50+ Top Networking Interview Questions and Answers (2026)

Preparing for a networking interview in 2026?
In this guide, we cover 60 most asked networking interview questions and answers for freshers and experienced professionals. You’ll learn networking basics, TCP/IP, VLANs, routing, troubleshooting, and real-world scenario questions commonly asked in companies.

This guide is created with insights from industry experts and CCIE-certified trainers at PyNet Labs to help you understand networking concepts in a simple and practical way.

About Networking

Networking is defined as two or more devices that are connected to each other via a transmission media. A network has the potential to be built with just a handful of devices limited within a single room or scaled up to cover millions of devices spread throughout the globe. In general, networks serve as a means of setting up connectivity among nodes, which may consist of a collection of devices or computers.

This guide, networking interview questions and answers, can prove to be a valuable resource for individuals interviewing for positions at the beginner or advanced levels. It can be helpful in enhancing one’s knowledge and achieving success in the interview. Let’s get started!

Networking Interview Questions and Answers for Freshers

Here are the top most asked Basic networking interview questions for freshers:

Q1. What is a Network?

A network is a collection of devices that can communicate with each other to share resources and information. Depending on its size and scope of use, a network can be of different types, such as PAN, LAN, WAN, etc.

Q2. What are the different types of networks?

Mainly there are four types of networks. These are:

1. Personal Area Network (PAN)

The Personal Area Network (PAN) is considered to be the fundamental form of computer networking. This network is limited to an individual user, meaning that the exchange of information among computer devices is limited only to the user’s personal workspace.

The PAN technology allows communication between devices within a range of 1 to 100 meters from the user. The transmission speed is relatively high, and its maintenance is simple and cost-effective.

2. Local Area Network (LAN)

LAN is a type of computer network that connects devices within a limited geographic area, such as a home, office, or school. LANs allow users to share resources, such as files, printers, and internet access, among the connected devices. One of the basic examples of Local Area Network (LAN) is a printer connected to a computer.

The maximum range of the system is 1-10 kilometers, and its transmission speed is significantly high.

3. Metropolitan Area Network (MAN)

The Metropolitan Area Network (MAN) is a network type that covers the network connection of an entire city or connection of a small area. The area covered by the network is connected using a wired network, like data cables.

This network mainly uses FDDI, CDDI, and ATM as the technology, ranging from 5km to 50km. Its transmission speed is average. It isn’t easy to maintain, and it comes with a high cost.

4. Wide Area Network (WAN)

WAN is a network that connects devices over a large geographical area, such as different cities or countries. WANs typically use public or leased telecommunication lines to transmit data. Examples of WANs are the Internet, corporate networks, and satellite networks. In most cases, the connection is established through wireless means and relies on radio towers for transmission.

WAN is a collection of Local Area Networks (LANs) that are connected with each other over a distance above 50 kilometers.

Q3. What are different network topologies?

Network topologies define how various devices are interconnected inside the network. Some of the common network topology types are:

• Star Topology
• Tree Topology
• Bus Topology
• Mesh Topology
• Ring Topology
• Point-to-Point Topology
• Hybrid Topology

Q4. What is latency?

Latency is the time it takes for data to make a round trip. We measure latency in milliseconds. A low number is good. A high number is bad.

You send a message and wait for a response. The time you wait is referred to as latency. It is the time for a signal to travel to a server and then come back to you.

When playing an online game, low latency is crucial. High latency causes lag. It makes the game feel slow. The same applies to video calls. High latency makes conversations difficult.

It is not the same as speed. Speed, or bandwidth, is how much data you can move at once. Latency refers to the time it takes for any piece of data to travel. You can have a fast connection with bad latency. This would feel like a big highway with a long delay at a traffic light.

Q5. What is OSI Model and why is it important?

