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1
00:00:00,000 --> 00:00:10,792

2
00:00:10,792 --> 00:00:11,750
DAVID Malan: Kull dritt.

3
00:00:11,750 --> 00:00:13,630
Dan huwa CS50.

4
00:00:13,630 --> 00:00:15,950
U dan huwa l-bidu ta 'seba' ġimgħa.

5
00:00:15,950 --> 00:00:19,120
Hekk illum, forsi Thankfully,
aħna jibdew transizzjoni tagħna

6
00:00:19,120 --> 00:00:21,630
mill-inqas livell
dinja ta 'programmazzjoni C

7
00:00:21,630 --> 00:00:24,290
għal-livell ogħla
dinja ta 'programmazzjoni web.

8
00:00:24,290 --> 00:00:28,060
U ma 'dan, aħna ser tagħti ħarsa
fil eżattament kif l-internet jaħdem,

9
00:00:28,060 --> 00:00:31,920
liema dawn il-magni u dawn internets
li inti kont qed tuża għal snin issa

10
00:00:31,920 --> 00:00:35,090
fil-fatt jagħmlu taħt il-barnuża lejn
fehim aħjar ta 'kif dan kollu

11
00:00:35,090 --> 00:00:37,660
xogħlijiet, u kif inti tista '
jagħmluha taħdem għalik.

12
00:00:37,660 --> 00:00:41,480
>> Lejn dak il-għan, għaliex ma we tagħti
ewwel ħarsa fuq clip minn juru TV

13
00:00:41,480 --> 00:00:45,680
imsejħa Numb3rs, li se tikseb us beda
dwar eżattament kif l-internet jaħdem.

14
00:00:45,680 --> 00:00:46,964

15
00:00:46,964 --> 00:00:47,630
[Daqq ta 'video]

16
00:00:47,630 --> 00:00:49,858
-Hija S A 32-bit indirizz IPP4.

17
00:00:49,858 --> 00:00:50,794
-IP.

18
00:00:50,794 --> 00:00:51,730
Dik hija l-internet.

19
00:00:51,730 --> 00:00:52,640
>> Netwerk -Private.

20
00:00:52,640 --> 00:00:53,865
Huwa netwerk privat Amita tal.

21
00:00:53,865 --> 00:01:06,635

22
00:01:06,635 --> 00:01:08,120
Oh, hi hekk aqwa.

23
00:01:08,120 --> 00:01:09,605

24
00:01:09,605 --> 00:01:11,120
>> -OH, Charlie.

25
00:01:11,120 --> 00:01:12,640
>> -Hija L-indirizz IP mera.

26
00:01:12,640 --> 00:01:15,672
Hi tal kiri us jaraw dak
hi qed jagħmel fil-ħin reali.

27
00:01:15,672 --> 00:01:16,505
[END daqq ta 'video]

28
00:01:16,505 --> 00:01:19,570
DAVID Malan: Allura hemm ħaġa waħda
lott ta ħażin ma 'dak TV juru.

29
00:01:19,570 --> 00:01:23,250
Mela ejja tease apparti eżattament
wieħed mill-ewwel affarijiet bħal dawn

30
00:01:23,250 --> 00:01:25,210
u ara jekk ma nkunux nistgħu nagħlaq
imħuħ tagħna madwaru.

31
00:01:25,210 --> 00:01:28,110
Allura l-aħħar qafas ta '
li movie, ta 'dik juru

32
00:01:28,110 --> 00:01:30,360
huwa dan wieħed hawn, li
jidher li tissuġġerixxi li dan

33
00:01:30,360 --> 00:01:33,300
huwa dak li xi wħud Hacker qed tuża
li jsibu rwieħhom xi sistema.

34
00:01:33,300 --> 00:01:33,875
>> Imma l-ebda.

35
00:01:33,875 --> 00:01:36,030
Jekk inti zoom fl fuq dan
kodiċi tas-sors, li

36
00:01:36,030 --> 00:01:40,210
huwa lingwa msejħa Għan C fil
li apps iPhone, apps iPad, u Mac

37
00:01:40,210 --> 00:01:42,060
Apps OS huma miktuba,
tkun taf tara li din

38
00:01:42,060 --> 00:01:45,400
huwa għal xi tip ta 'programm tpinġija
li għandha crayon bħala varjabbli.

39
00:01:45,400 --> 00:01:47,800

40
00:01:47,800 --> 00:01:51,880
>> Allura addizzjonalment, inti tista
nnotajt dan l-indirizz hawn.

41
00:01:51,880 --> 00:01:53,330
Issa, dan huwa bħala żbaljata.

42
00:01:53,330 --> 00:01:56,740
U dan huwa probabbilment deliberatament magħżula
li jkun indirizz invalidu hekk li

43
00:01:56,740 --> 00:02:00,010
fatt ma jwassalx x'imkien
jekk telespettatur TV attwalment żjarat dan.

44
00:02:00,010 --> 00:02:02,620
Iżda dan in-numru hawnhekk,
xi ħaġa dot ħaġa

45
00:02:02,620 --> 00:02:05,799
dot dot xi ħaġa xi ħaġa x'hemm
ġeneralment magħrufa bħala indirizz IP.

46
00:02:05,799 --> 00:02:07,840
U huwa attwalment tajba
segue għal dan is-suġġett aktar

47
00:02:07,840 --> 00:02:10,930
ġeneralment, magħrufa bħala
IP, protokoll internet.

