CERTIFICATION PREP SERIES
WGU D325 – NETWORKS
A+
(COMPTIA'S NETWORK+ CERTIFICATION
PRACTICE EXAM)
2026/2027
Official-Style Objective Assessment • Scenario-Based Items • Full Rationales
A+ 6 100%
QUESTIONS VERIFIED EXAM DOMAINS COVERED RATIONALES INCLUDED
CATEGORIES
■ 1. Networking Concepts
■ 2. Network Implementation – Switching & Routing
■ 3. Wireless, Cabling & Cloud Implementation
■ 4. Network Operations
■ 5. Network Security
■ 6. Network Troubleshooting
STUVIAACTUALEXAM
All content original • Aligned to public N10-009 domain weights • For educational practice only
, SECTION: NETWORKING CONCEPTS
Q1. A network engineer is mapping traffic flow for a new branch office and must decide which OSI layer is responsible for end-to-end
delivery, segmentation, and reassembly of data streams between two hosts. Which layer performs these functions?
A. Session layer
B. Data-link layer
C. Network layer
D. Transport layer
Correct Answer: D
Rationale: The Transport layer (Layer 4) provides end-to-end communication, segmentation, reassembly, and flow control between hosts. The Network layer
handles logical addressing and routing; Data-link deals with frames on a single link.
Q2. During a security audit an analyst notices that a server is listening on TCP port 22. Which service is most likely running and what
security implication follows?
A. SSH is active, providing encrypted remote administration
B. FTP data channel is open for bulk transfers
C. Telnet is active, transmitting credentials in clear text
D. SNMP is collecting management information unencrypted
Correct Answer: A
Rationale: TCP port 22 is assigned to SSH, which encrypts the entire session including authentication. Telnet uses port 23 and is plaintext; FTP uses 20/21;
SNMP uses 161/162.
Q3. A host is configured with the IPv4 address 169.254.37.12/16. What does this address indicate about the host’s network
configuration process?
A. The host is configured with a link-local IPv6 address mapped into IPv4
B. The address is a multicast address used for OSPF neighbor discovery
C. The host failed to obtain a DHCP lease and self-assigned an APIPA address
D. The host is using a private Class B address assigned by the administrator
Correct Answer: C
Rationale: Addresses in the 169.254.0.0/16 range are Automatic Private IP Addressing (APIPA) addresses assigned when a DHCP client cannot reach a
server. They are not routable and signal a DHCP failure.
Q4. An administrator needs to translate a fully qualified domain name into an IPv6 address. Which DNS resource record type must be
queried?
A. A
B. AAAA
C. PTR
D. MX
Correct Answer: B
Rationale: AAAA records map hostnames to 128-bit IPv6 addresses. A records map to IPv4; PTR records perform reverse lookups; MX records identify mail
exchangers.
Q5. A packet is captured that shows a three-way handshake completing with sequence and acknowledgment numbers. Which transport
protocol and purpose are demonstrated?
A. TCP establishing a reliable, connection-oriented session
B. UDP performing a connectionless DNS query
C. ICMP reporting an unreachable destination
D. SCTP establishing a multi-homed association
Correct Answer: A
Rationale: The three-way handshake (SYN, SYN-ACK, ACK) is the TCP mechanism for establishing a reliable, sequenced, connection-oriented session. UDP is
connectionless and has no handshake.
STUVIAACTUALEXAM Page 2 of 20 WGU D325 – NETWORKS
, Q6. While designing an IPv4 addressing plan, an engineer must choose a private range that can support at least 500 hosts on a single
subnet. Which CIDR block satisfies the requirement while remaining private?
A. 172.16.0.0/28
B. 192.168.100.0/25
C. 192.168.1.0/24
D. 10.10.0.0/23
Correct Answer: D
Rationale: A /23 prefix provides 512 addresses (510 usable), which meets the 500-host requirement. 10.0.0.0/8 is private; 192.168.1.0/24 yields only 254 usable
hosts.
Q7. A technician observes that frames are being forwarded based solely on MAC addresses within a single broadcast domain. At
which OSI layer is this decision occurring?
A. Transport layer
B. Network layer
C. Physical layer
D. Data-link layer
Correct Answer: D
Rationale: MAC-address-based forwarding is a Data-link (Layer 2) function performed by switches. Layer 3 devices forward on IP addresses; Layer 4
examines ports.
Q8. An application developer needs a protocol that guarantees ordered, error-checked delivery of data and supports windowing for
flow control. Which protocol should be selected?
A. IP
B. ICMP
C. UDP
D. TCP
Correct Answer: D
Rationale: TCP provides reliability through acknowledgments, sequence numbers, retransmissions, and sliding-window flow control. UDP offers none of these
services.
Q9. A network diagram shows a device that examines the destination IP address of each packet and selects the next-hop interface
according to a routing table. What is the primary role of this device?
A. Load balancer distributing sessions at Layer 4
B. Hub repeating signals to all ports
C. Router performing Layer-3 forwarding
D. Switch performing Layer-2 frame switching
Correct Answer: C
Rationale: Routers operate at Layer 3, consulting routing tables to forward packets based on destination IP addresses. Switches use MAC addresses; hubs are
Layer 1.
Q10. During subnetting practice an engineer is asked for the broadcast address of the network 172.16.40.0/22. Which address is
correct?
A. 172.16.47.255
B. 172.16.41.255
C. 172.16.40.255
D. 172.16.43.255
Correct Answer: D
Rationale: A /22 mask covers four Class-C-sized blocks (40–43). The last address in that range is 172.16.43.255, the broadcast address.