The OSI (Open Systems Interconnection) Model is a conceptual framework that standardizes the functions of a telecommunication or computing system. It divides the network communication process into seven layers:

1. Physical Layer
2. Data Link Layer
3. Network Layer
4. Transport Layer
5. Session Layer
6. Presentation Layer
7. Application Layer

The OSI model is important because it allows different network technologies to work together and enables troubleshooting by dividing complex network operations into manageable layers.

Q6. What is TCP/IP Model and how it differs from OSI Model?

The TCP/IP (Transmission Control Protocol/Internet Protocol) is a set of communication protocols that are used to connect network devices on the Internet. The TCP/IP model has 4 layers, unlike the 7 layers of the OSI model.

1. Network Interface Layer
2. Internet Layer
3. Transport Layer
4. Application Layer

The key difference is that TCP/IP is the actual protocol suite used in the real world, while the OSI model serves as a conceptual guideline.

Q7. Define IP Address and Its Types.

An IP (Internet Protocol) address is a unique identifier assigned to each device on a network. There are two types of IP Addresses:

1. IPv4: IPv4 addresses are 32-bit addresses written in dotted decimal format. It approximately allows 4.3 billion unique addresses. Example: 192.168.1.1
2. IPv6: IPv6 addresses are 128 bits and are represented in hexadecimal format. It enables a vast number of unique addresses to meet future demands. Example: 2001:0db8:85a3:0000:0000:8a2e:0370:7334

Q8. What is Subnet?

A subnet is a logical subdivision of an IP network. It allows a single network to be divided into smaller segments, each with its own range of IP addresses and network settings. It can improve network performance, security, and scalability.

Q9. What is DNS?

DNS is known as the phonebook that helps in translating the domain into a computer-readable IP address. DNS allows users to access websites without having to memorize long strings of numbers.

For example, instead of typing 104.26.10.228, you can type pynetlabs.com, and DNS will find your corresponding IP address.

Q10. What happens when you type a website address into your browser?

Your browser starts by looking up the website’s real address. The name you type is not the actual location. DNS servers translate this name into a numerical IP address.

Next, your browser creates a connection to that server. It utilizes the TCP protocol to establish a secure pathway for data transfer. This happens through a three-way handshake process. Your browser then requests the webpage. It sends an HTTP message requesting specific content from the server. This message includes details about what your browser can handle.

The server handles this request, and it responds by transmitting the webpage files. The latter consists of HTML, CSS, JavaScript code, and graphics. The files flow back to your device via the internet.

Your browser receives all of these components. It reads the code, applies the styling, and executes the scripts, displaying all on your screen as one whole web page.

Understanding how browsers, DNS, TCP/IP, and servers communicate is an important part of networking fundamentals and is commonly covered in CCNA training. If you want to learn these concepts practically with real lab experience, you can explore the CCNA Course by PyNet Labs taught by CCIE-certified trainers.

Q11. What are clients and servers in a network?

The client is the component responsible for initiating communication and requesting a network service, such as retrieving a web page, transferring a file, or transmitting an email.

The server is the component responsible for responding to client requests and delivering the requested service, such as transmitting a webpage, file, or email.

Computer application uses the client-server model.

Q12. What is a MAC address?

The Media Access Control (MAC) address holds significant importance in computer networking, similar to that of an IP address. It is also known as a physical, hardware, or burned-in address.

It is a 12-digit hexadecimal number divided into six octets. The first three octets indicate the organization that issued the address, and the last three identify the specific device.

MAC addresses direct data packets to the correct destination on a local network.

Q13. What is the role of ARP?

ARP translates a known IP address into a physical MAC address.

Devices on a local network need a MAC address to communicate directly. ARP is the protocol used to discover it. When a device needs to send data, it knows the destination IP address. It uses an ARP request to ask the network for the matching MAC address.

The device with that IP address sends an ARP reply. This reply contains its MAC address.

The requesting device can now send its data. ARP is an essential process for discovering addresses on a local network.

Q14. What is the difference between unicast, multicast, and broadcast traffic?

