Are you thinking about becoming a network engineer? Are you thinking about leaving your current job to start a new one at a different company? When was the last time you interviewed for a job as a network engineer?
Continue reading if you responded yes to any of these questions. We’ve put together a list of Network Security Interview Questions and some tips on how to do well in the interview.
Landing a job as a network security specialist is no easy feat. You’re up against some of the best technical minds out there. That’s why it’s absolutely crucial you nail the interview
If you give one wrong answer, you might not even be in the running. Don’t let a simple question trip up your chances.
To help you tackle even the toughest queries, I’ve compiled the top 30 network security interview questions For each one, you’ll find tips and sample answers to wow hiring managers.
Ready to launch your career defending companies from cyber threats? Let’s begin!
1. What is a Network?
A network refers to two or more computers or devices connected to share data and resources. The connection can be wired (Ethernet), wireless (Wi-Fi), or both. Devices in a network can communicate and exchange information with each other.
There are different types of computer networks including:
-
Local Area Network (LAN) – Connects devices within a limited physical area like a home, office building, or school.
-
Wide Area Network (WAN) – Covers a larger geographic area by connecting LANs across cities, states or even countries.
-
Personal Area Network (PAN) – Connects devices centered around an individual person. For example, a smartphone connected to a wireless headset.
Key components in a network include servers, clients, network media (wires, cables, radio waves), networking hardware (routers, switches, hubs) and network software.
2. What is a Protocol?
A protocol is a set of rules that define how devices communicate and exchange data across a network. Protocols allow devices with different hardware and software platforms to interconnect.
Some key functions of network protocols include:
-
Defining connections, including locating devices and establishing session rules
-
Managing data flow between devices – data sequencing, rate control, error detection etc.
-
Formatting and packaging data for transmission
-
Providing error handling and recovery mechanisms
Common network protocols include TCP/IP, HTTP, FTP, SMTP, DHCP etc. Each serves a distinct purpose like managing web traffic (HTTP), emails (SMTP) or IP addresses (DHCP).
3. What is Pipelining?
Pipelining refers to a technique in computer networks where multiple requests are handled simultaneously without waiting for previous ones to be fully processed.
It involves sending a new request before the response from an earlier one has been received. This allows for better resource utilization and faster data transfer.
For example, in the HTTP protocol, pipelining allows a web browser to send multiple requests to load images and assets from a webpage without waiting for previous requests to complete. This significantly improves page load time.
Pipelining is used in many network protocols like HTTP 1.1 and SMTP. It relies on the concept of persistent connections instead of opening and closing a new connection for every request-response cycle.
4. What is a Hub in Networking?
A hub is a common, simple device used to connect multiple Ethernet devices within a Local Area Network (LAN). When a data packet arrives at one port, the hub replicates it to all other connected ports enabling communication between devices.
Some key characteristics of a network hub include:
-
Works at the physical layer of the OSI model.
-
Has multiple ports to connect nodes on a network.
-
Is a “dumb” device that blindly forwards packets to all ports without examining the traffic.
-
Uses broadcast transmission where a packet is copied line-by-line bit-by bit to every connected device.
-
Prone to network congestion and collisions as nodes compete for bandwidth.
-
Cheap, easy to install but lacks intelligence of more advanced networking devices like switches.
Hubs were widely used to build simple networks but have now largely been replaced by smarter switches that are able to inspect packets and forward them selectively.
5. What is a Switch in Networking?
A switch is an intelligent network device that connects multiple segments of a Local Area Network (LAN) and selectively filters and forwards data traffic between them.
Key functions of a network switch include:
-
Operates at the data link layer (OSI layer 2).
-
Forwards data frames based on MAC addresses of connected devices.
-
Builds a MAC address table by examining incoming frames and recording port associations.
-
Filters unicast traffic by sending it only to the recipient device, saving bandwidth.
-
Supports micro-segmentation of a LAN into multiple collision domains.
-
Enables inter-connectivity between different LAN segments.
-
Provides additional security by limiting broadcast domains.
By enhancing performance, throughput and security, switches form the backbone of modern Ethernet networks.
6. What is Simplex in Networking?
Simplex refers to a one-way mode of communication between two networked devices. In simplex transmission, the sending device can send data but cannot receive data. The receiving device can only receive data but cannot send any data back.
Some key properties of simplex communication:
-
Uni-directional data transmission.
-
No reverse channel for acknowledgement or replies.
-
Common in broadcast networks like radio, television etc.
-
Used in some dedicated monitoring systems that only need to send data like security cameras.
-
Prone to data loss since receiving device cannot request retransmission in case of errors.
-
Contrast with half-duplex (two-way alternate transmission) and full duplex (simultaneous bidirectional transmission) modes.
