VPN

Question 1

What does VPN stand for?

Answer 1

Virtual Private Network

Question 2

What is the main purpose of a VPN?

Answer 2

To securely connect remote users or sites over an untrusted network like the internet

Question 3

What are the two main types of VPNs?

Answer 3

Remote Access VPN and Site-to-Site VPN

Question 4

Which VPN type is used for connecting a single user to a private network?

Answer 4

Remote Access VPN

Question 5

Which VPN type is used to connect two networks together securely?

Answer 5

Site-to-Site VPN

Question 6

What are two protocols used to establish VPNs at Layer 3?

Answer 6

IPsec and GRE

Question 7

What does IPsec stand for?

Answer 7

Internet Protocol Security

Question 8

What are the three main functions of IPsec?

Answer 8

Confidentiality; Integrity; and Authentication

Question 9

Which protocol in IPsec provides encryption?

Answer 9

Encapsulating Security Payload (ESP)

Question 10

Which protocol in IPsec provides authentication and integrity?

Answer 10

Authentication Header (AH)

Question 11

What are the two main IPsec tunnel modes?

Answer 11

Tunnel mode and Transport mode

Question 12

What mode is typically used in Site-to-Site VPNs?

Answer 12

Tunnel mode

Question 13

What mode is typically used in host-to-host VPNs?

Answer 13

Transport mode

Question 14

Which ports does IKE (Internet Key Exchange) use?

Answer 14

UDP 500 and UDP 4500 (for NAT traversal)

Question 15

What is the purpose of IKE in IPsec?

Answer 15

To negotiate and establish secure keys for the VPN

Question 16

What is a GRE tunnel?

Answer 16

A tunneling protocol that encapsulates a wide variety of network layer protocols

Question 17

What is a disadvantage of GRE?

Answer 17

It does not provide encryption or security by itself

Question 18

How can you add security to a GRE tunnel?

Answer 18

Combine GRE with IPsec

Question 19

What is DMVPN?

Answer 19

Dynamic Multipoint VPN – a Cisco solution for scalable; secure VPNs

Question 20

What technology does DMVPN rely on?

Answer 20

NHRP (Next Hop Resolution Protocol) and multipoint GRE

Question 21

What is the function of NHRP in DMVPN?

Answer 21

It maps public IP addresses to tunnel IPs

Question 22

What is the benefit of DMVPN over traditional Site-to-Site VPNs?

Answer 22

It allows spoke-to-spoke tunnels without static configurations

Question 23

What is SSL VPN?

Answer 23

A VPN that uses the SSL/TLS protocol to secure the connection; often through a web browser

Question 24

What is a common use case for SSL VPNs?

Answer 24

Secure remote access via web browser without a full VPN client

Question 25

Which VPN protocol is commonly supported natively in Windows?

Answer 25

PPTP (though outdated) and L2TP/IPsec

Question 26

What is split tunneling?

Answer 26

A method that allows VPN traffic and local internet traffic to coexist

Question 27

What is the risk of split tunneling?

Answer 27

It can expose the internal network to threats from the user's local network