Unicast: It involves a one-to-one transmission. One sender sends the data to a single and specific receiver. It can be described as direct communication between two devices.

Multicast: A one-to-many transmission is multicasting. Data is sent by one sender to multiple interested receivers.

Broadcast: It is a one-to-all transmission. One sender sends data to every device on the entire local network. All devices receive the data, whether they need it or not.

Q15. What is SD-WAN?

SD-WAN stands for Software-Defined Wide Area Network. It is a solution based on SDN architecture for simplifying WAN management. It separates the control and data planes to optimize application performance and reduce costs.

Q16. What are the benefits of SD-WAN?

Here are some benefits of SD-WAN:

• It simplifies WAN Management.
• It reduces WAN costs.
• Provides more security.
• Increased Bandwidth and efficiency.
• It provides easier network management.

Learn the benefits of SD-WAN in detail.

Q17. What are Nodes and Links?

Two or more computers form a network when some wire or fiber optics physically links them. In this configuration, the computers are referred to as nodes, and the link is the actual medium of communication, i.e., the physical medium.

Q18. Explain the concept of a VLAN 

Virtual local area network, also known as VLAN divides a large network into smaller independent sections. A device in one VLAN communicates with another device in the same VLAN, as though it is in its own bubble, despite existing in the same physical system. This makes things neat and safe. When a problem, such as a virus, occurs in one VLAN, it remains there and does not propagate. It also decreases network congestion; data travels at a higher rate. VLANs simplify management of networks without additional hardware or cables requirements. They are an intelligent means of managing devices, improving security and keeping things going effortlessly. 

Q19. What is VPN?

VPN stands for Virtual private network.

• It is considered VIRTUAL because it establishes a digital pathway, without needing a physical cable, between the user’s device and the VPN server.
• It is considered PRIVATE due to its ability to encrypt user data and conceal their Internet Protocol (IP) address.
• It is considered a NETWORK due to its ability to connect various computing devices, namely the user’s device and the VPN server.

Virtual Private Networks simplify the transmission of all network traffic to a virtual network, thus allowing users to access local network resources remotely and bypass Internet censorship. The majority of operating systems have built-in VPN support.

VPNs were initially designed to connect separate corporate networks over the internet securely or to provide remote access to a company’s network.

Q20. What is a firewall and how does it work?

Firewalls are a kind of network security technique used to restrict unauthorized access to the network. A device or program that is capable of filtering both incoming and outgoing data within a private network, applying a predefined set of regulations to identify and prevent cyber threats. They serve as an essential element of network security.

The majority of operating systems are equipped with a rudimentary integrated firewall. However, the utilization of a firewall application from a third-party source offers enhanced protection measures.

Working: Firewalls are used to monitor and control the flow of network traffic. It evaluates and determines what traffic to allow or restrict on a specific set of regulations. The firewall can be understood as a guard placed at the entry of a computer system, carefully allowing entry only to authorized sources or IP addresses within the network.

The regulations are derived from various factors as specified by the packet data, such as their origin, destination, and other relevant attributes. In order to prevent cyberattacks, traffic originating from suspicious sources is blocked.

Q21. What is the difference between Hub, Switch, and Router?

Here is a table explaining the difference between Hub, Switch, and Router –

Device	Layer (OSI Model)	Function	Example
HUB	It works on Layer 1 i.e., Physical Layer	Connects multiple devices on a single network and broadcasts data to all ports.	A hub can be used to connect four computers in a small office network.
Switch	It works on Layer 2 i.e., Data Link Layer	Connects multiple devices on one or more networks and forwards data to the destination port based on MAC address.	A switch can be used to create VLANs and reduce broadcast traffic.
Router	It works on Layer 3 i.e., Network Layer	Connects two or more networks and routes data based on IP address.	A router can be used to connect a home network to the internet and provide firewall protection.

Q22. What is Bandwidth?

