Network security is a higher level position. The main responsibility is to safeguard the business from threats. It also protects sensitive data like confidential business materials and personal information. In addition, network security enables protection of information shared among computers on the network.

If you are looking for a job as network engineer or considering a new job as network administrator; this Network security interview will help you face any type of questions asked during the interview.

Q1. Define protocol

Ans. It is a set of rules that govern all aspects of information communication.

Q2. What are the different layers of OSI?


  • Data link layer
  • Transport layer
  • Application layer
  • Session layer
  • Data link layer
  • Presentation layer

Q3. Explain pipelining?

Ans. When a task has begun before the previous task has ended is called Pipelining.

Q4. Difference between hub and switch?

Ans. A hub is a networking device that connects multiple computers together, while switch is a control unit that turns the flow of electricity in a circuit.

Q5. Which layers are referred as network support layers?


  • Data link layer
  • Physical layer
  • Network layer

Q6. Define simplex with an example?

Ans. A type of communication in which data is transmitted in one direction is known as simplex. Example: Monitor

Q7. What is RIP?

Ans. RIP stands for Routing Information Protocol, is a simple protocol used to exchange information between the routers.

Q8. What are the factors that affect the performance of the network?


  • Type of transmission media
  • Software
  • Number of users
  • Hardware

Q9. Difference between wired LAN and wireless LAN?

Ans. Wired LAN used Ethernet devices like router, hub and switch, while wireless LAN uses devices like mifi router and WLAN router.

Q10. Name some user support layers?


  • Application layer
  • Presentation layer
  • Session layer

Also Read>> Top CCNA Interview Questions & Answers

Q11. What is the use of TCP in the IP packets?

Ans. TCP is an acronym of transmission control protocol. It is used as a communications protocol in a private network.

Also Read>> Is CCNA the Right Certification for Networking Professionals?

Q12. Name the types of errors?

Ans. There are two types of errors:

  • Single bit error
  • Burst error

Q13. What is ALOHA?

Ans. It is used to solve the channel allocation issue. Two types of aloha:

  • Pure aloha
  • Slotted aloha

Also Read>> Cisco Certifications: CCNA Vs CCNP

Q14. What does VPN stand for?

Ans. VPN stands for virtual private network. It creates a secure network connection over a public network like the internet.

Q15. Which protocols uses application layer?


  • SMTP
  • DNS
  • FTP

Q16. What is intranet?

Ans. It is a private network based on TCP/IP protocols accessible only by the company’s members or someone with authorization.

Also Read>> Top Network Engineer Interview Questions & Answers

Q17. What are steps involved in creating the checksum?


  • Divide the data into sections
  • Add the sections together using 1’s complement arithmetic
  • Take the complement of the final sum

These are some of popular network security interview questions. If you are new to the subject, learn more about it through a professional certification course in Network security and gain the skills required to be an expert in this domain.