1. Fundamentals of Networking Discovery 1, Chapter 3 Connecting to the Network

2. Objectives Explain the concept of networking and the benefits of networks. Explain the concept of communication protocols. Explain how communication occurs across a local Ethernet network. Describe Access Layer devices and communication methods on a local Ethernet network. Describe Distribution Layer devices and communication methods across networks.

3. What’s a Network? Make a phone call, watching TV, radio, Internet, Gaming ▫ All depend on a reliable network Group of connected devices able to communicate with each other

4. Communication Now OLD: ▫ Separate, dedicated networks for voice, data, vide NOW: ▫ Converged into one over a single channel ▫ Can you name examples?

5. Networks

6. Basic Network Components 4 categories of components ▫ Hosts ▫ Shared peripherals ▫ Networking devices ▫ Networking media

7. Hosts They send & receive data Have an IP Address

8. Shared Peripherals Shared devices ARE connected to a host ▫ Rely on their connected hosts to share ▫ Software allows the sharing Print sharing with a USB connected printer

9. Networking devices Connect hosts & other devices ▫ Hubs, switches, routers Move & control network traffic

10. Networking media Connects Devices ▫ Can be wired or wireless

11. Activity

12. Handout Complete Handout 1

13. Computer Roles in a Network Host sends & receives data on a network ▫ Computer is a host ▫ Can act as a client and/or a server Server ▫ Provide info to other hosts on a network ▫ Simultaneously ▫ Email, web pages, file access  Separate server software for each Client ▫ Requests & displays info from the server ▫ Can check email & view web at same time  Web browser/IE, Outlook

14. Activity

15. Client-Server Hosts have an IP Address Hosts can act as a client or server ▫ Depends on software installed Server provides services to other hosts ▫ Like providing email or web services Clients request & display info from servers

16. Popular Client-Server Network World of Warcraft Players from all over the world connect & play

17. Peer-to-Peer Networks One computer can sometimes act as the server & the client Simplest: 2 connected devices ▫ Uses a crossover cable or wireless Multiple PC’s connect with a hub Disadvantage ▫ Host can slow down if doing both Not for large networks ▫ Dedicated servers to handle requests

18. Peer-to-Peer Networks

19. Famous Peer-to-Peer LimeWire ▫ Exchanging MP3’s with another user ▫ Only connected with that ONE user

20. Client, Server, or Both

21. Lab 3.1.5 Building a Peer-to-Peer Network

22. Physical Topology Layout/Map of network Shows where each host is located, wiring, network devices

23. Logical Topology Groups hosts by how they use the network ▫ Not physical location Host names, addresses, group info & applications can be recorded

24. Review What does SOHO stand for? ▫ Small office home office What interconnects hosts & controls traffic? ▫ Network devices Which cable connects 2 PC’s together? ▫ Crossover cable Hosts are devices that have what? ▫ IP Addresses Describe client-server.

25. Principles of Communication The Message Source or Sender Destination or Receiver Channel or Pathway Protocol or Rules

26. Rules of Human Communication What are some of our rules of communication? ▫ What if there were no rules?

27. Protocols Rules of Communication over a medium ▫ May be different depending on the medium Protocols define the details of how the message is transmitted and delivered This includes issues of:

28. Message Encoding Encoding Converting thoughts into words Bits are encoded for that medium  Light, electricity, or radio waves Destination will decode the message

29. Message Format for Delivery

30. Encapsulation of Data Computer messages packed in a FRAME ▫ Acts like an envelope ▫ Provides the addresses ▫ Must be properly addresses or won’t be delivered

31. Handout Complete Handout 2 & 3 Message Format Ordering

32. Review What 4 things do you need for communication? ▫ Source, destination, channel, protocol Describe encoding. ▫ Bits into electricity, light, or radio waves A message is encapsulated in what? ▫ Frame Which 2 address are in the frame? ▫ Source & destination MAC address

33. What We Talked About So Far

34. Message Size You talk in sentences. ▫ Length will vary depending on what can be processed or understood by the listener Messages sent across networks are broken into smaller pieces ▫ Size of a frame

35. Message Timing People use timing to determine when to speak, how fast or slow to talk, and how long to wait for a response. These are the rules of engagement. Access Method Flow Control Response Timeout

36. Message Timing Access Method ▫ When to begin sending & how to respond to errors ▫ Collision if two talk at same time Flow Control ▫ Sender can transmit messages faster than the destination can receive & process ▫ Use flow control to negotiate correct timing for successful communication Response Timeout ▫ How long to wait for responses & what to do

37. Unicast Message Pattern Unicast ▫ 1 to 1 single message

38. Multicast Message Pattern Multicast ▫ 1 to a group message

39. Broadcast Message Pattern Broadcast ▫ 1 to all

40. Activity

41. Review What is it called when one message format is placed in another message format? ▫ Encapsulation Bob is talking to Sally. Which type of message pattern is this? ▫ Unicast Which address is used in a frame? ▫ MAC address (source & destination)

