6. | Connect to the VPN Click the Connect button. Mac OS X connects to the VPN server, exchanges account information, and sets up the tunnel. You can then communicate directly with the hosts on the other side of the tunnel until you click the Disconnect button. | TIP Select the Show VPN status in menu bar check box to have the VPN status appear among the System Menu icons, in the right side of the Mac's global menu bar; this icon shows you how long you've been connected, as well as allowing you to select between multiple VPN tunnels and to open Internet Connect . |