A company’s legacy server requires administration using Telnet. Which of the following protocols could
be used to secure communication by offering encryption at a lower OSI layer? (Select TWO).

A.
IPv6

B.
SFTP

C.
IPSec

D.
SSHE. IPv4

Explanation:
Telnet supports IPv6 connections.
IPv6 is the communications protocol that provides an identification and location system for computers on
networks and routes traffic across the Internet. IPsec is a protocol suite for securing Internet Protocol (IP)
communications by authenticating and encrypting each IP packet of a communication session. IPsec is a
compulsory component for IPv6.
IPsec operates at Layer 3 of the OSI model, whereas Telnet operates at Layer 7.
Incorrect Answers:
B, D: SFTP is a protocol encrypted by SSH, which is a more secure replacement for Telnet.
E: Telnet supports IPv6 connections.

Stewart, James Michael, CompTIA Security+ Review Guide, Sybex, Indianapolis, 2014, pp. 40, 41, 42, 48
http://en.wikipedia.org/wiki/OSI_model
http://en.wikipedia.org/wiki/Telnet