48
00:02:10,930 --> 00:02:14,210
Allura inti ħadthom probabbilment inqas
jinstemgħu din il-frażi qabel.

49
00:02:14,210 --> 00:02:18,980
Imma dak li hu IP, jew bl-internet
protokoll kif inti tifhem dan illum?

50
00:02:18,980 --> 00:02:21,376

51
00:02:21,376 --> 00:02:23,625
Odds huma, jekk staqsejna għal
turija tal-idejn, ħafna minnkom

52
00:02:23,625 --> 00:02:26,880
probabilment qal li l-
kliem Indirizz IP qabel.

53
00:02:26,880 --> 00:02:27,955
Allura dak li ma inti jfisser?

54
00:02:27,955 --> 00:02:29,578

55
00:02:29,578 --> 00:02:30,779
>> UDJENZA: [inaudible]?

56
00:02:30,779 --> 00:02:31,820
DAVID Malan: X'hemm li?

57
00:02:31,820 --> 00:02:33,170
UDJENZA: [inaudible]?

58
00:02:33,170 --> 00:02:33,455
DAVID Malan: Darba aktar.

59
00:02:33,455 --> 00:02:34,840
UDJENZA: Indirizz tal-kompjuter.

60
00:02:34,840 --> 00:02:35,950
DAVID Malan: Il-
indirizz tal-kompjuter.

61
00:02:35,950 --> 00:02:36,949
Allura dak eżattament id-dritt.

62
00:02:36,949 --> 00:02:39,660
Jirriżulta li kull
kompjuter fuq l-internet,

63
00:02:39,660 --> 00:02:42,940
u dawn il-ġranet, kull telefon fil tiegħek
but u pillola backpack tiegħek,

64
00:02:42,940 --> 00:02:45,880
għandha l-indirizz IP, internet
indirizz protokoll, li

65
00:02:45,880 --> 00:02:49,379
huwa indirizz uniku li jidentifika
lilu matul l-internet kollu.

66
00:02:49,379 --> 00:02:51,920
Issa, li daqsxejn ta 'bajda
jinsabu għaliex id-dinja attwalment

67
00:02:51,920 --> 00:02:53,240
baqgħalna ta 'indirizzi IP.

68
00:02:53,240 --> 00:02:55,900
>> Allura aħna ħadthom bdew jużaw
indirizzi IP privati.

69
00:02:55,900 --> 00:02:57,160
Iżda aktar fuq li fil-mument.

70
00:02:57,160 --> 00:03:00,731
Iżda int tista 'taħseb ta' indirizz IP
bħala simili triq tiegħek servizz postali

71
00:03:00,731 --> 00:03:01,230
indirizz.

72
00:03:01,230 --> 00:03:04,160
Imxejna tuża l-eżempju ta 'Maxwell
Dworkin, il-bini CS, before-

73
00:03:04,160 --> 00:03:07,920
33 Oxford Street Cambridge,
Massa, 02138, USA.

74
00:03:07,920 --> 00:03:10,400
Dan huwa indirizz uniku tagħha fid-dinja.

75
00:03:10,400 --> 00:03:12,547
>> Bl-istess mod do kompjuters
jkollhom indirizzi uniċi.

76
00:03:12,547 --> 00:03:14,380
Huma biss jiġri li
tfittex different- ftit

77
00:03:14,380 --> 00:03:17,219
numru dot numru tikka
numru dot numru.

78
00:03:17,219 --> 00:03:19,760
U ħadd ma tassew taf
dak li l-firxa ta 'numri validu

79
00:03:19,760 --> 00:03:21,105
huwa għal kull wieħed minn dawk hashes?

80
00:03:21,105 --> 00:03:21,604
Yeah.

81
00:03:21,604 --> 00:03:23,045
>> UDJENZA: 0-255?

82
00:03:23,045 --> 00:03:23,920
DAVID Malan: Eżattament.

83
00:03:23,920 --> 00:03:25,450
0-255.

84
00:03:25,450 --> 00:03:28,360
U anki jekk inti ma taf
li, issa tinġibed konklużjoni,

85
00:03:28,360 --> 00:03:31,130
kemm bits huma użati biex jirrappreżentaw
kull wieħed minn dawn in-numri allura?

86
00:03:31,130 --> 00:03:32,232

87
00:03:32,232 --> 00:03:34,440
Tmienja apparentement minħabba
l-ogħla inti jista 'joqgħod

88
00:03:34,440 --> 00:03:36,720
huwa 255, li l-valur 8-bit.

89
00:03:36,720 --> 00:03:38,980
Allura b'kollox, l-indirizz IP huwa 32-bits.

90
00:03:38,980 --> 00:03:41,310
Forwarding daqstant b'mod mgħaġġel għall-
konklużjoni matematiċi,

91
00:03:41,310 --> 00:03:43,900
kemm indirizzi IP possibbli
hemm fid-dinja, allura?

92
00:03:43,900 --> 00:03:46,990

93
00:03:46,990 --> 00:03:50,100
>> Allura dak 8 plus 8 plus 8
plus 8, b'tali mod li 32 bits.

94
00:03:50,100 --> 00:03:52,490
U konna dejjem qal li
2 għall-32 hija bejn wieħed u ieħor?

95
00:03:52,490 --> 00:03:53,940

96
00:03:53,940 --> 00:03:54,440
OK.

