22 June, 2026 (Last Updated)

Top 50+ Networking Interview Questions for Freshers

Networking is a core skill for freshers preparing for IT support, system admin, cloud, cybersecurity, and technical interview roles.

Gartner forecasts worldwide enterprise network equipment spending to reach $112 billion in 2026, showing the continued importance of network infrastructure in modern businesses.

This guide covers basic, intermediate, advanced, and scenario-based networking interview questions for freshers with clear answers to help you revise computer networks concepts and prepare better for interviews.

Basic Networking Interview Questions

If you are new to networking, start with these basic networking interview questions for freshers to build a strong foundation.

These questions cover core concepts like IP address, DNS, protocols, OSI model, TCP/IP, routers, switches, and network types that are commonly asked in entry-level interviews.

1. What is a computer network?

A computer network is a collection of two or more devices connected together to share data, resources, and services. These devices can include computers, servers, printers, routers, switches, mobile phones, and IoT devices. Networks allow users to exchange files, access the internet, use shared applications, communicate through email or chat, and connect to centralized systems.

For example, when multiple computers in an office are connected to the same Wi-Fi or LAN and access the same printer or shared file server, they are part of a computer network.

2. What are the main types of computer networks?

Network Type	Full Form	Description	Example
PAN	Personal Area Network	A small network used for personal devices within a short range.	Bluetooth connection between phone and earbuds
LAN	Local Area Network	A network that connects devices within a limited area such as a home, office, or lab.	Office computer network
MAN	Metropolitan Area Network	A network that covers a city or large campus area.	City-wide cable network
WAN	Wide Area Network	A network that connects devices or networks across large geographical areas.	The internet

A LAN is usually faster and privately managed, while a WAN covers larger distances and may use public or leased communication lines.

3. What is an IP address?

An IP address is a unique logical address assigned to a device on a network. It is used to identify the device and deliver data to the correct destination. IP addresses are used at the network layer and can change based on the network configuration.

Example of IPv4 address:

192.168.1.10

Example of IPv6 address:

2001:db8::1

An IP address works like a house address in a network. When data is sent from one device to another, the IP address helps routers and network devices decide where the data should go.

4. What is the difference between IPv4 and IPv6?

Feature	IPv4	IPv6
Address Size	32-bit	128-bit
Format	Decimal numbers separated by dots	Hexadecimal values separated by colons
Example	192.168.1.1	2001:db8::1
Number of Addresses	Limited address space	Very large address space
Header Complexity	More complex header	Simplified header
Address Configuration	Manual or DHCP-based	Supports auto-configuration

IPv4 is still widely used, but IPv6 was introduced to solve the problem of limited IP addresses and support the growing number of internet-connected devices.

5. What is a MAC address?

A MAC address is a unique physical address assigned to a network interface card by the manufacturer. It works at the data link layer of the OSI model and is used to identify devices inside a local network.

Example:

00:1A:2B:3C:4D:5E

A MAC address is mainly used for local communication within the same network. While an IP address helps route data between networks, a MAC address helps deliver data to the correct device inside a local network.

6. What is the difference between an IP address and a MAC address?

Point	IP Address	MAC Address
Type	Logical address	Physical address
Layer	Network layer	Data link layer
Assigned By	Network administrator, DHCP, or ISP	Device manufacturer
Changeable	Can change depending on the network	Usually fixed
Used For	Identifying a device across networks	Identifying a device in a local network
Example	192.168.1.5	00:1A:2B:3C:4D:5E

An IP address is used for routing data between networks, while a MAC address is used for communication within the same local network.

7. What is the OSI model?

The OSI model is a conceptual framework that explains how data travels from one device to another over a network. It has seven layers, and each layer performs a specific function during communication.

Layer Number	Layer Name	Main Function
7	Application	Provides network services to applications
6	Presentation	Handles data formatting, encryption, and compression
5	Session	Manages sessions between devices
4	Transport	Provides end-to-end data delivery
3	Network	Handles logical addressing and routing
2	Data Link	Handles MAC addressing and frame delivery
1	Physical	Transfers raw bits through cables or wireless signals

The OSI model helps in understanding network communication and troubleshooting network problems layer by layer.

