After a network outage, a PC technician is unable to ping various network devices. The network
administrator verifies that those devices are working properly and can be accessed securely.
Which of the following is the MOST likely reason the PC technician is unable to ping those devices?

A.
ICMP is being blocked

B.
SSH is not enabled

C.
DNS settings are wrong

D.
SNMP is not configured properly

Explanation:
ICMP is a protocol that is commonly used by tools such as ping, traceroute, and pathping. ICMP offers no
information If ICMP request queries go unanswered, or ICMP replies are lost or blocked.
Incorrect Answers:
B: SSH is used to establish a command-line, text-only interface connection with a server, router, switch, or
similar device over any distance.
C: Domain name system (DNS) is the hierarchical naming scheme used for public and private networks.
D: You can use SNMP to interact with various network devices to obtain status information, performance
data, statistics, and configuration details.

Stewart, James Michael, CompTIA Security+ Review Guide, Sybex, Indianapolis, 2014, pp. 18, 20, 21