An extranet-based VPN uses the Internet as its main backbone network, allowing users, customers, and branch offices to access corporate network resources across various network architectures. Extranet VPNs are almost identical to intranet VPNs, except that they are intended for external business partners.
Answer option D is incorrect. An intranet-based VPN is an internal, TCP/IP-based, password-protected network usually implemented for networks within a common network infrastructure having various physical locations.
Intranet VPNs are secure VPNs that have strong encryption.
Answer option B is incorrect. A remote access VPN is one of the types of VPN that involves a single VPN gateway. It allows remote users and telecommuters to connect to their corporate LAN from various points of connections. It provides significant cost savings by reducing the burden of long distance charges associated with dial-up access. Its main security concern is authentication, rather than encryption. Answer option A is incorrect. The PPTP VPN is one of the types of VPN technology.