Bandwidth is a measurement that indicates the highest possible data transmission capacity of a wireless or wired communication channel within a network connection during a specific time frame.

Higher bandwidth means more data can be sent and received faster and with fewer errors.

Q23. What do you understand by NIC?

The full form of NIC is the Network Interface Card, which is a peripheral card connected to the PC to link to the network, and each NIC has its own MAC address that locates PCs over the network. It provides a wireless connection to a local area network and is allowed on desktop computers.

Q24. What is DHCP and how does it function?

DHCP (Dynamic Host Configuration Protocol) is a protocol that automatically assigns IP addresses to network devices. When a device joins the network, the DHCP server assigns it an IP address, gateway, and other network parameters, simplifying network management.

Q25. Explain the TCP three-way handshake.

The three-way handshake happens as:

1. SYN: The client sends a synchronization request to start a connection.
2. SYN-ACK: The Server acknowledges and sends a synchronization request.
3. ACK: The client acknowledges the server’s request and completes the handshake.

These are some of the top Networking Interview Questions and Answers for freshers, let’s move on to top questions for experienced people.

Networking Interview Questions and Answers for Experienced

Here are some of the most asked advanced networking Interview Questions and answers for Expereinced Candidates:

Q26. What is the difference between the ipconfig and ifconfig? 

ipconfig stands for Internet Protocol Configuration, whereas ifconfig stands for Interface Configuration. The two have similar functions, except that the ipconfig command is used with the Windows operating system, while the ifconfig command is used on Linux and Mac computers.

Both commands display network information. They display your IP address, network mask, and gateway information.

However, `ifconfig` is not limited to displaying information. `ifconfig` allows you to modify network settings directly. You can enable or disable network interfaces. You can also assign new IP addresses through this command. `ipconfig` is more limited in what it can do. It mainly shows network details. Its main extra feature is refreshing your network connection.

Many Linux users now prefer the newer `ip` command. It has replaced `ifconfig` in some newer distributions. But `ifconfig` is still commonly used and understood.

Q27. What is Piggy Backing?

The network is the communication between two nodes that are interconnected by each other to share resources and data. But when we think about acknowledgment in between two-way communications there were several issues are raised, in that network needs to utilize a lot of bandwidth, and there again needed solutions for the same.

So, there is a thing which is Piggybacking, which is used when we want to transfer data in two-way communication, and there is no need to send special acknowledgment with the frame.

Q28. What is CIDR? 

CIDR is Classless Inter-Domain Routing. It is a way of assigning IP addresses in a more efficient manner compared to older ones.

Before CIDR, IP addresses were divided into fixed classes. This wasted many addresses because organizations often got more than they needed. CIDR solved this problem by allowing flexible network sizes.

CIDR uses a slash notation to show network size, i.e., 192.168.1.0/24. The number after the slash will indicate the number of bits utilized by the network portion. The remaining bits are for individual device addresses.

This system allows networks to be any size needed. Small networks can get just a few addresses. Large networks can get thousands. This reduces the amount of information that routers must store and process. CIDR also helps routers work more efficiently. It allows them to group multiple networks together in a single routing table. This reduces the amount of information routers need to store and process.

Modern internet infrastructure cannot survive without the system. It helps control the scarcity of IPv4 addresses and is also expected to aid in the development of internet-enabled devices.

Q29. What is a trunk port?

A trunk port is a network link that carries data for many VLANs over a single connection. Its main job is to connect switches, allowing VLANs to stretch across multiple devices.

Trunk ports handle traffic from many different VLANs. Trunk ports add a special tag to each piece of data. This tag identifies which VLAN the data belongs to. The receiving switch reads the tag to send the data to the correct destination. This system makes the network more efficient and flexible.

Q30. What is the difference between TCP and UDP?

Below, we have presented the difference between TCP and UDP based on different factors.

