CCNA COMPLETE EXAM QUESTIONS AND VERIFIED
ANSWERS | 2026–2027 LATEST UPDATE | GUARANTEED
PASS | DETAILED RATIONALES | FULL STUDY GUIDE | EXAM
PREP | PRACTICE TEST | CERTIFICATION PREPARATION
1. A network administrator needs to identify the primary purpose of the OSI model. What is the
main benefit of using the OSI reference model?
A. It guarantees interoperability between all vendors' devices
B. It provides a standardized framework for understanding network functions
C. It eliminates the need for network protocols
D. It replaces TCP/IP in enterprise networks
Correct Answer: B. It provides a standardized framework for understanding network functions
Rationale:
The OSI model serves as a conceptual framework that helps networking professionals understand
how data moves through a network. It standardizes communication functions into layers, making
troubleshooting and Certification Preparation easier. It does not guarantee interoperability, eliminate
protocols, or replace TCP/IP.
2. Which device primarily operates at Layer 2 of the OSI model?
A. Router
B. Firewall
C. Switch
D. Hub
Correct Answer: C. Switch
Rationale:
Switches make forwarding decisions based on MAC addresses and primarily function at the Data Link
layer. Routers operate at Layer 3, hubs operate at Layer 1, and firewalls may function across multiple
layers depending on implementation.
3. A technician is troubleshooting a workstation that cannot communicate outside its local subnet.
Which configuration should be checked first?
A. DNS server address
B. MAC address table
C. Default gateway
D. VLAN ID
Correct Answer: C. Default gateway
Rationale:
The default gateway allows traffic to reach destinations outside the local subnet. Without a valid
gateway, communication remains limited to local devices. DNS affects name resolution rather than
routing, while MAC tables and VLAN IDs are less likely to cause this specific symptom.
4. Which IPv4 address class traditionally supports the largest number of hosts per network?
,A. Class A
B. Class B
C. Class C
D. Class D
Correct Answer: A. Class A
Rationale:
Class A networks provide the largest host capacity due to their large host portion. Although classful
addressing is largely obsolete, understanding it remains important for Exam Questions and
foundational networking concepts.
5. What is the purpose of ARP in an IPv4 network?
A. Resolve hostnames into IP addresses
B. Map IP addresses to MAC addresses
C. Encrypt traffic between hosts
D. Assign IP addresses dynamically
Correct Answer: B. Map IP addresses to MAC addresses
Rationale:
Address Resolution Protocol (ARP) resolves known IPv4 addresses into corresponding MAC addresses
for local communication. DNS resolves names, DHCP assigns addresses, and encryption is handled by
other technologies.
6. Which command displays the current IP configuration on a Cisco router interface?
A. show running-config
B. show interfaces status
C. show ip interface brief
D. show version
Correct Answer: C. show ip interface brief
Rationale:
The command show ip interface brief provides a concise summary of interface status and assigned IP
addresses. It is frequently used in Practice Test scenarios and real-world troubleshooting.
7. A network engineer wants to reduce broadcast traffic within a switched network. Which
technology should be implemented?
A. NAT
B. VLANs
C. DHCP
D. FTP
Correct Answer: B. VLANs
Rationale:
VLANs create separate broadcast domains, reducing unnecessary broadcast traffic and improving
network efficiency. NAT, DHCP, and FTP serve different purposes.
8. Which protocol dynamically assigns IP addresses to clients?
, A. DNS
B. DHCP
C. SNMP
D. SSH
Correct Answer: B. DHCP
Rationale:
DHCP automatically provides IP addressing information to clients. DNS resolves names, SNMP
manages devices, and SSH provides secure remote access.
9. What is the default administrative distance of a directly connected route on a Cisco router?
A. 0
B. 1
C. 90
D. 110
Correct Answer: A. 0
Rationale:
Directly connected routes have the highest level of trust and therefore an administrative distance of
0. Lower administrative distance values are preferred during route selection.
10. Which protocol is commonly used for secure remote management of network devices?
A. Telnet
B. HTTP
C. FTP
D. SSH
Correct Answer: D. SSH
Rationale:
SSH encrypts management traffic, protecting credentials and data. Telnet transmits data in clear text,
making it unsuitable for modern security best practices.
11. Which layer of the OSI model is responsible for logical addressing?
A. Network Layer
B. Data Link Layer
C. Physical Layer
D. Session Layer
Correct Answer: A. Network Layer
Rationale:
Logical addressing, such as IPv4 and IPv6 addresses, occurs at Layer 3. This layer determines path
selection and packet forwarding across networks.