8. What is the TCP/IP model?

The TCP/IP model is a practical networking model used for internet communication. It defines how data is packaged, addressed, transmitted, routed, and received over networks.

The TCP/IP model has four layers:

Layer	Function
Application Layer	Supports applications and protocols like HTTP, HTTPS, DNS, FTP, and SMTP
Transport Layer	Provides communication using TCP or UDP
Internet Layer	Handles IP addressing and routing
Network Access Layer	Handles physical transmission and local network communication

The TCP/IP model is widely used because it forms the foundation of the modern internet.

9. What is the difference between TCP and UDP?

Feature	TCP	UDP
Full Form	Transmission Control Protocol	User Datagram Protocol
Connection	Connection-oriented	Connectionless
Reliability	Reliable	Less reliable
Speed	Slower than UDP	Faster than TCP
Error Checking	Provides error checking and retransmission	Provides basic error checking
Data Delivery	Ensures ordered delivery	Does not guarantee order
Example Usage	Web browsing, email, file transfer	Video streaming, online gaming, VoIP

TCP is used when accuracy and reliability are important. UDP is used when speed is more important than guaranteed delivery.

10. What is DNS?

NS stands for Domain Name System. It converts human-readable domain names into IP addresses that computers use to communicate.

For example, when a user enters:

www.google.com

DNS translates it into an IP address such as:

142.250.183.206

Without DNS, users would need to remember numerical IP addresses for every website. DNS works like a phonebook for the internet by mapping domain names to their corresponding IP addresses.

11. What is DHCP?

DHCP stands for Dynamic Host Configuration Protocol. It automatically assigns IP addresses and other network configuration details to devices in a network.

DHCP can assign:

• IP address
• Subnet mask
• Default gateway
• DNS server address

For example, when a laptop connects to Wi-Fi, it usually receives an IP address automatically from the router using DHCP. This avoids the need to manually configure IP details for every device.

12. What is the difference between a router and a switch?

Feature	Router	Switch
Main Function	Connects different networks	Connects devices within the same network
Works At	Network layer	Data link layer
Uses	IP address	MAC address
Example Use	Connecting home network to the internet	Connecting office computers in a LAN
Traffic Handling	Routes packets between networks	Forwards frames within a network

A switch is used inside a LAN to connect devices, while a router is used to connect one network to another network.

13. What is the difference between HTTP and HTTPS?

Feature	HTTP	HTTPS
Full Form	HyperText Transfer Protocol	HyperText Transfer Protocol Secure
Security	Not encrypted	Encrypted using SSL/TLS
Default Port	80	443
Data Protection	Data can be intercepted	Data is protected during transmission
Usage	Less secure websites	Secure websites, banking, login pages, payments

HTTPS is preferred because it protects sensitive information such as passwords, payment details, and personal data while it travels between the browser and server.

14. What is a port number in networking?

Port number is a logical number used to identify a specific service or application running on a device. While an IP address identifies the device, the port number identifies the application or service on that device.

Common port numbers include:

Port Number	Protocol / Service
20 / 21	FTP
22	SSH
25	SMTP
53	DNS
80	HTTP
443	HTTPS

For example, when a browser opens a secure website, it usually connects to the server using port 443.

15. What is a firewall?

A firewall is a network security system that monitors and controls incoming and outgoing network traffic based on security rules. It helps protect systems from unauthorized access, malware, suspicious traffic, and network-based attacks.

A firewall can be:

• Hardware-based: A physical device placed between networks.
• Software-based: A security application installed on a system.
• Cloud-based: A firewall service used in cloud environments.

For example, a company may configure a firewall to allow HTTP and HTTPS traffic but block unknown or unsafe traffic from external sources.

Intermediate Networking Interview Questions

Once you understand the fundamentals, these computer networking interview questions will help you prepare for more practical interview discussions.

This section covers subnetting, DHCP, routing, switching, VLANs, NAT, firewalls, ports, and troubleshooting-based concepts often asked in technical rounds.

1. How does subnetting help in network management?

Subnetting is used to divide a large network into smaller logical networks called subnets. It helps improve IP address management, reduces unnecessary broadcast traffic, improves security, and makes troubleshooting easier.

For example, a company can divide its network into separate subnets for HR, Finance, Development, and Admin teams. This allows better control over traffic and access between departments.

