WGU D658 NETWORK AND SECURITY – FOUNDATIONS Comprehensive Practice Examination – 70 Questions Original Questions with Detailed RATIONALES All correct answers are highlighted in bold green.

WGU D658 NETWORK AND SECURITY – FOUNDATIONS Comprehensive
Practice Examination – 70 Questions Original Questions with Detailed
RATIONALES All correct answers are highlighted in bold green.




SECTION 1: NETWORK FUNDAMENTALS (1–20)
QUESTION 1
Which layer of the OSI model is responsible for routing packets
between different networks?
A) Data Link layer (Layer 2)
B) Network layer (Layer 3)
C) Transport layer (Layer 4)
D) Physical layer (Layer 1)
RATIONALE : The Network layer (Layer 3) handles logical
addressing and routing. IP operates at this layer. The Data Link layer
handles frames and MAC addresses. The Transport layer handles end-
to-end communication (TCP/UDP). The Physical layer transmits raw
bits.


QUESTION 2
Which protocol operates at the Transport layer of the OSI model and
provides reliable, connection-oriented communication?
A) UDP
B) IP

,C) TCP
D) HTTP
RATIONALE : TCP (Transmission Control Protocol) provides reliable,
ordered, error-checked delivery of data. UDP is connectionless and
unreliable. IP is a Network layer protocol. HTTP is an Application layer
protocol.


QUESTION 3
What is the primary function of a router in a network?
A) To connect devices within the same local network
B) To forward packets between different networks based on IP
addresses
C) To amplify wireless signals
D) To assign IP addresses to devices
RATIONALE : Routers operate at Layer 3 and use routing tables to
determine the best path for packets across networks. Switches connect
devices within the same network. DHCP servers assign IP addresses.


QUESTION 4
Which device operates at Layer 2 of the OSI model and forwards frames
based on MAC addresses?
A) Router
B) Switch
C) Hub
D) Firewall

, RATIONALE : A switch builds a MAC address table and forwards
frames only to the port where the destination device is connected. A
hub repeats signals to all ports. A router uses IP addresses. A firewall
filters traffic.


QUESTION 5
What does the acronym "MAC" in MAC address stand for?
A) Machine Access Control
B) Media Access Control
C) Multiple Access Channel
D) Memory Access Controller
RATIONALE : A MAC (Media Access Control) address is a unique 48-
bit identifier assigned to a network interface controller for
communications at the Data Link layer.


QUESTION 6
In the TCP/IP model, which layer corresponds to the OSI model's
Transport layer?
A) Application layer
B) Transport layer
C) Internet layer
D) Network Access layer
RATIONALE : The TCP/IP model's layers are: Application (OSI 5–7),
Transport (OSI 4), Internet (OSI 3), and Network Access (OSI 1–2). The
Transport layer is the same in both models.

, QUESTION 7
Which IP address is a loopback address used to test the local TCP/IP
stack?
A) 192.168.1.1
B) 127.0.0.1
C) 10.0.0.1
D) 169.254.0.1
RATIONALE : 127.0.0.1 (and the entire 127.0.0.0/8 range) is
reserved for loopback. Pinging 127.0.0.1 tests whether TCP/IP is
functioning on the local machine. 169.254.x.x is an APIPA address.


QUESTION 8
What is the subnet mask for a Class C network in dotted decimal
notation?
A) 255.0.0.0
B) 255.255.0.0
C) 255.255.255.0
D) 255.255.255.255
RATIONALE : Class C networks have a default subnet mask of
255.255.255.0 (/24), providing 254 usable host addresses. Class A uses
255.0.0.0. Class B uses 255.255.0.0.


QUESTION 9
Which protocol is used to automatically assign IP addresses to devices
on a network?