PC Support & Repair

1. PC Support & Repair Chapter 8 Fundamental Networks

2. Objectives • After completing this chapter, you will meet these objectives: • Explain the principles of networking. • Describe types of networks. • Describe basic networking concepts and technologies. • Describe the physical components of a network. • Describe LAN topologies and architectures. • Identify standards organizations. • Identify Ethernet standards. • Explain OSI and TCP/IP data models. • Describe how to configure a NIC and a modem. • Identify names, purposes, and characteristics of other technologies used to establish connectivity. • Identify and apply common preventive maintenance techniques used for networks. • Troubleshoot a network.

3. Computer Networks • 2 or more devices connected by networking equip. • Host • Devices that can send/receive on a network • Peripheral • Device connected to a host (needs host to operate) • Examples of each??? • Name devices that can connect to a network. • What resources can a network share?

4. How do devices link? • Copper • Ethernet • Sends electricity through cable • Fiber Optic • Uses glass fibers to carry light pulses • Wireless • Uses radio signals

5. Benefits of Networking • Fewer peripherals • One printer, one storage device, etc • Increased Communication • Email, chat, etc. • Lower Cost Licensing • For software • Site license costs less than single license • Central Administration • Manage & backup from one location

6. Activity

7. Describe Types of Networks • Describe a LAN. • Describe a WAN. • Describe a WLAN. • Explain peer-to-peer networks. • Explain client/server networks.

8. LAN • Small area • Under one admin control (access policy) • GCIT is a LAN • Your home is a LAN

9. WAN • Connects LANs that are far away • Internet is biggest WAN

10. WLAN • LAN with wireless • Wireless devices connect to AP • AP connects to wired part of network • Avg. distance inside is 100ft • Outside is more

11. Activity

12. Review • Which type of network includes an AP? • WLAN • The Internet is which type of network? • WAN • Explain what an AP does. • Connects wireless devices to the wired network • Why does some software cost less on a network? • May be able to get site license • What does an Ethernet cable use to send data? • Electricity

13. Peer to Peer Networks • Your house network • No server • Individual PC controls its own resources • No one computer in charge • No needs for administrator • Best for 10 or less computers • D: No admin to control network, no centralized security, difficult to manage, no centralized data storage

14. Client-Server Networks • Client requests, server provides service • Administrators • Maintain servers & control user access • Users have password for net access • Access central storage • Backed up daily

15. Client-Server Networks • Workgroup • Collection of PC’s & servers designed to communicate with each other • Each computer has its own account security log in • Domain • Logical grouping of computers, may be far away • Domain controller server manages them • You can log into any computer in the domain

16. Review • Which type of network would daily backups be done on? • Client-server • Which network would have better, secure access? • Client-server • Which network would you typically store data on your own hard drive? • Peer to peer • Which specific network type is managed from a central server because the computers may be in far away locations? • Domain

17. Basic Concepts & Technologies • Explain bandwidth and data transmission. • Describe IP addressing. • Define DHCP. • Describe Internet protocols and applications. • Define ICMP.

18. Bandwidth • Amount of data transmitted in a time period • Data is broken into chunks, called packets • Packets have headers which tell how to put the chunks back together • bps – bits per second • kbps – kilobits per second • Mbps – megabits per second • Latency • Time it takes data to travel • More devices = more latency

19. BandwidthPicture Example

20. Data Transmission Modes • Simplex • Unidirectional, one-way • Half-Duplex • Send OR receive at a time • Full-Duplex • Send AND receive at same time • Better for network • 100Mbps Ethernet and more

21. MAC & IP Addresses • NIC has a MAC address • Burned onto card; unique; PHYSICAL • ID’s your physical PC • Like your fingerprint; ID’s you • Attaches FRAME to packet for NIC to identify • IP identifies where a host is on network • Location to find you; mailing address • Each MUST be unique; LOGICAL • Must have to communicate

22. Review • Which transmission mode allows “talking/listening” at the same time? • Full-duplex • Which mode works like a walkie-talkie? • Half-duplex • Which address is burned in the NIC? • MAC address • Which address can be changed in software? • IP address

