Top 70 CCNA Interview Questions and Answers for 2024 (Updated)

Are you preparing for a CCNA (Cisco Certified Network Associate) interview? The CCNA certification is a highly sought-after credential in the networking industry, and the interview process can be challenging. To help you ace your next CCNA interview, we’ve compiled a comprehensive list of the top 70 CCNA interview questions and answers for 2022.

What is CCNA?

Before we dive into the questions, let’s first understand what CCNA is. CCNA stands for Cisco Certified Network Associate. It is an entry-level certification offered by Cisco Systems, a leading provider of networking hardware and software solutions. The CCNA certification validates an individual’s skills in installing, configuring, operating, and troubleshooting medium-sized routed and switched networks.

Why Pursue CCNA Certification?

Obtaining a CCNA certification can open up numerous career opportunities in the networking field. Here are some of the key benefits of becoming CCNA certified:

• Validate your networking skills and knowledge
• Increase your chances of getting hired or promoted
• Demonstrate your commitment to professional development
• Gain a competitive edge in the job market
• Earn a higher salary compared to non-certified professionals

CCNA Interview Questions and Answers

Without further ado, let’s explore the top 70 CCNA interview questions and answers to help you prepare for your upcoming interview.

CCNA Interview Questions and Answers for Freshers

1. What is Routing?
   Routing is the process of finding a path on which data can pass from source to destination. Routing is done by a device called a router, which is a network layer device.

2. What is the purpose of the Data Link Layer?
   The job of the Data Link Layer is to check that messages are sent to the right device. Another function of this layer is framing.

3. What is the key advantage of using switches?
   When a switch receives a signal, it creates a frame out of the bits that were from that signal. With this process, it gains access and reads the destination address, after which it forwards that frame to the appropriate port. This is a very efficient means of data transmission, instead of broadcasting it on all ports.

4. When does network congestion occur?
   Network congestion occurs when too many users are trying to use the same bandwidth. This is especially true in large networks that do not resort to network segmentation.

5. What is a Window in networking terms?
   A Window refers to the number of segments that are allowed to be sent from source to destination before an acknowledgment is sent back.

6. Does a bridge divide a network into smaller sections?
   Not really. What a bridge actually does is to take the large network and filter it, without changing the size of the network.

7. Which LAN switching method is used in CISCO Catalyst 5000?
   CISCO Catalyst 5000 uses the Store-and-forward switching method. It stores the entire frame to its buffers and performs a CRC check before deciding whether or not to forward that data frame.

8. What is the role of the LLC sublayer?
   The LLC sublayer stands for Logical Link Control. It can provide optional services to an application developer. One option is to provide flow control to the Network Layer by using stop/start codes. The LLC can also provide error correction.

9. How does RIP differ from IGRP?
   RIP (Routing Information Protocol) relies on the number of hops to determine the best route to a network. On the other hand, IGRP (Interior Gateway Routing Protocol) takes into consideration many factors before deciding the best route, such as bandwidth, reliability, MTU (Maximum Transmission Unit), and hop count.

10. What are the different memories used in a CISCO router?
    Different memories used in a CISCO router are:

    • NVRAM (Non-Volatile Random Access Memory) stores the startup configuration file.
    • DRAM (Dynamic Random Access Memory) stores the configuration file that is being executed.
    • Flash Memory stores the Cisco IOS (Internetwork Operating System).

11. What is BootP?
    BootP (Bootstrap Protocol) is a protocol used to boot diskless workstations that are connected to the network. It is short for Boot Program. Diskless workstations also use BootP to determine their own IP address and the IP address of the server PC.

12. What is the function of the Application Layer in networking?
    The Application Layer supports the communication components of an application and provides network services to application processes that span beyond the OSI (Open Systems Interconnection) reference model specifications. It also synchronizes applications on the server and client.

13. Differentiate User Mode from Privileged Mode.
    User Mode is used for regular tasks when using a CISCO router, such as viewing system information, connecting to remote devices, and checking the status of the router. On the other hand, Privileged Mode includes all options available for User Mode, plus more. You can use this mode to make configurations on the router, including performing tests and debugging.

14. What is 100BaseFX?
    100BaseFX is Ethernet that uses fiber-optic cable as the main transmission medium. The “100” stands for 100 Mbps, which is the data speed.

15. Differentiate full-duplex from half-duplex.
    In full-duplex communication, both the transmitting device and the receiving device can communicate simultaneously, meaning they can transmit and receive data at the same time. In the case of half-duplex communication, a device cannot receive while it is transmitting, and vice versa.