97
00:03:54,440 --> 00:03:55,273
I ser 'qasam dan wieħed.

98
00:03:55,273 --> 00:03:55,864
Erba 'biljun.

99
00:03:55,864 --> 00:03:58,780
U tkellimna dwar li fil-ġimgħa
żero meta tkellimna dwar kotba tat-telefon

100
00:03:58,780 --> 00:04:00,170
b'numri crazy ta 'paġni.

101
00:04:00,170 --> 00:04:03,450
Iżda t-tip ta 'dan huwa li hemm
numru finit ta 'indirizzi IP.

102
00:04:03,450 --> 00:04:05,740
U anki jekk erba 'biljun
jistgħu jidhru simili ħafna,

103
00:04:05,740 --> 00:04:07,770
aħna bnedmin kienu
jikkunsmaw pjuttost ftit

104
00:04:07,770 --> 00:04:10,350
minnhom għal kulħadd ta 'servers tagħna
u mezzi u ibqa 'sejjer hekk.

105
00:04:10,350 --> 00:04:12,170
>> Allura dan huwa attwalment issir problema.

106
00:04:12,170 --> 00:04:16,500
Issa, hemm tendenza li tkun
iskema wara li jkun dak IP.

107
00:04:16,500 --> 00:04:18,560
Per eżempju, ħafna
il-kompjuters fil-Harvard

108
00:04:18,560 --> 00:04:21,810
jkollhom indirizzi uniċi li jibdew
ma 'waħda minn dawn iż-żewġ valuri.

109
00:04:21,810 --> 00:04:23,560
MIT, b'mod simili, għandha prefiss.

110
00:04:23,560 --> 00:04:26,889
U ħafna ta 'kumpaniji u l-universitajiet
ikollhom prefiss uniku tagħhom stess.

111
00:04:26,889 --> 00:04:29,680
U mbagħad ħafna minna għall-dar tagħna
konnessjonijiet internet u simili,

112
00:04:29,680 --> 00:04:33,575
aħna naqsmu xi prefiss li Comcast
jew xi ħadd bħal dik jiġri li stess.

113
00:04:33,575 --> 00:04:36,640
U dan huwa biss li jgħidu li jekk inti
ħares lejn kompjuters aktar fuq il-kampus,

114
00:04:36,640 --> 00:04:40,070
theyd probabbilment ikollhom IP
indirizz li tidher bħal dan.

115
00:04:40,070 --> 00:04:43,180
>> Issa, inti tista 'wkoll kultant tara
indirizz IP jibda bħal dan.

116
00:04:43,180 --> 00:04:46,150
Fil-fatt, jekk kwalunkwe inti kiber
b'aċċess għall-internet fid-dar,

117
00:04:46,150 --> 00:04:49,270
u inti kienu qatt biżżejjed
teknikament kurjużi biex poke madwar

118
00:04:49,270 --> 00:04:51,800
settings tal-kompjuter tiegħek,
inti probabilment minflok

119
00:04:51,800 --> 00:04:56,990
raw indirizz li jixbah aktar
dan, li beda bil 10, jew 172.6,

120
00:04:56,990 --> 00:05:00,480
jew 192.168, jew xi varjazzjonijiet tal-istess.

121
00:05:00,480 --> 00:05:04,025
>> U dan ifisser biss li d-dinja
titwarrab mazz sħiħ ta 'numri

122
00:05:04,025 --> 00:05:06,400
li jkunu privati, li jfisser
inti tista 'tużahom fid-dar tiegħek,

123
00:05:06,400 --> 00:05:08,941
inti tista 'anki tuża minnhom fuq tiegħek
kampus u fi ħdan il-kumpanija tiegħek,

124
00:05:08,941 --> 00:05:10,970
imma inti ma tista 'tużahom
fuq l-internet in ġenerali.

125
00:05:10,970 --> 00:05:13,320
>> U hekk dawn privata
IPs kienu soluzzjoni

126
00:05:13,320 --> 00:05:16,990
lejn l-iżgurar li mill-inqas hekk
Safejn id-dinja kollha huwa kkonċernat,

127
00:05:16,990 --> 00:05:18,890
aħna mhux qed tuża indirizzi IP li ħafna.

128
00:05:18,890 --> 00:05:22,840
Iżda mill-inqas, nistgħu, fuq tagħna stess
kampus, ikollhom pretty ħafna kif ħafna IPs

129
00:05:22,840 --> 00:05:23,590
kif irridu.

130
00:05:23,590 --> 00:05:24,410
Iżda quién?

131
00:05:24,410 --> 00:05:28,500
X'hemm-rilevanza ta 'dan kollu
għal użu attwali ta 'l-internet?

132
00:05:28,500 --> 00:05:31,450
>> Well, ejja tagħti ħarsa lejn
forsi stampa sempliċi hawn.

133
00:05:31,450 --> 00:05:33,550
Let me kemm permezz ta '
dawn il-up fuq l-iskrin.

134
00:05:33,550 --> 00:05:36,050
U nahfru kalligrafija tiegħi hawn.

135
00:05:36,050 --> 00:05:39,500
Imma jekk naħsbu ta 'ruħna bħala
qed dan il-laptop ftit hawn

136
00:05:39,500 --> 00:05:41,830
x'imkien fuq il-kampus,
dawn il-jiem hija għandha Wi-Fi.

