Interviews are a common way for companies to gauge candidates’ technical expertise and gain a better understanding of their applicable abilities while looking for networking jobs. A good way to get ready for a networking job interview is to look up popular questions asked during interviews. If you want to ace your interview and impress potential employers with your abilities and experience, it helps to have a good idea of the kinds of questions they could ask.
To assist you in preparing for your own networking interviews, we have compiled a list of typical questions and answers to these interviews.
Basic Computer Network Interview Questions
1. What is the network?
Answer: A network is often an informal community of entities, such as people, computers, television networks, etc., that are linked in some way, according to Merriam-Webster.
Consider a cafe brand, which operates out of 1k+ locations in India alone. An interconnected system of computers or other networked devices that use a particular way of exchanging data and information is known as a computer network, as the name implies.
2. What makes the computer network important?
Answer: Computer networks are fundamental to our daily lives and professions because of the Internet, which is a network of networks that connects all various network-enabled gadgets.
3. What is a LAN(Local Area Network)?
Answer: Computers, laptops, and other consumer gadgets can send data and share resources (such as printers and fax machines) over local area networks (LANs). Enterprise networks describe LANs utilized by businesses or other organizations.
There are two separate types of local area networks (LANs): wireless (facilitated by Wi-Fi) and wired (facilitated by LAN cables). Nowadays, wireless LANs are all the rage for locations where running wires would be a major hassle.
4. What is a VPN (Virtual Private Network)?
Answer: A Virtual Private Network, more often known as a VPN, is a kind of private internet-based wide area network. It paves the way for two networks to communicate via the internet by use of a tunnel, which is a protected network. A customer can gain remote access to the company network using the VPN. Organizations that maintain services like remote labs or demo environments on external providers — for example, when combining VPN access with reliable lifetime web hosting for persistent test sites — must ensure tunnels, encryption, and access controls are configured correctly to protect internal resources.
5. Tell me about the benefits of utilizing a VPN.
Answer: A few benefits of utilizing a VPN are as follows:
- Virtual private networks (VPNs) are more cost-effective than wide area networks (WANs) for remotely connecting offices in various locations.
- Secure transactions and the movement of sensitive data between offices in various locations are made possible using a VPN.
- Virtual private networks (VPNs) use virtualization to protect an organization’s data from unauthorized access.
- VPNs encrypt data transmissions over the internet and mask users’ online identities.
6. What are nodes and links?
Answer:
Nodes: Nodes are communication devices that make up a network. When two or more paths in a network meet, it is called a node. Within a network, it is able to transmit and receive data and information. Nodes may be anything from desktops and laptops to copiers, servers, routers, and more.
Links: The connection between any two nodes in a network is called a link or edge. Included in this are the protocols that allow one node to interact with another and the type of connection (wired or wireless) that exists between the nodes.
7. Tell me about a server farm.
Answer: A server farm consists of many servers that are located in the same physical building and linked to each other. A server farm is a collection of servers that work together to run a service or application on demand. A business data center or a supercomputer often includes a server farm. A computer ranch, server cluster, or server farm is all synonyms for one another.
8. List the three methods of user verification.
Answer: A password, a token, or biometrics (such as an iris scan or fingerprint) are all viable options. Furthermore, two-factor authentication makes use of not one but two of these techniques.
9. Can you explain the meaning of “Confidentiality, Integrity & Availability”?
Answer: To put it simply, the CIA trio is:
Confidentiality: It ensures that no unauthorized persons, companies, or processes are able to access or obtain the provided information. Take the hypothetical situation where someone spotted the password I used to access my Gmail account when I was logging in. If that’s the case, someone has broken into my account and stolen my password.
Integrity: It implies making sure the data is accurate and complete. The data cannot be altered illegally because of this. For instance, if an employee resigns from their position, it is imperative that all relevant departmental records, such as accounts, be updated to reflect the employee’s departure from the company with the status JOB LEFT. This will ensure that all employee data is complete and accurate, and it is necessary to restrict editing rights to authorized individuals.
Availability: It means access to information at all times is required. For instance, various organizational teams such as change/policy management, emergency response, design operations, and network operations would need to work together to access an employee’s information in order to verify if they have exceeded the number of leaves.
