Top 25 Switching Interview Questions and Answers

Top 25 Switching Interview Questions and Answers

Employers are constantly on the lookout for all-rounded employees who can help the company or business meet its objectives, which explains why recruitment methods are getting more thorough as time goes by.

You have to offer something extra to land a job. In this article, we look at some of the questions you should expect in a switching interview. These should give you a good foundation and help you ace the interview.

We have also crafted our unique responses to guide you on how to answer the questions. Let’s delve deeper into these:

1.    What Do You Understand by Switching?

Switching is an important component in computer networking. It is the exchange of information between various computer networks and computer segments. It is the framework that allows one to access the internet or another computer network remotely or even send messages through a range of connected devices.

2.      What is a Switch?

A switch is a device responsible for sharing resources, which it achieves by forging a connection between devices. These connected devices can then share information and communicate with one another, be it physically or remotely. One, therefore, needs switches to tie devices together in a small business network.

3.      Please Use Your Experience to Define What Port Security Is and How It Works with a Managed Switch?

Port security prevents unknown devices from forwarding packets, thus securing the network. It ensures that all the dynamically locked addresses are freed in the event of a link go-down. It is implemented in two ways: dynamic locking and static locking.

For dynamic locking, you have the liberty to specify the number of MAC addresses that can be learned on a port, whereas in static locking, you specify the static MAC addresses for the port.

4.      How Would You Define VLAN and What Are Some of The Common Types That You Know?

Fully known as the Virtual Local Area Network, it is a custom network generated from one or more local area networks. It creates a Virtual LAN by allowing devices in a different network to be combined in one logical network.

There are three main types of VLAN, which are port-based, protocol and MAC-based VLAN. As the name suggests, the first uses a port to group virtual area networks. Protocol VLAN, on the other hand, uses traffic based on a protocol, whereas MAC-based VLAN allows the assigning of Virtual LAN to untagged packets.

5.      Can You Please Tell Us More About Unicast Traffic?

This is usually associated with the learning process of the network switch. Here, the switches locate the MAC addresses of the accessible devices by their ports before coming up with a table to decide the destination of every arriving frame.

However, it may lead to unicast flooding whose periods range from poor performance to zero network.

6.      Having Dealt with Switches, Could You Please Tell Us Some of Their Functions?

There are four main functions of a switch. The first is learning the MAC or physical address of a given device on a switch port. The second is framing, which established a unicast and an unknown unicast. The third one is filtering, where the frame is forwarded through a switch port where the switch has learned the MAC address, and the last is loop avoidance through spanning tree protocols. (You do not have to be too detailed. However, you can explain more)

7.      You Mentioned MAC Address While Answering One of The Questions. What Is It and Why Is It Needed?

Fully known as the media access address, it uniquely identifies all the devices in a given network. It is manufactured into each network card, be it an ethernet or Wi-Fi card and cannot be changed. Its main work is, therefore, identification.

8.      Could You Please Differentiate a HUB and a Switch?

A hub is used as a connection point for various devices in a Local Area Network and works with several ports. A switch uses packet switching to receive and relay data within a network. It is, therefore, more efficient and intelligent than the hub.

The main difference between these two comes in how they deliver the data packets.  A switch records the addresses of connected devices and learn each of them and can therefore improve the speed of networks.

9.      Could You Please Define ARP and Tell Us Some of The Instances When It Is Required?

The address resolution protocol is fully known as the address resolution protocol. It connects the Internet Protocol, popularly known as IP address, to the MAC address, a fixed machine address, when connected in a local area network. It comes in handy owing to the difference in length of the IP and MAC addresses. It, therefore, acts as a translator or bridge that brings the two together.

10. What Is Spanning Tree Protocol? Could You Please Explain Form Your Experience in This Field?

Spanning Tree Protocol, popularly known as STP, does away with the undesirable network loops, which normally occur from trying to offer several levels of redundancy. It is a link management protocol that offers path redundancy, thus eliminating this problem.

It allows only one path to destinations in the wake of multiple links. The switches, therefore, facilitate information exchange via bridge protocol data units.

11. Could You Please Differentiate Broadcast and Collision Domain?

  • A collision domain allows traffic flow in a network section where traffic flows back and forth, whereas the broadcast domain is a domain that allows the traffic to flow all over the network.
  • Switches normally break in the collision domain, which does not happen in a broadcast domain.
  • Every port on the router is found in separate broadcast domains in a collision domain, whereas in the broadcast domain, all the ports on the switch or hub are found in the same place.
  • The devices in a collision domain can include the devices of other IP subnetworks, a limit that broadcast domains do not face.

