PCs on a Network

1
Chapter 18

• PCs on a Network

2
You Will Learn

• About different types of physical network
  architectures
• How networking works with Windows
• How to install a network card and a network
  protocol using Windows

3
You Will Learn (continued)

• About sharing resources on a network
• Troubleshooting tools and tips for network
  connections
• How to connect networks to each other

4
Physical Network Architectures

• Ethernet (most popular)
• Wireless LAN
• Token ring
• FDDI (Fiber Distributed Data Interface)

5
Network Architecture Terminology

• Network adapter
• Provides direct connection between PC and
  network usually an expansion card (NIC)
• Matches type and speed of physical network
• Network port matches connectors on network

6
Network Architecture Terminology (continued)

• Network protocols
• OS protocols (eg, NetBEUI, TCP/IP)
• Hardware protocols (eg, Ethernet, Token Ring)
• Data transmission
• Packets, datagrams, or frames

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Ethernet Variations, Distinguished by Speed
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Ethernet Cable Types
continued
9
Ethernet Cable Types (continued)
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Ethernet Topology

• Bus topology
• Connects each node in a line
• Has no central connection point
• Star topology
• Connects all nodes to a centralized hub
• More popular easier to maintain
• Patch cables and crossover cables

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Bus and Star Topologies
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Ethernet Hub Broadcasting a Data Packet
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A Hub
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Star Bus Topology
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Repeaters

• Amplify signals on a network
• Help overcome limitations on length of cables
  that can be used signals can travel farther
• Two kinds
• Amplifier repeater
• Signal-regenerating repeater (used by Ethernet)

16
Repeaters (continued)
17
Wireless LANs

• Use radio waves or infrared light to connect
  computers or devices
• Wireless NIC includes antenna to send and receive
  signals
• Standards
• 1999 IEEE 802.11b (Wi-Fi or AirPort)
• Bluetooth
• Slower than wired networks
• Security is an issue

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Wireless LANs (continued)
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Token Ring

• Physical star logical ring
• Data packet is preceded by a token
• Transmits data at 4 Mbps or 16 Mbps
• Uses a centralized device called a MAU
  (Multistation Access Unit)
• Uses UTP or STP cables (two twisted pairs)
• Uses RJ-45 or UDC connectors

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FDDI

• Uses tokens structured as a ring, but does not
  require a centralized hub
• Multiple nodes can have data on the ring at the
  same time
• Provides data transfer at 100 Mbps
• Used as
• Network technology for a large LAN
• Backbone network to connect several LANs

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Now NICs Work

• Plug into motherboard expansion slot
• Provide port(s) on back of card for connection to
  network
• Manage communication and hardware network
  protocol for the PC

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Network Cards
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Network Cards

• Send and receive data
• To and from system bus in parallel
• To and from network in series
• Use a transceiver for signal conversion
• Identified by a MAC address
• Require an IRQ and an I/O address range
• May be PnP legacy cards can use jumpers or DIP
  switches

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Ethernet Combo Card
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Considerations When Selecting a Network Card

• Speed and type of network
• Type of cable (shielded twisted-pair, coaxial, or
  fiber-optic)
• Type of slot (PCI or ISA)

26
Segmenting a Network

• Communication on a local network uses MAC address
  of NIC to identify the destination computer
• Other computers discard the packet because it is
  not addressed to them
• Bridges and switches
• Reduce traffic on each segment and improve
  network performance
• More intelligent than hubs

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How Bridges Work
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Bridges and Switches
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Bridges and Switches (continued)

• Bridges
• Send broadcast messages not good for large
  networks
• Effective at separating high-volume areas on a
  LAN
• Best for connecting LANs that do not communicate
  outside their immediate network

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Bridges and Switches (continued)

• Switches
• Send a packet only to network segment for which
  it is destined
• Both keep source and destination MAC addresses in
  routing tables and learn new addresses

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Bridges Compared with Switches
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Windows on a Network

• Workgroup model and domain model
• Networking protocols supported at physical level
• Ethernet
• ATM
• Token Ring
• Protocols supported at OS level
• TCP/IP
• IPX/SPX
• NetBEUI

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Windows on a Network (continued)
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OS Protocols

• Automatically bind themselves to any NICs they
  find
• More than one can be associated with a single NIC

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Addressing on a Network
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MAC Addresses and IP Addresses
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IP Configuration
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MAC Addresses and IP Addresses
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Classes of IP Addresses
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IP Addresses
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Different Ways of Assigning IP Addresses

• Public, private, and reserved IP addresses
• Dynamically assigned IP addresses
• DHCP server
• Network Address Translation (NAT)

