Lecture 3: CSCI E-1 Spring 2013

Slide 1

Slide 1 text

Computer Science E-1 Lecture 3: Internet

Slide 2

Slide 2 text

From last time...

Slide 3

Slide 3 text

http://youtu.be/j84eEjP-RL4

Slide 4

Slide 4 text

Review: March 4

Slide 5

Slide 5 text

http://youtu.be/9ntPxdWAWq8

Slide 6

Slide 6 text

traceroute cnn.com

Slide 7

Slide 7 text

Clients v. Servers

Slide 8

Slide 8 text

Routers

Slide 9

Slide 9 text

Network

Slide 10

Slide 10 text

No content

Slide 11

Slide 11 text

No content

Slide 12

Slide 12 text

No content

Slide 13

Slide 13 text

Internet Service Provider

Slide 14

Slide 14 text

No content

Slide 15

Slide 15 text

LAN

Slide 16

Slide 16 text

WAN

Slide 17

Slide 17 text

No content

Slide 18

Slide 18 text

traceroute reddit.com

Slide 19

Slide 19 text

IP Address

Slide 20

Slide 20 text

10.251.202.239

Slide 21

Slide 21 text

4,294,967,296

Slide 22

Slide 22 text

“640K ought to be enough for anybody”

Slide 23

Slide 23 text

IPv4

Slide 24

Slide 24 text

IPv6

Slide 25

Slide 25 text

http://www.worldipv6launch.org/

Slide 26

Slide 26 text

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

Slide 27

Slide 27 text

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

Slide 28

Slide 28 text

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

Slide 29

Slide 29 text

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

Slide 30

Slide 30 text

Private IP Address

Slide 31

Slide 31 text

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

Slide 32

Slide 32 text

NAT

Slide 33

Slide 33 text

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

Slide 34

Slide 34 text

NAT Request • request from 10.0.0.1 reaches router

Slide 35

Slide 35 text

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

Slide 36

Slide 36 text

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

Slide 37

Slide 37 text

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

Slide 38

Slide 38 text

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

Slide 39

Slide 39 text

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

Slide 40

Slide 40 text

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

Slide 41

Slide 41 text

http://www.whatismyip.com/

Slide 42

Slide 42 text

DHCP

Slide 43

Slide 43 text

DHCP • Client broadcasts “I would like to join”

Slide 44

Slide 44 text

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

Slide 45

Slide 45 text

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

Slide 46

Slide 46 text

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

Slide 47

Slide 47 text

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

Slide 48

Slide 48 text

No content

Slide 49

Slide 49 text

Connection Speeds

Slide 50

Slide 50 text

No content

Slide 51

Slide 51 text

Wireless Networks

Slide 52

Slide 52 text

WEP, WPA, WPA2

Slide 53

Slide 53 text

3G, 4G

Slide 54

Slide 54 text

Firewall

Slide 55

Slide 55 text

No content

Slide 56

Slide 56 text

VPN

Slide 57

Slide 57 text

Domains

Slide 58

Slide 58 text

DNS

Slide 59

Slide 59 text

HOSTS.TXT

Slide 60

Slide 60 text

DNS Server

Slide 61

Slide 61 text

Root DNS Server

Slide 62

Slide 62 text

root-servers.org

Slide 63

Slide 63 text

TLD DNS Server

Slide 64

Slide 64 text

Authoritative Name Server

Slide 65

Slide 65 text

Domain Resolution • hosts ﬁle?

Slide 66

Slide 66 text

Domain Resolution • hosts ﬁle? • cache DNS server?

Slide 67

Slide 67 text

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

Slide 68

Slide 68 text

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

Slide 69

Slide 69 text

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

Slide 70

Slide 70 text

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

Slide 71

Slide 71 text

No content

Slide 72

Slide 72 text

Net Neutrality

Slide 73

Slide 73 text

No content

Slide 74

Slide 74 text

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

Slide 75

Slide 75 text

Conﬁguring DNS

Slide 76

Slide 76 text

No content

Slide 77

Slide 77 text

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

Slide 78

Slide 78 text

TLDs

Slide 79

Slide 79 text

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

Slide 80

Slide 80 text

ccTLDs

Slide 81

Slide 81 text

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

Slide 82

Slide 82 text

http://gtldresult.icann.org/

Slide 83

Slide 83 text

Registrars

Slide 84

Slide 84 text

URL

Slide 85

Slide 85 text

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

Slide 86

Slide 86 text

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

Slide 87

Slide 87 text

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

Slide 88

Slide 88 text

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

Slide 89

Slide 89 text

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

Slide 90

Slide 90 text

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

Slide 91

Slide 91 text

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

Slide 92

Slide 92 text

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

Slide 93

Slide 93 text

Key-Value Pairs

Slide 94

Slide 94 text

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?

Slide 95

Slide 95 text

q=e&1?

Slide 96

Slide 96 text

URL Encoding

Slide 97

Slide 97 text

q=e%261%3F

Slide 98

Slide 98 text

URI

Slide 99

Slide 99 text

urn:isbn:9780811822749

Slide 100

Slide 100 text

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

Slide 101

Slide 101 text

API

Slide 102

Slide 102 text

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

Slide 103

Slide 103 text

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

Slide 104

Slide 104 text

http://youtu.be/Ve7_4ot-Dzs

Slide 105

Slide 105 text

Summary

Slide 106

Slide 106 text

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

Slide 107

Slide 107 text

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

Slide 108

Slide 108 text

Computer Science E-1 Lecture 3: Internet