Internet Protocol Security (IPSec) is a standard-based protocol that provides the highest level of VPN security.
IPSec can encrypt virtually everything above the networking layer. It is used for VPN connections that use the
L2TP protocol. It secures both data and password. IPSec cannot be used with Point-to-Point Tunneling
Protocol (PPTP).
Answer option B is incorrect. The Internet Protocol (IP) is a protocol used for communicating data across a
packet-switched inter-network using the Internet Protocol Suite, also referred to as TCP/IP.IP is the primary
protocol in the Internet Layer of the Internet Protocol Suite and has the task of delivering distinguished protocol
datagrams (packets) from the source host to the destination host solely based on their addresses. For this
purpose, the Internet Protocol defines addressing methods and structures for datagram encapsulation. The
first major version of addressing structure, now referred to as Internet Protocol Version 4 (IPv4), is still the
dominant protocol of the Internet, although the successor, Internet Protocol Version 6 (IPv6), is being deployed
actively worldwide.
Answer option C is incorrect. Point-to-Point Protocol (PPP) is a remote access protocol commonly used to
connect to the Internet. It supports compression and encryption and can be used to connect to a variety of
networks. It can connect to a network running on the IPX, TCP/IP, or NetBEUI protocol. It supports multi-
protocol and dynamic IP assignments. It is the default protocol for the Microsoft Dial-Up adapter.
Answer option A is incorrect. Layer 2 Tunneling Protocol (L2TP) is a more secure version of Point-to-Point
Tunneling Protocol (PPTP). It provides tunneling, address assignment, and authentication. It allows the transfer
of Point-to-Point Protocol (PPP) traffic between different networks. L2TP combines with IPSec to provide
tunneling and security for Internet Protocol (IP), Internetwork Packet Exchange (IPX), and other protocol
packets across IP networks.