McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 Chapter 31 Security Protocols in the Internet

McGraw-Hill © ©The McGraw-Hill Companies, Inc., IP Level Security Security Association Two Modes Two Security Protocols Encapsulating Security Payload (ESP) Authentication Header (AH)

McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 Figure 31.1 Transport mode

McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 Figure 31.2 Tunnel mode

McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 Figure 31.3 AH

McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 The AH protocol provides source authentication and data integrity, but not privacy. Note:

McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 Figure 31.4 ESP

McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 ESP provides source authentication, data integrity, and privacy. Note:

McGraw-Hill © ©The McGraw-Hill Companies, Inc., Transport Layer Security Position of TLS Two Protocols

McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 Figure 31.5 Position of TLS

McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 Figure 31.6 Handshake protocol

McGraw-Hill © ©The McGraw-Hill Companies, Inc., Application Layer Security Pretty Good Privacy

McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 Figure 31.7 PGP at the sender site

McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 Figure 31.8 PGP at the receiver site

McGraw-Hill © ©The McGraw-Hill Companies, Inc., Firewalls Packet-Filter Firewalls Proxy Firewalls

McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 Figure 31.9 Firewall

McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 Figure Packet-filter firewall

McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 A packet-filter firewall filters at the network or transport layer. Note:

McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 Figure Proxy firewall

McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 A proxy firewall filters at the application layer. Note:

McGraw-Hill © ©The McGraw-Hill Companies, Inc., Virtual Private Networks Private Networks Achieving Privacy VPN Technology

McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 Table 31.1 Addresses for private networks PrefixRangeTotal 10/ to / to / to

McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 Figure Private network

McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 Figure Hybrid network

McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 Figure Virtual private network

McGraw-Hill © ©The McGraw-Hill Companies, Inc., 2004 Figure Addressing in a VPN