137
00:05:41,830 --> 00:05:44,180
>> Iżda fil imgħoddi u jekk
issib l-adapter dritt,

138
00:05:44,180 --> 00:05:47,420
dan jista 'jkollu cable ethernet
li bl-istess mod let

139
00:05:47,420 --> 00:05:49,130
inti jgħaqqdu xi tip ta 'mezz.

140
00:05:49,130 --> 00:05:51,090
U inti tista 'sejħa dan
kwalunkwe numru ta 'affarijiet.

141
00:05:51,090 --> 00:05:55,930
Imma jien ser jimxi 'l quddiem u sejħa dan,
għal issa, kif madwar punt ta 'aċċess?

142
00:05:55,930 --> 00:05:57,690
>> Allura dan huwa laptop tiegħi.

143
00:05:57,690 --> 00:06:01,130
Dan huwa AP tiegħi, jew punt ta 'aċċess,
u dan huwa xi apparat bla wajers,

144
00:06:01,130 --> 00:06:04,400
b'differenza ma dawk li Harvard
għandu kollha fuq il-limiti massimi

145
00:06:04,400 --> 00:06:07,420
u l-ħitan madwar kampus
li jkollhom dwal Teptip

146
00:06:07,420 --> 00:06:10,930
u li huma dak laptops tiegħek
użati biex jitkellmu wirelessly

147
00:06:10,930 --> 00:06:12,160
għall-bqija tan-netwerk.

148
00:06:12,160 --> 00:06:14,880
>> Allura b'xi dan il-laptop qed jitkellem
għal dak ħaġa fuq il-ħajt,

149
00:06:14,880 --> 00:06:16,540
fis-sala dining, jew x'imkien ieħor.

150
00:06:16,540 --> 00:06:21,410
Issa, sadanittant, f'dak il-punt l-aċċess huwa
konnessi ma xi ħaġa oħra fuq il-kampus.

151
00:06:21,410 --> 00:06:24,810
U huwa probabbilment xi ħaġa
magħrufa bħala swiċċ.

152
00:06:24,810 --> 00:06:27,690
U huma jfittxu ħafna aktar interessanti
minn sempliċiment dawn dijagrammi kaxxa.

153
00:06:27,690 --> 00:06:29,760
>> Iżda b'xi, li ħaġa l
konness ma 'swiċċ.

154
00:06:29,760 --> 00:06:31,900
U min-naħa, b'xi
li swiċċ huwa konness

155
00:06:31,900 --> 00:06:35,890
għal mezz li probabbilment
daqsxejn akbar, imsejħa router.

156
00:06:35,890 --> 00:06:37,930
U mbagħad, sadanittant,
Harvard huwa konness

157
00:06:37,930 --> 00:06:41,210
għall-internet kollu li
aħna ser tiġbed dan sħaba hawn,

158
00:06:41,210 --> 00:06:43,850
permezz xi numru ta 'wires
jew teknoloġija mingħajr fili.

159
00:06:43,850 --> 00:06:46,670
>> Allura hemm ħafna ta 'passi bejn
lili u l-bqija tad-dinja.

160
00:06:46,670 --> 00:06:49,620
U fil-fatt, anke fi ħdan
din l-istampa hawn,

161
00:06:49,620 --> 00:06:52,634
hemm xi servers oħra
jew servizzi involuti.

162
00:06:52,634 --> 00:06:54,800
U jien biss se tiġbed
dawn kemmxejn astratt

163
00:06:54,800 --> 00:06:57,050
biss hekk li għandna
l-akronimi li għandna quddiemna.

164
00:06:57,050 --> 00:06:57,993
>> Wieħed huwa msejjaħ DHCP.

165
00:06:57,993 --> 00:06:59,330

166
00:06:59,330 --> 00:07:03,440
U ieħor, ftit aktar
interessanti għal-lum, huwa msejjaħ DNS.

167
00:07:03,440 --> 00:07:09,160
Allura dawn huma servers li huma b'xi mod
aċċessibbli għall-kompjuter tiegħi kif ukoll.

168
00:07:09,160 --> 00:07:10,910
Allura issa, ejja tease
apparti daqsxejn ta 'jargon.

169
00:07:10,910 --> 00:07:13,410
Allura l-punt ta 'aċċess huwa
biss dan l-apparat bla wajers

170
00:07:13,410 --> 00:07:16,079
spiss ma 'antenni li attwalment
tavżak kellem lil wirelessly.

171
00:07:16,079 --> 00:07:17,870
Fid-dar, inti tista 'sejħa
dan router dar.

172
00:07:17,870 --> 00:07:21,550
Hija tista 'ssir mill Linksys, jew Apple,
jew D-Link, jew kwalunkwe numru ta 'kumpaniji.

173
00:07:21,550 --> 00:07:23,930
Li, imbagħad, huwa konness
għal bidla ta 'xi tip.

174
00:07:23,930 --> 00:07:28,287
Jew lura d-dar, dak li huwa tiegħek Wi-Fi
apparat probabbilment konness mal minflok?

175
00:07:28,287 --> 00:07:30,370
Għaliex inti probabilment ma
stess dan it-tagħmir kollu.

176
00:07:30,370 --> 00:07:31,900

177
00:07:31,900 --> 00:07:32,400
Yeah.

178
00:07:32,400 --> 00:07:36,379
Modem tal-kejbil jew modem DSL lura d-dar
li inti ltqajna minn Verizon, jew Comcast,

179
00:07:36,379 --> 00:07:37,420
jew wieħed minn dawk it-trasportaturi.