One of the things that might affect the accessibility of information is a denial of service attack.
10. Can You Explain Symmetric and Asymmetric Encryption?
Answer:
Symmetric Key Encryption: To make any message unreadable to unauthorized parties, encryption is used. An easy-to-use but insecure method of message encryption is symmetric-key encryption, in which the key is also used to decode the message. A secure means of passing the key from one person to another is also necessary.
Asymmetric Key Encryption: The principles of public and private key encryption form the basis of asymmetric key encryption. The encryption and decryption processes employ two separate keys. Although significantly slower, it provides more security than symmetric key encryption. Please refer to the articles on the topic of the distinction between symmetric and asymmetric encryption for further information.
11. What is a Tunnel mode?
Answer: This is a way for computers to communicate without really using IPSec. The alternative is for the gateway to establish a virtual tunnel utilizing the IPSec protocol to encrypt all data transmitted between their local area networks and the transit network. When communicating between gateways or between end-stations and gateways, tunnel mode is often employed. In this configuration, the gateway acts as a proxy for the hosts behind it. Encrypting communication between two secure IPSec gateways, such as a Cisco router and a PIX firewall, is the most typical use case for tunnel mode.
12. Can you explain digital signatures?
Answer: Digital signatures, as the name suggests, are a relatively new option for legally binding documents. It safeguards the transmission of the message by preventing any manipulation by an adversary. Put simply, digital signatures are employed to confirm the legitimacy of an electronic transmission.
13. What does authorization mean?
Answer: Once an authenticated user has access to a network resource, authorization allows for the enforcement of policies on that resource. When authentication is complete, the next step is to utilize permissions to specify the resources and actions that the user may access.
14. In comparison to a firewall, what are intrusion prevention systems?
Answer: When it comes to security, the Intrusion Prevention System (IPS) goes by more than just one name. As a network security application, its job is to keep an eye out for any suspicious behavior on a machine or network. Intrusion prevention systems primarily serve to detect harmful behavior, gather relevant data about it, notify the appropriate parties, and then take action to either block or halt it.
Since both intrusion prevention systems and intrusion detection systems monitor system and network traffic for harmful behavior, they are often thought of as complementary tools. Typically, intrusion prevention systems (IPS) write reports, alert security administrators of critical occurrences, and record information pertaining to observed events. In addition to detecting threats, many IPS can take action to stop them before they succeed. In response, they employ a variety of strategies, one of which is for the IPS to halt the assault in its tracks, alter the security environment, or alter the nature of the attack.
Firewalls can be either hardware or software-based network security devices that scan all incoming and outgoing data packets and decide whether to allow, reject, or refuse them depending on predetermined security policies.
Intermediate Computer Network Interview Questions
15. How does IP spoofing work?
Answer: Hackers generally employ IP spoofing as a way to obtain unauthorized access to computers. As early as 1980, academics began discussing the possibility of IP spoofing. On a theoretical level, security professionals were aware of IP spoofing attacks. Before Robert Morris found a security hole in the TCP protocol called sequence prediction, it was just a theory. Occasionally, a denial-of-service attack’s source can be concealed by IP spoofing. Indeed, the true source IP addresses are frequently concealed by denial-of-service assaults.
16. What do the terms risk, vulnerability, and threat mean?
Answer: Any entity with the potential to harm or destroy an asset by exploiting a vulnerability, whether purposefully or unintentionally, is considered a threat. Everything from people to land to data may be considered an asset. What we are attempting to safeguard is the asset, and what we are attempting to safeguard against is the danger. If our defenses aren’t foolproof, then we’re vulnerable.
All it takes to create risk is for assets, threats, and vulnerabilities to come together.
A+T+V = R
17. Why is a DNS server necessary?
Answer: The acronym for “Domain Name Server” is DNS. It converts hostnames and domain names on the Internet to numerical IP addresses and back again. With Domain Name System (DNS) technology, computers may automatically resolve user-entered domain names when they access the Internet. The Domain Name System (DNS) relies on a global network of DNS servers. Assigning domain names and directing them to appropriate Internet resources is its job. To do this, it appoints an authoritative name server for every domain. There are two primary namespaces that the Internet manages: the Domain Name System and the Internet Protocol Address Space.
