This is the essential reference for any IT professional deploying virtual private networks (VPNs) using Windows Server 2003 and Windows XP. The book thoroughly details how to implement remote access and site-to-site VPN connections and their related authentication technologies for a Windows environment. You'll learn how to deploy VPN solutions that use the latest Internet-standard VPN protocols and security technologies including Point-to-Point Tunneling Protocol (PPTP) and Layer Two Tunneling Protocol with Internet Protocol security (L2TP/IPSec) and authentication infrastructure components such as Remote Authentication Dial-In User Service (RADIUS) using the Windows Internet Authentication Service (IAS), the Active Directory directory service, public key infrastructure (PKI), and Extensible Authentication Protocol-Transport Layer Security (EAP-TLS) for certificate authentication. The book also includes a detailed summary of deployment best practices and four different step-by-step test lab configurations so that you can get a working configuration up and running quickly, from which you can experiment and adapt configuration options to best suit your production deployment of Windows-based VPNs.