Factors	TCP (Transmission Control Protocol)	UDP (User Datagram Protocol)
Connection	Connection-oriented	Connectionless
Reliability	Reliable	Unreliable
Ordering	Preserve the order of packets	Does not preserve the order of packets
Congestion Control	Have a congestion control mechanism	Does not have a congestion control mechanism
Header size	20 bytes	8 bytes
Speed	Slower than UDP	Faster than TCP
Application	Web browsing, email, and file transfer	Streaming media, online gaming, voice-over IP

Q31. What is 10Base2?

10Base2 defines the data transfer rate, i.e., 10Mbps, where Base is the “Baseband” and T defines the cable type.

The IEEE 802.3a standard defines 10Base2, which includes data transmission rates of 10Mbps and a maximum segment length of 185 meters through the utilization of RG-58 coaxial cable. The 10Base2 protocol is characterized by a physical bus topology and employs BNC connectors that are equipped with 50-ohm terminators at both ends of the cable. It is necessary to ground one of the physical ends of every segment.

Q32. What is Kerberos?

Kerberos is a network security protocol initially developed by MIT (Massachusetts Institute of Technology) that is specifically utilized for authenticating service requests among multiple trusted hosts over an untrusted network, such as the Internet.

It works via various crucial elements. These are:

• Client: The individual attempting to establish a connection with a particular service.
• Server: The server is responsible for hosting the service.
• Authentication Server (AS): Verifies the identity of the user. Upon successful client authentication, a Ticket Granting Ticket (TGT) is generated as evidence of the client’s authenticity.
• Ticket Granting Server (TGS): A server application that generates and delivers service tickets.
• Key Distribution Center (KDC): A server that hosts AS, database, and TGS.

Q33. What is MPLS, and how does it improve network traffic flow?

MPLS, or Multiprotocol Label Switching, is a method for directing traffic on a network. It uses labels to forward data instead of long network addresses. This makes the process simpler and faster. Once data enters an MPLS network, it gets a label. Then the data is sent rapidly by network devices using this shorter label along an already established path. This eliminates the need for complicated routing choices at each step. Through this, a more efficient and reliable network is achieved, which can be helpful to businesses that require high-quality connections to run their applications. MPLS improves traffic flow in several ways:

• It uses labels for faster forwarding decisions.

• It creates predictable paths for data to follow.

• It reduces the work routers have to do.

• It allows for prioritizing important traffic.

• It helps manage network congestion better.

Q34. What is NAT?

NAT stands for Network Address Translation. The process of NAT involves converting a specific range of private IP addresses to a single public IP address linked to a gateway device. The network address translation process allows a single device to act as an intermediary or agent between a private, localized network and a public network, such as the Internet.

The main focus of NAT is to conserve public IP addresses.

Q35. What is an Anycast address?

Anycast address is a single IP address utilized by a set of servers at different sites. When one directs any request to an Anycast address, the address is redirected to the nearest server. This will improve the speed and consistency of network services since the distance the information needs to travel is reduced. It is also able to help manage heavy traffic at the same time.

How it works:

• The same IP address is used for many servers.

• The network finds the closest server to you.

• Your request is sent to that server automatically.

• If one server fails, traffic is redirected to the next closest server.

Q36. What is the difference between synchronous and asynchronous transmission?

Here are some differences between synchronous and asynchronous transmission –

Synchronous transmission	Asynchronous transmission
Data is sent in blocks or frames	Data is sent in bytes or characters
Requires synchronization between sender and receiver	Does not require synchronization between the sender and receiver
Fast and efficient for large amounts of data	Slow and economical for small amounts of data
Uses timing signals to coordinate data transfer	Uses start and stop bits to indicate data boundaries
Examples: Telephonic conversations, video conferencing, online gaming	Examples: Email, file transfer, online forms

Q37. What is ICMP?

The Internet Control Message Protocol (ICMP) is designed for reporting errors and information related to network connectivity issues to the origin of the failed transmission. It is primarily utilized by network administrators to diagnose and resolve issues related to Internet connectivity.