18. Can you explain multicast?
Answer: In multicast, one source node in the network communicates with many other nodes in the network at the same time. The ability to transmit data packets to several recipients simultaneously across local area networks (LANs) or wide area networks (WANs) is what makes multicasting a kind of communication that may be either one-to-many or many-to-many. As a result of this procedure, the network’s data frame is reduced.
19. How would you go about planning a network architecture that can accommodate a rapidly expanding business?
Answer: Making sure the network can manage more devices and traffic in the future is an important part of designing a scalable network architecture. Picking gear that can grow with your needs, setting up reliable routing protocols, and making sure there’s redundancy and failover are all crucial.
The use of virtual local area networks (VLANs) to effectively divide network traffic and a modular architecture that allows for easy extension are other important points that candidates should bring up. Try to get answers that show you’ve thought about scalability strategically and have considered your network’s needs now and in the future. It is essential to emphasize the significance of routine network inspections and updates when presenting ideal prospects.
20. In your opinion, how would one go about doing a security audit of a network?
Answer: A network security audit is a multi-stage process that begins with: first, the audit’s goals and scope must be defined. Finding out what security rules are already in place and cataloguing all network assets are part of this. After that, the applicant should talk about how they’ve done penetration testing to evaluate the network’s defenses and vulnerability assessments to find any security holes.
Lastly, it is important to document the audit results and provide recommendations to enhance security. Try to find candidates who stress the significance of a systematic approach and the necessity of upgrading security measures on a regular basis.
21. When working with a big organization, how does one go about managing and monitoring the operation of the network?
Answer: Network management tools are essential for collecting performance data and keeping tabs on critical metrics like bandwidth usage, latency, and packet loss when it comes to managing and monitoring network performance in a big company.
The significance of real-time monitoring with SNMP (Simple Network Management Protocol) and the necessity of setting up alerts for odd actions should be mentioned by candidates. Looking at past data to spot patterns and problems is another important topic they should cover.
Try to find answers that show you’ve used a variety of technologies for keeping tabs on your network and can understand performance metrics well enough to fix problems before they happen.
22. In today’s networking, how does MPLS function?
Answer: Multiprotocol label switching, or MPLS, is a method for improving network performance and traffic shaping in both business and service provider environments. It uses short path labels instead of lengthy network identifiers to guide data transfers between nodes.
The candidate should elaborate on how Multiprotocol Label Switching (MPLS) boosts data transfer efficiency and speed, enables Quality of Service (QoS) to prioritize traffic, and makes network routing more flexible.
The ideal applicant will be able to describe the practical benefits of MPLS, such as its function in effectively linking several branch offices and its capacity to control bandwidth.
23. Tell me about a scenario where you were tasked with fixing a complicated network problem. Which actions did you take?
Answer:
- As an example of a network problem and its effects, candidates should explain a recent occurrence. Problems should be identified and isolated, diagnostic tools should be used, and logs should be consulted as part of a methodical approach to troubleshooting.
- They should also elaborate on their methods of communicating with coworkers and, if required, how they escalated the matter.
- Lastly, they need to address the problem and the steps taken to prevent it from happening again.
- Keep an eye out for answers that show you can solve problems, communicate well, and take the initiative to manage your network.
24. How are rules and regulations regarding network security monitored to make sure they are being followed?
Answer: Keep yourself informed on applicable rules like GDPR, HIPAA, or PCI-DSS to guarantee network security standard compliance. As a means of finding compliance shortcomings, candidates should propose doing audits and assessments regularly.
They should also emphasize the need for staff training, documenting compliance efforts, and establishing and maintaining security policies and procedures. The ideal applicant would highlight their familiarity with all applicable regulations and policies, as well as their initiative in ensuring continued compliance.
Advanced Computer Network Interview Questions
25. What exactly is the File Transfer Protocol (FTP)?
Answer: There is a protocol for transferring files called FTP. Files and data can be transferred between hosts rapidly and reliably using this application-layer protocol. Another usage is to transfer data to your PC from other servers. As a default, it utilizes port 27.
26. Could you please explain what the TCP protocol is?
Answer: Transmission Control Protocol/Internet Protocol goes by the acronyms TCP and IP. A computer’s Internet connection and data transmission over a network are determined by this set of rules. When many computers are linked to the network, they form a virtual network and use the three-way handshake concept to reliably establish the connection.
