1. Figure 6-1 Growth pattern of Internet hosts MillionMillionMillionMillion

2. Figure 6-2 The Internet Hierarchy Subscribers ISPs NAPs The Internet Infrastructure HOME Dial-up, DSL, Cable Businesses T-1s ISP POPs T-3s Backbone

3. Figure 6-3 A Router joining three networks Router Switch Internet

5. Figure 6-5 Distance Vector vs. Link State Source Destination X Destination unreachable Link State vs Distance Vector Pure Distance Vector A B C D Cost = 5 Cost = 10 Cost = 1 Cost = 3

6. Figure 6-6 Interior and Exterior Protocols AS300 AS200 AS100 Exterior protocol running here Interior protocol running here AS (Autonomous Systems)

7. Figure 6-7 The Anatomy of an IPv4 address NNNNHHHH Network Octet 1 11110000 - 11111111 11100000 - 11101111 11000000 - 11011111 10000000 - 10111111 00000000 - 01111111 First Octet Binary Range values Host 240 - 255E 224 - 239 192 - 223 128 - 191 0 - 127 First Octet Decimal range values Host D Network C Host Network B Host A Octet 4 Octet 3 Octet 2 Class Octet = 8 bits N = network portion of the IP address H = host portion of the IP address 10.212.215.33 Class A 128.219.34.254 Class B 199.111.6.200 Class C 224.89.67.222 Class D 242.224.128.0 Class E Examples :

8. Figure 6-8 Network Address Translation PRIVATE Network PUBLIC Network Internet OUT IN NAT Router LAN A NAT router translates IP addresses coming into and leaving the private network Inside IP address: 172.16.20.1 outside IP address: 62.134.17.252 e-bay 66.135.192.87 Your IP address: 172.16.20.33

9. Figure 6-9 A firewall using DMZ Internet DMZ Firewall Router Switch Web server File server E-mail server Protected Zone Web server FTP ServerE-mail server NIC 3 NIC 2 NIC 1

10. Figure 6-10 Firewalls using Protocol Switching Internet Firewall Router Switch Web server File server E-mail server Protected Zone Router Switch Web server File server E-mail server IPX/SPX Protected Zone TCP/IP IPX/SPX only Dead zone TCP/IP IPX/SPX only TCP/IP

11. Chapter 6 Figure 6-1Growth pattern of Internet hosts Figure 6-2The Internet Hierarchy Figure 6-3Router with three networks Figure 6-4Client/Server Relationship Figure 6-5TCP/IP Suite of Protocols Figure 6-6Chat screen Figure 6-7Distance Vector vs. Link State Figure 6-8Interior and Exterior Routing Protocols Figure 6-9Network Address Translation Figure 6-10A home network firewall

13. Figure 6-4 Client Server Client Server Printer

14. Figure 6-6 Interior and Exterior Protocols AS 200AS 100 AS 300 Interior Routing Protocol Exterior Routing Protocol AS (Autonomous Systems)