12. A switch receives a frame with an unknown destination MAC address. What action will it take?
A. Drop the frame immediately
B. Send it to the default gateway
ANSWERS | 2026–2027 LATEST UPDATE | GUARANTEED
PASS | DETAILED RATIONALES | FULL STUDY GUIDE | EXAM
PREP | PRACTICE TEST | CERTIFICATION PREPARATION
1. A network administrator needs to identify the primary purpose of the OSI model. What is the
main benefit of using the OSI reference model?
A. It guarantees interoperability between all vendors' devices
B. It provides a standardized framework for understanding network functions
C. It eliminates the need for network protocols
D. It replaces TCP/IP in enterprise networks
Correct Answer: B. It provides a standardized framework for understanding network functions
Rationale:
The OSI model serves as a conceptual framework that helps networking professionals understand
how data moves through a network. It standardizes communication functions into layers, making
troubleshooting and Certification Preparation easier. It does not guarantee interoperability, eliminate
protocols, or replace TCP/IP.
2. Which device primarily operates at Layer 2 of the OSI model?
A. Router
B. Firewall
C. Switch
D. Hub
Correct Answer: C. Switch
Rationale:
Switches make forwarding decisions based on MAC addresses and primarily function at the Data Link
layer. Routers operate at Layer 3, hubs operate at Layer 1, and firewalls may function across multiple
layers depending on implementation.
3. A technician is troubleshooting a workstation that cannot communicate outside its local subnet.
Which configuration should be checked first?
A. DNS server address
B. MAC address table
C. Default gateway
D. VLAN ID
Correct Answer: C. Default gateway
Rationale:
The default gateway allows traffic to reach destinations outside the local subnet. Without a valid
gateway, communication remains limited to local devices. DNS affects name resolution rather than
routing, while MAC tables and VLAN IDs are less likely to cause this specific symptom.
4. Which IPv4 address class traditionally supports the largest number of hosts per network?
,A. Class A
B. Class B
C. Class C
D. Class D
Correct Answer: A. Class A
Rationale:
Class A networks provide the largest host capacity due to their large host portion. Although classful
addressing is largely obsolete, understanding it remains important for Exam Questions and
foundational networking concepts.
5. What is the purpose of ARP in an IPv4 network?
A. Resolve hostnames into IP addresses
B. Map IP addresses to MAC addresses
C. Encrypt traffic between hosts
D. Assign IP addresses dynamically
Correct Answer: B. Map IP addresses to MAC addresses
Rationale:
Address Resolution Protocol (ARP) resolves known IPv4 addresses into corresponding MAC addresses
for local communication. DNS resolves names, DHCP assigns addresses, and encryption is handled by
other technologies.
6. Which command displays the current IP configuration on a Cisco router interface?
A. show running-config
B. show interfaces status
C. show ip interface brief
D. show version
Correct Answer: C. show ip interface brief
Rationale:
The command show ip interface brief provides a concise summary of interface status and assigned IP
addresses. It is frequently used in Practice Test scenarios and real-world troubleshooting.
7. A network engineer wants to reduce broadcast traffic within a switched network. Which
technology should be implemented?
A. NAT
B. VLANs
C. DHCP
D. FTP
Correct Answer: B. VLANs
Rationale:
VLANs create separate broadcast domains, reducing unnecessary broadcast traffic and improving
network efficiency. NAT, DHCP, and FTP serve different purposes.
8. Which protocol dynamically assigns IP addresses to clients?
, A. DNS
B. DHCP
C. SNMP
D. SSH
Correct Answer: B. DHCP
Rationale:
DHCP automatically provides IP addressing information to clients. DNS resolves names, SNMP
manages devices, and SSH provides secure remote access.
9. What is the default administrative distance of a directly connected route on a Cisco router?
A. 0
B. 1
C. 90
D. 110
Correct Answer: A. 0
Rationale:
Directly connected routes have the highest level of trust and therefore an administrative distance of
0. Lower administrative distance values are preferred during route selection.
10. Which protocol is commonly used for secure remote management of network devices?
A. Telnet
B. HTTP
C. FTP
D. SSH
Correct Answer: D. SSH
Rationale:
SSH encrypts management traffic, protecting credentials and data. Telnet transmits data in clear text,
making it unsuitable for modern security best practices.
11. Which layer of the OSI model is responsible for logical addressing?
A. Network Layer
B. Data Link Layer
C. Physical Layer
D. Session Layer
Correct Answer: A. Network Layer
Rationale:
Logical addressing, such as IPv4 and IPv6 addresses, occurs at Layer 3. This layer determines path
selection and packet forwarding across networks.
12. A switch receives a frame with an unknown destination MAC address. What action will it take?
A. Drop the frame immediately
B. Send it to the default gateway