12. Could You Please Differentiate Static and Dynamic VLAN?

Static VLAN, also called the port-based VLAN, is created when a port is manually assigned to a VLAN. On the other hand, the dynamic VLAN is created when a host, plugged in to a switch through hardware addresses stored in a database, is assigned to a VLAN.

The latter uses a central server known as the VLAN Membership Policy Server, or the VMPS, which is equipped with a database containing the MAC addresses of all the devices connected to the network. In short, it creates a VLAN to MAC address mapping.

13. What Do You Understand by VLAN Tagging?

Also called frame tagging, this method was created to help systems identify all the packets travelling through a trunk link. A special VPN tag is normally created during such occurrences and added to the frame before being sent across the link. The tag is then removed, and the frame sent to the right access link port once it reaches the end of the trunk line.

14. Could You Please Explain the Concept of Cut-through LAN Switching Using Your Years of Switching Experience?

In this type of switching, the router sends out a data frame immediately after it receives it. This is done to forward the frame to the next network segment once it has read its destination address. It is one of the most intriguing types of switching.

15. What Do Data Pockets Consist of?

A data packet is made up of four contents. It consists of the sender’s and recipient’s information, the data contained and the identification number. An identification number is a numeric number that defines both the packet number and order.

Whenever data is sent across a network, it is broken down into data packets, which carry bits of information. The data packets, therefore, carry both the information and routing configuration for the transferred message.

16. Could You Please Differentiate Between LAN, MAN and WAN?

LAN, fully known as the Local Area Network, offers a means through which computers and network devices connect. This usually occurs in the same building or area and are connections of high speed. A good example is ethernet.

MAN is known as the metropolitan area network and, unlike LAN, offers a wide range of connection, usually within several buildings but in the same city. A good example is the IUB network.

Lastly, WAN is a wide area network that limits networks to only one enterprise or organization but can be accessed by the public. It, therefore, forges a connection between several LANs. A good example is the internet.

17. Could You Please Differentiate Unicast, Multicast, Broadcast and Anycast?

Unicast is information exchange between a single source and destination. The packets sent have the data address of the receiver and are therefore relayed directly to the receiver. Broadcast is the exchange of information or messages between one sender and all the possible receivers.

On the other hand, multicast involves the exchange of messages between a sender and multiple receivers. However, unlike in broadcast, it is the network settings that determine the receiving clients. Lastly, anycast is where messages are exchanged from one host to the other. This uses both TCP and UDP protocols, and a copy of each data packet is remitted to the right host.

18. Differentiate Between ARP and RARP

ARP is known as the Address Resolution Protocol used to map an IP address to a physical device. In contrast, RARP is the Reverse Address Resolution Protocol used to map the MAC address to the IP address.

19. What Do You Understand by an IP Adress? Could You Please Define What It Is?

The Internet protocol address is a 32 to 128 bits identifier given to any device on TCP/IP protocol. It is usually a unique number or figure, which helps identify the connected device and is clearly defined for communication purposes. The IP address has two principal functions, which are the host and location address. There also exist two versions: IPv4, which is the 32-bits and IPv6, which is the 128-bits.

20. What Is Your Understanding of Network Congestion?

Network congestion occurs when a network node carries more data than which the network can handle. In such instances, the network node loses packets and information, which means that the receiver cannot get the appropriate information.

21. Briefly Explain How Switches Work. Has This Evolved Over Time Based on Your Experience?

 The working mechanism of switches has been constant all through. These devices receive signals to create frames. Data packets are forwarded between various LAN segments as the switch supports packet control whenever data is sent to the Data Link or the network layer of the OSI model.

It is worth noting that the signals are enabled when sending packets and can therefore be accessed when the switch reads the destination address.

22. Please Tell Us the Different Layers of The OSI Model?

The OSI model has seven different layers with their unique functionality in the model. The first layer is the physical layer, the second is the data link layer, and the third is the network layer. The other four layers ate the transport layer, session layer, presentation layer and application layer.

Remember, all these layers have their unique functionalities in the OSI model.

23. Now That You Have Listed the Different Layers of The OSI Model, Please Explain the Function of The Application Layer regarding Networking.

The application layer offers support to the communication components of an application. It also offers the required network services to application processes beyond the specifications of the OSI reference model specifications.

24. Mention the Two Main IPX Access Lists

The two existing types of IPX access lists are standard and extended. The standard access lists only filter the source or destination IP address. In contrast, the extended access lists engage the source and destination IP addresses, protocol and socket to filter a network. 

25. What Do You Understand by Subnetting?

It is the creation of smaller networks from a parent network. All the subnets are usually assigned additional parameters which indicate their subnet numbers.


These are some of the most common switching interview questions and answers. Please go through them and have an idea of what to expect in a switching-related interview.

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