Lecture 3: CSCI E-1 Spring 2013

Transcript

1. Computer Science E-1
   Lecture 3: Internet
   

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2. From last time...
   

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3. http://youtu.be/j84eEjP-RL4
   

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4. Review: March 4
   

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5. http://youtu.be/9ntPxdWAWq8
   

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6. traceroute cnn.com
   

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7. Clients v. Servers
   

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8. Routers
   

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9. Network
   

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13. Internet Service Provider
    

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15. LAN
    

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16. WAN
    

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18. traceroute reddit.com
    

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19. IP Address
    

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20. 10.251.202.239
    

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21. 4,294,967,296
    

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22. “640K ought to be
    enough for anybody”
    

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23. IPv4
    

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24. IPv6
    

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25. http://www.worldipv6launch.org/
    

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26. 2001:0db8:85a3:0042:
    1000:8a2e:0370:7334
    

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27. 340,282,366,920,938,463,463,374,
    607,431,768,211,456
    

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28. http://samsclass.info/ipv6/
    exhaustion.htm
    

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29. http://www.google.com/ipv6/
    statistics.html#tab=ipv6-adoption
    

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30. Private IP Address
    

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31. 10.*.*.*
    172.16.*.*
    192.168.*.*
    

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32. NAT
    

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33. Device Private IP Public IP Source Port
    Macbook 10.0.0.1 74.125.26.228 1000
    iPhone 10.0.0.2 74.125.26.228 1001
    iPad 10.0.0.3 74.125.26.228 1002
    

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34. NAT Request
    • request from 10.0.0.1 reaches router
    

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35. NAT Request
    • request from 10.0.0.1 reaches router
    • router looks up source port for 10.0.0.1
    

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36. NAT Request
    • request from 10.0.0.1 reaches router
    • router looks up source port for 10.0.0.1
    • router changes source IP to 74.125.26.228, adds source port 1000
    

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37. NAT Request
    • request from 10.0.0.1 reaches router
    • router looks up source port for 10.0.0.1
    • router changes source IP to 74.125.26.228, adds source port 1000
    • router sends modified request to destination
    

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38. NAT Response
    • router receives response to 74.125.26.228 with source port 1000
    

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39. NAT Response
    • router receives response to 74.125.26.228 with source port 1000
    • router looks up IP address for source port 1000
    

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40. NAT Response
    • router receives response to 74.125.26.228 with source port 1000
    • router looks up IP address for source port 1000
    • router forwards response to original client
    

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41. http://www.whatismyip.com/
    

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42. DHCP
    

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43. DHCP
    • Client broadcasts “I would like to join”
    

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44. DHCP
    • Client broadcasts “I would like to join”
    • Server responds “I can help”
    

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45. DHCP
    • Client broadcasts “I would like to join”
    • Server responds “I can help”
    • Client requests an IP address
    

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46. DHCP
    • Client broadcasts “I would like to join”
    • Server responds “I can help”
    • Client requests an IP address
    • Server offers client an IP address
    

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47. DHCP
    • Client broadcasts “I would like to join”
    • Server responds “I can help”
    • Client requests an IP address
    • Server offers client an IP address
    • Client confirms IP address
    

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49. Connection Speeds
    

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51. Wireless Networks
    

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52. WEP, WPA, WPA2
    

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53. 3G, 4G
    

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54. Firewall
    

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56. VPN
    

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57. Domains
    

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58. DNS
    

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59. HOSTS.TXT
    

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60. DNS Server
    

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61. Root DNS Server
    

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62. root-servers.org
    

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63. TLD DNS Server
    

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64. Authoritative Name Server
    

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65. Domain Resolution
    • hosts file?
    

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66. Domain Resolution
    • hosts file?
    • cache DNS server?
    

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67. Domain Resolution
    • hosts file?
    • cache DNS server?
    • root DNS server
    

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68. Domain Resolution
    • hosts file?
    • cache DNS server?
    • root DNS server
    • TLD DNS server
    

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69. Domain Resolution
    • hosts file?
    • cache DNS server?
    • root DNS server
    • TLD DNS server
    • authoritative name server
    

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70. http://www.simpledns.com/lookup-
    dg.aspx
    

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72. Net Neutrality
    

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74. http://www.popsci.com/technology/article/
    2010-07/order-seven-cyber-guardians-
    around-world-now-hold-keys-internet
    

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75. Configuring DNS
    

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77. DNS Records
    • NS: name servers
    • MX: email
    • A: IPv4 address
    • AAAA: IPv6 address
    • CNAME: domain alias
    

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78. TLDs
    

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79. TLD Usage
    .com Companies
    .edu Education
    .gov US Government
    .info Information
    .mil US Military
    .net Networks
    .org Organizations
    

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80. ccTLDs
    

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81. ccTLDs
    • bit.ly: Libya
    • about.me: Montenegro
    • del.icio.us: US
    • nic.tm: Turkmenistan
    

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82. http://gtldresult.icann.org/
    

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83. Registrars
    

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84. URL
    

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85. http://username:password@
    foo.example.com:1234/cs/e1/is.html
    ?fun=yes&boring=no#awesome
    

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86. http://username:password@
    foo.example.com:1234/cs/e1/is.html
    ?fun=yes&boring=no#awesome
    Scheme
    

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87. http://username:password@
    foo.example.com:1234/cs/e1/is.html
    ?fun=yes&boring=no#awesome
    Authentication
    

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88. http://username:password@
    foo.example.com:1234/cs/e1/is.html
    ?fun=yes&boring=no#awesome
    Domain
    

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89. http://username:password@
    foo.example.com:1234/cs/e1/is.html
    ?fun=yes&boring=no#awesome
    Port
    

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90. http://username:password@
    foo.example.com:1234/cs/e1/is.html
    ?fun=yes&boring=no#awesome
    Path
    

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91. http://username:password@
    foo.example.com:1234/cs/e1/is.html
    ?fun=yes&boring=no#awesome
    Query String
    

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92. http://username:password@
    foo.example.com:1234/cs/e1/is.html
    ?fun=yes&boring=no#awesome
    Fragment
    

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93. Key-Value Pairs
    

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94. query=cse1&page=3
    • client
    • the query I want is cse1
    • the page I want is 3
    • server
    • what query and page should I look for?
    

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95. q=e&1?
    

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96. URL Encoding
    

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97. q=e%261%3F
    

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98. URI
    

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99. urn:isbn:9780811822749
    

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100. http://cse1.net/psets/pset3.pdf
     

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101. API
     

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102. http://developer.mbta.com/lib/rthr/
     red.json
     

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103. https://developers.facebook.com/
     tools/explorer/
     

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104. http://youtu.be/Ve7_4ot-Dzs
     

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105. Summary
     

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106. Networking
     • router
     • IP address
     • ISP
     • network
     • WAN, LAN
     • IPv6
     • private IP address
     • NAT
     • DHCP
     • 802.11n
     • 3G, 4G
     • mbps
     • firewall
     • VPN
     

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107. Domain Name System
     • DNS
     • domains
     • hosts file
     • root DNS server
     • TLD DNS server
     • authoritative name server
     • net neutrality
     • A record
     • CNAME record
     • TLD, ccTLD
     • registrar
     • URL
     • URI
     • API
     

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108. Computer Science E-1
     Lecture 3: Internet
     

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