1. The Basics of Networking

2. Rick Graziani graziani@cabrillo.edu2 What is networking? Communication! An interconnection of computers and other devices: –Printers –Servers (computers) –Scanners –Network Devices Hubs Switches Routers Firewall Modem

3. Rick Graziani graziani@cabrillo.edu3 Most successful networking applications?

4. Rick Graziani graziani@cabrillo.edu4 What is in a network? Computers…

5. Rick Graziani graziani@cabrillo.edu5 What is in a network? Hubs and Switches… Hub: Only one device at a time can talk. Switch: Multiple devices can talk at the same time.

6. Rick Graziani graziani@cabrillo.edu6 What is in a network? Telephone Modems…

7. Rick Graziani graziani@cabrillo.edu7 What is in a network? DSL and Cable Modems…

8. Rick Graziani graziani@cabrillo.edu8 Extending your network and protecting yourself!

9. Rick Graziani graziani@cabrillo.edu9 Connecting your DSL or Cable Modem When using NAT (Network Address Translation, the Router helps hide your network. 204.180.205.1 192.168.1.10

10. Rick Graziani graziani@cabrillo.edu10 They also allow more devices on your home network!

11. Rick Graziani graziani@cabrillo.edu11 What is the Internet? The Internet was originally designed by DARPA (Defense Advanced Research Projects Agency) in response to the U.S.S.R. launching Sputnik, the first satellite. Out of this came the Internet, a way for computers to communicate from different parts of the world. These computers can be any type of computer using any type of operating system, as long as they are using the protocol TCP/IP.

12. Rick Graziani graziani@cabrillo.edu12 What is TCP/IP? What is a protocol? A protocol is nothing more than an agreement, a standard way of organizing network information. The sender and receiver, and everyone in between, must agree on how this information is organized. The actual letter (data) is inside (encapsulated) the envelope.

13. Rick Graziani graziani@cabrillo.edu13 TCP/IP Transmission Control Protocol / Internet Protocol TCP/IP is a suite of protocols. IP (Internet Protocol) is used for sender and receiver addressing. Every computer on the Internet or a network must have an IP address to communicate. Part of the IP address is the network address. Example: The destination address is 192.168.1.0 which includes all computers from 192.168.1.1 to 192.168.1.254. Source IP Address: 172.16.10.5 Destination IP Address 192.168.1.10 This is known as an IP Packet

14. Rick Graziani graziani@cabrillo.edu14 What is the IP Address on my computer?

15. Rick Graziani graziani@cabrillo.edu15 Pinging another computer

16. Rick Graziani graziani@cabrillo.edu16 Routers Routers are network devices that connect two or more networks together. Computers usually belong to a single network. Router connect multiple networks.

17. Rick Graziani graziani@cabrillo.edu17 DSL Router When using NAT (Network Address Translation, the Router helps hide your network. 204.180.205.1 192.168.1.10

18. Rick Graziani graziani@cabrillo.edu18 Rick’s IP Packet Analogy…

19. Rick Graziani graziani@cabrillo.edu19 Do I need to know IP Addresses? No! Domain is a related group of networked computers: –Cabrillo.edu –Yahoo.com –Google.com All you need to know is the domain name.

20. Rick Graziani graziani@cabrillo.edu20 Domain Name Servers (DNS) I know the Domain Name but IP uses IP addresses. How does a Domain Name (yahoo.com) get translated to an IP address (216.109.125.69)? Using a Domain Name Server 216.109.125.69 172.16.22.73 Source IP address Destination IP address

21. Rick Graziani graziani@cabrillo.edu21 Domain Name Servers (DNS)

22. Rick Graziani graziani@cabrillo.edu22 Domain Name Servers (DNS)

23. Rick Graziani graziani@cabrillo.edu23 Domain Name Servers (DNS)

24. Rick Graziani graziani@cabrillo.edu24 Domain Name Servers (DNS)

25. Rick Graziani graziani@cabrillo.edu25 Does my computer use a DNS server? Yes!

26. Rick Graziani graziani@cabrillo.edu26 Ethernet Networks Most Local Area Networks (LANs) use the Ethernet protocol. Each Ethernet Network Interface Card (NIC) has an “Ethernet Address”. Yes, computers have two addresses: Ethernet Address and an IP Address

27. Rick Graziani graziani@cabrillo.edu27 Ethernet Networks So, how is an Ethernet Address used?

28. Rick Graziani graziani@cabrillo.edu28 Ethernet Networks How is the Ethernet address used? The packet is put inside an Ethernet frame. The Ethernet source address (MAC address) is your computer. If the two computers are on the same LAN (Local Area Network) then the destination MAC address is the other computer. If the two computers are on different LANs then the destination MAC address is that of the router. Much more in CIS 81. Inside the packet Inside the Ethernet Frame Source Ethernet address Destination Ethernet address

29. Rick Graziani graziani@cabrillo.edu29 Ethernet Networks Hubs and Switches connect Ethernet devices on the same LAN. Routers connect LANs together over WANs (Wide Area Networks).

30. Rick Graziani graziani@cabrillo.edu30 WANs (Wide Area Networks) Telecommunications companies –SBC –Quest –MCI –AT&T

31. What does an IT (Information Technology) or Networking person do? Networks are no longer a luxury, but a requirement to keep the organization running.

32. Rick Graziani graziani@cabrillo.edu32 Computer Support Specialist Installing computer hardware and software. Troubleshooting Maintenance and upgrades

33. Rick Graziani graziani@cabrillo.edu33 Networking: System Administrator Installing, configuring, and maintaining network servers UNIX, LINUX, Microsoft Web, DNS, DHCP, Mail Servers Backup and recovery, user administration Security

34. Rick Graziani graziani@cabrillo.edu34 Networking: Network Technician/Analyst Install, manage, troubleshoot network infrastructure: –Routers, Switches, Cables, Wireless Access Points Issues: Security, Quality of Service, Video On Demand, Voice over IP

35. Rick Graziani graziani@cabrillo.edu35 Keeping up on technology Wireless Security

36. Rick Graziani graziani@cabrillo.edu36 Knowing what you are doing…

37. Rick Graziani graziani@cabrillo.edu37 Understanding what others do not