42. Review Which message is one to all? ▫ Broadcast

43. Importance of Protocols Computers need rules to communicate Local network devices MUST speak same language Most common wired protocol is ETHERNET

44. Early Days of Computing Each vendor had their own rules Standards had to be created

45. Standardizing IEEE maintains standards approvals ▫ Assigned a # ▫ 802.3 is Ethernet ▫ 100Base-T  100 megabit Ethernet  Baseband Transmission  Twisted Pair Cabling

46. Physical Addressing Remember encapsulating frames? ▫ Source & destination address needed Each host on Ethernet has a physical address (MAC Address) ▫ Burned into NIC NIC encapsulates source & dest. MAC Host that receives frame reads dest. MAC ▫ If it contains its own MAC, it will process it ▫ If not, it ignores it

47. Example

48. Lab 3.3.3 Determine the Mac Address Ipconfig /all

49. Ethernet Frame Structure Frames are also called PDU’s ▫ Protocol Data Units ▫ 64-1518 bytes each frame ▫ Preamble for timing ▫ SFD is end of timing, begin frame ▫ FCS- helps check for damaged frames

50. Activity

51. MAC & IP- Happy Together! IP MAC

52. Hierarchical Design Structure MAC Address is like your name ▫ Doesn’t tell where you are on the network ▫ Not efficient by itself ▫ Imagine if all hosts on Internet could only be identified by a MAC address Ethernet is a broadcast technology ▫ Sent to all in a network ▫ Too much traffic & collisions, slows network Separate into smaller networks

53. Hierarchical in Life

54. Hierarchical Design in Networks Dividing your network into smaller groups or layers ▫ Keeps local traffic local ▫ Only data intended for other networks will move on to other layers Access Layer ▫ Provides connections to hosts in a local Ethernet network. Distribution Layer ▫ Interconnects the smaller local networks. Core Layer ▫ A high-speed connection between distribution layer devices.

55. 3 Layer Model

56. Access Layer Hosts/Clients connect to hubs/switches Local segmented networks

57. Distribution Layer Routers Routing occurs Traffic delivered to other local networks Security (ACL)

58. Core Layer High-speed backbone Redundant paths Powerful routers/switches ▫ Just sends the data ▫ No changes here

59. Goals of 3 Layer Model Think how you can limit traffic from going to where it doesn’t need to be ▫ Less collisions ▫ More efficient data paths ▫ Better placement of devices Radio File Storage Server Teacher File Server- GCIT PowerSchool Server

60. IP Addressing Your name doesn’t change but where you live might ▫ MAC stays on NIC ▫ Doesn’t change no matter where you move IP Address is like your address ▫ It is logical, not physical Needed to go beyond your network ▫ Stay local or go elsewhere???

61. IP Addressing 2 parts ▫ Identify the network ▫ Identify the host Network portion is same for all devices on a local network 209.120.5.72

62. IP Network Example

63. Lab 3.3.6 Determine the IP Address of the Computer Let’s do this together How do we find the IP Address through the command prompt? ▫ Ipconfig /all Why is an IP address important?

64. Handout 3 Layer Model & Addressing Activity

65. Review 1.What is the process of placing one format into another (like a letter into an envelope to be sent in the mail)? ▫ Encapsulation 2.Which device is typically at the Distribution Layer? ▫ Router 3.When a PC receives a message, which address is used to determine if it for that PC? ▫ Destination MAC

66. Review 1.Which organization creates & maintains the standards? ▫ IEEE ▫ Why? 2.A frame contains which 2 addresses? ▫ Source & Destination MAC 3.What does FCS stand for & what does it do? ▫ Frame Check Sequence, checks for errors

67. Hubs At Access Layer Simple Device (DUMB) ▫ Message in one port, out all others ▫ Does not send to specific device ▫ Sends one message at a time  Collisions can occur  They wait for silence, & then resend randomly  Too many collisions slow the network  Keep these collision domains SMALL

68. Pictures of Hubs

69. Hub Example

70. Hub & Collision Domain

71. Handout Hubs

72. Switches Access Layer Connects multiple hosts like a hub ▫ Forwards a message to a specific host! ▫ Reads the destination MAC Has a MAC address table ▫ Ports & MAC addresses on them Creates a virtual circuit to destination No bandwidth sharing between hosts No collisions!