STUVIAACTUALEXAM Page 3 of 20 WGU D325 – NETWORKS
WGU D325 – NETWORKS
A+
(COMPTIA'S NETWORK+ CERTIFICATION
PRACTICE EXAM)
2026/2027
Official-Style Objective Assessment • Scenario-Based Items • Full Rationales
A+ 6 100%
QUESTIONS VERIFIED EXAM DOMAINS COVERED RATIONALES INCLUDED
CATEGORIES
■ 1. Networking Concepts
■ 2. Network Implementation – Switching & Routing
■ 3. Wireless, Cabling & Cloud Implementation
■ 4. Network Operations
■ 5. Network Security
■ 6. Network Troubleshooting
STUVIAACTUALEXAM
All content original • Aligned to public N10-009 domain weights • For educational practice only
, SECTION: NETWORKING CONCEPTS
Q1. A network engineer is mapping traffic flow for a new branch office and must decide which OSI layer is responsible for end-to-end
delivery, segmentation, and reassembly of data streams between two hosts. Which layer performs these functions?
A. Session layer
B. Data-link layer
C. Network layer
D. Transport layer
Correct Answer: D
Rationale: The Transport layer (Layer 4) provides end-to-end communication, segmentation, reassembly, and flow control between hosts. The Network layer
handles logical addressing and routing; Data-link deals with frames on a single link.
Q2. During a security audit an analyst notices that a server is listening on TCP port 22. Which service is most likely running and what
security implication follows?
A. SSH is active, providing encrypted remote administration
B. FTP data channel is open for bulk transfers
C. Telnet is active, transmitting credentials in clear text
D. SNMP is collecting management information unencrypted
Correct Answer: A
Rationale: TCP port 22 is assigned to SSH, which encrypts the entire session including authentication. Telnet uses port 23 and is plaintext; FTP uses 20/21;
SNMP uses 161/162.
Q3. A host is configured with the IPv4 address 169.254.37.12/16. What does this address indicate about the host’s network
configuration process?
A. The host is configured with a link-local IPv6 address mapped into IPv4
B. The address is a multicast address used for OSPF neighbor discovery
C. The host failed to obtain a DHCP lease and self-assigned an APIPA address
D. The host is using a private Class B address assigned by the administrator
Correct Answer: C
Rationale: Addresses in the 169.254.0.0/16 range are Automatic Private IP Addressing (APIPA) addresses assigned when a DHCP client cannot reach a
server. They are not routable and signal a DHCP failure.
Q4. An administrator needs to translate a fully qualified domain name into an IPv6 address. Which DNS resource record type must be
queried?
A. A
B. AAAA
C. PTR
D. MX
Correct Answer: B
Rationale: AAAA records map hostnames to 128-bit IPv6 addresses. A records map to IPv4; PTR records perform reverse lookups; MX records identify mail
exchangers.
Q5. A packet is captured that shows a three-way handshake completing with sequence and acknowledgment numbers. Which transport
protocol and purpose are demonstrated?
A. TCP establishing a reliable, connection-oriented session
B. UDP performing a connectionless DNS query
C. ICMP reporting an unreachable destination
D. SCTP establishing a multi-homed association
Correct Answer: A
Rationale: The three-way handshake (SYN, SYN-ACK, ACK) is the TCP mechanism for establishing a reliable, sequenced, connection-oriented session. UDP is
connectionless and has no handshake.
STUVIAACTUALEXAM Page 2 of 20 WGU D325 – NETWORKS
, Q6. While designing an IPv4 addressing plan, an engineer must choose a private range that can support at least 500 hosts on a single
subnet. Which CIDR block satisfies the requirement while remaining private?
A. 172.16.0.0/28
B. 192.168.100.0/25
C. 192.168.1.0/24
D. 10.10.0.0/23
Correct Answer: D
Rationale: A /23 prefix provides 512 addresses (510 usable), which meets the 500-host requirement. 10.0.0.0/8 is private; 192.168.1.0/24 yields only 254 usable
hosts.
Q7. A technician observes that frames are being forwarded based solely on MAC addresses within a single broadcast domain. At
which OSI layer is this decision occurring?
A. Transport layer
B. Network layer
C. Physical layer
D. Data-link layer
Correct Answer: D
Rationale: MAC-address-based forwarding is a Data-link (Layer 2) function performed by switches. Layer 3 devices forward on IP addresses; Layer 4
examines ports.
Q8. An application developer needs a protocol that guarantees ordered, error-checked delivery of data and supports windowing for
flow control. Which protocol should be selected?
A. IP
B. ICMP
C. UDP
D. TCP
Correct Answer: D
Rationale: TCP provides reliability through acknowledgments, sequence numbers, retransmissions, and sliding-window flow control. UDP offers none of these
services.
Q9. A network diagram shows a device that examines the destination IP address of each packet and selects the next-hop interface
according to a routing table. What is the primary role of this device?
A. Load balancer distributing sessions at Layer 4
B. Hub repeating signals to all ports
C. Router performing Layer-3 forwarding
D. Switch performing Layer-2 frame switching
Correct Answer: C
Rationale: Routers operate at Layer 3, consulting routing tables to forward packets based on destination IP addresses. Switches use MAC addresses; hubs are
Layer 1.
Q10. During subnetting practice an engineer is asked for the broadcast address of the network 172.16.40.0/22. Which address is
correct?
A. 172.16.47.255
B. 172.16.41.255
C. 172.16.40.255
D. 172.16.43.255
Correct Answer: D
Rationale: A /22 mask covers four Class-C-sized blocks (40–43). The last address in that range is 172.16.43.255, the broadcast address.
STUVIAACTUALEXAM Page 3 of 20 WGU D325 – NETWORKS
