The Remote Access VPN Gateway must use a separate authentication server (e.g., Lightweight Directory Access Protocol [LDAP], Remote Authentication Dial-In User Service [RADIUS], Terminal Access Controller Access-Control System+ [TACACS+] to perform user authentication.

The VPN interacts directly with public networks and devices and should not contain user authentication information for all users. Authentication, Authorization, and Accounting (AAA) network security services provide the primary framework through which a network administrator can set up access control and authorization on network points of entry or network access servers. It is not advisable to configure access control on the VPN gateway or remote access server. Separation of services provides added assurance to the network if the access control server is compromised.