Top 24 Most Popular CCNA Interview Questions And Answers

By Archer Charles 23-Jun-2022
Top 24 Most Popular CCNA Interview Questions And Answers
CCNA is short for Cisco Certified Network Associate. Cisco Systems make up over 50% of the global networking market.
To train professionals for specific roles, Cisco Certification offers different training and globally recognised certification programs that span the domain of networking. This includes routing, switching, wireless, data centres and security, among other areas.

Let's take a look at some of the most important CCNA interview questions you should prepare for.

Q1. What is Routing?
Routing refers to the process of locating a path through which data can travel from the source to the destination. This is done using a device known as a router, which is a type of network layer device. 
Q2. What is the aim of a Data Link?
The role of a Data Link layer is checking that messages get sent to the correct device destination. Framing is another important function that this layer serves. 
Q3. What is the primary advantage of switches?
The process begins when switches receive a signal. The switch then creates a frame using the bits from this signal. This process provides the switch with access to the destination address and allows it to read and forward the frame to the right port. This is an effective method of transmitting data as an alternative to broadcasting across all available ports. 
Q4. What is Networking?
Networking is the system and process of connecting or operating within a network. This process creates and uses wireless or wired networks to exchange ideas, information and files among other e-communication. 
In addition to networking, Cisco certification helps in building up a solid foundation in networking concepts.
Q5. What is the meaning of a protocol?
A protocol can be defined as a set of rules connecting at least two devices while transferring data from one device to the other. Protocols provide insight into how data gets transferred from network to network while communicating.
Q6. Explain the OSI reference model.
The OSI reference model tells the user how data and information are understood and communicated over networks. OSI can also be termed a conceptual framework for understanding transmission relationships within a network. 
Q7. How many layers does the OSI model have? What are they?
The OSI reference model has seven layers, where every layer has a different functionality within the model. These layers are:
  • Physical - Layer 1
  • Data Link - Layer 2
  • Network - Layer 3
  • Transport - Layer 4
  • Session - Layer 5
  • Presentation - Layer 6
  • Application - Layer 7
Q8. What are switches and why are they used?
A switch enables the reception of a signal and creates a frame. It pushes packets forward between the different segments in a LAN. Switches support packet control when information is being sent to the Network or Data Link layers within the OSI reference model.
When packets are sent, the signal is enabled and becomes accessible through the reading of the destination address. The switch then forwards the frame to the correct port.
Q9. What is the difference between routers, switches and the hub?
Router: A router is a networking gateway device that forwards data packets to a selected computer network. It is connected using at least one LAN with its IP address or using a WAN or LAN. Routers support 2 broadcast domains.
Switch: A switch receives the signal and creates a frame. Switches are used to push packets forward between various LAN segments. They are the platform for controlling packets when data is transmitted to the Network or Data Link layers of the OSI reference model. A switch supports multiple collision domains and a singular broadcast domain. 
Hub: In the hub, anything coming into its port is sent out to others. The hub is more cost-effective and has the lowest complexity level. It supports single broadcast and collision domains.
Q10. What causes Network Congestion?
When too many data centres or users try to access the same bandwidth at the same time, it results in network congestion. This is true especially for big networks that do not carry out network segmentation. 
Q11. In Networking terms, What is a Window?
A window is a reference to the exact number of segments that are allowed to be transmitted from the source to the destination, followed by an acknowledgement sent back to the source. 
Q12. Can a bridge divide a network into multiple smaller sections?
That might not be accurate to say. The purpose of a bridge is taking a large network and filtering it without the network size changing in any way. 
Q13. Which method of LAN switching does CISCO Catalyst 5000 use?
The Store-and-forward method of switching is used by CISCO Catalyst 5000. This method stores entire frames in its buffers. A CRC check is then performed to decide whether to forward the data frame or not.
Q14. What is the LLC sublayer’s role?
LLC is short for Logical Link Control. The LLC sublayer provides several optional services to app developers. One of the options is providing flow control to the Network layer with start and stop codes. It also facilitates error correction. 
Q15. How is RIP different from IGRP?
RIP depends on the total count of hops while determining the best possible route leading to a network.
IGRP takes many factors into consideration - which includes bandwidth, reliability, hop count and MTU - before deciding on the best route.
Q16. What are the types of memories a CISCO router uses?
A CISCO router uses multiple memory storage types. These are
  • NVRAM for storing startup configuration files
  • DRAM for storing the configuration file presently being executed
  • Flash memory for storing the CISCO IOS.
Q17. What do you know about BootP?
BootP, the short name of Boot Program, is the name of a protocol that boots diskless workstations which are connected within a network. Another function that Boot Program serves is that it is used by diskless workstations to determine their IP addresses and the address of the server system.
Q18. What is the role of the Application layer within networking?
The OSI model has seven layers. The Application layer’s main role is to support the other components related to communications in an app. It also works to provide network services to processes that go beyond the specifications of the OSI model. The Application layer also syncs applications for clients on the network server. 
Q19. How is User Mode different from Privileged Mode?
User mode is primarily used for general tasks while using a router, to view information about the system, for example, or connect to remote devices, or to check the router status. 
Privileged mode covers all the available options covered in User mode and many more. This mode can be used by organisations and professionals to change configuration settings on the router, such as testing and debugging. 
Q20. What are the differences between WAN, LAN and MAN?
LAN is short for local area network, referring to a system where network devices and computers connect to each other within the same area, like a building or an entire floor. A LAN connection needs to be extremely high speed. One example of a LAN is the ethernet. 
MAN refers to metropolitan area networks. These networks connect a wider area, like multiple buildings in a city or town. 
WAN refers to a wide area network. In this type, networks are not limited to an organisation or enterprise and are accessible to the public. A WAN connects multiple LANs together. The speed of a WAN is very high as well as costly. The internet is the best example of a WAN.
Q21. What is an IP address?
The IP or internet protocol address is an identifier that is either 32-bit or 128-bit, made for devices based on the TCP/ IP protocol. For proper communication, a device’s IP address should be defined uniquely. 
An IP address has two primary functions- hosting address and location address identification. There are two versions of an IP - IPv4 (32-bit) and IPv6 (128-bit).
Q22. Which IP address would you use for a loopback address and why?
The IP address is primarily used for loopback addresses and the purpose of local testing. The meaning of loopback is looping to an organisation’s own network and checking their internal systems. A loopback address also tests if the TCP/ IP stack is installed correctly or not. 
Q23. What is encapsulation and de-encapsulation of data?
When data goes to a lower layer from a higher one, every layer adds a little more information to the original data. The data added is called the header, while this entire process is known as encapsulation.
When data goes to a higher layer from a lower one, certain information is removed at each layer. This process is known as de-encapsulation.
Q24. Describe the two route types that are available in routers.
The two types of routes are:
  • Static: If one route is fixed, it remains fixed. If this link is down for technical reasons, it cannot reach or connect to the destination despite the presence of alternate paths. Smaller networks use this route. 
  • Dynamic route: This is where it chooses the path itself. These paths are found using routing protocols. When one path fails, the dynamic route finds out the next option available. 


CCNA certification course is a computer networking certificate that provides you with knowledge of network access, IP services, IP connectivity, automation, security fundamentals, and programmability. Works well when you have roles such as network specialist, network administrator, and network engineer.
So there you go! There are many more CCNA interview questions you should prepare for, but these are the most important ones. 
Archer Charles

Archer Charles has top education industry knowledge with 4 years of experience. Being a passionate blogger also does blogging on the technology niche.

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