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Reserved IP Addresses
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Configuring a DHCP Server
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Using NAT
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How Computers Find Each Other on a LAN

• Checks NetBIOS name cache
• Queries WINS server, if it has its IP address
• Sends broadcast message to all computers on LAN
  asking for IP address of computer with
  broadcasted NetBIOS name
• Checks LMHosts file
• If IP address still not discovered, computer
  assumes network is using DNS and checks Hosts
  file
• Queries DNS server, if it has its IP address

46
Installing a Network Card and Connecting to a
Network

• Physically install the card and device drivers
• Configure the NIC using Windows so it has
  appropriate addresses on the network and correct
  network protocols
• Give the computer a name
• Test the NIC to verify that PC can access
  resources on the network

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Installing a NIC Using Windows 2000/XP
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Installing a NIC Using Windows 2000/XP (continued)
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Installing a NIC Using Windows 2000/XP (continued)
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Installing and Configuring TCP/IP Using Windows
2000/XP

• Will PC use dynamic or static addressing?
• If static addressing, what are IP address, subnet
  mask, and default gateway?
• If you use DNS, what are the IP addresses of the
  DNS servers?
• If a proxy server is used to connect to other
  networks, what is IP address of proxy server?

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Installing a NIC UsingWindows 9x

• Physically install NIC and turn computer on
• Windows 9x automatically detects the card and
  guides you through driver installation
• Assign computer name
• Install TCP/IP using Select Network Protocol
  Window (Windows 98)
• Configure TCP/IP by selecting binding and
  clicking Properties (Windows 98)

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Installing a Wireless NIC

• Use NICs configuration software to specify
  wireless network parameters
• Computer must be within acceptable range of an
  access point or another wireless device that it
  will communicate with directly
• Distance determined by type of technology used
  most likely 802.11b

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Installing a Wireless NIC (continued)
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Installing a Wireless NIC (continued)
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Installing a Wireless NIC (continued)
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Using Resources on the Network

• LAN
• Assign all users to same workgroup or domain with
  My Network Places (Windows 2000/XP) or Network
  Neighborhood (Windows 9x)
• Peer-to-peer network
• Install Client for Microsoft Networks and File
  and Printer Sharing
• Share resources

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Sharing Files, Folders, and Applications
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Installing Windows XP Components Needed to Share
Resources
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Installing Windows 98 Components Needed to Share
Resources
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Sharing Files and Folders with the Workgroup
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Sharing Files and Folders with the Workgroup
(continued)
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Network Drive Maps

• Using NFS client/software, network drive map
  makes one PC (client) appear to have new hard
  drive when that hard drive space is actually on
  another host computer (server)
• Use Windows Explorer to map a network drive

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Results of Drive Mapping
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Symptoms of NIC Problems

• Cannot make connection to network
• My Network Places or Network Neighborhood does
  not show other computers on network
• Error message appears during installation of NIC
  drivers
• Device Manager shows yellow exclamation point or
  red X beside name of NIC
• No lights on NIC

65
Troubleshooting Network Connections

• Check the following
• Cabling and ports for PC
• NIC itself
• BIOS
• Device drivers
• Troubleshooting tools
• Ping (TCP/IP utility)
• Ipconfig (Windows NT/2000/XP)
• Winipcfg (Windows 9x)

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Connecting Networks with Routers

• Use IP addresses to determine path by which to
  send a packet
• Tables determine most efficient available route
• Stateless devices - concerned about destination
  address
• Unconcerned about data
• Transmit data packet to remote network only if
  routable protocol was used to produce data packet

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Connecting Networks with Routers (continued)
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Brouter

• Functions both as a bridge and a router
• As a router
• Routes routable protocols (TCP/IP and IPX/SPX
  packets)
• As a bridge
• Forwards packets that are not routable (NetBEUI
  packets) to other local networks

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Connecting Networks with Bandwidth Technologies

• Bandwidth measure of data capacity
• Greater bandwidth faster communication
• Common bandwidth technologies
• Regular telephone lines
• Cable modem
• ISDN (Integrated Services Digital Network)
• DSL (Digital Subscriber Line)
• Satellite access
• Wireless access

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Bandwidth Technologies
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Bandwidth Technologies (continued)
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Bandwidth Technologies (continued)
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Bandwidth Technologies (continued)
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Summary

• How local networks are built
• How bridges and switches can segment large local
  networks
• How routers connect networks
• Technologies used to connect PCs and networks to
  the Internet
• Supporting PCs that are connected to a network
• How computers are identified over a network
• How to share computer resources over a network
• How to troubleshoot a network connection