WGU E025 NETWORK SECURITY
— COMPREHENSIVE TOPIC TEST
2026 : QUESTIONS AND
RATIONALES/GRADED A+
UPDATE 100% CORRECT
🔷 Domain 1: Network Foundations & Models (OSI &
TCP/IP)
1. A network administrator is configuring a new switch. It operates at which layer of
the OSI model?
A. Physical
B. Data Link
C. Data Link (highlighted)
D. Network
Rationale: Switches operate at Layer 2 (Data Link) because they forward frames
using MAC addresses.
2. Which OSI layer is responsible for encryption and compression of data?
A. Application
B. Session
C. Presentation (highlighted)
D. Transport
Rationale: The Presentation layer handles data translation, encryption, and
compression.
,3. At which OSI layer do routers primarily operate?
A. Physical
B. Data Link
C. Session
D. Network (highlighted)
Rationale: Routers forward packets based on logical IP addresses at the Network
layer.
4. Which TCP/IP layer is responsible for ensuring reliable, error-corrected delivery of
data between hosts?
A. Application
B. Transport (highlighted)
C. Network
D. Network Interface
Rationale: The Transport layer (TCP/UDP) provides end-to-end reliability and flow
control.
5. A company is deploying a proxy server. This device works at which OSI layer(s)?
A. Physical
B. Data Link
C. Network
D. Application (highlighted)
Rationale: Proxies operate at the Application layer because they interpret
application-level protocols like HTTP and HTTPS.
6. Which of the following is a connectionless protocol at the Transport layer?
A. TCP
B. UDP (highlighted)
C. IP
D. ICMP
Rationale: UDP is connectionless and does not guarantee delivery, making it faster
but less reliable.
, 7. Encapsulation occurs as data moves down the OSI stack. What is the unit of data at
the Network layer?
A. Frame
B. Packet (highlighted)
C. Segment
D. Bit
Rationale: The Network layer encapsulates segments into packets. Frames are at
Layer 2.
8. Which protocol is associated with the TCP/IP Application layer and is used to assign
IP addresses dynamically?
A. HTTP
B. FTP
C. DHCP (highlighted)
D. SSH
Rationale: DHCP dynamically allocates IP addresses to devices on a network.
9. The address resolution protocol (ARP) operates at which layer of the OSI model?
A. Physical
B. Data Link (highlighted)
C. Network
D. Transport
Rationale: ARP maps IP addresses to MAC addresses and functions within Layer 2.
10. Which OSI layer is responsible for establishing, managing, and terminating sessions
between applications?
A. Application
B. Session (highlighted)
C. Presentation
D. Transport
Rationale: The Session layer manages dialogue control and session synchronization.
— COMPREHENSIVE TOPIC TEST
2026 : QUESTIONS AND
RATIONALES/GRADED A+
UPDATE 100% CORRECT
🔷 Domain 1: Network Foundations & Models (OSI &
TCP/IP)
1. A network administrator is configuring a new switch. It operates at which layer of
the OSI model?
A. Physical
B. Data Link
C. Data Link (highlighted)
D. Network
Rationale: Switches operate at Layer 2 (Data Link) because they forward frames
using MAC addresses.
2. Which OSI layer is responsible for encryption and compression of data?
A. Application
B. Session
C. Presentation (highlighted)
D. Transport
Rationale: The Presentation layer handles data translation, encryption, and
compression.
,3. At which OSI layer do routers primarily operate?
A. Physical
B. Data Link
C. Session
D. Network (highlighted)
Rationale: Routers forward packets based on logical IP addresses at the Network
layer.
4. Which TCP/IP layer is responsible for ensuring reliable, error-corrected delivery of
data between hosts?
A. Application
B. Transport (highlighted)
C. Network
D. Network Interface
Rationale: The Transport layer (TCP/UDP) provides end-to-end reliability and flow
control.
5. A company is deploying a proxy server. This device works at which OSI layer(s)?
A. Physical
B. Data Link
C. Network
D. Application (highlighted)
Rationale: Proxies operate at the Application layer because they interpret
application-level protocols like HTTP and HTTPS.
6. Which of the following is a connectionless protocol at the Transport layer?
A. TCP
B. UDP (highlighted)
C. IP
D. ICMP
Rationale: UDP is connectionless and does not guarantee delivery, making it faster
but less reliable.
, 7. Encapsulation occurs as data moves down the OSI stack. What is the unit of data at
the Network layer?
A. Frame
B. Packet (highlighted)
C. Segment
D. Bit
Rationale: The Network layer encapsulates segments into packets. Frames are at
Layer 2.
8. Which protocol is associated with the TCP/IP Application layer and is used to assign
IP addresses dynamically?
A. HTTP
B. FTP
C. DHCP (highlighted)
D. SSH
Rationale: DHCP dynamically allocates IP addresses to devices on a network.
9. The address resolution protocol (ARP) operates at which layer of the OSI model?
A. Physical
B. Data Link (highlighted)
C. Network
D. Transport
Rationale: ARP maps IP addresses to MAC addresses and functions within Layer 2.
10. Which OSI layer is responsible for establishing, managing, and terminating sessions
between applications?
A. Application
B. Session (highlighted)
C. Presentation
D. Transport
Rationale: The Session layer manages dialogue control and session synchronization.