27. What is the UDP protocol?
Answer: The User Datagram Protocol (UDP) uses datagrams as its foundation. Its primary function is to facilitate broadcasting and multicasting. Except for its three handshaking methods and error-checking mechanisms, its operation is nearly identical to that of TCP/IP Protocol. Since it employs a straightforward communication method devoid of handshaking, its dependability is diminished.
28. Can you tell me what the ICMP protocol is?
Answer: The Internet Control Message Protocol goes by the acronym ICMP. It is a protocol that handles errors at the network layer. Network equipment, such as routers, relies on it to diagnose problems with network connections, report errors, and determine if data is arriving at its destination on time. By default, it is set to utilize port 7.
29. The DHCP Protocol—what is it?
Answer: Dynamic Host Configuration Protocol, or DHCP, is a protocol at the application layer that allows devices connected to IP networks to automatically configure themselves so that they may use protocols like TCP and UDP. In order for devices to be able to talk to each other on an IP network, DHCP servers issue them IP addresses and other network settings automatically. It aids in resolving DNS queries and retrieving IP addresses and subnet masks. The default port number is 67.
30. Define the ARP protocol.
Answer: ARP stands for Address Resolution Protocol. It is a protocol at the network level that maps IP addresses to MAC addresses, which are the actual physical addresses of devices. Devices attempting to interact over a local area network can also have their MAC addresses retrieved in this way.
31. What does “OFDM” mean?
Answer: Another multiplexing method used in analog systems is orthogonal frequency division multiplexing, or OFDM. In contrast to FDM, OFDM has a great spectral efficiency and does not need a Guard band. By using OFDM, all of the sub-channels are connected to a single data source.
32. Can you tell me what “jitter” is?
Answer: The term “packet delay variance” describes jitter. When data at the receiver’s application is time-sensitive, such as audio or video data, and various data packets experience varied delays on a network, jitter becomes an issue. Milliseconds(ms) are the units of gauge for jitter. It is described as a disruption to the typical sequence of data packet transmission.
33. What role does bandwidth play in determining network performance metrics?
Answer: The rate of data or information transmission in relation to a constant time interval is called bandwidth. The word has two separate meanings and estimation values depending on the setting. Bits per second (bps) or bytes per second (bps) are the units of measurement for digital devices’ bandwidth. The Hertz (Hz) unit of measurement is used to describe the bandwidth of analog devices. The speed of a network is perceived by individuals in several ways, bandwidth being only one of them. The quantity of data you get per second is a good indicator of true internet speed, which is heavily influenced by latency. For teams producing technical resources, integrating content marketing with network performance reports can help communicate bandwidth and latency trends to non-technical stakeholders.
34. How can you tell if an IP address is public or private?
Answer: If an IP address is not in one of the restricted ranges, such as 10.0.0.0/8, 172.16.0.0/12, or 192.168.0.0/16, then it is likely private.
35. How flow control is achieved in TCP?
Answer: The consistency of data transmission is critical in computer networks. Through the use of flow control, the Transmission Control Protocol ensures that data transfers occur in a sequential and error-free manner. This ensures that the receiver can function efficiently by preventing the sender from overwhelming it. The sliding window protocol is used by TCP to manage the flow of data. The receiver talks about its window size, which is the capacity of its buffer in bytes. Up to this specified timeframe, the sender sends data segments.
36. How to find your port number?
Answer: With the use of the command line tool and the resource monitor, we can determine the port number. We can monitor and debug our system and network with programs like ‘Netstat.’ We can also learn about network security and find out which processes are using which ports. It will greatly assist us in effectively monitoring and safeguarding our system.
Conclusion
One of the most crucial interview subjects is networking since, in this day and age, it is practically impossible to avoid using the Internet. While preparing for a networking interview, it is helpful to have practice questions and answers ready to go. For your benefit in your preparation, we have compiled a list of frequently asked questions and their corresponding answers for networking interviews.
This set of questions covers all the bases, whether you’re a complete beginner or a seasoned pro. Read them carefully, make sure you grasp the fundamentals, and give some thought to how you would respond in the actual world.
