Transcript Presentation

Chapter 18
PCs on a Network
You Will Learn…
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About different types of physical network
architectures
How networking works with Windows
How to install a network card and a network protocol
using Windows
About sharing resources on a network
Troubleshooting tools and tips for network
connections
How to connect networks to each other
Network Architecture
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Connecting devices on a LAN provides a way for
workstations, servers, printers, and other devices to
communicate and share resources
Describes overall design of the network
• Physical components
• Network technologies
• Interfacing software
• Protocols needed to establish reliable communication
among nodes
Most Popular Physical Network
Architectures
 Ethernet (most popular)
 Wireless LAN technology
 Token ring
 FDDI (Fiber Distributed Data Interface)
Network Architecture Terminology
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Network adapter
• Most often an expansion card called a network interface
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card (NIC)
Must match type and speed of physical network in use
Network port must match type of connectors used on the
network
Network protocols
• Hardware protocols (eg, Ethernet, Token Ring)
• OS protocols (eg, NetBEUI, TCP/IP)
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Network Architecture Terminology
 Packets, datagrams, or frames
• Packets have maximum size depending on type of
network
 Checksum
• Verifies data integrity
 CRC (cyclical redundancy check)
• Technique of calculating and comparing values
Ethernet Variations, Distinguished by
Speed
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10-Mbps Ethernet
• Uses either shielded twisted-pair (STP) cable, unshielded
twisted-pair (UTP) cable, or coaxial cable
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100-Mbps Ethernet or Fast Ethernet
• Uses UTP or STP cable
• 100BaseFX uses fiber-optic cable (single-mode, multimode, and plastic)
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1000-Mbps or Gigabit Ethernet
• Uses twisted-pair and fiber-optic cable
Networking Cables
Networking Cables
Network Cabling
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
Ethernet Topology
Ethernet Using Star Topology
Ethernet Hub
Ethernet Using Star Bus Topology
Repeaters
 Devices that amplify signals on a network
 Help overcome limitations on the length of
cables that can be used
 Two kinds
• Amplifier repeater
• Signal-regenerating repeater (used by Ethernet)
Repeaters
Wireless LANs (WLANs)
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Make connections using a wireless NIC
Communicate directly or connect to a LAN by way of
a wireless access point (AP)
Popular where cables are difficult to install
Slower than wired networks
Security is an issue
Standards
• 1999 IEEE 802.11b (Wi-Fi, AirPort)
• Bluetooth
WLANs
Token Ring
 Physical star; logical ring
 Transmits data at 4 Mbps or 16 Mbps
 Uses a centralized device called a MAU
(Multistation Access Unit)
 Less popular than Ethernet
FDDI
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Uses a token that travels in a ring
Data frames travel on the ring without the token
Multiple nodes can have data on the ring at the same
time
Provides data transfer at 100 Mbps
Often used for a large LAN in a large company or as a
backbone network to connect several LANs in a large
building
How 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
Network Cards
FDDI
Token ring
Network Cards
Ethernet
Wireless
How NICs Work
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Network card
• Sends and receives data to and from system bus in parallel
• Sends and receives data to and from network in series
• Uses a transceiver for signal conversion
Network in use is transparent to applications software
using it
Network nodes are identified by a MAC (Media
Access Control) address
Ethernet Combo Card
Network Card Requirements
 IRQ
 I/O address
 Upper memory addresses (for DOS and
Windows 9x real mode)
 May be PnP or can use jumpers or DIP
switches to determine resources to request
Considerations When Selecting a
Network Card
 Speed and type of network
 Type of cable (shielded twisted-pair, coaxial,
or fiber-optic) – except for wireless
connections
 Type of slot (PCI or ISA)
Segmenting a Network
 Decreases amount of traffic on overall network
 Done through use of bridges and switches
• More intelligent than hubs; make decisions about
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whether or not to allow traffic to pass, or where to
forward that traffic
Use MAC addresses, which they store in routing
tables, to determine where to send packets
