COMPTIA NETWORK+ CERTIFICATION EXAM
Newest 2026-2027 Updated Practice Exam |
150+ Actual Most Tested Questions Collections
& Verified Detailed Answers From Past Papers
| Expert Verified Success Exam) Graded A+
1. A network administrator is troubleshooting intermittent connectivity issues
on a switched network. Users report slow performance during peak hours.
Which metric should be examined first?
A. CPU utilization on the switch
B. DNS response time
C. Number of DHCP leases
D. ARP cache size
Correct Answer: CPU utilization on the switch ✓
Rationale: High CPU utilization on a switch can indicate broadcast storms, loops,
or excessive traffic processing, which directly impacts network performance
during peak usage.
2. A technician is implementing VLANs in a corporate environment. What is
the primary benefit of VLAN segmentation?
A. Increased cable length support
B. Improved collision detection
C. Reduced broadcast domains
D. Automatic IP addressing
Correct Answer: Reduced broadcast domains ✓
Rationale: VLANs logically segment networks, reducing broadcast traffic,
improving performance and security isolation.
, 3. Which protocol is used to dynamically assign IP addresses to network
hosts?
A. DNS
B. DHCP
C. ARP
D. FTP
Correct Answer: DHCP ✓
Rationale: DHCP (Dynamic Host Configuration Protocol) automatically assigns IP
addresses, subnet masks, and gateways to devices.
4. A user cannot reach external websites but can access internal resources.
What is the MOST likely cause?
A. Incorrect subnet mask
B. DNS failure
C. Default gateway misconfiguration
D. Duplicate MAC address
Correct Answer: Default gateway misconfiguration ✓
Rationale: A missing or incorrect default gateway prevents communication
outside the local network.
5. Which OSI layer is responsible for logical addressing?
A. Physical
B. Data Link
C. Network
D. Transport
Correct Answer: Network ✓
Rationale: Layer 3 (Network layer) handles IP addressing and routing between
networks.
6. What is the primary function of NAT?
,A. Encrypt data in transit
B. Translate private IPs to public IPs
C. Assign MAC addresses
D. Resolve hostnames
Correct Answer: Translate private IPs to public IPs ✓
Rationale: NAT allows multiple devices to share a single public IP address,
conserving IPv4 space.
7. Which wireless standard operates exclusively in the 5 GHz band?
A. 802.11b
B. 802.11g
C. 802.11n
D. 802.11ac
Correct Answer: 802.11ac ✓
Rationale: 802.11ac uses only 5 GHz, offering higher speeds and less
interference.
8. A network technician detects a loop in a switched network. Which protocol
prevents switching loops?
A. OSPF
B. STP
C. BGP
D. RIP
Correct Answer: STP ✓
Rationale: Spanning Tree Protocol (STP) prevents Layer 2 switching loops by
blocking redundant paths.
9. Which port number is used by HTTPS?
A. 21
B. 80
, C. 443
D. 110
Correct Answer: 443 ✓
Rationale: HTTPS uses TCP port 443 for secure web communication.
10.A technician is analyzing packet loss. Which tool provides route information
across networks?
A. ping
B. tracert
C. nslookup
D. ipconfig
Correct Answer: tracert ✓
Rationale: Tracert shows the path packets take and hop-by-hop latency, useful
for diagnosing routing issues.
11.Which device operates at Layer 2 of the OSI model?
A. Router
B. Switch
C. Firewall
D. Modem
Correct Answer: Switch ✓
Rationale: Switches operate at Layer 2 (Data Link) using MAC addresses.
12.What type of attack involves overwhelming a system with traffic from
multiple sources?
A. Phishing
B. DoS
C. DDoS
D. Spoofing
Newest 2026-2027 Updated Practice Exam |
150+ Actual Most Tested Questions Collections
& Verified Detailed Answers From Past Papers
| Expert Verified Success Exam) Graded A+
1. A network administrator is troubleshooting intermittent connectivity issues
on a switched network. Users report slow performance during peak hours.
Which metric should be examined first?
A. CPU utilization on the switch
B. DNS response time
C. Number of DHCP leases
D. ARP cache size
Correct Answer: CPU utilization on the switch ✓
Rationale: High CPU utilization on a switch can indicate broadcast storms, loops,
or excessive traffic processing, which directly impacts network performance
during peak usage.
2. A technician is implementing VLANs in a corporate environment. What is
the primary benefit of VLAN segmentation?
A. Increased cable length support
B. Improved collision detection
C. Reduced broadcast domains
D. Automatic IP addressing
Correct Answer: Reduced broadcast domains ✓
Rationale: VLANs logically segment networks, reducing broadcast traffic,
improving performance and security isolation.
, 3. Which protocol is used to dynamically assign IP addresses to network
hosts?
A. DNS
B. DHCP
C. ARP
D. FTP
Correct Answer: DHCP ✓
Rationale: DHCP (Dynamic Host Configuration Protocol) automatically assigns IP
addresses, subnet masks, and gateways to devices.
4. A user cannot reach external websites but can access internal resources.
What is the MOST likely cause?
A. Incorrect subnet mask
B. DNS failure
C. Default gateway misconfiguration
D. Duplicate MAC address
Correct Answer: Default gateway misconfiguration ✓
Rationale: A missing or incorrect default gateway prevents communication
outside the local network.
5. Which OSI layer is responsible for logical addressing?
A. Physical
B. Data Link
C. Network
D. Transport
Correct Answer: Network ✓
Rationale: Layer 3 (Network layer) handles IP addressing and routing between
networks.
6. What is the primary function of NAT?
,A. Encrypt data in transit
B. Translate private IPs to public IPs
C. Assign MAC addresses
D. Resolve hostnames
Correct Answer: Translate private IPs to public IPs ✓
Rationale: NAT allows multiple devices to share a single public IP address,
conserving IPv4 space.
7. Which wireless standard operates exclusively in the 5 GHz band?
A. 802.11b
B. 802.11g
C. 802.11n
D. 802.11ac
Correct Answer: 802.11ac ✓
Rationale: 802.11ac uses only 5 GHz, offering higher speeds and less
interference.
8. A network technician detects a loop in a switched network. Which protocol
prevents switching loops?
A. OSPF
B. STP
C. BGP
D. RIP
Correct Answer: STP ✓
Rationale: Spanning Tree Protocol (STP) prevents Layer 2 switching loops by
blocking redundant paths.
9. Which port number is used by HTTPS?
A. 21
B. 80
, C. 443
D. 110
Correct Answer: 443 ✓
Rationale: HTTPS uses TCP port 443 for secure web communication.
10.A technician is analyzing packet loss. Which tool provides route information
across networks?
A. ping
B. tracert
C. nslookup
D. ipconfig
Correct Answer: tracert ✓
Rationale: Tracert shows the path packets take and hop-by-hop latency, useful
for diagnosing routing issues.
11.Which device operates at Layer 2 of the OSI model?
A. Router
B. Switch
C. Firewall
D. Modem
Correct Answer: Switch ✓
Rationale: Switches operate at Layer 2 (Data Link) using MAC addresses.
12.What type of attack involves overwhelming a system with traffic from
multiple sources?
A. Phishing
B. DoS
C. DDoS
D. Spoofing
