What is the primary function of IPSec?

A.
It thwarts denial-of-service attacks

B.
It provides encryption

C.
It authenticates users

D.
It provides access control

Explanation:
IPSec (IP Security) is the encryption of data, usually network data. It is used to encrypt tunnel traffic on Windows 2000 L2TP (Layer 2 tunnelling protocol) VPNs. It was originally used for router to router encryption of data streams when the medium between the two routers could be compromised.
Incorrect Answers:
A: IPSec cannot help reduce denial of service attacks.
C: Authentication of a user could happen since only the proper user will have the encryption keys, however it is not the purpose of IPSec to be an authentication protocol.
D: IPSec is not used for access control. Again, only someone with the encryption keys could read the stream, but it is no the purpose or intent that IPSec be used as an access control mechanism.
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