Bridges
Bridges and Switches
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Bridges
• Send broadcast messages; not
good for large networks
• Effective at separating highvolume areas on a LAN
• Work best when used to
connect LANs that usually do
not communicate outside their
immediate network
Switches
• Send a packet only to network
segment for which it is
destined
Bridges and Switches
Bridges Compared with Switches
Windows on a Network
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Supports three suites of protocols
• TCP/IP (Transmission Control Protocol/Internet Protocol)
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Protocol suite for the Internet
• IPX/SPX (Internetwork Packet Exchange/Sequenced
Packet Exchange)
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Designed for use with Novell NetWare
Not supported on Internet
• NetBEUI (NetBIOS Extended User Interface)
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Proprietary Windows protocol for use on networks isolated from the
Internet
Windows on a Network
Using Protocols on a Network
 Physically connect computer to network by
installing the NIC and connecting network
cable to hub or device
 Install protocol in OS
• Once installed, it automatically binds itself to any
NICs it finds
Using Protocols on a Network
Addressing on a Network
 MAC addresses
 IP addresses
 Character-based names (domain names, host
names, NetBIOS names)
 Port addresses
• A number between 0 and 65,535 identifies a
program running on a computer
MAC Addresses
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Unique addresses that are permanently embedded in a
NIC and identify a device on a LAN
Expressed as six pairs of hexadecimal numbers and
letters
A local address
Used at the lowest (physical) networking level for
NICs and other devices on the same network to
communicate
MAC and IP Addresses
Using Winipcfg to See MAC and IP
Addresses
Using Ipconfig to See MAC and IP
Addresses
IP Addresses
 32-bit addresses consisting of a series of four
8-bit numbers separated by periods that
identify a computer or device on a TCP/IP
network (eg, 190.180.40.120)
• First part identifies the network
• Last part identifies the host
 A long distance address
Classes of IP Addresses
Division of IP Address into Network and
Host Portions
Ways of Assigning IP Addresses
 Public, private, and reserved IP addresses
 Dynamic IP addressing
• Dynamic Host Configuration Protocol (DHCP)
DHCP Server
Network Address Translation
 Uses a single public IP address to access the
Internet on behalf of all hosts on the network
using other IP addresses
 Proxy server sometimes does double duty as a
firewall
Proxy Server
Host Names and NetBIOS Names
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Use characters rather than numbers to identify a
computer on a network
Easier to remember and use than IP addresses
Two name resolution services track relationships
between character-based names and IP addresses
• DNS (Domain Name System) tracks host names
• Microsoft WINS (Windows Internet Naming Service)
tracks NetBIOS names
Host Names and NetBIOS Names
 Windows 98 assumes a computer has a
NetBIOS name (up to 15 characters)
 Windows 2000/XP assumes a host name that
uses TCP/IP convention; up to 63 characters
 Applications that use TCP/IP for network
communication use WinSock to make API
calls to the OS
How Computers Find Each Other on a
LAN
 For Windows 98 using NetBIOS names, the
computer runs through a checklist to discover
the IP address
 NetBEUI uses DNS to resolve the name, not
WINS
How Computers Find Each Other on a
LAN
Installing a Network Card and
Connecting to a Network
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Connecting a PC to a network requires:
• NIC
• Network cable (patch cable or straight-through cable)
• Device for PC to connect to (eg, a hub)
General steps for installing and connecting
• Put NIC in the PC; install NIC’s drivers
• Configure NIC using Windows, so it has appropriate
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addresses on the network and correct network protocols
Test the NIC to verify that the PC can access resources on
the network
Installing a NIC Using
Windows 9x
 Set DIP switches or jumpers if necessary
 Turn on PC; Found New Hardware wizard
launches; use manufacturer’s drivers
 Open Device Manager to verify that drivers
installed successfully
 Connect network patch cable to NIC port and
to network hub or a wall jack connected to a
hub
Viewing Resources in Device Manager
Connecting to a NetBEUI Network
Assigning NetBIOS Names
Viewing Computers with Network
Neighborhood
Connecting to a TCP/IP Network
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Will PC use dynamic or static IP addressing?