The ICMP protocol operates by generating and transmitting messages to the originating IP address, signaling the inability to access an Internet gateway for the purpose of delivering packets. The process involves the transmission of datagrams that comprise an IP header, which encapsulates the ICMP data.

Error messages such as:

• Destination unreachable
• Source quench message 
• Redirection message
• Time exceeded message
• Parameter problem

Q38. What is SNMP?

SNMP stands for Simple Network Management Protocol. SNMP is a network protocol that allows data collection, organization, and transmission among network devices. SNMP is a prevalent tool in network management, utilized to configure various network devices such as hubs, servers, routers, printers, and switches.

Critical components of SNMP are:

• Management Information Base (MIB)
• SNMP Manager
• SNMP Agent
• Managed device

Q39. What is anonymous FTP?

It is used to allow users to receive files on a public server. In other words, Anonymous FTP allows users to get data into these servers without having to verify themselves but rather by logging in as anonymous guests.

Q40. Can IP multicast be load-balanced?

No, because the IP multicast multipath command separates traffic, not balances traffic. Traffic coming from a source will be allowed only one way, even if the traffic far exceeds traffic coming from other sources.

Q41. Can a routing table contain two entries with the same destination address in a datagram network?

No, a routing table cannot have two entries with the same destination address in a datagram network because either the destination address or the receiver address is unique.

Q42. Define the term OFDM.

OFDM stands for Orthogonal Frequency Division Multiplexing, which is also a multiplexing technique used in analog systems. In OFDM, a guard band is not necessary, and the spectral efficiency of OFDM is high, which negates FDM. Additionally, an individual data source connects all the sub-channels in it.

Q43. What do you understand by Sneakernet?

It is the earliest form of networking where data is physically transferred through removable media.

Q44. Define the functionality of the OSI session layer.

The OSI session layer provides the protocol and means for two devices on the network to communicate with each other by keeping a session. It is responsible for session establishment, management of session time information exchange, and tear-down process based on session termination.

Q45. Explain the term Jitter.

Jitter refers to a “packet delay variance,” which is a problem when multiple packets of data encounter multiple delays in the network, and the data at the acceptor application is time-critical, i.e., audio or video data. It is calculated in milliseconds and is described as interference with the normal process of sharing data packets.

These are all the important networking interview questions and answers for both fresher and experienced candidates.

Q46. What is a Proxy Server?

A proxy server is a computer or system that works like a middleman between your device and the internet. It is used for better security, privacy, control, and faster access to some websites.

If you want to open a website on your browser, you just type the address, and it will open the website. But when a proxy server is used, your request first goes to the proxy server, which then sends it to the website.

Why do companies use a proxy server?

There are many reasons for using a proxy server. Here are some important ones:

1. Security: A proxy server hides the real IP Address of users. It can help protect systems from hackers.

2. Control: Companies use it to block websites like games or social media during work hours.

3. Faster Browsing: Some proxy servers save copies of websites in memory. If the user reloads this website, the server will serve it faster.

4. Privacy: A proxy server can hide the real identity of the user by showing its own server.

Q47. What is the difference between a forward proxy and a reverse proxy?

A forward proxy and a reverse proxy both work as a middleman in a network, but their differences lie in who they protect and where they are placed in a network.

Forward Proxy	Reverse Proxy
It works for users/clients.	It mainly works for servers.
It sits in front of users.	It sits in front of the servers.
It is used to hide the client’s identity.	It is used to hide the server’s identity.
Used inside organizations	Used in data centers and websites
It primarily controls the user’s internet access.	It primarily controls incoming user requests.

Q48. What are port numbers, and what are some well-known ports?

A port number is a logical number used by computers to identify all the services or applications running on a device. A Computer can perform many services at the same time, like:

• Web browsing

• Email

• File transfer

• Video calls, etc.

