As I've explained, VPNs come in a wide variety of shapes and sizes. Leopard contains built-in client software for two popular VPN types (PPTP and L2TP over IPsec) and Snow Leopard adds support for Cisco IPsec VPNs. In all cases, these settings are accessed through the Network pane of System Preferences, and it's not difficult to configure (although not necessarily obvious either). Third-party VPN utilities offer some capabilities missing in Mac OS X and also provide support for additional VPN varieties. This section provides an overview of the major ways to configure Mac OS X as a client for VPN access.
Mac OS X includes support for both PPTP and L2TP over IPsec (and, in Snow Leopard, for Cisco IPsec VPNs). You configure these using the Network pane of System Preferences. Although both protocols have a number of options, I describe only basic setup here.
To configure Mac OS X to use a PPTP, L2TP over IPsec, or Cisco IPsec VPN, follow these steps:
Choose System Preferences to open System Preferences and then click Network to open the Network pane.
If the lock icon in the lower-left corner of the pane is in the locked state, click it, type an administrator's username and password, and then click OK ...