23. IP Address • 32 bits • Four octets of 8 bits • Network & host portion of address • Routers read network portion only • To send to correct network • 192.168.2.16 • Network is 192.168.2 • .16 is the host portion

24. IP Address Classes

25. Subnet Mask • Helps determine what network an address is on • All hosts in a LAN have same SM • There are default SM for each class • Can subnet (split)

26. Manually Enter IP & SM • TCP/IP properties in NIC • Easy to do in a small net • Large nets use DHCP • Auto assign of IP & SM

27. Communication Example

28. Lab • Handout • ID the class of each address

29. DHCP • Dynamically assigns IP addresses to hosts • DHCP Server manages the process • You give it a list to give out • Address given out for a time • After time expires, it goes back into list to give out • Gives out: IP, SM, Default Gateway, DNS

30. DHCP • If it can’t connect to DHCP server, Windows gives PC an address • 169.254.0.0 to 169.254.255.255 • You won’t be able to communicate • Automatic Private IP Addressing (APIPA) • Every 5 min. it tries to talk to DHCP for real address • NAT • Translates a private, internal address to communicate over Internet • How your home network, school, most businesses do it

31. Ipconfig or ipconfig /all

32. Protocols • Set of rules for communication • Common Protocols used in communications

33. Activity • Activity & Review Handout

34. ICMP • Sends control message for troubleshooting • PING • Command line test for connectivity • Ping an IP address • Echo request/reply 4x default • Ping a website to get the IP address

35. Review • Which protocol is used for web page transmission on port 80? • HTTP • Which command will display a computer’s IP address? • Ipconfig • You have a network of 100 devices. Which process will easily allow all computers to automatically be able to communicate on a network by assigning IP addresses? • DHCP

36. Review • Your computer has an IP address of 169.254.1.1. What does this mean to you? • It did not get an IP from the DHCP server • Which class address is 201.17.55.9? • C • Which utility can test connectivity? • Ping • Which protocol allows remote login, but is not secure? • Telnet

37. Physical Components of a Network • Identify names, purposes, and characteristics of network devices. • Identify names, purposes, and characteristics of common network cables.

38. Hubs • Simple • Extends network • Data goes in one port & out all others • No thinking involved • Relies on devices to decide on message • Creates more network traffic

39. Hub Network

40. Switch • Data sent in small packets • MAC addresses added • Packaged into a FRAME • Data enters a port, then sent out the one port • Smarter than bridge • Knows MAC address on each port • MAC address table

41. Switch Network

42. Router • Connects different networks • Reads IP addresses • Directs packets to networks • Doesn’t care about specific PC’s

43. Router Network

44. Wireless Access Point (WAP) • Allows wireless devices to connect to wired network • Uses radio waves • Limited range • May have several in building

45. Multipurpose Device • Router, Switch, WAP; all in one

46. Review • This device connects networks. • Router • This basic device extends the network, as it does not segment it. • Hub • You are asked to install equipment that will allow laptops with wireless cards to gain access to your existing wired network. What equipment is this? • Wireless access point

47. Review • Which current networking devices receives data and sends it out a single port based on MAC addresses? • Switch • What address does a router use to make a decision about sending data to the correct network? • IP address • If a device can connect you to other networks, allow multiple computers to connect to it, allow wireless devices to connect to it, and it assigns IP addresses, then what kind of device is it? • Multi-purpose device (all in one)

48. Cables- Twisted-Pair • Ethernet • 8 wires, 4 pairs • 1 pair transmit; 1 pair receive • UTP • Most common • 100m (328ft) • Interference prone (EMI/RFI) • STP • Each pair is shielded ($$ & thicker) • Reduces interference

49. UTP Category of Cables • Cat 3 for phones • RJ11 connector • 2 or 4 pins/wires • Cat 5, 5e, 6 • RJ45 connector • 8 pins/wires • 5e has more twists

50. Coax Cable • Copper shielding • RG-6 • TV • Used to be used in networks • Slower speed 10Mbps