Top 25 VPN Interview Questions and Answers in 2024

There is an increase in the usage of computers, mobile phones, systems, and the internet. Networking has become one of the most sought-after career options for many.  As someone interviewing for a role in network administration, you must prepare to answer practical questions.

This article contains a detailed breakdown of frequently asked questions and answers to help you prepare for your VPN interview.  These questions will help you evaluate your skills and gauge your understanding of the role you’re to play.

1. Describe What A Network Is?

A network consists of two or more computers linked to share resources (such as printers and CDs), exchange files, or allow electronic communications.  These computers are connected through cables, telephone lines, radio waves, satellites, or infrared light beams.

2. What Are The Advantages One Expects From The Use Of A Vpn? 

A VPN software gives you access to a secure connection between your computer or gadgets and the internet.  It achieves this by running your traffic through encryption.

This encryption helps keep your internet traffic and online activities private by concealing your accurate IP address.

Some advantages a VPN provides include:

• Bypass Geo-locked Content

• Provide Safety Through Anonymity

• Secure Connection for Remote Work

• Security

• Gaming Pros

3. How Does A VPN Works?

A VPN encrypts your data traffic and sends it to the VPN server through a secure connection.  The data goes through your ISP (Internet Service Provider), but because of the encryption, the internet service provider can’t decipher it.

The VPN server decrypts the encrypted data from your computer. Then sends your data to the internet, which sends a reply to you, the user.  Once again, the VPN server encrypts the data traffic and sends it to the user.

4. As A Network Administrator, Do You Think VPNs Will Offer A Long-Lasting Solution?

VPNs will offer long-lasting solutions because it addresses privacy over a public network, which is required for a long time.  VPNs will exist from the desktop to the server and the action data level.

5. What Is A Virtual Private Network (VPN)?

A VPN describes the opportunity to establish a protected network connection when using public networks.  VPNs encrypt your internet traffic and hide your online identity.  Third parties can’t track your activities online and steal your data because the encryption keeps your traffic and online activities private and your data safe.

6. What Is IPsec VPN?

IPsec VPN means VPN over IP Security.  It allows two or more users to communicate securely by authenticating and encrypting each IP packet of a communication session, thereby providing data confidentiality, data integrity, and data authentication between participating peers.

7. In Simple Terms, What Are Confidentiality, Integrity, And Authentication?

Confidentiality: VPN provides encryption for the message content to ensure that data is not disclosed to unauthorized parties. Encryption algorithms include DES (Data Encryption Standard), 3DES (Triple-DES), and AES (Advanced Encryption Standard).

Authentication: In networking, authenticity verifies that the packet received is from the claimed sender.  Some methods used for authentication include pre-shared keys and digital certificates.

Integrity: This step ensures that the contents of the packet have not been altered in between by the man-in-middle.

8. In VPNs, Encryption Seems To Be The Most Crucial Advantage. List And Explain The Types Of Encryption.

There are two types of encryption: Symmetric and

Asymmetric encryption.

In symmetric encryption, a single key encrypts and decrypts traffic. And all communicating parties use the same (secret) key for encryption and decryption.  Asymmetric encryption uses two keys.

The first key encrypts, and the other key decrypts.  The decryption key is kept private and can’t be shared (hence the “private key” name), while the encryption key is public and shared for anyone to use (hence the “public key” name).

9. What Do You See As The Objective Of Data Encryption Within A Business Or Organization? 

The goal of data encryption includes: preventing unauthorized network access, protecting the privacy of all users, defending the networks from malware, hackers, and DDoS attacks, and securing all data from corruption and theft.

10. What Are The Possible Effects Of An Attack On A Computer Network?

In the event of an attack on a computer network, it reflects poorly on the privacy, integrity, and security of the organization.  There is a loss or deterioration of sensitive data, diminished reputation, reduced brand value, and reduction in profit for the affected organization.  The affected organization should make efforts to fix the issue, reassure and re-establish trust with the users.

11. How Well Can You Defend And Protect Your Home Network?

Some effective techniques I use to protect my home network are changing my router password, updating my router’s firmware, disabling remote access, and creating a separate network for guests. I also use a VPN.  

12. What Are The Three Main Security Services That IPsec VPN Provides?

IPsec VPN provides three primary security services: Peer Authentication, Data confidentiality, and Data integrity.  These three security features play a vital role in protecting user data.