2. Explain the purpose of a subnet mask.

A subnet mask is used to identify which part of an IP address represents the network and which part represents the host. It helps devices understand whether the destination device is present in the same local network or in a different network.

Example:

IP Address	Subnet Mask	Meaning
192.168.1.10	255.255.255.0	Network part is 192.168.1, host part is 10

If two devices have the same network portion, they can communicate directly within the LAN. If not, the traffic is sent through a router or default gateway.

3. Why is a default gateway required in a network?

A default gateway is required when a device needs to communicate with another device outside its local network. It is usually the router’s IP address.

For example, if a laptop with IP 192.168.1.20 wants to access a website on the internet, the request first goes to the default gateway. The router then forwards the traffic to the external network.
Without a default gateway, the device can communicate only with devices in the same local network.

4. How does ARP work in a local network?

ARP stands for Address Resolution Protocol. It is used to find the MAC address of a device when its IP address is known.

The process works like this:

• A device wants to send data to an IP address in the same network.
• It sends an ARP request asking, “Who has this IP address?”
• The device with that IP replies with its MAC address.
• The sender uses that MAC address to send the data frame.

For example, if a computer wants to send data to 192.168.1.5, it uses ARP to find the MAC address of that device before sending the data.

5. Compare static IP and dynamic IP addresses.

Feature	Static IP	Dynamic IP
Assignment	Manually assigned	Automatically assigned by DHCP
Change Frequency	Usually fixed	Can change over time
Best Used For	Servers, printers, routers	Laptops, mobiles, general user devices
Management	Requires manual configuration	Easy to manage automatically
Example Use Case	Web server or database server	Office laptop connected to Wi-Fi

Static IP is preferred for devices that must always be reachable at the same address. Dynamic IP is useful for regular devices because it reduces manual configuration.

6. How does NAT work and why is it used?

NAT stands for Network Address Translation. It allows multiple devices in a private network to access the internet using a single public IP address.

For example, many devices in a home network may have private IP addresses like:

• 192.168.1.2
• 192.168.1.3
• 192.168.1.4

When these devices access the internet, the router translates their private IP addresses into one public IP address. NAT helps conserve public IP addresses and also hides internal private IPs from external networks.

7. Explain the TCP three-way handshake.

The TCP three-way handshake is the process used to establish a reliable connection between a client and a server before data transfer begins.

Step	Packet	Purpose
Step 1	SYN	Client requests to start a connection
Step 2	SYN-ACK	Server accepts and acknowledges the request
Step 3	ACK	Client confirms the connection

After these three steps, the TCP connection is established and data transfer can begin. This is why TCP is considered reliable and connection-oriented.

8. Why is VLAN used in a network?

VLAN stands for Virtual Local Area Network. It is used to logically divide a physical network into multiple separate networks.

For example, even if HR, Finance, and IT teams are connected to the same physical switch, VLANs can separate their traffic logically.

Benefits of VLAN:

• Reduces broadcast traffic
• Improves security
• Separates departments or user groups
• Makes network management easier
• Helps control access between teams

VLANs are commonly used in offices, colleges, data centres, and enterprise networks.

9. How does DNS resolution work when a user opens a website?

When a user enters a domain name in a browser, DNS converts that domain name into an IP address.

The process usually works like this:

• The browser checks its local DNS cache.
• If not found, the request goes to the operating system DNS cache.
• Then it queries the configured DNS resolver.
• The resolver contacts root, TLD, and authoritative DNS servers if needed.
• The correct IP address is returned to the browser.
• The browser uses that IP address to connect to the website server.

For example, when a user enters www.example.com, DNS finds the IP address of that domain so the browser can load the website.

10. Differentiate between public IP and private IP addresses.

Feature	Public IP	Private IP
Scope	Used on the internet	Used inside local networks
Assigned By	ISP or cloud provider	Router or network administrator
Uniqueness	Globally unique	Unique only within a private network
Example	8.8.8.8	192.168.1.10
Accessibility	Can be accessed over the internet	Not directly accessible from the internet

Private IP addresses are used inside homes, offices, and internal networks. Public IP addresses are used for communication over the internet.

