Top 38 CCNA Interview Questions

Top 38 CCNA Interview Questions: Here are the top interview questions of CCNA. Be prepared for the interview. You can download the entire questions in a pdf format. so guys All the best for your interview.

1) What is the difference between switch and hub?

Basis of ComparisonHubSwitch
DescriptionHub is a networking device that connects the multiple devices to a single network.A switch is a control unit that turns the flow of electricity on or off in a circuit.
LayerHubs are used at the physical layer.Switches are used at the data link layer.
Transmission typeTransmission type can be unicast, broadcast or multicast.Initially, the transmission type is broadcast and then is unicast.
PortsHub has 4/12 ports.The switch has 24/48 ports.
Transmission modeHalf duplexHalf/Full duplex.
CollisionsCollisions occur commonly in a Hub.No collisions occur in a full duplex switch.
Address used for data transmissionHub uses MAC address for data transmission.The switch uses a MAC address for data transmission.
Data transmission formElectrical signal is a data transmission form of a hub.A Frame is a data transmission form of a switch.

2) What is the difference between Switch and Router?

Points of DifferenceRoutersSwitches
Mode of transmission of dataIt Transmits data in the form of packets.It Transmits data in the form of frames.
Address used for the purpose of data transmission.It makes use of IP address for the purpose of data transmission.It makes use of MAC address for the purpose of data transmission.
Layer of OSI ModelIt makes use of layer 3 of OSI model. Layer 3 is the network layer.It makes use of layer 2 of OSI model. Layer 2 is the Data Link Layer.
PortsRouters contain 2 Ports by default like fast Ethernet Ports. However, we can add serial ports explicitly.Switches, on the contrary, are available with different Ports i.e – 8, 16, 24, 48 and 64.
TableIt makes use of the Routing Table for routes to get to the destination IP.It makes use of CAM (Content addressable Memory) table for MAC address.
Broadcast domainRouters break the broadcast domain and it does not propagate broadcast domain.Switches allow the broadcast domain and contain per port collision domain.
FunctionRouter in networking is used to connect two different NetworksIt is used to connect End devices such as computers, printers, scanners etc.
Used forIt is used for both WAN/LAN networks.It is only used for the LAN networks.
Mode of TransmissionBy default, Router is in full duplex mode. However, we can change them manually into half-duplex.Switches are used in half as well as full duplex mode. However, we can also make them in auto-negotiation.
NAT (Network Address Translation) and PAT (Port Address Translation).In Routers, we can perform Network Address Translation as well as Port Address TranslationIn Switches, we can neither perform Network Address Translation nor Port Address Tran

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3) What are the advantages of using Switches?

Advantages of using Switches:

  • Switches are used to receive a signal and create a frame out of the bits from that signal. The signals enable you to get access and read the destination address and after reading that it forward that frame to appropriate frame. So, switches are the significant part of the transmission.

4) What is Routing?

  • Routing is a process of finding a path to transfer data from source to destination.
  • Routing can be performed in a variety of networks such as circuit switched networks and computer networks.
  • In packet switching networks, routing makes a decision that directs the packets from source to the destination.
  • Routing makes use of a routing table, which maintains the routes of various destinations.

Types of routing:

  1. Static routing: Static routing is a routing technique where an administrator manually adds the routes in a routing table. Static routes are used when the route selections are limited. Static routes can also be used in those situations where the devices are fewer and no need to change in the route configuration in future.
  2. Dynamic routing: Dynamic routing is a routing technique where protocols automatically update the information of a routing table.

5) What are Routers?

  • The devices known as Routers do the process of routing. Routers are the network layer devices.
  • The router is a networking device which is used to transfer the data across the networks, and that can be wired or wireless.
  • Routers use headers and routing table to determine the best route for forwarding the packets.
  • Router analyzes the data which is being sent over the network, changes how it is packaged and send it over the network.

Examples of routers are:

  1. Brouter: Brouter stands for “Bridge Router”. It serves both as a router and bridge.
  2. Core router: Core router is a router in the computer network that routes the data within a network, but not between the networks.
  3. Edge router: An edge router is a router that resides at the boundary of a network.
  4. Virtual router: A virtual router is a software-based router. The virtual router performs the packet routing functionality through a software application. A Virtual Router Redundancy protocol implements the virtual router to increase the reliability of the network.
  5. Wireless router: A wireless router is a router that connects the local networks with another local network.