180
00:07:37,420 --> 00:07:41,520
Allura taħseb ta 'dan kollu kumplessità
bħala sostenn università jew verament

181
00:07:41,520 --> 00:07:42,920
negozju bħal Comcast.

182
00:07:42,920 --> 00:07:44,690
U tassew, l-għalf
li fil-dar tiegħek

183
00:07:44,690 --> 00:07:46,800
huwa probabbilment fuq din in-naħa
tal-ħajt plus forsi

184
00:07:46,800 --> 00:07:50,380
wieħed minn dawn id-dar route-- wieħed
minn dawn huma modems kejbil jew DSL

185
00:07:50,380 --> 00:07:51,720
modems huma jistgħu jipprovdu.

186
00:07:51,720 --> 00:07:55,650
>> Allura bidla hija biss mezz ma
mazz sħiħ ta 'jacks data fiha.

187
00:07:55,650 --> 00:07:58,940
Fil-fatt, jekk inti recall li l-aħbarijiet
Rapport aħna lagħbu fuq l-iskrin big

188
00:07:58,940 --> 00:08:01,930
ftit ġimgħat ilu fejn aħna
kienu jitkellem dwar xokk qoxra,

189
00:08:01,930 --> 00:08:03,270
u kif bad dan kien?

190
00:08:03,270 --> 00:08:05,850
U kien hemm minn dawn
ritratti ta 'kejbils, u ġakkijiet,

191
00:08:05,850 --> 00:08:07,569
u affarijiet li tfittex tekniku?

192
00:08:07,569 --> 00:08:10,360
Dawk kienu biss swiċċijiet mutu li
biss internet jgħaqqad kompjuters

193
00:08:10,360 --> 00:08:12,810
minn fejn jitwaħħal cables ġo fihom.

194
00:08:12,810 --> 00:08:14,140
>> Allura li kollox bidla hija.

195
00:08:14,140 --> 00:08:16,363
Issa, dawn il-mezzi jiksbu
ftit aktar interessanti.

196
00:08:16,363 --> 00:08:16,863
DHCP.

197
00:08:16,863 --> 00:08:17,846

198
00:08:17,846 --> 00:08:20,470
Jekk inti ħadthom poked madwar tiegħek
kompjuter fid-dar jew anke fuq il-kampus,

199
00:08:20,470 --> 00:08:21,845
inti tista raw dan akronimu.

200
00:08:21,845 --> 00:08:24,480
Hawn xi ħadd jaf liema server DHCP huwa?

201
00:08:24,480 --> 00:08:25,560

202
00:08:25,560 --> 00:08:27,360
Dynamic protokoll konfigurazzjoni ospitanti?

203
00:08:27,360 --> 00:08:28,324

204
00:08:28,324 --> 00:08:30,490
Mhux it-tip ta 'ħaġa inti
verament bżonn biex jikteb.

205
00:08:30,490 --> 00:08:30,990
DHCP.

206
00:08:30,990 --> 00:08:32,480

207
00:08:32,480 --> 00:08:33,891
xi ħadd fil-livelli kollha?

208
00:08:33,891 --> 00:08:34,390
Kull dritt.

209
00:08:34,390 --> 00:08:35,520
Mela ejja kontrina l-istorja.

210
00:08:35,520 --> 00:08:39,210
Jekk l-istorja hawn fil-idejn hija affermata
fuq tiegħi li jkollhom indirizz uniku

211
00:08:39,210 --> 00:08:42,909
fid-dinja, l-indirizz IP,
fejn ma li jiġu minn?

212
00:08:42,909 --> 00:08:44,640
Fil imgħoddi, meta
inti stajt ltqajna biex kampus,

213
00:08:44,640 --> 00:08:47,790
inti fil-fatt kellhom titlob lil xi ħadd fi
Harvard, dak li għandu l-indirizz IP tiegħi jkun.

214
00:08:47,790 --> 00:08:49,873
U inti manwalment
tip li fil-kompjuter tiegħek.

215
00:08:49,873 --> 00:08:53,770
Iżda aktar reċentement, teknoloġiji
jeżistu li jippermettu li inti dinamikament,

216
00:08:53,770 --> 00:08:58,460
DHCP, tikseb l-indirizz IP sempliċiment meta
inti plagg fil-kampus wirelessly

217
00:08:58,460 --> 00:08:59,220
jew ma 'wajer.

218
00:08:59,220 --> 00:09:03,800
Allura server DHCP hija biss server
li jagħti kompjuter tiegħek IP unika

219
00:09:03,800 --> 00:09:06,349
indirizz, kemmxejn saltwarjament
jew permezz xi algoritmu.

220
00:09:06,349 --> 00:09:08,390
Imma jekk inti taħseb lura
ftit ġimgħat jew ftit snin,

221
00:09:08,390 --> 00:09:10,670
meta inti l-ewwel irreġistrati
kompjuter tiegħek fuq il-kampus,

222
00:09:10,670 --> 00:09:13,957
inti kienu javżak Harvard, jawtorizza
me li tagħti me l-indirizz IP.

223
00:09:13,957 --> 00:09:15,915
Issa DNS tibda tikseb
ftit aktar interessanti.

224
00:09:15,915 --> 00:09:17,050

225
00:09:17,050 --> 00:09:18,940
Sistema isem tad-dominju.

