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Chapter 6 - Network Hardware


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Chapter 6 - Network Hardware

  1. 1. Chapter Six Networking Hardware
  2. 2. Network Adapters <ul><li>Also called network interface cards (NICs) </li></ul><ul><li>Connectivity devices enabling a workstation, server, printer, or other node to receive and transmit data over the network media </li></ul><ul><li>In most modern network devices, network adapters contain the data transceiver </li></ul>
  3. 3. Types of Network Adapters <ul><li>For a desktop or tower PC, network adapter is likely to be a type of expansion board </li></ul><ul><ul><li>Expansion boards connect to the system board through expansion slots </li></ul></ul><ul><li>The circuit used by the system board to transmit data to the computer’s components is the computer’s bus </li></ul>
  4. 4. Types of Network Adapters <ul><li>PC bus types you may encounter: </li></ul><ul><ul><li>Industry Standard Architecture (ISA) </li></ul></ul><ul><ul><li>MicroChannel Architecture (MCA) </li></ul></ul><ul><ul><li>Extended Industry Standard Architecture (EISA) </li></ul></ul><ul><ul><li>Peripheral Component Interconnect (PCI) </li></ul></ul>Figure 6-1: The four primary bus architectures
  5. 5. Types of Network Adapters Figure 6-2: A system board with multiple bus types
  6. 6. Types of Network Adapters <ul><li>PCMIA </li></ul><ul><ul><li>Developed in early 1990s to provide standard interface for connecting any type of device to a portable computer </li></ul></ul><ul><ul><li>More commonly known as PC Cards </li></ul></ul>Figure 6-3: Typical PC Card network adapter
  7. 7. Types of Network Adapters <ul><li>USB (universal serial bus) port </li></ul><ul><ul><li>Standard external bus that can be used to connect multiple types of peripherals </li></ul></ul>Figure 6-4: A USB network adapter
  8. 8. Types of Network Adapters Figure 6-5: A parallel port network adapter
  9. 9. Types of Network Adapters Figure 6-6: Wireless network adapters
  10. 10. Types of Network Adapters Figure 6-7: A variety of Ethernet network adapters
  11. 11. Types of Network Adapters Figure 6-8: Token Ring network adapters
  12. 12. Types of Network Adapters Figure 6-9: Ethernet network adapters for printers
  13. 13. Installing Network Adapters <ul><li>To install modern network adapters, first install hardware, then install software shipped with NIC </li></ul><ul><li>In some cases you must perform a third step: </li></ul><ul><ul><li>Configure the firmware </li></ul></ul><ul><li>Electrically erasable programmable read-only memory (EEPROM) </li></ul><ul><ul><li>Type of ROM found on a circuit board </li></ul></ul><ul><ul><li>Configuration information can be erased and rewritten through electrical pulses </li></ul></ul>
  14. 14. Installing and Configuring Network Adapter Hardware Figure 6-10: A properly inserted network adapter
  15. 15. Installing and Configuring Network Adapter Hardware Figure 6-11: Installing a PC Card network adapter
  16. 16. Installing and Configuring Network Adapter Hardware <ul><li>Jumper </li></ul><ul><ul><li>Small, removable piece of plastic that contains a metal receptacle </li></ul></ul>Figure 6-12: A jumper and a row of pins indicating two different settings
  17. 17. Installing and Configuring Network Adapter Hardware <ul><li>DIP switch </li></ul><ul><ul><li>Small, plastic toggle switch that represents “on” or “off” status </li></ul></ul>Figure 6-13: DIP switches on a NIC
  18. 18. Installing and Configuring Network Adapter Software <ul><li>Ensure that the correct device driver is installed for the network adapter and that it is configured properly </li></ul><ul><li>Device driver </li></ul><ul><ul><li>Software that enables an attached device to communicate with computer’s operating system </li></ul></ul>
  19. 19. IRQ (Interrupt Request Line) <ul><li>Message to the computer that instructs it to stop what it is doing and pay attention to something else </li></ul><ul><li>An interrupt is the wire on which a device issues voltage to signal this request </li></ul><ul><li>Each interrupt must have a unique IRQ number </li></ul>
  20. 20. IRQ (Interrupt Request Line) Table 6-1: IRQ assignments
  21. 21. Memory Range and Base I/O Port <ul><li>Memory range </li></ul><ul><ul><li>Hexadecimal number indicating the area memory that the network adapter and CPU will use for exchanging, or buffering, the data </li></ul></ul><ul><li>Base I/O port </li></ul><ul><ul><li>Setting that specifies, in hexadecimal notation, which area of memory will act as a channel for moving data between the network adapter and CPU </li></ul></ul>
  22. 22. Choosing the Right Network Adapter Table 6-2: Network adapter characteristics
  23. 23. Repeaters <ul><li>Connectivity devices that regenerate and amplify an analog or digital signal </li></ul>Figure 6-16: Repeaters
  24. 24. Hubs <ul><li>Multiport repeater containing multiple ports to interconnect multiple devices </li></ul>Figure 6-17: Detailed diagram of a hub
  25. 25. Hubs <ul><li>Elements shared by most hubs: </li></ul><ul><ul><li>Ports </li></ul></ul><ul><ul><li>Uplink port </li></ul></ul><ul><ul><li>Port for management console </li></ul></ul><ul><ul><li>Backbone port </li></ul></ul><ul><ul><li>Link LED </li></ul></ul>
  26. 26. Hubs <ul><li>Elements shared by most hubs (cont.): </li></ul><ul><ul><li>Traffic (transmit or receive) LED </li></ul></ul><ul><ul><li>Collision LED (Ethernet hubs only) </li></ul></ul><ul><ul><li>Power supply </li></ul></ul><ul><ul><li>Ventilation fan </li></ul></ul>