Simplex represents the most basic form of network communication with devices having defined roles as either transmitter or receiver. It has limited applicability today given the need for two-way communication in most networks.
7. What are the Factors that Affect Network Performance?
Some key factors that determine the performance of a network include:
-
Bandwidth – Maximum data transfer capacity of the network medium and hardware. Higher bandwidth enables faster data speeds.
-
Throughput – Actual rate of data transfer over a network, influenced by other factors like number of users, packet size etc.
-
Latency – Delay between sending and receiving data across the network. Lower latency results in better response times.
-
Jitter – Variation in delay times for individual data packets being transmitted. High jitter disrupts streaming applications.
-
Load – Amount of traffic on the network from connected devices. Heavier usage leads to congestion and slower response.
-
Utilization – Percentage of total capacity used on a network link over a period. Over-utilization can cause bottleneck.
-
Error rate – Frequency of corrupted or lost packets needing retransmission, reducing effective throughput.
-
Topology – Physical layout of the network – bus, star, mesh etc. Impacts fault tolerance, expandability etc.
8. What is a LAN in Networking?
A Local Area Network (LAN) is a network that interconnects computing devices within a limited physical area such as a home, office building, university campus or even a group of nearby buildings. Key characteristics of a LAN include:
-
Spans a small geographic area like a single office or building.
-
Uses twisted pair copper wire, coaxial cable or fiber optics as transmission medium.
-
Operates at high speeds – 10 Mbps to 10 Gbps.
-
Owned and operated by a single entity like a business organization.
-
Enables shared access to resources like files/storage, printers, internet etc.
-
Communication technologies used include primarily Ethernet and Wi-Fi.
-
Connects devices like computers, printers, servers, phones, security cameras etc.
LANs are extremely common and underpin connectivity in offices, schools, hospitals and other environments with many networked devices concentrated in one location needing high-speed communication.
9. What is a Protocol?
A protocol is a set of rules and procedures for communication between electronic devices on a network. Protocols allow devices with diverse hardware and software platforms to communicate seamlessly. Key functions include:
-
Establishing connection between devices on a network.
-
Organizing and presenting data for transmission.
-
Managing data flow and error control during transmission.
-
Setting rules for communication between sender and receiver.
Some common protocols used in networking include:
-
TCP/IP: Core protocol for Internet communication. Defines IP addresses and data encapsulation.
-
HTTP & HTTPS: Manages client-server web traffic. HTTP for unsecured, HTTPS for secured web sites.
-
FTP: Transfers files between network hosts. Uses TCP, enables uploading and downloading of files.
-
SMTP: Governs sending and routing of email messages between servers and clients.
-
SSH: Enables secure remote login and encrypted communication between devices.
10. What is Pipelining?
Pipelining is a technique used in computer networks to enhance data transfer performance. It involves sending a new request without waiting for a response to the previous one.
Pipelining reduces delays and improves network utilization by enabling multiple requests and responses to be “in-flight” simultaneously over a single channel.
For example, in HTTP 1.1, pipelining allows a web browser to send multiple requests to loa
System Security Hardening Techniques
System hardening is a general term for a set of tools and steps that an organization can use to manage weak spots in its systems, apps, firmware, and other parts.
While system hardening reduces the number of possible attacks and makes the system less vulnerable to them, the goal is to improve security.
The many forms of system hardening are as follows:
Stored and Reflected XSS attacks Difference
Stored XSS Attacks: In these attacks, the scripts that are injected stay on the target servers for a long time. So when the victim requests information from the server, the malicious script is executed.
Reflected XSS Attacks: In this type of attack, the attacker does whatever it takes to get the user to click on a link that takes them to a website that isn’t secure. This lets the attacker get the user’s information.
Cyber Security Interview Questions You Must Know (Part 1)
FAQ
What does a network security specialist do?
What are the 3 aspects of security in network security?
How to prepare for a network security interview?
And preparing for your network security interview will have a massive boost when you familiarise yourself with the most common network security interview questions and answers which also, add to your knowledge base with certification courses.
What does a network security interview entail?
Your interviewer is looking for evidence that you have a comprehensive, methodical approach to network security. This question tests your understanding of the different components of a secure network, and your ability to implement procedures that protect sensitive data.
What questions should you ask in a network specialist job interview?
To help you excel in your network specialist job interview, we’ve gathered some commonly asked questions together with insights on how to approach them and sample answers that will guide you in crafting your own well-informed responses. 1. Can you explain the difference between a hub, switch, and router?
Will I be asked all the network security interview questions?
There’s no guarantee that you will be asked ALL of these network security interview questions, or that other network security questions not included here won’t be asked. Still, be assured that the following are more likely than not to be asked.
