3 - VPN

Question 1

VPN

Answer 1

Virtual Private Network,

Provides access to secure private networks

Question 2

VPN Protocols

Answer 2

PPTP (Point to point)
- obsolete
L2F (Layer 2 Forwarding)
L2TP (L2 Tunnelling)
IPSec

Question 3

VPN Encryption Modes

Answer 3

Tunnel Mode
- protects packet from header to payload
- more resources useful if destination should be hidden

Transport Mode
- only protects payload
- doesn’t conceal endpoint identity

Question 4

Software VPN Advantages

Answer 4

• Easy install
• Decent conneciton speed
• Portable

Question 5

Software VPN Disadvantages

Answer 5

• Difficult to configure
• VPN Server is exposed

Question 6

Hardware VPN Advantages

Answer 6

• Designed for routing
• Designed for good security
• Big network organisations

Question 7

Hardware VPN Disadvantages

Answer 7

• Cost
• CHecking compatibility with other devices

Question 8

IPSec services examples

Answer 8

• Access control
• COnnectionless integrity
• Data origin authentication
• Rejection of replayed packets
• Confidentiality

Question 9

IPSec Packet

Answer 9

IP Header
IPSec Header
Secure IP Payload

Question 10

IPsec VPN negotiation

Answer 10

A and B
1. A sends traffic to B
2. RouterA and RouterB negotiate an IKE Phase 1 session
3. Then an IKE Phase 2 session
4. Info exchanged via IPsec tunnel
5. tunnel terminated