If you are exploring the job options in the networking sector then most probably you will be asked some VPN interview questions during job selection. We have gathered the questions which can help the candidates to have an idea about VPN and thus to clear the interview. VPN interview questions and answers will be for job profiles like Network Administrator, Network Test Manager, Network Engineer.
Table of Contents
VPN Interview Questions
What is VPN?
VPN is the virtual connection that creates a private network over a public network that provides users online privacy and anonymity. It is a network of hosts which communicate over a public network with encryption and authentication to keep data secure and hidden from theft, unauthorized access.
What is the full form of VPN?
VPN is Virtual Private Network.
Name the security services VPN provides?
- Confidentiality
- Integrity
- Authentication
- Availability
- Anti-replay
- Encrypted data
What are VPN types?
There are two types of VPN.
- Remote Access VPN
- Site to Site VPN.
Name all the VPN protocols?
- PPTP (Point-to-Point Tunneling Protocol)
- L2TP (Layer 2 Tunneling Protocol)
- IPsec (Internet Protocol Security)
- GRE (Generic Routing Encapsulation)
- TSL (Transport Layer Security)
- SSL (Secure Sockets Layer)
- IKEv2
- WireGuard
What is PPTP?
Point-to-Point Tunneling is one of the oldest techniques in network security. PPTP client establishes a tunnel which then transports all your data online and also encrypting at the same time. It uses the TCP port 1723. It operates at layer 2 of the OSI model. It supports Voluntary Tunneling and Compulsory Tunneling.
What is L2TP?
Layer 2 Tunneling Protocol (L2TP) is an extension of PPTP and is a tunneling protocol that establishes a VPN over a public network. It was first published in 1999 combing the features from Microsoft PPTP and Cisco L2F. L2TP tunneling initiates a connection between two endpoints LAC (L2TP Access Concentrator) and LNS (L2TP Network Server), once this is established then the traffic moves bidirectionally. L2TP packed includes the payload and L2TP header that is sent within UDP with port number 1701.
What is IPsec?
IPsec term stands for “IP” internet Protocol and “sec” is for secure. It provides starting authentication mechanism, data encryption and authenticates the source where the data came from. IPsec works on the network layer of the OSI model and it provides security to IPV4 and IPv6. IPsec is a group of various protocols like Security Associations (SA), Encapsulating Security Payloads (ESP), Authentication Header (AH), Internet Key Exchange (IKE & IKEv2), Internet Security Association, and Key Management Protocol (ISAKMP). IPsec used port 500.
Which port does IKE use?
UDP port 500.
Which layers IPsec works on?
IPsec protocol suite works on the network layer of the OSI model.
What are the three main security services IPsec provides?
Message confidentiality
Message integrity
Traffic analysis protection
What is GRE?
Generic Routing Encapsulation is a protocol for encapsulating the data packets.
What is TSL?
Transport layer security is a protocol to provide privacy and data security over the internet. TLS is used to encrypt communication between web applications and servers and can encrypt voice over IP, messaging, and email.
What is SSL?
Secure Socket Layer is an encryption-based internet security protocol that operates on presentation layer 6 of the OSI model.
What is the SSL port number?
SSL VPN uses port 443.
What are data packets?
It is a bit of data from a bigger message which is transmitted over internet protocol. Data packets have headers that contain the routing information. In TCP/IP model packets are known as datagrams.
What is encapsulation?
Whenever we send data it is encapsulated from the sender’s side and de-encapsulated at the receiver end.
The term used in both layers to represent encapsulated data.
| Term | OSI layer | TCP/IP layer |
| Data | Application | Application |
| Data | Presentation | |
| Data | Session | |
| Segment | Transport | Transport |
| Packet | Network | Network |
| Frame | Data Link | Data Link |
| Bits | Physical | Physical |
TCP IP Interview Questions
What is authorization?
It is a process to give users access to perform some operations on the platform. For example, in order to login into Gmail, you need a google account and username and password.
What are Symmetric and Asymmetric Encryption?
Difference between transport and tunnel mode?
What are the different authentication methods used in VPN?
What is VRRP?
What is GLBP?
What is HSRP?
What Is The Relationship Between VPN And Firewalls?
Is VPN good or bad?
What is Diffie-Hellman?
How Diffie-Hellman works?
What is Transform set?
What is the difference between Static Crypto Maps and Dynamic Crypto Maps?
What is Cisco Easy VPN?
What is DMVPN?
What are the three phases of DMVPN?
Who Are The Major Players In The Market?
Explain SSL Handshake?
Name some of the encryption methods?
At what layer does IPSEC and SSL VPN work on?
Other VPN Interview Questions
What are VPN advantages?
The advantages of VPN are
- Data Security
- Private Network Access
- Bandwidth
- Cost Reduction
- Deployment Flexibility
- Network Scalability
What are VPN disadvantages?
- It is illegal in some countries.
- Privacy is not always guaranteed.
- Slows the internet speed.
- Good VPN is expensive.
- VPN companies might monitor your activity online.
- VPN increases data consumption.
- VPN does not protect from Malware and phishing attack.
What are the disadvantages of IPsec?
VPN FAQ
Can you be tracked if you use VPN?
What is illegal to do with VPN?
Why should we use VPN?
How to choose the best VPN?
What is VPN kill switch?
Difference between free and paid VPN?
If VPN is legal in my country?
How to set up VPN on device?
How much does VPN cost?
How to check if VPN is working?
Please let us know if VPN interview questions have been asked to you during an interview, this will give another candidate an idea of what to expect in networking interview questions.
please provide interview IPsec VPN GRE QUEStion and answer