226
00:09:18,940 --> 00:09:21,970
Ħadd ma tixtieq li tieħu stab
lejn dak li din hija ħaġa hawn?

227
00:09:21,970 --> 00:09:26,195
>> Huwa servers waħda jew aktar li
twettaq xogħol pjuttost sempliċi li l-

228
00:09:26,195 --> 00:09:26,945
tip ta 'importanti.

229
00:09:26,945 --> 00:09:30,150

230
00:09:30,150 --> 00:09:31,130
Yeah.

231
00:09:31,130 --> 00:09:33,810
>> UDJENZA: tittraduċi URLs [inaudible].

232
00:09:33,810 --> 00:09:34,560
DAVID Malan: Yeah.

233
00:09:34,560 --> 00:09:38,970
Hija jittraduċi URLs li PI
indirizzi u viċi versa.

234
00:09:38,970 --> 00:09:41,310
Ikkunsidra, wara kollox, li
meta inti tmur fuq il-websajt,

235
00:09:41,310 --> 00:09:46,200
inti tip xi ħaġa bħal facebook.com,
jew google.com, jew harvard.edu,

236
00:09:46,200 --> 00:09:50,620
inti żgur qatt ittajpjat
x'aktarx indirizz IP numerika.

237
00:09:50,620 --> 00:09:52,490
>> U inti tista 'taħseb l-raġuni għaliex.

238
00:09:52,490 --> 00:09:54,910
Lura fil-ġurnata, anke
issa sa ċertu punt,

239
00:09:54,910 --> 00:09:58,030
meta inti tagħmel telefon
sejħa lil kumpannija,

240
00:09:58,030 --> 00:10:02,275
huma verament jippruvaw diffiċli biex jixtru infushom
numru 800 li attwalment għandha kliem

241
00:10:02,275 --> 00:10:06,140
fiha, bħal 1-800-jiġbru jew xi ħaġa
thats memorabbli bħal dik hekk li

242
00:10:06,140 --> 00:10:10,692
nies ma jkollhomx biex tiftakar dak
C-O--L L-E-C-T attwalment tespandi biex.

243
00:10:10,692 --> 00:10:12,400
Allura aħna stajt tidher dan
heuristic fil-passat.

244
00:10:12,400 --> 00:10:15,720
U fil-fatt, dan huwa dak indirizzi IP
u dak li aħna ser sejħa ismijiet ospitanti

245
00:10:15,720 --> 00:10:18,120
jew kompletament ikkwalifikat
ismijiet ta 'domain do għalina.

246
00:10:18,120 --> 00:10:22,610
Dan jippermetti li jindirizzaw servers
bil-kliem minflok ta 'numri.

247
00:10:22,610 --> 00:10:24,560
Allura kif do we attwalment
tara din il-konverżjoni.

248
00:10:24,560 --> 00:10:26,393
Jien ser jimxi 'l quddiem
u jiftħu programm.

249
00:10:26,393 --> 00:10:26,975

250
00:10:26,975 --> 00:10:29,350
Jien biss se jmorru 'l quddiem
u jiftħu tieqa terminal.

251
00:10:29,350 --> 00:10:31,933
U jien ser jimxi 'l quddiem u
nuruk dak server DNS ma.

252
00:10:31,933 --> 00:10:35,700
Per eżempju, jekk jien ridt li tara
dak l-indirizz IP huwa ta 'Facebook,

253
00:10:35,700 --> 00:10:37,720
I tista tip f'terminal
pront bħal this--

254
00:10:37,720 --> 00:10:40,010
u inti tista 'tagħmel dan anki
ġewwa tal appliance tiegħek.

255
00:10:40,010 --> 00:10:41,595
U li facebook.com lookup.

256
00:10:41,595 --> 00:10:43,220

257
00:10:43,220 --> 00:10:44,500
>> U nara mazz ta 'affarijiet.

258
00:10:44,500 --> 00:10:48,097
Dan l-ewwel rispons huwa
Server-- DNS Harvard

259
00:10:48,097 --> 00:10:49,930
li stampa li stajt
mfassla hemmhekk. --that ta

260
00:10:49,930 --> 00:10:54,300
me javżak li PI Facebook
indirizz huwa dan apparentement.

261
00:10:54,300 --> 00:10:58,650
So let me go l quddiem u
kopja li 173.252.120.16.

262
00:10:58,650 --> 00:11:00,960
U let me jiftħu Chrome fuq Mac tiegħi.

263
00:11:00,960 --> 00:11:06,690
U let me mur http: // u pejst
dak l-indirizz IP fil u hit Ikteb.

264
00:11:06,690 --> 00:11:08,950
>> U fil-fatt, I find myself fil Facebook.

265
00:11:08,950 --> 00:11:11,090
Allura b'xi dik konverżjoni,
tabilħaqq, ġara.

266
00:11:11,090 --> 00:11:15,314
U jekk I tagħmel dan mill-ġdid, ejja
do nslookup, www.google.com.

267
00:11:15,314 --> 00:11:17,302
I nikseb lura mazz sħiħ ta 'tweġibiet.

268
00:11:17,302 --> 00:11:20,010
U fil-fatt, hemm modi differenti
li l-kumpaniji jimplimentaw dan.

269
00:11:20,010 --> 00:11:22,440
Kultant, huma tell-dinja
ikollhom waħda indirizz IP.

