Question

Works at Layer 2 of the OSI model. Combination of PPTP and Cisco's Layer 2 Forwarding Protocol (L2F). Offers additional methods for authentication; PPTP offers two, whereas L2TP offers five. In addition to CHAP and EAP, L2TP offers PAP, SPAP, and MS-CHAP. L2TP works over standard IP networks, but also X.25 and ATM.

A) Layer 2 Tunneling Protocol (L2TP)
B) Point-to-Point Protocol (PPTP)
C) Cisco's Layer 2 Forwarding Protocol (L2F)
D) Authentication Protocols

Answer 1

L2TP (Layer 2 Tunneling Protocol) is the correct answer, functioning at Layer 2 of the OSI model, incorporating features from both PPTP and Cisco's L2F, and offering five authentication methods for enhanced security.

Step-by-step explanation:

The correct answer to the given question is A) Layer 2 Tunneling Protocol (L2TP). L2TP is a networking protocol that operates at Layer 2 of the OSI model and is a combination of PPTP (Point-to-Point Tunneling Protocol) and Cisco's L2F (Layer 2 Forwarding Protocol). It is widely used to support virtual private networks (VPNs). Unlike PPTP, which offers two methods for authentication, L2TP significantly increases security by offering five different authentication methods. These methods include CHAP (Challenge Handshake Authentication Protocol), EAP (Extensible Authentication Protocol), PAP (Password Authentication Protocol), SPAP (Shiva Password Authentication Protocol), and MS-CHAP (Microsoft Challenge Handshake Authentication Protocol). Moreover, L2TP's flexibility allows it to operate over various networks including standard IP networks, X.25, and ATM (Asynchronous Transfer Mode).