16. What is MTU?
    MTU stands for Maximum Transmission Unit. It refers to the maximum packet size that can be sent out onto the data line without the need for fragmentation.

17. How does cut-through LAN switching work?
    In Cut-Through LAN switching, as soon as the router receives the data frame, it will immediately send it out again and forward it to the next network segment after reading the destination address.

18. What is latency?
    Latency is the amount of time delay that measures the point from which a network device receives a data frame to the time it sends it out again towards another network segment.

19. Utilizing RIP, what is the limit when it comes to the number of hops?
    The maximum limit is 15 hop counts. Anything higher than 15 indicates that the network is considered unreachable.

20. What is a Frame Relay?
    Frame Relay is a WAN (Wide Area Network) protocol that provides connection-oriented communication by creating and maintaining virtual circuits. It has a high-performance rating and operates at the Data Link and Physical Layers.

CCNA Interview Questions and Answers for Experienced

1. What are the advantages of a layered model in the networking industry?
   A layered network model offers several advantages:

   • It allows administrators to make changes in one layer without the need to make changes in the other layers.
   • It encourages specialization, allowing the network industry to make progress faster.
   • It allows administrators to troubleshoot problems more efficiently.

2. Why is UDP preferred over TCP in certain scenarios?
   UDP (User Datagram Protocol) is preferred over TCP (Transmission Control Protocol) in scenarios where reliability and sequencing are not critical, such as video streaming or online gaming. UDP is connectionless and does not establish virtual circuits or acknowledge data delivery, making it more efficient for real-time applications.

3. What are some standards supported by the Presentation Layer?
   The Presentation Layer supports various standards to ensure that data is presented correctly, such as:

   • PICT, TIFF, and JPEG for graphics
   • MIDI, MPEG, and QuickTime for video/audio

4. What’s the easiest way to remotely configure a router?
   In cases where you need to configure a router remotely, the most convenient method is to use the Cisco AutoInstall Procedure. However, the router must be connected to the WAN (Wide Area Network) or LAN (Local Area Network) through one of its interfaces.

5. What does the show protocol command display?
   The show protocol command displays:

   • The routed protocols configured on the router
   • The address assigned to each interface
   • The encapsulation method configured on each interface

6. How do you depict an IP address?
   An IP address can be depicted in three possible ways:

   • Using Dotted-decimal notation (e.g., 192.168.0.1)
   • Using Binary notation (e.g., 10000010.00111011.01110010.01110011)
   • Using Hexadecimal notation (e.g., 82 1E 10 A1)

7. How do you go to Privileged Mode? How do you switch back to User Mode?
   To access Privileged Mode, you enter the enable command on the prompt. To switch back to User Mode, enter the disable command.

8. What is HDLC?
   HDLC (High-Level Data Link Control) is a proprietary protocol used by Cisco. It is the default encapsulation method operated within Cisco routers.

9. How are internetworks created?
   Internetworks are created when networks are connected using routers. Specifically, the network administrator assigns a logical address to every network that connects to the router.

10. What is Bandwidth?
    Bandwidth refers to the transmission capacity of a medium. It is a measure of how much volume a transmission channel can handle, and it is measured in Kbps (Kilobits per second).

11. How does Hold-downs work?
    Hold-downs prevent regular update messages from reinstating a downed link by removing that link from update messages. It uses triggered updates to reset the hold-down timer.

12. What are packets?
    Packets are the result of data encapsulation. These are data that have been wrapped under the different protocols of the OSI (Open Systems Interconnection) layers. Packets are also referred to as datagrams.

13. What are segments?
    Segments are sections of a data stream that come from the upper OSI layers and are ready for transmission towards the network. Segments are the logical units at the Transport Layer.

14. Give some benefits of LAN switching.
    Some benefits of LAN switching include:

    • Allows full-duplex data transmission and reception
    • Enables media rate adaptation
    • Facilitates easy and efficient migration

15. What is Route Poisoning?
    Route Poisoning is the process of inserting a table entry of 16 to a route, making it unreachable. This technique is used to prevent problems caused by inconsistent updates on a route.

16. How do you find valid hosts in a subnet?
    The best way to find valid hosts in a subnet is to use the equation: 256 minus the subnet mask. The hosts that are considered valid are those that can be found between the subnets.

17. What is DLCI?
    DLCI (Data Link Connection Identifiers) are assigned by a frame relay service provider to uniquely identify each virtual circuit that exists on the network.

18. Briefly explain the conversion steps in data encapsulation.
    From a data transmitter’s point of reference, the conversion steps in data encapsulation are:

    1. Data from the end-user is converted to segments.
    2. Segments are passed to the other layers and converted into packets or datagrams.
    3. Packets are converted into frames before passing on to the network interface.
    4. Frames are converted to bits prior to actual data transmission.