11. How would you troubleshoot if a system is connected to Wi-Fi but cannot access the internet?

I would troubleshoot the issue step by step:

• Check whether the device has received a valid IP address.
• Verify the default gateway and DNS server settings.
• Use ping to test connectivity with the gateway.
• Ping a public IP like 8.8.8.8 to check internet reachability.
• Try pinging a domain name to check DNS resolution.
• Restart the network adapter or reconnect to Wi-Fi.
• Check router, firewall, proxy, or ISP-related issues.

If IP ping works but domain ping fails, the issue is likely related to DNS. If even the gateway is not reachable, the issue may be with local connectivity.

12. Explain the difference between bandwidth, latency, and throughput.

Term	Meaning	Example
Bandwidth	Maximum capacity of a network link	100 Mbps connection
Latency	Delay in data travel from source to destination	50 ms response time
Throughput	Actual amount of data successfully transferred	80 Mbps actual speed

Bandwidth is the theoretical capacity, throughput is the real achieved speed, and latency is the delay. A network can have high bandwidth but still feel slow if latency is high.

13. How does a firewall filter network traffic?

A firewall filters network traffic based on predefined security rules. It checks incoming and outgoing packets and decides whether to allow or block them.

Firewall rules may be based on:

• Source IP address
• Destination IP address
• Port number
• Protocol
• Application type
• Direction of traffic
• Security policy

For example, a firewall may allow HTTPS traffic on port 443 but block unwanted traffic on unused ports. This helps protect systems from unauthorized access and network attacks.

14. Explain the role of a load balancer in networking.

A load balancer distributes incoming traffic across multiple servers. It helps improve performance, availability, and fault tolerance.

For example, if a website receives heavy traffic, a load balancer can distribute user requests across three backend servers instead of sending all requests to one server.

Benefits of load balancing:

• Prevents server overload
• Improves application availability
• Supports high traffic
• Helps during server failure
• Improves user experience

If one server fails, the load balancer can redirect traffic to healthy servers.

15. How does VPN provide secure communication?

A VPN, or Virtual Private Network, creates an encrypted connection between a user’s device and a private network or VPN server. It protects data from being read by unauthorized users while it travels over the internet.

A VPN helps with:

• Secure remote access
• Data encryption
• IP masking
• Safe communication over public Wi-Fi
• Access to internal company resources

For example, an employee working from home can use a VPN to access company servers and internal applications securely.

Advanced Networking Interview Questions

These advanced network engineer interview questions are useful for freshers who want to show a deeper technical understanding.

The questions cover routing protocols, network security, packet flow, VPNs, load balancing, network monitoring, real-world troubleshooting, and scenario-based networking interview questions and answers.

1. How does a router decide the best path for forwarding packets?

A router uses its routing table to decide where to forward packets. The routing table contains destination networks, next-hop addresses, interfaces, and metrics.

The router checks the destination IP address of the packet and matches it with the most specific route in the routing table. This is called the longest prefix match.

Factor	Meaning
Destination network	Network where the packet needs to go
Next hop	Next router or gateway to forward the packet
Metric	Cost value used to choose the best route
Interface	Router port used to send the packet

If multiple routes are available, the router selects the route with the best metric. If no specific route is found, the packet is forwarded to the default route.

2. Explain the difference between static routing and dynamic routing.

Feature	Static Routing	Dynamic Routing
Configuration	Manually configured	Automatically learned using routing protocols
Flexibility	Less flexible	More flexible
Network Changes	Requires manual updates	Adapts automatically
Resource Usage	Uses fewer resources	Uses more CPU and memory
Best For	Small or simple networks	Medium and large networks

Static routing is useful when the network is small and routes do not change often. Dynamic routing is useful in larger networks where routers need to automatically update routes based on network changes.

3. What is OSPF and how does it work?

OSPF stands for Open Shortest Path First. It is a dynamic routing protocol used inside an organisation’s network. OSPF uses link-state information to calculate the shortest path to a destination.

OSPF works by:

• Discovering neighbouring routers
• Exchanging link-state information
• Building a topology map of the network
• Using the SPF algorithm to calculate the best route
• Updating routes when network changes occur

OSPF is commonly used in enterprise networks because it is fast, scalable, and supports hierarchical network design using areas.

4. What is BGP and why is it important?

BGP stands for Border Gateway Protocol. It is a routing protocol used to exchange routing information between different networks on the internet.