6) Does a bridge divide a network into smaller sections?

Top 38 CCNA Interview Questions 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?

Top 38 CCNA Interview Questions RIP relies on the number of hops in order to determine the best route to a network. On the other hand, IGRP takes consideration of many factors before it decides the best route to take, such as bandwidth, reliability, MTU and hop count.

10) What are the different memories used in a CISCO router?

Different memories used  in a CISCO router are:

– NVRAM stores the startup configuration file
– DRAM stores the configuration file that is being executed
– Flash Memory – stores the Cisco IOS.

11) Define IP Address?

Internet Protocol (IP Address) is a 32-bits to 128-bits identifier for a device on TCP/IP protocol. The IP address of a device must be uniquely defined for communication.

It has 2 principal functions which include host and location address. And it has two versions which are IPv4 (32-bits) and IPv6 (128-bits).

12) In how many ways can data be transferred in CCNA?

Data can be transferred in 3 ways:

  • Simplex
  • Half-duplex
  • Full-duplex

13) What is the difference between Unicast, Multicast, Broadcast, and Anycast?

Unicast:  It is the exchange of messages between a single source and a single destination. In Unicast, while sending packets from a sender, it contains a data address of the receiver so that it can go there directly.

Broadcast: It is the exchange of messages between one sender to possible multiple receivers. It works only on a local network. Broadcasting of data can’t be done on the public internet due to a massive amount of unrelated and unnecessary data.

Multicast: It is the exchange of messages between one sender and multiple receivers. In multicast, the network settings determine your receiving clients and sort of broadcasting.

Anycast: It is the exchange of messages between one host to another host. It uses TCP and UDP protocol. Copy of each data packet goes to every host that requests it.

14) What are the different types of network in CCNA?

There are two types of network:

  • Server-based network
  • Peer-to-Peer network

15) What is a Network subnet?

Top 38 CCNA Interview Questions It is the subdivision of an IP address which is divided into two parts such as the network prefix and the host identifier.

16) What is the difference between static IP addressing and dynamic IP addressing?

Following are the differences between static IP addressing and dynamic IP addressing:

Basis of ComparisonStatic IP addressDynamic IP address
DescriptionStatic IP address is a fixed number assigned to the computer.The dynamic IP address is a temporary number assigned to the computer.
Provided ByStatic IP address is provided by ISP(Internet Service Provider).The dynamic IP address is provided by DHCP(Dynamic Host Configuration Protocol).
Change requirementIt is static means that IP address does not change.It is non-static means that IP address changes whenever the user connects to a network.
SecurityIt is not secure as IP address is constant.It is secure because each time IP address changes.
CostIt is costlier than Dynamic IP address.It is cheaper than the Static IP address.
Device trackingStatic IP address is trackable as IP address is constant.The dynamic IP address is untraceable as IP address is always changing.

17) What is the difference between CSMA/CD and CSMA/CA?

CSMA/CD stands for Carrier Sense Multiple Access with Collision Detection. It is a media access control method used in local area networking using early Ethernet technology to overcome the occurred collision.

CSMA/CA stands for Carrier Sense Multiple Access with Collision Avoidance. It is used in the wireless network to avoid the collision.

Following are the differences between CSMA/CD and CSMA/CA:

CSMA/CDCSMA/CA
Full form of CSMA/CD is carrier sense multiple access with collision detection.Full form of CSMA/CA is carrier sense multiple access with carrier avoidance.
CSMA/CD detects the collision, and once the collision is detected, then it stops continuing the data transmission.CSMA/CA does not deal with the recovery of the collision.
Wired installation is used in a CSMA/CD to detect the collision.Wireless installation is used in a CSMA/CA as it avoids the collision. Therefore, it does not need a wired network.
An 802.3 Ethernet network uses CSMA/CD.An 802.11 ethernet network uses CSMA/CA.
CSMA/CD takes effect after the occurrence of a collision.CSMA/CA takes effect before the occurrence of a collision.

18) What is the purpose of Data Link Layer?

The main purpose of the data link layer is to check that whether messages are sent to the right devices. Another function of the data link layer is framing.


19) What is VLAN?

VLAN stands for Virtual Local Area Network.


20) What is the subnet? Why is it used?