13. Are You Interested In Network Security-Related News, And How Often Do You Check Out These Stories? Also, Where Do You Get Your Security News? 

As someone who has chosen network administration as a path, I often interact with news on data breaches, data loss, and hacking.  I stay informed by plugging into sites like Verizon DBIR report, google, privacy rights clearinghouse, hackers news, Krebs on security, cyber scoop, Cymru, and Twitter.  I’m open to suggestions on other platforms offering good information on security-related news.

14. Do You Think Every Organization Needs VPN?

In this digital age, a user’s search data is used to optimize the browsing experience and display ads. An organization values its data and seeks to ensure there is no breach.

VPNs will not always be reliable, but it’s an effective way to secure user data and avoid an unauthorized breach.  Beyond enhancing our privacy and helping protect our sensitive data, VPNs make the digital lives of those in conflict regions safer.

To this end, I agree that every organization needs VPNs.  Although it isn’t the ultimate solution, it avoids data breaches effectively.

15. Explain The Site-To-Site Virtual Private Network And The Remote Access Virtual Private Network.

Site-to-Site VPN: A secure connection between two geographically separated locations is made possible by a site-to-site VPN.  Most security gates today feature this VPN functionality.

As an illustration, a next-generation firewall (NGFW) installed at the network’s perimeter safeguards the business network and functions as a VPN gateway.  This gateway encrypts the traffic supplied to the gateway on the other side and handles all traffic between the two locations.  And the gateway sends the data to its destination after decryption.

Remote Access VPN: A secure connection between remote users and a business network is made possible by a remote access VPN.

16. What Are The Limitations And Security Risks Of Virtual Private Networks (VPN)?

As mentioned earlier, Virtual Private Networks (VPNs) are effective software that helps encrypt data.  However, it has its limitations.

Some of these limitations are:

No Integrated Security: An organization needs to deploy additional security solutions behind the VPN to identify and block malicious content and implement other access controls.

Fragmented Visibility: VPNs provide secure pinpoint-point connectivity with every VPN user on their link. This feature makes it difficult for an organization’s security team to maintain the complete network visibility required to detect threats.

Not all VPNs have a strong connection; Certain websites block VPN users; VPNs are illegal or questionable in specific countries; There’s no way of knowing how well a VPN encrypts your data, and some VPNs log and sell browsing data to third parties.

17. What Are The Different VPN Protocols?

VPNs use an encrypted connection called a tunnel.  There are several ways (protocols) to set up a VPN connection.  The essence of this is to keep your data safe and secure.

Some of these Virtual Private Networks (VPN) Protocols include:

Open VPN: It is one of the most widely used protocols. Platforms like Microsoft, Android, Linux, and others, use Open VPN as their source protocol.  Many consider it to be the best choice.

IPsec: This is a good choice when an open VPN isn’t available.  Most operating systems use this protocol.

IKEv2: This network protocol can switch between networks.  This feature makes it a better-suited Protocol for smartphones.  It also bases on the IPsec protocol.

PPTP: This is called Point-to-Point Tunneling Protocol.  I advise you use this protocol only if speed is more important to you than data security.  Although it was one of the first widely used protocols, it has a few leaks which can compromise your data security. Wireguard- This protocol is new and currently still in development.

18. What Are The Requirements For A VPN Checklist When Deciding To Use (Or Deploy) And Maintain The VPN?

Before choosing a VPN, it should satisfy these requirements.  It must be able to interoperate with other IPsec-compliant vendors; it should have the IPsec compliant; the VPN should support the automatic creation of user-level VPNs (for mobile users) because, in a vast organization, the system manager wouldn’t want to create VPN accounts for every user manually.

Lastly, the VPN should be certified by a recognized organization.  The ICSA has a certification and testing process for VPNs.

19. What’s A Man In The Middle Attack, And How Can It Be Resolved? 

A man-in-the-middle attack is a type of cyber attack that occurs when a perpetrator positions himself in a conversation between a user and an application, either to eavesdrop or to impersonate one of the parties.  It disguises to make the unsuspecting parties see it as a routine exchange of information.

