WGU D412 NETWORKING TROUBLESHOOTING AND
DOCUMENTATION ESSENTIAL GUIDE FOR IT
SUPPORT OBJECTIVE ASSESSMENT (OA) ACCURATE
EXAM 2026/2027 COMPLETE ACTUAL QUESTIONS
AND CORRECT DETAILED ANSWERS (VERIFIED
ANSWERS) A NEW UPDATED VERSION
|GUARANTEED PASS A+
1. A user reports no network connectivity. The NIC link light is off. What
should be checked FIRST?
Answer: Physical cable connection
Rationale: Always start at OSI Layer 1 (Physical) before software or
configuration checks.
2. A PC has an IP address of 169.254.32.10. What is the MOST likely
cause?
Answer: DHCP server is unreachable
Rationale: APIPA addresses indicate DHCP failure.
3. Which troubleshooting step comes immediately after identifying the
problem?
,Answer: Establish a theory of probable cause
Rationale: This exact order is tested on the OA.
4. A user can ping 8.8.8.8 but cannot access google.com. What is
failing?
Answer: DNS resolution
Rationale: IP connectivity works; name resolution does not.
5. Which OSI layer is responsible for MAC addresses?
Answer: Data Link layer
Rationale: MAC addressing is Layer 2.
6. All users lose network access at the same time. What is the MOST
likely scope?
Answer: Infrastructure issue
Rationale: Multiple users affected points to shared equipment.
7. Which command shows a system’s default gateway in Windows?
Answer: ipconfig
Rationale: ipconfig displays IP, subnet, and gateway.
8. What should be documented after resolving an issue?
,Answer: Resolution and preventive steps
Rationale: Documentation ensures repeatability and future prevention.
9. A wireless user has strong signal strength but cannot connect. What
should be checked NEXT?
Answer: Security credentials
Rationale: Authentication issues are common once signal is confirmed.
10. Which protocol is connectionless?
Answer: UDP
Rationale: UDP does not establish sessions like TCP.
11. Which layer handles routing between networks?
Answer: Network layer
Rationale: IP routing is Layer 3.
12. A user reports slow network speeds. Which is the BEST first action?
Answer: Verify the issue and gather details
Rationale: Always confirm symptoms before changing configurations.
13. Which private IP range is valid?
, Answer: 192.168.1.0
Rationale: 192.168.0.0/16 is reserved for private use.
14. Which command tests name resolution?
Answer: nslookup
Rationale: Specifically queries DNS servers.
15. What should be done BEFORE implementing a fix?
Answer: Establish a plan of action
Rationale: Planning prevents unintended consequences.
16. Which issue is MOST likely caused by duplex mismatch?
Answer: Slow network performance
Rationale: Duplex mismatches cause retransmissions.
17. A user cannot print, but others can. What is the scope?
Answer: Single-user issue
Rationale: Isolated problems are local.
18. Which OSI layer handles encryption?
Answer: Presentation layer
Rationale: Layer 6 manages encryption and formatting.
DOCUMENTATION ESSENTIAL GUIDE FOR IT
SUPPORT OBJECTIVE ASSESSMENT (OA) ACCURATE
EXAM 2026/2027 COMPLETE ACTUAL QUESTIONS
AND CORRECT DETAILED ANSWERS (VERIFIED
ANSWERS) A NEW UPDATED VERSION
|GUARANTEED PASS A+
1. A user reports no network connectivity. The NIC link light is off. What
should be checked FIRST?
Answer: Physical cable connection
Rationale: Always start at OSI Layer 1 (Physical) before software or
configuration checks.
2. A PC has an IP address of 169.254.32.10. What is the MOST likely
cause?
Answer: DHCP server is unreachable
Rationale: APIPA addresses indicate DHCP failure.
3. Which troubleshooting step comes immediately after identifying the
problem?
,Answer: Establish a theory of probable cause
Rationale: This exact order is tested on the OA.
4. A user can ping 8.8.8.8 but cannot access google.com. What is
failing?
Answer: DNS resolution
Rationale: IP connectivity works; name resolution does not.
5. Which OSI layer is responsible for MAC addresses?
Answer: Data Link layer
Rationale: MAC addressing is Layer 2.
6. All users lose network access at the same time. What is the MOST
likely scope?
Answer: Infrastructure issue
Rationale: Multiple users affected points to shared equipment.
7. Which command shows a system’s default gateway in Windows?
Answer: ipconfig
Rationale: ipconfig displays IP, subnet, and gateway.
8. What should be documented after resolving an issue?
,Answer: Resolution and preventive steps
Rationale: Documentation ensures repeatability and future prevention.
9. A wireless user has strong signal strength but cannot connect. What
should be checked NEXT?
Answer: Security credentials
Rationale: Authentication issues are common once signal is confirmed.
10. Which protocol is connectionless?
Answer: UDP
Rationale: UDP does not establish sessions like TCP.
11. Which layer handles routing between networks?
Answer: Network layer
Rationale: IP routing is Layer 3.
12. A user reports slow network speeds. Which is the BEST first action?
Answer: Verify the issue and gather details
Rationale: Always confirm symptoms before changing configurations.
13. Which private IP range is valid?
, Answer: 192.168.1.0
Rationale: 192.168.0.0/16 is reserved for private use.
14. Which command tests name resolution?
Answer: nslookup
Rationale: Specifically queries DNS servers.
15. What should be done BEFORE implementing a fix?
Answer: Establish a plan of action
Rationale: Planning prevents unintended consequences.
16. Which issue is MOST likely caused by duplex mismatch?
Answer: Slow network performance
Rationale: Duplex mismatches cause retransmissions.
17. A user cannot print, but others can. What is the scope?
Answer: Single-user issue
Rationale: Isolated problems are local.
18. Which OSI layer handles encryption?
Answer: Presentation layer
Rationale: Layer 6 manages encryption and formatting.
