20 VPN Interview Questions and Answers

VPN, or Virtual Private Network, is a private network that is used to connect remote users to a company’s network. It allows employees to securely access company resources and information from anywhere in the world. When interviewing for a position that requires VPN knowledge, you can expect to be asked about your experience and understanding of the technology. In this article, we will review some common VPN interview questions and provide tips on how to answer them.

VPN Interview Questions and Answers

Here are 20 commonly asked VPN interview questions and answers to prepare you for your interview:

1. What is a VPN?

A VPN, or Virtual Private Network, is a private network that is created over a public network. A VPN allows for secure communication between two or more devices over the internet. This is often used by businesses in order to allow employees to securely connect to the company network from outside of the office.

2. Can you explain the difference between a LAN and WAN?

A LAN is a local area network, which is typically used in a single building or home. A WAN is a wide area network, which can span multiple buildings or even countries.

3. How do you establish a secure connection in your network?

There are a few different ways to establish a secure connection in your network. One way is to use a VPN, or virtual private network. This is a private network that uses a public network, such as the internet, to connect remote sites or users together. This allows for a secure connection between the two points. Another way to establish a secure connection is to use a secure socket layer, or SSL. This is a protocol that is used to encrypt communication between two points.

4. Can you explain how a VPN works?

A VPN, or Virtual Private Network, is a private network that is created over a public network. This allows for secure communication between two parties, as the data is encrypted. In order to set up a VPN, you need a VPN server which is connected to the public network. You then connect to the VPN server from your computer, which will encrypt all of your data.

5. Is it possible to use Internet Protocol Security (IPSec) over Layer 2 Tunneling Protocol (L2TP)? If yes, then how can this be done?

Yes, it is possible to use IPSec over L2TP. In order to do this, you need to configure both protocols on your VPN server. You will also need to make sure that your VPN client supports IPSec.

6. What are the three main components of an IPSec architecture?

The three main components of an IPSec architecture are the Authentication Header (AH), the Encapsulating Security Payload (ESP), and the Internet Key Exchange (IKE). AH provides authentication and integrity for IPSec packets, ESP provides confidentiality and data integrity for IPSec packets, and IKE is responsible for establishing and maintaining IPSec security associations.

7. Are there any disadvantages with using Virtual Private Networks? If yes, what are they?

There are a few potential disadvantages with using Virtual Private Networks. One is that they can be slower than a direct connection, since your data has to travel through an extra server. Additionally, if the VPN server is located in a different country, you may experience slower speeds due to distance. Finally, if the VPN server is not properly configured, it could be less secure than a direct connection.

8. What is the significance of encryption when establishing a VPN connection?

Encryption is important when establishing a VPN connection because it helps to ensure that the data being transmitted between the two points is secure and private. Without encryption, it would be possible for someone to intercept the data and read it, which would defeat the purpose of using a VPN in the first place.

9. In context with VPNs, what does PPP stand for? What is its purpose?

PPP stands for Point-to-Point Protocol. It is a network protocol that allows two computers to connect and communicate with each other over a point-to-point connection.

10. What is the importance of tunnel mode in context with IPsec?

Tunnel mode is important because it allows for the creation of a secure tunnel between two devices. This tunnel can then be used to transmit data securely between the two devices. IPsec is often used in conjunction with tunnel mode to create a secure connection.

11. Can you explain the difference between an encrypted hash-based message authentication code (HMAC) vs. plain HMAC?

The main difference between an encrypted HMAC and a plain HMAC is that the former is encrypted with a key, while the latter is not. This means that an encrypted HMAC is more secure, as it is more difficult for an attacker to tamper with the message without being detected.

12. What is the difference between MPLS and VPLS?

VPLS is a Layer 2 VPN service that uses MPLS to provide a scalable, flexible solution for connecting multiple sites. MPLS, on the other hand, is a Layer 3 VPN service that uses IP to provide a more secure connection between sites.

13. What’s the difference between MPLS and IPVPN?

MPLS is a type of VPN that uses a label switching protocol to direct traffic between network nodes. IPVPN is a type of VPN that uses IP addresses to direct traffic between network nodes.

14. What routing protocols are commonly used in VPNs?

The two most common routing protocols used in VPNs are the Border Gateway Protocol (BGP) and the Routing Information Protocol (RIP). BGP is typically used in larger VPNs because it can scale to accommodate a large number of routes. RIP is typically used in smaller VPNs because it is simpler to configure.

15. What are some ways that you can configure VPNs?

There are a few different ways that you can configure VPNs. One way is to use the built-in VPN client on your operating system. Another way is to use a third-party VPN client. Finally, you can also use a VPN service that provides you with a pre-configured VPN client.

16. Can you explain how PPTP works?

PPTP is a protocol that uses the Point-to-Point Protocol (PPP) to create a virtual private network (VPN) between two points. It works by encapsulating PPP packets in IP datagrams and then sending them over the network. The PPTP server then decapsulates the packets and sends them to the PPP client.

17. What is the difference between L2F and L2TP?

L2F, or Layer 2 Forwarding, is a tunneling protocol that was developed by Cisco. L2TP, or Layer 2 Tunneling Protocol, is an extension of the Point-to-Point Tunneling Protocol that was developed jointly by Microsoft and Cisco. L2F is designed to work with Cisco routers, while L2TP is designed to work with a variety of different routers.

18. What is the difference between MPLS and Ethernet?

The main difference between MPLS and Ethernet is that MPLS is a layer 2 protocol while Ethernet is a layer 1 protocol. MPLS is also a lot more expensive than Ethernet.

19. What are some advantages of using remote access VPNs instead of site-to-site networks?

Some advantages of using remote access VPNs instead of site-to-site networks include increased flexibility, scalability, and cost-effectiveness. With a remote access VPN, users can connect to the network from anywhere in the world, which is ideal for organizations with employees who travel or work remotely. Additionally, remote access VPNs are often more affordable than site-to-site networks and can be more easily scaled up or down to meet the changing needs of an organization.

20. What are the differences between SSL and IPsec? Which one would you recommend in certain situations?

SSL and IPsec are two different protocols that can be used to create a VPN. SSL is typically used for creating a secure connection between a web browser and a web server, while IPsec is typically used for creating a secure connection between two devices on a network. In general, SSL is easier to set up and use than IPsec, but IPsec is more secure. If security is your primary concern, then you should use IPsec. If ease of use is your primary concern, then you should use SSL.