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Chapter 05

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LANs and WLANs

LANs and WLANs

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  • Figure 5-20
  • Figure 5-44
  • Transcript

    • 1. Chapter 5 LANs and WLANsComputer Concepts 2012
    • 2. 5 Chapter Contents  Section A: Network Building Blocks  Section B: Wired Networks  Section C: Wireless Networks  Section D: Using LANs  Section E: Security Through EncryptionChapter 5: LANs and WLANs 2
    • 3. 5 SECTION A Network Building Blocks  Network Classifications  LAN Standards  Network Devices  Clients, Servers, and Peers  Physical Topology  Network Links  Communications ProtocolsChapter 5: LANs and WLANs 3
    • 4. 5 Network Classifications  Personal Area Network (PAN) – interconnection of personal digital devices or consumer electronics  Local Area Network (LAN) – usually connects computers in a single building  Metropolitan Area Network (MAN) – public high-speed network with range of about 50 miles  Wide Area Network (WAN) – covers a large geographical area and typically consists of several smaller networksChapter 5: LANs and WLANs 4
    • 5. 5 LAN Standards  LAN technologies are standardized by the Institute of Electrical and Electronics Engineers (IEEE) Project 802 – Local Network Standards – IEEE 802.3 – ARCnet – Token Ring – FDDI – EthernetChapter 5: LANs and WLANs 5
    • 6. 5 Network Devices  Each connection point on a network is referred to as a node  To connect to a LAN, a computer requires network circuitry, sometimes referred to as a network interface card (NIC)  A networked peripheral, or network-enabled peripheral, is any device that contains network circuitry to directly connect to a network  A network device, or network appliance, is any electronic device that broadcasts network data, boosts signals, or routes data to its destinationChapter 5: LANs and WLANs 6
    • 7. 5 Network DevicesChapter 5: LANs and WLANs 7
    • 8. 5 Clients, Servers, and Peers  Network devices can function as clients or as servers – Application server – File server – Print server  Networks that include one or more servers can operate in client/server modeChapter 5: LANs and WLANs 8
    • 9. 5 Physical Topology  The arrangement of devices in a network is referred to as its physical topology – Star – Ring – Bus – Mesh – Tree  Two similar networks can be connected by a device called a bridge  Gateway is a generic term for any device or software code used to join two networksChapter 5: LANs and WLANs 9
    • 10. 5 Network Links  A communications channel, or link, is a physical path or frequency for signal transmissions  Bandwidth is the transmission capacity of a communications channel – Broadband – NarrowbandChapter 5: LANs and WLANs 10
    • 11. 5 Communications Protocols  Rules for efficiently transmitting data from one network node to another: – Divide messages into packets – Affix addresses to packets – Initiate transmission – Regulate flow of data – Check for transmission errors – Acknowledge receipt of transmitted dataChapter 5: LANs and WLANs 11
    • 12. 5 Communications Protocols  A packet is a “parcel” of data that is sent across a computer network – Circuit-switching technology vs. packet switching technologyChapter 5: LANs and WLANs 12
    • 13. 5 Communications Protocols  Every packet that travels over a network includes the address of its destination device  A MAC address is a unique number assigned to a network interface card when it is manufactured  An IP address is a series of numbers used to identify a network device  IP addresses can also be obtained through DHCPChapter 5: LANs and WLANs 13
    • 14. 5 SECTION B Wired Networks  Wired Network Basics  Ethernet  Ethernet Equipment  Ethernet SetupChapter 5: LANs and WLANs 14
    • 15. 5 Wired Network Basics  A wired network uses cables to connect network devices  Wired networks are fast, secure, and simple to configure  Devices tethered to cables have limited mobilityChapter 5: LANs and WLANs 15
    • 16. 5 Ethernet  Simultaneously broadcasts data packets to all network devices – IEEE 802.3 – CSMA/CD protocol  Vary in speed from 10Mbps to 100GbpsChapter 5: LANs and WLANs 16
    • 17. 5 EthernetChapter 5: LANs and WLANs 17
    • 18. 5 Ethernet EquipmentChapter 5: LANs and WLANs 18
    • 19. 5 Ethernet Equipment  Ethernet adapter (designed to support the Ethernet protocols)  Network hub  Network switch  Network router  RJ45 connectorChapter 5: LANs and WLANs 19
    • 20. 5 Ethernet SetupChapter 5: LANs and WLANs 20
    • 21. 5 Ethernet SetupChapter 5: LANs and WLANs 21
    • 22. 5 Ethernet SetupChapter 5: LANs and WLANs 22
    • 23. 5 SECTION C Wireless Networks  Wireless Basics  Bluetooth  Wi-Fi  Wi-Fi Equipment  Wi-Fi SetupChapter 5: LANs and WLANs 23
    • 24. 5 Wireless Basics  A wireless network transports data from one device to another without cables or wires – RF signals • Transceiver – Microwaves – Infrared light  Slower than wired networks  Security concernsChapter 5: LANs and WLANs 24