270
00:11:22,440 --> 00:11:25,824
>> Iżda dak l-indirizz IP wieħed gets solvuti
jew mapped servers multipli.

271
00:11:25,824 --> 00:11:27,740
Jew fil-każ ta 'Google,
huma tell-dinja,

272
00:11:27,740 --> 00:11:29,510
għandna mazz sħiħ ta 'indirizzi IP.

273
00:11:29,510 --> 00:11:33,910
Laptop tiegħek hija milqugħa biex jitkellmu
kuntatt kwalunkwe wieħed minn dawn is-servers.

274
00:11:33,910 --> 00:11:36,200
Allura kollha ta 'li kien għaddej
fuq taħt il-barnuża.

275
00:11:36,200 --> 00:11:40,830
>> Meta inti tip fil www.google.com Ikteb
fil-browser tiegħek, browser tiegħek,

276
00:11:40,830 --> 00:11:46,180
u min-naħa operattiva tiegħek, Mac
OS, jew Windows, jew Ubuntu Linux,

277
00:11:46,180 --> 00:11:51,010
titlob lill-server DNS fil-qrib, dak li huwa
l-indirizz attwali ta 'dan is-server.

278
00:11:51,010 --> 00:11:54,330
Minħabba li l-aħħar apparat
fil din l-istampa, router,

279
00:11:54,330 --> 00:11:57,840
huwa dak li l-għan fil-
ħajja huwa li l-informazzjoni rotta,

280
00:11:57,840 --> 00:12:01,150
rotta pakketti biex ngħidu hekk,
pakketti ta 'informazzjoni diġitali

281
00:12:01,150 --> 00:12:06,320
li jkun fihom zeroes u dawk minn
mittent id-destinazzjoni, minn oriġini

282
00:12:06,320 --> 00:12:07,200
li riċevitur.

283
00:12:07,200 --> 00:12:09,760
>> U hekk Jittieħed rotot router.

284
00:12:09,760 --> 00:12:13,000
Allura għaliex huwa dan kollu
partikolarment rilevanti?

285
00:12:13,000 --> 00:12:16,000
Well, ejja tagħti ħarsa
lejn kif dan jista 'jintuża.

286
00:12:16,000 --> 00:12:21,600
Jissoponi li għandi hawn
stampa ta 'Rob Boden.

287
00:12:21,600 --> 00:12:22,690

288
00:12:22,690 --> 00:12:25,150
So jissoponi li nixtieq li
tibgħat din l-istampa ta 'Rob Boden

289
00:12:25,150 --> 00:12:27,530
fis Dan fid-dahar
tas-sala lecture.

290
00:12:27,530 --> 00:12:29,976
>> So I am a-kompjuter
bħal laptop tiegħi, u Dan

291
00:12:29,976 --> 00:12:31,600
hija xi kompjuter ieħor fuq l-internet.

292
00:12:31,600 --> 00:12:34,380
U nixtieq li tibgħat packet
ta 'informazzjoni mill me lilu.

293
00:12:34,380 --> 00:12:37,952
Li iqajjem il-kwistjoni, kif do I
attwalment rotta dan packet lilu.

294
00:12:37,952 --> 00:12:40,660
Ukoll, f'termini umani, nixtieq ngħid,
ħej, inti tista tgħaddi dan Dan?

295
00:12:40,660 --> 00:12:42,826
>> U mbagħad, mazz tal inti
probabbilment jgħaddu lura

296
00:12:42,826 --> 00:12:45,890
u lura u lura sakemm
eventwalment tagħmel mod tiegħu fuq l Dan.

297
00:12:45,890 --> 00:12:47,700
Iżda li l-impreċiżi ftit.

298
00:12:47,700 --> 00:12:50,370
Kompjuters probabilment ikollok bżonn li
jkun ftit aktar metodiku.

299
00:12:50,370 --> 00:12:53,190
Allura probabbilment, Dan għandu l-indirizz IP.

300
00:12:53,190 --> 00:12:57,190
Allura dak li verament I tagħmel hu li I għandhom
tieħu, per eżempju, pakkett vojt

301
00:12:57,190 --> 00:12:58,140
bħal dan.

302
00:12:58,140 --> 00:13:00,130
U jien ma nafx liema
Dan l-indirizz IP huwa.

303
00:13:00,130 --> 00:13:04,300
>> Hekk jien biss se
tiġġeneralizza bħala IP Dan l.

304
00:13:04,300 --> 00:13:07,511
U jien ser tpoġġi dan fil-
il-qasam ta envelop tiegħi.

305
00:13:07,511 --> 00:13:09,010
U sadanittant, I jkollu indirizz IP.

306
00:13:09,010 --> 00:13:10,610
Ma jimpurtax illum dak li hu.

307
00:13:10,610 --> 00:13:15,130
Hekk jien biss se ngħid tiegħi
IP fil-kantuniera lura hemmhekk.

308
00:13:15,130 --> 00:13:19,350
U mbagħad, jien ser jimxi 'l quddiem u mqiegħda
din l-istampa ġewwa ta 'dan il-pakkett.

309
00:13:19,350 --> 00:13:22,800
>> U mbagħad, kull inti, preżumibbilment,
kif routers fuq l-internet,

310
00:13:22,800 --> 00:13:25,470
ġew preconfigured mill
bnedmin ġeneralment jew xi kultant

311
00:13:25,470 --> 00:13:29,854
permezz ta 'algoritmi awtomatizzati li tkun taf li
jekk Dan l-indirizz IP jibda bil-1,

312
00:13:29,854 --> 00:13:30,770
għandhom imorru mod.