Now, the computer needs a way to understand which data belongs to which application. That is where the port number is used.

Think of a computer like a big apartment building.

• The IP Address is the building address.

• The port number is the apartment number.

The IP Address helps the data reach the correct computer, and the port number helps the data reach the correct application inside the computer.

Port number ranges from 0 to 65535.

Well-known ports are standard ports that are used by common network services. These numbers are fixed so that devices know which service they should connect to.

Some well-known ports are:

Port Number	Protocol/Service	Purpose
20/21	FTP	File transfer
22	SSH	Secure remote login
23	Telnet	Remote login (not secure)
25	SMTP	Sending emails
53	DNS	Domain name to IP conversion
67/68	DHCP	Automatic IP address assignment
80	HTTP	Normal web browsing
110	POP3	Receiving emails
143	IMAP	Email access
443	HTTPS	Secure web browsing

Q49. What is Spanning Tree Protocol, and how does it work?

Spanning Tree Protocol (STP) is a protocol used in switches to prevent network loops. A network loop happens when there are multiple paths between switches, and data keeps moving in circles inside the network.

STP helps prevent these loops by blocking extra paths and keeping only one active path.

STP works in a few simple steps:

Step 1: STP chooses one switch as the main switch, called the Root Bridge.

Step 2: Every switch finds the shortest path to the root bridge.

Step 3: If there are multiple paths, STP blocks the unnecessary ports. This removes the loops from the network.

Q50. What is QoS (Quality of Service)?

Quality of Service (QoS) is a networking feature that gives important network traffic higher priority than less important traffic. In simple words, it controls which data should move first in the network when the network gets busy.

A network carries many types of data:

• Video calls

• Voice calls

• YouTube Videos

• File Downloads

• Emails

• Online games, etc.

But not all traffic is equally important. Without QoS, all the traffic is treated the same way, which can cause:

• Voice breaking

• Video buffering

• Slow application performance

• Lag during meetings, etc.

QoS solves these problems by giving priority to important traffic.

These are some of the most asked Interview questions related to networking that are asked to any expereinced candidate. Let’s see some scenario-based Networing interview questions with their answers.

Scenario based Networking Interview Questions and Answers

Here are top 10 scenario-based networking interview questions and answers that you should definitely practice.

Q51. Suppose some users can access the Internet but cannot access the company server. What should you troubleshoot first?

First, check whether the server is reachable on the local network. You can use commands like “ping” or “traceroute” to check this. If the user can access the Internet but not the internal server, the issue must be related to:

• Incorrect VLAN configuration

• Firewall rules are blocking access

• DNS resolution issue

• Server down or disconnected

• Incorrect gateway settings

You should also verify:

• IP configuration of the client

• Server status

• Switch port VLAN assignment

• ACLs or firewall policies

Q52. A user reports “limited connectivity” on their PC. How will you troubleshoot this issue?

You can troubleshoot this issue by:

• Checking the physical connectivity (cable/Wi-Fi)

• After that, you should verify the IP Address using the command “ipconfig /all”

• Next, check whether the PC received a valid IP address, Subnet mask, default gateway, and DNS server.

If the IP starts with 169.254.x.x, it clearly shows a DHCP failure. If it is so, then you should:

• Get the IP address renewed

• Test ping to the gateway

• Check the availability of the DHCP server

• Verify switch port status

Q53. Two PCs are in the same VLAN but cannot communicate. What could be the issue?

Here is a list of possible reasons:

• Incorrect subnet mask

• The host firewall is blocking traffic

• Duplicate IP addresses

• Switch port security restrictions

• One port accidentally assigned to another VLAN

• NIC issues

Here’s how you can solve it:

• First, you should verify IP configurations

• Then, check VLAN membership

• Ping both devices

• Check the ARP table

• Inspect switch configuration

Q54. The network becomes very slow during office hours. How would you identify the problem?