73. How a switch works

74. More about Switches… What if destination MAC is NOT in the table? ▫ Floods message out all ports, except one it came in on ▫ Compare the destination MAC in frame ▫ Correct one processes the message

75. Switch Table How does the switch add the MAC address to its table? ▫ It examines the source MAC & port it came in on ▫ When it responds to a message, it adds it Updates table for every message

76. Example Go to Slide 3.4.3-2 Look at example

77. What else about Switches? Hub attached to switch port scenario Separate collision domains for each switch port

78. Switch Handout

79. Review 1.Hubs & Switches are at which design layer? ▫ Access Layer 2.Which device creates a virtual circuit from the source to destination? ▫ Switch 3.Which device sends data in one port & out all ports regardless of the destination? ▫ Hub

80. Review 1.Which address does a NIC read when deciding if the message is for itself? ▫ Destination MAC 2.In 100Base-T, what does the 100 mean? ▫ 100Mbps ▫ How about the T?  Twisted Pair Cabling 3.If a switch receives a frame & doesn’t have the dest. MAC in its table, what happens? ▫ Floods it out all ports, except one it came in on

81. Broadcasts One host can send messages to all other LOCAL hosts ▫ Find info from others ▫ Tell others something One destination MAC in a frame only ▫ There’s a special MAC address that all hosts will receive & process ▫ 48 bits, all binary 1’s ▫ In hexadecimal, FF:FF:FF:FF:FF:FF Look at 3.4.4

82. Broadcast Domain Too many hosts in a domain, causes traffic backup ▫ This is why you divide into smaller LAN’s

83. Let’s Practice Together Slide 3.4.5

84. MAC & IP What if you want to send data, but only know their IP address and not their MAC? ▫ ARP (Address Resolution Protocol)

85. ARP Host sends out a broadcast frame w/ the IP address of the destination host ▫ FF:FF:FF:FF:FF:FF Each host receives & compares the IP address to see if it is their own Matching host sends its MAC address back to source Source then adds it to its ARP table Then it can send the message

86. ARP Example

88. Review 1.A broadcast frame contains which MAC address? ▫ All F’s 2.How many bits is a MAC address? ▫ 48 3.Describe a broadcast 4.What separates broadcasts?

89. Distribution Layer Separates & connects your small networks ▫ Connects your Access Layer networks ▫ Can filter traffic & provide security

90. Routers Distribution Layer Connects different local networks Reads the packet encaps. in frame ▫ Destination IP Address (network portion) ▫ Subnet Mask Finds best path to that destination network

91. Routers- The Path… Each port connects a different local network Rips open to find destination IP Looks in Routing Table ▫ In the table:  Encapsulates in new frame  Sends it out port towards or connected to that destination Routers DO NOT forward broadcasts!

92. Path Example- H1 to H4

93. Default Gateway When sending a message on your local network you use ARP to find dest. MAC When sending a message on another network ▫ You encapsulate:  Source IP  Source MAC  Destination IP  You don’t know the destination MAC!  So you include the MAC of the router port!  Router will receive & process this MAC, BUT NOT THE ARP MAC broadcast!

94. Default Gateway This IP is set in TCP/IP settings Router port that your host connects to- same local network ▫ If the host knows the IP, it will use ARP to find out the MAC address on router port ▫ Example on next slide

95. Default Gateway

97. Lab Complete 3.5.3-2

98. Routing Tables Networks & best path to reach them Knows this info by: ▫ Dynamically learned from other routers ▫ Manually entered by admin No route in table? ▫ Drop it OR ▫ Default Route is set by admin

99. Routing Tables

100. Where does data go? Directly to the network destined for To another router When router forwards the frame, it MUST include a destination MAC ▫ If it is connected, it will use the dest MAC from its ARP table ▫ If not, it will sub MAC address of connected router’s port ARP table for each port/local network

101. Look at… 3.5.4.2 3.5.4.3 activity

102. LAN Network over a small area ▫ Under one administration ▫ Router will separate

103. How many local networks?

104. Adding hosts to a LAN Advantages/Disadvantages?

105. Adding hosts to a LAN Advantages/Disadvantages?

106. Planning a Network Ethernet is most popular Planning is key! First, gather this info: ▫ The number & type of hosts to be connected ▫ The applications to be used ▫ Sharing & Internet connectivity requirements ▫ Security & privacy considerations ▫ Reliability & uptime expectations ▫ Connectivity requirements including, wired and wireless

107. Plan & Document Maps of topology Physical environment ▫ Temperature ▫ Power Physical configuration ▫ Location of network devices ▫ Length of cables ▫ Hardware config Logical Configuration ▫ Broadcast & collision domains ▫ IP & Naming Scheme

108. Physical Topology How many broadcast, collision & networks?

109. Review 1.Describe a default gateway. 2.Each router port has an _______ table that hold the MAC addresses of devices connected to each port. ▫ ARP 3.Which one device will separate or segment a network? ▫ Router 4.Describe a routing table.

110. Multifunction Devices Integrated Routers ▫ Usually for SOHO ▫ Switch/router/access point in one ▫ Single point of failure Cisco ISR ▫ Separate components to add/replace

111. Linksys

113. Connecting the Linksys All connected to switch ports MUST be in same IP network to communicate Display IP configuration settings ▫ Ipconfig ▫ Ipconfig /all

114. Lab 3.6.4

115. Sharing Resources XP has simple file sharing ▫ You can set more specific ▫ Full Control ▫ Modify ▫ Read & Execute ▫ List Folder Contents ▫ Read ▫ Write Look at 3.6.5

116. 3: Connecting to the Network Networking for Home & Small Business