Which choice below is NOT an element of IPSec?

A.
Encapsulating Security Payload

B.
Authentication Header

C.
Layer Two Tunneling Protocol

D.
Security Association

Explanation:
The Layer Two Tunneling Protocol (L2TP) is a layer two tunneling
protocol that allows a host to establish a virtual connection. Although
L2TP, an enhancement to Layer Two Forwarding Protocol (L2F) and
supporting some features of Point to Point Tunneling Protocol (PPTP),
may coexist with IPSec, it is not natively an IPSec component. Answer
a, the Authentication Header (AH), is an authenticating protocol that
uses a hash signature in the packet header to validate the integrity of
the packet data and the authenticity of the sender.
* the Security Association (SA), is a component of the IPSec architecture that contains

the information the IPSec device needs to process incoming and outbound IPSec packets. IPSec
devices embed a value called the Security Parameter Index (SPI) in the header to associate a
datagram with its SA, and store SAs in a Security Association Database (SAD).
* the Encapsulating Security Payload (ESP), is an authenticating and encrypting protocol that
provides integrity, source authentication, and confidentiality services. Source: Implementing IPSec
by Elizabeth Kaufman and Andrew Newman (Wiley, 1999).