The VPN will block attempts of where the MiTM( Man in the Middle) attacks are coming from, although it might not always be the case.  Ensure your Wi-Fi networks are secure and up-to-date by updating default usernames and passwords on your routers and all connected devices. Use strong and unique passwords.  Stay alert and monitor search engine notifications that tell you a website is unsecured or suspicious.

20. As An Organization That Wants To Secure Its Data And As A Network Administrator, Can The Organization Get Hacked Even If They Use A VPN? 

Yes.  While VPNs shouldn’t be discouraged, there should be a basic understanding of networks and strict adherence to security practices.

Something as insignificant as clicking ok sites, or downloading attachments (such as videos, images, or links), can reveal or expose sensitive data, giving full access to hackers.  VPNs encrypt our data and send it through the server to whoever is operating it.

However, this doesn’t excuse the software from malware attacks. That is why there is a need to adhere strictly to security practices like using only trusted and vetted VPNs.

21. Following Your Experience And Knowledge With Networks, What Protection Do Virtual Private Networks (VPNs) Give And How?

A VPN helps me worry less about the risks of having my data compromised or breached. However, it doesn’t eliminate the chance.  But that’s a start.

VPNs use encryption to hide the details of my browsing activity as it travels between my device and the VPN server.  If an attacker intercepts my connection on an unprotected WiFi network, they would only see strings of unintelligible letters and numbers.

Also, VPN protects me from ISP surveillance, Man-in-the-Middle attacks, network monitoring, and other forms of surveillance.

22. What Are The Most Crucial Security Features A VPN Must Have?

Important security features a VPN must have include: PFS, protocol, cipher, audit, bug bounty, no logs, diskless servers, secure history, and leak protection.

23. When Choosing A Virtual Private Network (VPN) Vendor, What Are Some Of The Things You Check To Know If They Meet Your Requirements?

As a Virtual Private Network (VPN) specialist or administrator, I will work with only vendors that meet the requirements for the selected appropriate technology.  I consider the speed, security, accessibility, reliable encryption, number of servers, ease of use, and versatility before choosing a VPN Vendor.

Also, I check the provider’s logging policy and the website for third-party reviews to know their performance.  I believe all this is essential information that needs to be checked and confirmed if they meet the requirements

24. What Do You Understand From The Term ‘Transform Set’?

A transform set is a collection of individual IPsec transforms designed to enforce a specific traffic security policy.  A transform set specifies the integrity and encryption algorithms the peer will use to protect data communications.

Two peers must use the same algorithm to communicate and configure up to 16 transform sets on the security appliance.

25. Can You Walk Me Through The Steps Of An SSL Handshake? 

The SSL handshake is a process that allows the client and server to establish the encryption algorithms, choose the secret keys they will use to communicate with each other securely, and exchange and validate each other’s digital certificates.

  • The client sends a “client hello”message.  The message includes the client’s SSL version number, cipher settings, session-specific data, and other important information.
  • The server responds to the “client’s hello” with a “server hello” message containing the server’s SSL certificate, the server’s choice cipher suite, session-specific data, an SSL version number, and other pertinent data.
  • The client creates a session key, encrypts it with the server’s public key, and sends it to the server.  The client verifies the server’s SSL certificate and sends a random string of bytes, known as premaster key, for the server to decrypt with the private key.
  • The client and server generate session keys to arrive at the same result.  The client and server encrypt a “finished” message with the choice session keys, which they will use for further communication.
  • At the end of the SSL handshake, both the client and the server will have a valid session key which they will use to encrypt or decrypt data.  After which, the public key and the private key will not be used anymore.


When preparing for an interview, research the organization you’re interviewing for to learn all you can.  It would help if you understood what they do, their value, and their uniqueness.

You must also learn everything you can about your role and the necessary skills.  Your answers to the interview questions should align with what you know about the organization.  It would give you an edge over other candidates.

If you’re new to this field, learn the basics and research other information.  During the interview, show the interviewer you’re open to new challenges and experiences.

Experience can also be a great way to catch your interviewer’s attention.  Please talk about your experiences, volunteer work, problem-solving, e.t.c, but ensure it is relevant to the question asked.

The degree of difficulty of the technical questions asked during an interview will differ depending on your role.  For entry-level positions, the interviewer will ask questions on general terminology and practices. For advanced VPN systems specialist roles, the interviewer will focus on more in-depth technical questions and practices. Ensure you’re ready to ace your interview. Good luck!

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