You should first check these things:

• Bandwidth utilization

• Broadcast storms

• Duplex mismatch

• High CPU usage on network devices

• Excessive downloads or streaming

• Malware or abnormal traffic

You can use tools such as:

• Wireshark

• SNMP monitoring

• NetFlow

• Interface statistics on switches/routers

You should also check:

” show interfaces

show processes cpu”

Q55. A branch office is unable to connect to the headquarters through VPN. How will you troubleshoot it?

To troubleshoot this, we need to check:

• Internet connectivity

• Next, we need to look at the status of the VPN Tunnel

• ISAKMP/IPsec negotiation

• Any mismatch between the authentication or pre-shared key

• Issues in ACL or NAT

You can use these commands:

“show crypto isakmp sa”

“show crypto ipsec sa”

You should also verify:

• Routing

• Firewall rules

• Source of Tunnel and Reachability of the Destination

Q56. A user can ping an IP address, but cannot open any website using its Domain name. What might be the issue?

This usually happens because of a DNS issue. In this scenario, network connectivity is working because IP communication succeeds, but name resolution is failing.

You should check the configured DNS Server, using:

“nslookup google.com”

• Verify internet DNS reachability

• If the issue doesn’t get resolved, you can change the DNS to public DNS for some time, using 8.8.8.8 and 1.1.1.1

Q57. Suppose you connect a new switch to a network, and the entire network starts flapping. What could be the reason for this?

An issue that can cause the entire network to flap is a Layer 2 loop. It can be caused by improper cabling or Spanning Tree issues.

Some symptoms of this issue are:

• Flapping of MAC Address

• High broadcast traffic

• The network will be very slow

• CPU spikes on switches

To troubleshoot the issue, you can:

• Check the status of STP

• Find the links that can be reduced

• Verify BPDU exchange

• And disconnect suspected loop links

The commands you need:

“show spanning-tree”
“show mac address-table”

Q58. If an employee complains that the voice calls over the IP Phones are very choppy.  How will you fix it?

You should first check the configuration of Quality of Service (QoS) because voice traffic is very sensitive to delay, jitter, and packet loss.

To fix this, you should first check QoS policies and bandwidth utilization.

Next, you should:

• Give priority to VoIP traffic

• Inspect WAN Congestion

• And verify duplex/speed settings

You should also test the network’s latency and packet drops.

Q59. Suppose you configure a static route, but traffic still isn’t reaching the destination. What could be the reason?

Some of the reasons for this issue can be:

• Next-hop IP might be wrong

• The return route might be wrong

• Interface down

• The subnet mask might be wrong

• Routing loops

• The firewall may be blocking the traffic

You can verify using these commands:

“show ip route
ping
traceroute”

You should also make sure that the destination device has a route back to the source network.

Q60. Suppose a company wants network redundancy between 2 core switches. What solution would you recommend?

The best thing to recommend in such a case is:

• EtherChannel/LACP for link redundancy

• HSRP or VRRP for gateway redundancy

• Dynamic routing protocols for failover

• Spanning Tree optimization

Here are some benefits of it:

• High availability

• Downtime will be reduced

• Load balancing

• Automatic failover

These top 60 networking interview questions are curated with insights from CCIE-certified trainers at PyNet Labs to help freshers and professionals improve their networking knowledge and prepare confidently for technical interviews and IT job roles.

For a more practical understanding, you can also watch this detailed Youtube Networking Interview Questions video by PyNet Labs, where industry experts explain important networking concepts, interview tips, and real-world scenarios commonly asked in technical interviews.

Conclusion

In this blog, we have covered some of the basic, advanced and scenerio based networking interview questions and answers for freshers and experienced candidates as well. Whether you are applying for a network engineer or any other role, these questions will help you demonstrate your knowledge and skills in computer networks. We hope that this blog has given you some insights into the networking interview questions that you can expect in your interviews.

Remember to prepare well, practice your answers, and be confident. Good luck with your networking career!