Explanation/Reference:
Explanation:
PPTP is an encapsulation protocol based on PPP that works at OSI layer 2 (Data Link) and that enables a single point-to-point connection, usually between a client and a server. While PPTP depends on IP to establish its connection. As currently implemented, PPTP encapsulates PPP packets using a modified version of the generic routing encapsulation (GRE) protocol, which gives PPTP to the flexibility of handling protocols other than IP, such as IPX and NETBEUI over IP networks. PPTP does have some limitations: It does not provide strong encryption for protecting data, nor does it support any token-based methods for authenticating users. L2TP is derived from L2F and PPTP, not the opposite.
Incorrect Answers:
A: PPTP relies on the Point-to-Point Protocol (PPP) being tunneled to implement security functionality.
B: PPTP uses PPP for encryption. The PPP protocol has only the capability to encrypt data with 128-bit so it ensures low security.
C: The PPTP specification does not include authentication. In the Microsoft implementation, the tunneled PPP traffic can be authenticated with PAP, CHAP, MS-CHAP v1/v2 , but not with any token-based authentication scheme.
References:
Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, New York, 2013, p. 708