    • 25. 5 Bluetooth  Bluetooth is a short-range, wireless network technology designed to make its own connections between electronic devices, without wires, cables, or any direct action from a userChapter 5: LANs and WLANs 25
    • 26. 5 Wi-Fi  Wireless networking technologies that are compatible with Ethernet  MIMO technology uses two or more antennas to send multiple sets of signals between network devicesChapter 5: LANs and WLANs 26
    • 27. 5 Wi-Fi EquipmentChapter 5: LANs and WLANs 27
    • 28. 5 Wi-Fi Equipment  If your computer is not pre-equipped with wireless circuitry, you can purchase and install a Wi-Fi adapterChapter 5: LANs and WLANs 28
    • 29. 5 Wi-Fi Equipment  Wireless network setups – Wireless ad-hoc network – Wireless infrastructure network • Wireless access point • Wireless router – MiFiChapter 5: LANs and WLANs 29
    • 30. 5 Wi-Fi Setup  Set up the router  Connect to the router with a computer  Configure the router  Access the router setup utility  Create a new router passwordChapter 5: LANs and WLANs 30
    • 31. 5 Wi-Fi Setup  Enter an SSID for the network  Activate WEP, WPA, or PSK and create an encryption key  Set up the wireless workstations  Connect an Internet access deviceChapter 5: LANs and WLANs 31
    • 32. 5 Wi-Fi SetupChapter 5: LANs and WLANs 32
    • 33. 5 SECTION D Using LANs  LAN Advantages and Challenges  Sharing Files  Sharing Printers  Network TroubleshootingChapter 5: LANs and WLANs 33
    • 34. 5 LAN Advantages and Challenges  LANs enable people to work together  Sharing networked software can reduce costs  Sharing data on a LAN can increase productivity  Sharing networked hardware can reduce costs  Sharing networked hardware can provide access to a wide range of services and specialized peripheral devicesChapter 5: LANs and WLANs 34
    • 35. 5 LAN Advantages and Challenges  Resources become unavailable when network malfunctions  Networks may be vulnerable to unauthorized access – More vulnerable than standalone computers  Wireless networks can be tapped from any computers within range of the wireless signal  Networked computers are susceptible to an increasing number of worms, Trojan horses, and blended threatsChapter 5: LANs and WLANs 35
    • 36. 5 Sharing Files  If you use Windows, it automatically detects available LANs any time you turn on a workstation  To connect to a shared resource, you might be asked for a user ID and passwordChapter 5: LANs and WLANs 36
    • 37. 5 Sharing FilesChapter 5: LANs and WLANs 37
    • 38. 5 Sharing FilesChapter 5: LANs and WLANs 38
    • 39. 5 Sharing Files  A homegroup is a collection of trusted networked computers that automatically share files and foldersChapter 5: LANs and WLANs 39
    • 40. 5 Sharing Printers  Three setups allow for printer sharing: – Set up printer sharing using a workstation printer – Set up printer sharing using a print server – Install printer with built-in networkingChapter 5: LANs and WLANs 40
    • 41. 5 Sharing PrintersChapter 5: LANs and WLANs 41
    • 42. 5 Troubleshooting  Network problems can stem from a variety of sources – Cables – Signal strength – Security – Interference – Network devices – Settings – SwitchesChapter 5: LANs and WLANs 42
    • 43. 5 SECTION E Security Through Encryption  Wi-Fi Security  EncryptionChapter 5: LANs and WLANs 43
    • 44. 5 Wi-Fi Security  Wireless networks are much more susceptible to unauthorized access and use than wired networks  LAN jacking, or war driving, is the practice of intercepting wireless signals by cruising through an areaChapter 5: LANs and WLANs 44
    • 45. 5 Wi-Fi Security  Wireless encryption scrambles data transmitted between wireless devices and then unscrambles the data only on devices that have a valid encryption key – WEP (Wired Equivalent Privacy) – WPA (Wi-Fi Protected Access) – WPA2 – PSK  Activate encryption by using a wireless network keyChapter 5: LANs and WLANs 45
    • 46. 5 Wi-Fi SecurityChapter 5: LANs and WLANs 46
    • 47. 5 Encryption  Encryption transforms a message so that its contents are hidden from unauthorized readers – Plaintext has not yet been encrypted – An encrypted message is referred to as ciphertext  Decryption is the opposite of encryption – Cryptographic algorithm – Cryptographic keyChapter 5: LANs and WLANs 47
    • 48. 5 Encryption  Weak vs. strong encryption  AES (Advanced Encryption Standard)  Encryption methods can be broken by the use of expensive, specialized, code-breaking computers – Brute force attackChapter 5: LANs and WLANs 48
    • 49. 5 Encryption  Public key encryption (PKE) eliminates key-distribution problem, by using one key to encrypt a message and another key to decrypt the messageChapter 5: LANs and WLANs 49
    • 50. 5 Encryption  When personal computer users want to encrypt e-mail or other documents, they turn to public key encryption software called PGP (Pretty Good Privacy)Chapter 5: LANs and WLANs 50
    • 51. Chapter 5 CompleteComputer Concepts 2012

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