BGP is important because it helps internet service providers, large companies, and cloud providers decide how data should travel between different autonomous systems.

Point	Description
Full Form	Border Gateway Protocol
Used For	Routing between large networks
Works Between	Autonomous Systems
Common Use	Internet routing

For example, when a user in India accesses a website hosted in the US, BGP helps decide the path the traffic should take across different networks.

5. How does CIDR help in IP address allocation?

CIDR stands for Classless Inter-Domain Routing. It allows flexible allocation of IP addresses instead of using fixed class-based networks like Class A, B, and C.

Example:

192.168.1.0/24

Here, /24 means the first 24 bits are used for the network portion, and the remaining bits are used for host addresses.
CIDR helps in:

• Reducing IP address wastage
• Creating flexible network sizes
• Supporting route aggregation
• Improving routing efficiency

CIDR is widely used in modern networking, cloud networking, and subnet planning.

6. How would you troubleshoot packet loss in a network?

Packet loss happens when data packets fail to reach their destination. It can affect video calls, online meetings, file transfers, and application performance.

To troubleshoot packet loss, I would check:

• Network cable or Wi-Fi signal quality
• Router and switch interface errors
• Bandwidth usage and congestion
• Firewall or security filtering
• Routing issues
• Server-side performance
• ISP or external network issues

Useful commands include:

Command	Purpose
ping	Checks basic reachability and packet loss
traceroute / tracert	Shows the path taken by packets
pathping	Combines ping and route analysis
netstat	Checks active connections

If packet loss occurs only after a specific hop, the issue may be near that router, ISP path, or destination network.

7. What is MTU and why can it cause network issues?

MTU stands for Maximum Transmission Unit. It defines the largest packet size that can be sent over a network link without fragmentation.

For Ethernet networks, the common MTU size is 1500 bytes.

If the MTU is too high for a network path, packets may get fragmented or dropped. This can cause slow connections, failed website loading, VPN issues, or application timeouts.

For example, VPNs often add extra headers to packets. If MTU is not adjusted correctly, packets may become too large and fail during transmission.

8. Explain the difference between proxy and reverse proxy.

Feature	Proxy	Reverse Proxy
Works For	Client	Server
Main Purpose	Hides or controls client requests	Protects and manages server requests
Used By	Users or internal networks	Websites, APIs, applications
Example	Employee browsing through company proxy	Nginx forwarding traffic to backend servers

A proxy server sits in front of clients and forwards their requests to the internet. A reverse proxy sits in front of servers and forwards client requests to the correct backend server.

9. How does SSL/TLS secure data transmission?

SSL/TLS secures data by encrypting communication between a client and a server. It is commonly used in HTTPS websites.

The basic process includes:

• The client connects to the server.
• The server sends its digital certificate.
• The client verifies the certificate.
• Both sides agree on encryption keys.
• Data is transmitted securely using encryption.

SSL/TLS helps protect passwords, payment details, login sessions, and personal information from being read by attackers during transmission.

10. What is a DMZ in networking?

A DMZ, or Demilitarized Zone, is a separate network zone placed between the internal private network and the public internet. It is used to host public-facing services while protecting the internal network.

Common systems placed in a DMZ include:

• Web servers
• Mail servers
• DNS servers
• Public application servers

If a public-facing server in the DMZ is attacked, the internal company network still remains separated and more protected.

11. How does QoS help in network performance?

QoS stands for Quality of Service. It is used to prioritize important network traffic over less critical traffic.

For example, voice and video traffic need low latency and low jitter. QoS can give higher priority to video calls and VoIP traffic while giving lower priority to large downloads or background updates.

QoS helps improve:

• Voice call quality
• Video meeting performance
• Application response time
• Bandwidth management
• Network reliability during congestion

12. What is the difference between IDS and IPS?

Feature	IDS	IPS
Full Form	Intrusion Detection System	Intrusion Prevention System
Main Role	Detects suspicious traffic	Detects and blocks suspicious traffic
Action	Alerts administrators	Takes preventive action
Traffic Flow	Usually passive	Usually inline
Example	Sends alert for attack attempt	Blocks malicious packet

IDS monitors network traffic and alerts when suspicious activity is detected. IPS goes one step further and can block or prevent the malicious traffic automatically.

