1. Security Protocols in the Internet
Chapter 31
Security Protocols in
the Internet

2. 31.1 IP Level Security Security Association Two Modes
Two Security Protocols
Authentication Header (AH)
Encapsulating Security Payload (ESP)

3. Figure Transport mode

4. Figure Tunnel mode

5. Figure AH

6. Note:
The AH protocol provides source authentication and data integrity, but not privacy.

7. Figure ESP

8. ESP provides source authentication, data integrity, and privacy.
Note:
ESP provides source authentication, data integrity, and privacy.

9. 31.2 Transport Layer Security
Position of TLS
Two Protocols

10. Figure Position of TLS

11. Figure 31.6 Handshake protocol

12. 31.3 Application Layer Security
Pretty Good Privacy

13. Figure 31.7 PGP at the sender site

14. Figure 31.8 PGP at the receiver site

15. Firewalls
Packet-Filter Firewalls
Proxy Firewalls

16. Figure Firewall

17. Figure 31.10 Packet-filter firewall

18. A packet-filter firewall filters at the network or transport layer.
Note:
A packet-filter firewall filters at the network or transport layer.

19. Figure Proxy firewall

20. A proxy firewall filters at the application layer.
Note:
A proxy firewall filters at the application layer.

21. 31. 5 Virtual Private Networks
Achieving Privacy
VPN Technology

22. Table 31.1 Addresses for private networks
Prefix
Range
Total
10/8 to
224
172.16/12 to
220
/16 to
216

23. Figure 31.12 Private network

24. Figure Hybrid network

25. Figure 31.14 Virtual private network

26. Figure 31.15 Addressing in a VPN