If static addressing, what are IP address, subnet mask,
and gateway for this computer?
How will DNS work? Enabled or disabled? If
enabled, what are IP addresses of DNS servers?
Is proxy server used to connect to other networks? If
so, what is IP address of proxy server?
Installing TCP/IP Using Windows 98
Configuring TCP/IP Using Windows 98
Configuring DNS Service under TCP/IP
for Windows 98
Installing a NIC Using
Windows 2000/XP
Installing a NIC Using
Windows 2000/XP
Installing and Configuring TCP/IP
Using Windows 2000/XP
Installing a Wireless NIC
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Use NIC’s configuration software to specify wireless
network parameters
• State
• Current Channel
• Current Tx Rate
• Throughput, Link Quality, and Signal Strength
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
Configuring a Wireless NIC
Configuring a Wireless NIC
Configuring a Wireless NIC
Sharing Files, Folders, and Applications
 Users on a LAN must be assigned to the same
workgroup or domain
 Windows 9x shares resources by way of
Network Neighborhood
 Windows 2000/XP uses My Network Places
 Peer-to-peer network requires installation of
Client for Microsoft Networks and File and
Print Sharing
Viewing and Accessing Shared
Resources in Windows 2000
Sharing Resources in
Windows 98
Sharing Resources in
Windows 98
Sharing Resources in
Windows 98
Windows 2000/XP Components Needed
to Share Resources
Sharing Files and Folders with the
Workgroup
Sharing Files and Folders with the
Workgroup
Network Drive Maps
 One of the most powerful and versatile
methods of communicating over a network
 Make one PC (client) appear to have a new
hard drive when that hard drive space is
actually on another host computer (server)
 Make files and folders on a host computer
available even to network-unaware DOS
applications
Setting Up a Network Drive
Setting Up a Network Drive
Results of Drive Mapping
Direct Cable Connection
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Allows you to connect two PCs, using either a null
modem cable or a parallel cable
• Each end of the cable must have a PC connector, not a
printer connector
Setting Up a Direct Cable Connection
• Set up both computers to share their resources
• Install Direct Cable Connection component and run it on
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both computers
Make one PC the host, the other the guest
Select a port for the connection (serial or parallel)
Symptoms of NIC Problems
 Cannot make connection to network
 Network Neighborhood or My Network Places
does not show other computers on the network
 Error message during installation
 Device Manager shows yellow exclamation
point or red X beside name of NIC
 No lights on NIC
Troubleshooting a Network Connection
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Check connections in rest of network
Reboot PC and reset network connections
Make sure NIC and its drivers are installed
Check for an IRQ conflict
Check cabling and ports
Confirm most current version of motherboard BIOS
Verify you can access other resources on the remote
computer
Testing TCP/IP Configuration and
Connectivity
 Enter Ipconfig /all at command prompt or run
Winipcfg
 Try loopback address test
 Ping IP address of default gateway
 Ping host computer you are trying to reach
 If IP address works, but domain name does not
work, the problem lies with DNS
Connecting Networks with Routers
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Responsible for data
traveling across
interconnected networks
Use IP addresses to
determine path for packet
Stateless devices
Transmit data packet to a
remote network only if data
packet is a routable protocol
Using Routers to Connect Networks
Communicating with Bandwidth
Technologies
 Measure of data capacity
 Greater bandwidth = faster communication
Bandwidth Technologies
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Bandwidth Technologies
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Bandwidth Technologies
Common Bandwidth Technologies
 Regular telephone lines
 Cable modem
 ISDN (Integrated Services Digital Network)
 DSL (Digital Subscriber Line)
 Satellite access
 Wireless access
Chapter Summary
 How to connect PCs in networks and how to
connect those networks to each other
 How local networks are built
 How bridges and switches can segment large
local networks
 How routers connect networks
 Different technologies used to connect PCs and
networks to the Internet
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Chapter Summary
 How to support PCs connected to a network
 How computers are identified on a network
 How to share computer resources over a
network
 How to troubleshoot a network connection