13. How would you troubleshoot DNS-related issues?

DNS issues can cause websites or services to fail even when the internet connection is working.

To troubleshoot DNS issues, I would:

• Check whether the device has the correct DNS server configured.
• Use ping with an IP address to confirm internet connectivity.
• Use nslookup or dig to test domain name resolution.
• Clear the local DNS cache.
• Try using another DNS server.
• Check if the DNS record exists and is correctly configured.

Useful commands:

Command	Purpose
nslookup domain.com	Checks DNS resolution
dig domain.com	Shows detailed DNS query result
ipconfig /flushdns	Clears DNS cache on Windows
ping 8.8.8.8	Checks connectivity without DNS

If IP ping works but domain name ping fails, the issue is usually related to DNS.

14. What is network segmentation and why is it important?

Network segmentation means dividing a network into smaller parts to improve security, performance, and management.

For example, a company may separate its network into:

• Employee network
• Guest Wi-Fi network
• Server network
• Finance department network
• Development network

Network segmentation helps limit the spread of attacks, reduce broadcast traffic, control access, and simplify troubleshooting. VLANs, subnets, firewalls, and access control rules are commonly used for segmentation.

15. How does high availability work in network design?

High availability means designing a network so that services remain accessible even when one component fails. It reduces downtime and improves reliability.

High availability can be achieved using:

• Redundant routers
• Multiple switches
• Backup internet links
• Load balancers
• Failover systems
• Clustering
• Multiple availability zones in cloud networks

For example, if one router fails, another router can automatically take over traffic forwarding. This ensures users can continue accessing applications with minimal interruption.

Conceptual Networking Interview Questions

This section covers scenario-based topics like slow internet, packet loss, DNS issues, IP conflicts, routing problems, firewall blocking, and troubleshooting methods commonly asked in networking interview questions and answers.

1. A user reports that their system shows “Limited Connectivity.” How would you approach the issue?

Limited connectivity usually means the device is connected to the network but cannot communicate properly with other systems or the internet. I would first check whether the system has received a valid IP address, subnet mask, gateway, and DNS details.

If the IP configuration is missing or incorrect, I would try renewing the IP address, reconnecting the network, restarting the adapter, and checking whether the DHCP service is working. If the system has a valid IP but still shows limited connectivity, I would check firewall rules, switch port status, Wi-Fi signal strength, and router configuration.

2. A device is connected through LAN, but the network speed is very low. What could be the reasons?

Slow LAN speed can happen because of cable issues, port speed mismatch, faulty switch ports, duplex mismatch, high traffic, or outdated network drivers. I would first check whether the Ethernet cable is damaged and whether the network adapter is connected at the expected speed, such as 100 Mbps or 1 Gbps.

I would also check switch port errors, collisions, bandwidth usage, and whether any background application is consuming network traffic. If only one system is affected, the issue may be with the cable, adapter, or driver. If many users are affected, the issue may be with the switch, uplink, or network congestion.

3. A company wants to allow employees to access only business websites and block social media. Which network device or feature can help?

This can be handled using a firewall, web filtering solution, proxy server, or secure web gateway. These tools can inspect web traffic and apply rules based on domain names, URLs, categories, users, or IP addresses.

For example, the company can allow business-related websites and block categories like social media, gaming, or streaming. In larger networks, such policies are usually managed centrally so that all employees follow the same internet access rules.

4. A server is reachable from the internal network but not from outside the company. What could be the reason?

If a server is reachable internally but not externally, the server itself may be working fine, but external access may be blocked or misconfigured. I would check public IP mapping, NAT rules, firewall rules, router configuration, and whether the correct port is open for external users.

For example, if a web server runs on port 443, the firewall and NAT rule must allow external HTTPS traffic to reach that internal server. I would also check whether the domain points to the correct public IP and whether the ISP or cloud security rules are blocking access.

5. A user says they can access websites from mobile data but not from office Wi-Fi. What does this indicate?

This usually indicates that the issue is with the office network, not with the website itself. The problem may be related to office DNS settings, firewall policies, proxy configuration, blocked domains, routing rules, or internet gateway issues.