19. What are the different types of passwords used in securing a CISCO router?
    There are five types of passwords that can be used to secure a Cisco router:

    • Enable secret
    • Virtual terminal
    • Console
    • Auxiliary

20. Why is network segmentation a good idea when managing a large network?
    Network segmentation is a good idea when managing a large network because it helps ease network traffic and ensures that high bandwidth is made available at all times for all users. This translates to better performance, especially for a growing network.

21. What are the things that can be accessed in a CISCO router’s identifying information?
    The things that can be accessed in a Cisco router’s identifying information are:

    • Hostname: The name of your router
    • Interfaces: Fixed configurations that refer to the router ports

22. Differentiate Logical Topology from Physical Topology.
    Logical Topology refers to the signal path through the physical topology. Physical Topology is the actual layout of the network medium.

23. What causes a triggered update to reset the router hold-down timer?
    A triggered update can reset the router hold-down timer when:

    • The hold-down timer has already expired
    • The router received a processing task that incidentally was proportional to the number of links in the internetwork

24. In configuring a router, what command must be used if you want to delete the configuration data that is stored in the NVRAM?
    The command erase startup-config must be used to delete the configuration data stored in the NVRAM (Non-Volatile Random Access Memory).

25. Referring to the commands shown, what command must next be used on the branch router prior to traffic being sent to the router?

    angelscript

    Copy

    Hostname: Branch Hostname: RemotePH# 123-6000, 123-6001 PH# 123-8000, 123-8001SPID1: 32055512360001 SPID1: 32055512380001SPID2: 32055512360002 SPID2: 32055512380002ISDN switch-type basic niusername Remote password ciscointerface bri0IP address 10.1.1.1 255.255.255.0encapsulation PPPPPP authentication chapISDN spid1 41055512360001ISDN spid2 41055512360002dialer map IP 10.1.1.2 name Remote 1238001dialer-list 1 protocol IP permit

    The command (config-if)# dialer-group 1 must be used next on the branch router prior to traffic being sent to the router.

26. When configuring a router utilizing both physical and logical interfaces, what factor must be considered in determining the OSPF router ID?
    When configuring a router utilizing both physical and logical interfaces, the highest IP address of any physical interface must be considered in determining the OSPF (Open Shortest Path First) router ID.

27. What is the difference between a switch, hub, and router?

    Device	Description
    Hub	A hub has a single broadcast domain and collision domain. Anything that comes in one port is sent out to the other ports.
    Switch	A switch is a device that filters and forwards packets between LAN segments. Switches have a single broadcast domain and multiple collision domains. They support any packet protocol and operate at the Data Link Layer (Layer 2) and Network Layer (Layer 3).
    Router	A router is a device that transmits data packets along networks.

28. What is the size of an IP address?
    The size of an IP address is:

    • 32 bits for IPv4 (Internet Protocol Version 4)
    • 128 bits for IPv6 (Internet Protocol Version 6)

29. What does a data packet consist of?
    A data packet consists of:

    • Sender’s information
    • Recipient’s information
    • The data being transmitted
    • A numeric identification number that defines the packet number and order

30. What does DHCP stand for?
    DHCP stands for Dynamic Host Configuration Protocol. DHCP assigns IP addresses automatically to workstation clients.

31. What is BOOTP?
    BOOTP (Bootstrap Protocol) is a computer networking protocol used to deploy IP addresses to network devices from a configuration server.

32. Explain why UDP is less favored when compared to TCP.
    UDP (User Datagram Protocol) is less favored than TCP (Transmission Control Protocol) because UDP is unsequenced and unreliable. It is not capable of creating virtual circuits and acknowledgments.

33. State the difference between dynamic IP and static IP addressing.
    Dynamic IP addresses are provided by a DHCP (Dynamic Host Configuration Protocol) server, while static IP addresses are assigned manually.

34. What are the ranges for private IP addresses?
    The ranges for private IP addresses are:

    • Class A: 10.0.0.0 – 10.255.255.255
    • Class B: 172.16.0.0 – 172.31.255.255
    • Class C: 192.168.0.0 – 192.168.255.255

35. In how many ways can you access a router?
    You can access a router in three ways:

    • Telnet (IP)
    • AUX (Telephone)
    • Console (Cable)

36. What is EIGRP?
    EIGRP (Enhanced Interior Gateway Routing Protocol) is a routing protocol designed by Cisco Systems. It is enabled on a router to share routes with other routers within the same autonomous