Chapter 1 – Introduction to Networking

1. Chapter 1 – Introduction to Networking Einführung CISCO 1 The Computer is the Network.

2. Agenda • Basics • What is networking? • Physical connections • Installing Network Interface Cards (NICs) • Using Ping • Networks

3. Outline • What is networking? • Physical connections • Installing Network Interface Cards (NICs) • Using Ping

4. The role of an IT (Information Technology) Professional • Networks are no longer a “luxury”, but a required resource necessary for an organization to conduct business. • In most organizations, networks must be operational 24x7, for anything from mission critical applications to accessing email and information from off-campus. • 9 out of 10 jobs in the IT (Information Technology) industry are in non-IT companies (ITAA).

5. Computer Technician • Desktop and Network support • Responsible for setting up and maintaining the users’ computers. • Helping users with network access. • Direct user support. • Adding hardware and software • Setting up accounts, email, and access to servers • Security • Troubleshooting • Helping users

6. Network Technician • Connecting the computers to the network. • Install, manage, troubleshoot network infrastructure: • Routers, Switches, Cables, Wireless Access Points • Issues: • Security • Quality of Service • Video On Demand • IP Telephony or Voice over IP • Wireless network access. • Configure the routers and switches. • Basic configurations • Security • Traffic flow

7. System Administrator • Maintaining the “file servers”, the computers that store the software and data used by everyone. • Email, Web, DNS • Security Systems • Setting up usernames and passwords for controlling access to the network. • Setting up and maintaining the servers that control Email. • Keep the computers secure from viruses and hackers.

8. Understanding what is happening…

9. What is networking? • Communication! • An interconnection of computers and other devices: • Printers • Servers (computers) • Scanners • Network Devices • Hubs • Switches • Routers • Firewall • Modem • Wired and Wireless

10. Most successful networking applications?

11. Outline • What is networking? • Physical connections • Installing Network Interface Cards (NICs) • Using Ping

12. Requirements for Internet connection • Physical connection from a computer (PC) to a network • Telephone Modem (Analog) • Network Interface Card (NIC)

13. Requirements for Internet connection • Logical connection uses standards called protocols (rules for how information is transmitted): (More LATER!) • Ethernet • TCP/IP, a “suite of protocols”

14. Requirements for Internet connection • Applications that interprets the data and displays the information in an understandable form: • Web browser • File Transfer Protocol (FTP)

15. Four things you need to connect to other computers over the Internet and most networks • IP Address • Subnet Mask • Default Gateway Address • DNS (Domain Name Server) Address

16. Outline • What is networking? • Physical connections • Installing Network Interface Cards (NICs) • Using Ping

17. Network interface cards (NIC) A NIC is used to connect a device (computer) to a LAN (Local Area Network). The LAN is usually connected to a ISP (Internet Service Provider) When selecting a NIC, consider the following factors: • Protocols – Ethernet, Token Ring (becoming obsolete), wireless protocols: 802.11a, b, or g • Types of media – Twisted-pair, coaxial (older technology), wireless, or fiber-optic • More LATER!

18. NIC and modem installation • A modem, or modulator-demodulator, is a device that provides the computer with connectivity to a telephone line. • Converts signals from analog to digital, and digital to analog. • Depending upon your “Internet connection”, you may have just a NIC, just a modem or both.

19. Overview of high-speed and dial-up connectivity

20. Outline • What is networking? • Physical connections • Basic computer components • Installing Network Interface Cards (NICs) • Using Ping

21. TCP/IP description and configuration • Transmission Control Protocol/Internet Protocol (TCP/IP) is a set of protocols or rules developed to allow cooperating computers to share resources across a network. • Includes a “unique” (well, not always) address assigned to your computer • Much more LATER!

22. Verify IP Configuration: Win XP, NT, 2000 • ipconfig • ipconfig /all 3 1 2

23. Verify IP Configuration: Win 9x 2 1 3 4

24. TCP/IP description and configuration

25. Verify IP Configuration: MAC OS • From the Apple menu, open your Control Panel, and select the TCP/IP option. (older MacOS versions use the MacTCP control panel.) • Click on the "Info" button in the TCP/IP configuration dialog. • The configuration dialog shown to the right will be displayed. Look at the address listed next to the line "This Macintosh" • In this example, the IP address is 192.168.10.30

26. Verify IP Configuration: MAC OS X • Select the Apple Menu, choose the System Preferences option, and the Network control panel. • Select the TCP/IP tab.

27. Verify IP Configuration: Linux/Unix

28. Testing connectivity with ping Loopback Address • The ping command works by sending multiple IP packets to a specified destination. Each packet sent is a request for a reply. • The ping command is used to test the NIC transmit/receive function, the TCP/IP configuration, and network connectivity.

29. Agenda • Basics • What is networking? • Physical connections • Installing Network Interface Cards (NICs) • Using Ping • Networks

30. Time Sharing • Early networks utilized time sharing • Computer OS managed individual users, giving each one a slice of time. • Computer was fast enough so it looked as if each user had exclusive access to the computer.

31. Computer to Computer Communications • Prior to TCP/IP and the Internet, computer to computer communications was very difficult. • Difficult to share data between computers. • Different hardware • Different operating systems • Different protocols

32. Circuits Dedicated:= für eine Tätigkeit zugeordnet

33. Circuit Switching vs Packet Switching Circuit Switched Networks (PSTN – Public Switched Telephone Network, ISDN) • A type of communications where a channel or circuit is established for the duration of the call. • That circuit is dedicated to the two end nodes using it. • 1950’s/60’s the networks were analog, circuit switched networks. • Telephony companies invested millions/billions of dollars in equipment over tens of years, for that investment to be paid off over many years. • Its about guaranteed levels of service

34. Packet Switching Packet Switched Networks (Frame Relay, ATM) • Packets (messages or fragments of messages) are individually routed between nodes over data links which might be shared by many other nodes. • Packets between the same two nodes may take different routes. • Link fails or becomes unavailable, other links may be used. • More efficient use of inter-network links.

35. Circuit Switch and Packet Switched • Although the network itself may be a circuit switched or packet switched connection, that circuit could be used for a packet switched traffic (IP packets). • This will become more clear later.

36. Chapter 1 – Introduction to Networking Einführung CISCO 1 The Computer is the Network. Danke !! http://www.netzmafia.de/skripten/netze/