I would compare the behaviour on another device connected to the same office Wi-Fi. If all users face the same issue, it may be a network-level restriction or gateway problem. If only one user is affected, I would check that user’s IP configuration, proxy settings, browser settings, and local firewall.

6. Why can two devices on different VLANs not communicate directly?

Devices in different VLANs belong to separate logical networks. A switch keeps VLAN traffic isolated, so devices in one VLAN cannot directly communicate with devices in another VLAN unless routing is configured between them.

To allow communication between VLANs, inter-VLAN routing is required. This can be done using a router or a Layer 3 switch. Access control rules can also be applied to decide which VLANs are allowed to communicate.

7. A user is able to send emails but not receive them. What network or service areas would you check?

If sending works but receiving does not, the outgoing mail path is likely working, but the incoming mail path may have an issue. I would check mail server settings, MX records, spam filtering, mailbox quota, firewall rules, and whether the mail service is running properly.

For incoming mail, DNS MX records are important because they tell other mail servers where to deliver emails. I would also check whether any security gateway, antivirus filter, or mail rule is blocking incoming messages.

8. A video call keeps breaking even though internet speed looks good. What could be the network reason?

Video calls depend not only on speed but also on latency, jitter, and packet stability. Even if bandwidth is high, calls can break if the network has unstable latency, packet drops, Wi-Fi interference, or congestion.

I would check whether the user is on Wi-Fi or LAN, test latency, check packet loss, and see if other applications are using heavy bandwidth. For real-time applications like video calls and VoIP, consistent network quality is more important than only high download speed.

9. A branch office needs to securely connect to the head office network. What solution would you suggest?

A site-to-site VPN can be used to securely connect a branch office network with the head office network. It creates an encrypted tunnel between the two locations so users in both offices can access shared internal resources securely.

This is useful when employees in the branch office need access to file servers, internal applications, databases, or ERP systems hosted at the head office. The VPN ensures that data travelling over the internet remains encrypted and protected.

10. An application works inside the office but fails when accessed through a public URL. What could be wrong?

If the application works internally but fails through a public URL, the issue may be with public DNS, NAT, firewall rules, SSL certificate, reverse proxy, or load balancer configuration. The internal application may be healthy, but the external access path may be broken.

I would check whether the public domain resolves to the correct public IP, whether required ports are open, whether the SSL certificate is valid, and whether the reverse proxy or load balancer is forwarding requests to the correct backend server.

Best Ways to Prepare for Networking Interviews

Learn Networking Basics Step by Step: Start with core concepts like computer networks, LAN, WAN, IP address, MAC address, DNS, DHCP, OSI model, TCP/IP model, routers, switches, firewalls, and ports. A strong foundation will help you answer both basic and technical networking interview questions confidently.

Revise Important Networking Models: Focus on the OSI model and TCP/IP model because many computer networking interview questions are based on layers, protocols, data flow, and troubleshooting. Understand what each layer does instead of memorising only the names.

Practise MCQs and Interview Questions: Solve regular MCQs on IP addressing, subnetting, DNS, DHCP, routing, TCP, UDP, HTTP, HTTPS, VPN, NAT, VLAN, and network security. This helps improve speed, accuracy, and concept clarity before interviews.

Solve Troubleshooting-Based Questions: Practise real-world scenarios like slow internet, DNS failure, IP conflict, server not reachable, packet loss, Wi-Fi issues, firewall blocking, or website not opening. These questions are common in IT support, system admin, cloud, cybersecurity, and network engineer interview questions.

Use PlacementPreparation.io for Practice: Use PlacementPreparation.io to practise networking MCQs, technical questions, mock tests, and interview-based exercises. It helps learners prepare for placement exams, technical interviews, and fresher-level networking rounds.

Learn with GUVI Courses: GUVI courses can help you learn networking, CCNA, cloud computing, cybersecurity, Linux, and IT fundamentals in a structured way. This is useful if you want to build technical basics before preparing for interviews. Choose GUVI Zen Class for Guided Learning.

Final Words

Networking is a must-have skill for freshers entering IT support, system administration, cloud computing, cybersecurity, DevOps, and network engineering roles.

To prepare well, practise networking interview questions and answers, MCQs, mock tests, troubleshooting scenarios, and hands-on exercises regularly.

The more you understand real network behaviour, the easier it becomes to answer technical questions with confidence.

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