 LANs and WLANs LANs and WLANs1

 Network Building Blocks  Wired Networks  Wireless Networks  Using LANs  Security Through Encryption LANs and WLANs2

Network Building Blocks Network Classifications LAN Standards Network Devices Clients, Servers, and Peers Physical Topology Network Links Communications Protocols LANs and WLANs3

 Personal Area Network (PAN) – interconnection of personal digital devices  Neighborhood Area Network (NAN) – connectivity spread over several buildings  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) – consists of several smaller networks LANs and WLANs4

 LAN technologies are standardized by the Institute of Electrical and Electronics Engineers (IEEE) Project 802 – Local Network Standards  IEEE  Ethernet LANs and WLANs5

 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 destination LANs and WLANs6

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 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 mode LANs and WLANs8

 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 networks LANs and WLANs9

 A communications channel, or link, is a physical path or frequency for signal transmissions  Bandwidth is the transmission capacity of a communications channel  Broadband  Narrowband LANs and WLANs10

 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 data LANs and WLANs11

 A packet is a “parcel” of data that is sent across a computer network  Circuit-switching technology vs. packet switching technology  Voice over IP (VoIP) LANs and WLANs12

 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 DHCP LANs and WLANs13

LANs and WLANs14  Wired Network Basics  HomePNA and Powerline Networks  Ethernet  Ethernet Equipment  Ethernet Setup

 A wired network uses cables to connect network devices  Wired networks are fast, secure, and simple to configure  Devices tethered to cables have limited mobility LANs and WLANs15

 HomePNA networks utilize existing telephone wiring to connect network devices  Special NICs and cables are required  Powerline networks transmit data over power lines as low-frequency radio waves LANs and WLANs16

 Simultaneously broadcasts data packets to all network devices  IEEE  CSMA/CD protocol  Vary in speed from 10Mbps to 10Gbps LANs and WLANs17

LANs and WLANs18 On an Ethernet, data travels on a first come, first served basis. If two workstations attempt to send data at the same time, a collision occurs. That data must be resent.

LANs and WLANs19 Checking a workstation for an Ethernet port

 Ethernet adapter (designed to support the Ethernet protocols)  Network hub  Network switch  Network router  RJ45 connector LANs and WLANs20

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 The Network Connection window helps you check your connection LANs and WLANs23

 Wireless Basics  Bluetooth  Wi-Fi  Wi-Fi Equipment  Wi-Fi Setup LANs and WLANs24

 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 concerns LANs and WLANs25

 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 user LANs and WLANs26

 Wireless networking technologies that are compatible with Ethernet  MMO technology uses two or more antennae to send multiple sets of signals LANs and WLANs27

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 If your computer is not pre-equipped with wireless circuitry, you can purchase and install a Wi-Fi card LANs and WLANs29

 Wireless network setups  Wireless ad-hoc network  Wireless infrastructure network  Wireless access point  Wireless router LANs and WLANs30

 Set up the router  Connect to the router with a computer  Configure the router  Access the router setup utility  Create a new router password LANs and WLANs31

 Enter an SSID for the network  Activate WEP, WPA, or WPA2 and create an encryption key  Set up the wireless workstations  Connect an Internet access device LANs and WLANs32

LANs and WLANs33

 LAN Advantages and Challenges  Sharing Files  Sharing Printers  LAN Parties  Troubleshooting LANs and WLANs34

 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 devices LANs and WLANs35

 Resources become unavailable when network malfunctions  Networks may be vulnerable to unauthorized access  More vulnerable than standalone computers  Wireless networks can be tapped from a “snooping” computer  Networked computers are susceptible to an increasing number of worms, Trojan horses, and blended threats LANs and WLANs36

LANs and WLANs37 Change the default password for your router when you install a wireless network.

 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 password LANs and WLANs38

LANs and WLANs39 In this drive mapping example, a server’s drive C is mapped as drive F by a workstation. After the mapping is complete, the server’s hard disk appears in the workstation’s directory as drive F and can be used just as though it were a drive connected directly to the workstation.

LANs and WLANs40 To allow other network users to access files or folders on your Windows computer, you have to designate them as shared.

 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 networking LANs and WLANs41

 In Windows, use the Printers and Faxes dialog box to allow other users to share the printer attached to your workstation LANs and WLANs42

 A LAN party is a gathering of people who connect their own computers to a LAN, usually to play multiplayer computer games  No special hardware usually is required  Game must have multiplayer capability LANs and WLANs43

 Network problems can stem from a variety of sources  Cables  Signal strength  Interference  Network devices  Security  Settings LANs and WLANs44

 Wi-Fi Security  Encryption LANs and WLANs45

 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 area LANs and WLANs46

 An offshoot of war driving is a gambit called war chalking LANs and WLANs47

 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  Activate encryption by using a wireless network key LANs and WLANs48

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 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 key LANs and WLANs50

 Weak vs. strong encryption  AES (Advanced Encryption Standard)  Encryption methods can be broken by the use of expensive, specialized, code-breaking computers  Brute-force method LANs and WLANs51

 Public key encryption (PKE) eliminates key- distribution problem, by using one key to encrypt a message and another key to decrypt the message LANs and WLANs52

 When personal computer users want to encrypt or other documents, they turn to public key encryption software called PGP (Pretty Good Privacy) software LANs and WLANs53