  27. 27. Hubs Figure 6-18: Hubs in a network design
  28. 28. Hubs <ul><li>Passive hubs </li></ul><ul><ul><li>Only repeats signal </li></ul></ul><ul><li>Intelligent hubs </li></ul><ul><ul><li>Possesses processing capabilities </li></ul></ul>
  29. 29. Standalone Hubs <ul><li>Hubs that serve a group of computers that are isolated from the rest of the network </li></ul><ul><ul><li>Best suited to small, independent departments, home offices, or test lab environments </li></ul></ul><ul><li>Disadvantage to using a single hub for many connection ports is that it introduces a single point of failure on the network </li></ul>
  30. 30. Stackable Hubs <ul><li>Physically designed to be linked with other hubs in a single telecommunications closet </li></ul>Figure 6-20: Stackable hubs Figure 6-21: Rack-mounted stackable hubs
  31. 31. Modular Hubs and Intelligent Hubs <ul><li>Modular hubs </li></ul><ul><ul><li>Provide a number of interface options within one chassis </li></ul></ul><ul><li>Intelligent hubs </li></ul><ul><ul><li>Also called managed hubs </li></ul></ul><ul><ul><li>Network administrators can store the information generated by intelligent hubs in a MIB (management information base) </li></ul></ul>
  32. 32. Installing a Hub <ul><li>As with network adapters, the best way to ensure a hub is properly installed is to follow the manufacturer’s guidelines </li></ul>Figure 6-22: Connecting a workstation to a hub
  33. 33. Choosing the Right Hub <ul><li>Factors to consider when selecting the right hub for your network: </li></ul><ul><ul><li>Performance </li></ul></ul><ul><ul><li>Cost </li></ul></ul><ul><ul><li>Size and growth </li></ul></ul><ul><ul><li>Security </li></ul></ul><ul><ul><li>Management benefits </li></ul></ul><ul><ul><li>Reliability </li></ul></ul>
  34. 34. Switches <ul><li>Subdivide a network into smaller logical pieces </li></ul>Figure 6-25: Examples of LAN switches
  35. 35. Cut-Through Mode and Store and Forward Mode <ul><li>Cut-through mode </li></ul><ul><ul><li>Switching mode in which switch reads a frame’s header and decides where to forward the data before it receives the entire packet </li></ul></ul><ul><ul><li>Cut-through switches can detect runts , or packet fragments </li></ul></ul><ul><li>Store and forward mode </li></ul><ul><ul><li>Switching mode in which switch reads the entire data frame into its memory and checks it for accuracy before transmitting the information </li></ul></ul>
  36. 36. Using Switches to Create VLANs <ul><li>Virtual local area networks (VLANs) </li></ul><ul><ul><li>Network within a network that is logically defined by grouping its devices’ switch ports in the same broadcast domain </li></ul></ul><ul><li>Broadcast domain </li></ul><ul><ul><li>Combination of ports that make up a Layer 2 segment and must be connected by a Layer 3 device </li></ul></ul>
  37. 37. Using Switches to Create VLANs Figure 6-26: A simple VLAN design
  38. 38. Routers <ul><li>Multiport connectivity device </li></ul><ul><li>Can integrate LANs and WANs running at different transmission speeds and using a variety of protocols </li></ul><ul><li>Routers operate at the Network layer (Layer 3) of the OSI Model </li></ul>
  39. 39. Router Features and Functions <ul><li>Modular router </li></ul><ul><ul><li>Router with multiple slots that can hold different interface cards or other devices </li></ul></ul>Figure 6-27: Routers
  40. 40. Router Features and Functions <ul><li>Filter out broadcast transmission to alleviate network congestion </li></ul><ul><li>Prevent certain types of traffic from getting to a network </li></ul><ul><li>Support simultaneous local and remote activity </li></ul><ul><li>Provide high network fault tolerance through redundant components </li></ul><ul><li>Monitor network traffic and report statistics to a MIB </li></ul><ul><li>Diagnose internal or other connectivity problems and trigger alarms </li></ul>
  41. 41. Router Features and Functions <ul><li>Static routing </li></ul><ul><ul><li>Technique in which a network administrator programs a router to use a specified paths between nodes </li></ul></ul><ul><li>Dynamic routing </li></ul><ul><ul><li>Automatically calculates best path between nodes and accumulates this information in a routing table </li></ul></ul><ul><li>Hop </li></ul><ul><ul><li>Term used in networking to describe each trip data take from one connectivity device to another </li></ul></ul>
  42. 42. Router Features and Functions Figure 6-28: The placement of routers on a LAN
  43. 43. Routing Protocols <ul><li>To determine the best path , routers communicate with each other through routing protocols </li></ul><ul><li>In addition to its ability to find the best path, a routing protocol can be characterized according to its convergence time and bandwidth overhead </li></ul><ul><ul><li>Convergence time </li></ul></ul><ul><ul><ul><li>The time it takes for a router to recognize a best path in the event of a change or outage </li></ul></ul></ul><ul><ul><li>Bandwidth overhead </li></ul></ul><ul><ul><ul><li>Burden placed on an underlying network to support the routing protocol </li></ul></ul></ul>
  44. 44. Routing Protocols <ul><li>The four most common routing protocols: </li></ul><ul><ul><li>RIP (Routing Information Protocol) for IP and IPX </li></ul></ul><ul><ul><li>OSPF (Open Shortest Path First) for IP </li></ul></ul><ul><ul><li>EIGRP (Enhanced Interior Gateway Routing Protocol) for IP, IPX, and AppleTalk </li></ul></ul><ul><ul><li>BGP (Border Gateway Protocol) for IP </li></ul></ul>