Subnets are used in IP network to break up the larger network into the smaller network. It is used to optimize the performance of the network because it reduces traffic by breaking the larger network into smaller networks. It is also used to identify and isolate network’s problem and simplify them.

21) How do you configure a Cisco router to route IPX?

Top 38 CCNA Interview Questions The initial thing to do is to enable IPX routing by using the “IPX routing” command. Each interface that is used in the IPX network is then configured with a network number and encapsulation method.

22) What are the different IPX access lists?

There are two types of IPX access lists

1. Standard

2. Extended.

Standard Access List can only filter the source or destination IP address. An Extended Access List uses the source and destination IP addresses, port, socket, and protocol when filtering a network.

23) Explain the benefits of VLANs.

VLANs allow the creation of collision domains by groups other than just physical location. Using VLANs, it is possible to establish networks by different means, such as by function, type of hardware, protocol, among others. This is a big advantage when compared to conventional LANs wherein collision domains are always tied to a physical location.

24) What is subnetting?

Subnetting is the process of creating smaller networks from a big parent network. As a  part of a network, each subnet is assigned some additional parameters or identifier to indicate its subnet number.

25) What are the advantages of a layered model in the networking industry?

A layered network offers many advantages. It allows administrators to make changes in one layer without the need to make changes in the other layers. Specialization is encouraged, allowing the network industry to make progress faster. A layered model also lets administrators troubleshoot problems more efficiently.

26) What are the different types of cables that are used in routing?

Three different types of cables that are used include:

  • Straight cable – (switch-router)
  • Cross cable – (PC-PC, switch-switch)
  • Rollover cable – (Console port to computer)

27) Define Logical Topology.

Logical Topology is the network from where the data packets are sent from the source to destination, which we can see as well.

28) What is the difference between static and dynamic IP addresses?

Static IP address won’t change over the time and is reserved statically whereas dynamic IP address changes each time when you connect to the Internet.

29) What is Peer to Peer network?

The P2P network is a distributed and decentralized network where individual nodes i.e. Peers in the networks act as both suppliers and consumers of the resources.

30) What is the IEEE standard for wireless networking?

IEEE 802.11

31) What is BootP?

Top 38 CCNA Interview Questions BootP is a short form of Boot Program. It is a protocol that is used to boot diskless workstation connected to the network. BootP is also used by diskless workstations to determine its IP address and also the IP addresses of server PC.


32) What is a Frame Relay?

Frame Relay is used to provide connection-oriented communication by creating and maintaining virtual circuits. It is a WAN protocol that is operated at the Data Link and physical layer to sustain high-performance rating.

How frame relay works.

Frame relay multiplexes the traffic coming from different connections over a shared physical medium using special purpose hardware components such as routers, bridges, switch that packages the data into a frame relay messages. It reduces network latency, i.e., the number of delays. It also supports the variable sized packet for the efficient utilization of network bandwidth.


33) What is Latency?

Latency is the amount of time delay. It is measured as the time difference between at the point of time when a network receives the data, and the time it is sent by another network.


34) What is the MAC address?

MAC address stands for Media Access Control address. This is an address of a device which is identified as the Media Access Control Layer in the network architecture. The MAC address is unique and usually stored in ROM.


35) What is the difference between ARP and RARP?

ARP stands for Address Resolution Protocol. ARP is a protocol that is used to map an IP address to a physical machine address.

RAPR stands for Reverse Address Resolution Protocol. RARP is a protocol that is used to map a MAC address to an IP address.

Following are the differences between ARP and RARP:

Basis of ComparisonARPRARP
Full formFull form of ARP is address resolution protocol.Full form of RARP is reverse address resolution protocol.
DescriptionARP contains the logical address, and it retrieves the physical address of the receiver.RARP includes the physical address and retrieves the logical address of a computer from the server.
MappingARP is used to map 32-bit logical address to 48-bit physical address.RARP is used to map 48-bit physical address to 32-bit logical address.

36) What are packets?

Packets are the results of data encapsulation. These are data that have been wrapped under the different protocols of the OSI layers. Packets are also referred to as datagrams.

37) What are segments?

Top 38 CCNA Interview Questions Segments are sections of a data stream that comes from the upper OSI layers and ready for transmission towards the network. Segments are the logic units at the Transport Layer.

38) Give some benefits of LAN switching.

– allows full duplex data transmission and reception
– media rate adaption
– easy and efficient migration