313
00:13:30,770 --> 00:13:33,300
Jekk Dan l-indirizz IP tibda bil
ta '2, għandhom imorru mod.

314
00:13:33,300 --> 00:13:34,450
Forsi 3 tmur il-mod.

315
00:13:34,450 --> 00:13:35,575
Forsi 4 tmur il-mod.

316
00:13:35,575 --> 00:13:36,700
U li ftit wisq.

317
00:13:36,700 --> 00:13:38,670
Simplistiku iżda li l-idea ġenerali.

318
00:13:38,670 --> 00:13:42,370
Kull wieħed minn dawn routers-- u hemm jista
jkun daqs 30 bejni u Dan.

319
00:13:42,370 --> 00:13:45,140
--have xi tip ta 'spreadsheet
ġewwa tal-memorja tagħhom,

320
00:13:45,140 --> 00:13:49,070
tabella database, li biss jgħid,
Indirizz IP li tidher bħal dan,

321
00:13:49,070 --> 00:13:49,730
tmur b'dan il-mod.

322
00:13:49,730 --> 00:13:51,960
Indirizz IP li jistenna
bħal dan, tmur il-mod.

323
00:13:51,960 --> 00:13:54,750
U li kif tagħmel
deċiżjonijiet pjuttost simplistika.

324
00:13:54,750 --> 00:13:59,440
>> Iżda jirriżulta li dawn routers do
xi ħaġa aktar minn dak, potenzjalment.

325
00:13:59,440 --> 00:14:03,550
Dawn jippermettu kompjuters sabiex
kunsinna ta 'garanzija, l-inqas

326
00:14:03,550 --> 00:14:05,000
bi probabbiltà għolja.

327
00:14:05,000 --> 00:14:08,340
Allura inti tista ', wisq, smajt, anke jekk
inti stajt qatt pjuttost kkultivat jew CROWLEY

328
00:14:08,340 --> 00:14:12,140
dak li hi, inti tista smajt
ta 'xi ħaġa minn dan akronimu.

329
00:14:12,140 --> 00:14:15,500
Ejja ħa mmorru lura fuq hawn għal
ftit mument u iġbed up dan.

330
00:14:15,500 --> 00:14:18,550
>> TCP, protokoll ta 'kontroll ta' trasmissjoni.

331
00:14:18,550 --> 00:14:21,494
Mod tekniku ieħor ta 'ftit
jiddeskrivi teknoloġija oħra

332
00:14:21,494 --> 00:14:22,660
li użaw fuq l-internet.

333
00:14:22,660 --> 00:14:24,809
Allura IP, protokoll internet
huwa użat għall-indirizzar.

334
00:14:24,809 --> 00:14:27,100
Hija xi standard li l-
dinja ħarāet ma 'dak imsemmi,

335
00:14:27,100 --> 00:14:31,059
inti tpoġġi wieħed indirizz IP hawn għal Dan,
u wieħed indirizz IP hawn għalik innifsek,

336
00:14:31,059 --> 00:14:33,100
u allura inti tpoġġi xi
informazzjoni fl-istess pakkett.

337
00:14:33,100 --> 00:14:36,600
>> Iżda TCP huwa teknoloġija oħra,
jintużaw flimkien ma IP.

338
00:14:36,600 --> 00:14:38,970
U fil-fatt, jekk inti stajt qatt
raw dawn akronimi qabel,

339
00:14:38,970 --> 00:14:42,110
inti stajt probabbilment jidhru
TCP mmejla IP li biss

340
00:14:42,110 --> 00:14:43,900
ifisser nies għandhom tendenza li jużawhom flimkien.

341
00:14:43,900 --> 00:14:47,570
Ukoll, TCP huwa tip ta '
jibred għaliex tippermetti

342
00:14:47,570 --> 00:14:50,220
inti tiżdied il-probabbiltà
li d-data hija attwalment

343
00:14:50,220 --> 00:14:51,970
se tikseb mill me għal Dan.

344
00:14:51,970 --> 00:14:54,080
>> Fil-fatt, l-internet huwa post crazy.

345
00:14:54,080 --> 00:14:56,530
M'hemm l-ebda garanzija li
jekk I tibgħat id-data b'dan il-mod

346
00:14:56,530 --> 00:14:58,530
li huwa għaddej biex tmur
li mod ħin li jmiss madwar.

347
00:14:58,530 --> 00:14:59,905
Huwa jista 'jmur mod jew b'dak il-mod.

348
00:14:59,905 --> 00:15:02,680
L-iqsar distanza bejn
żewġ punti mhuwiex neċessarjament

349
00:15:02,680 --> 00:15:04,860
dritta jew l-istess linja.

350
00:15:04,860 --> 00:15:07,170
>> Barra minn hekk, xi wħud minnkom
guys jista 'jagħmel żbalji

351
00:15:07,170 --> 00:15:09,780
jew tikseb b'rikjesti wisq
ħafna pakketti li ġejjin tiegħek mod.

352
00:15:09,780 --> 00:15:10,940
Allura inti biss tmur
jċedu u litteralment

353
00:15:10,940 --> 00:15:13,050
qatra xi wħud minn dawn
envelops fuq l-art.

354
00:15:13,050 --> 00:15:16,930
U fl-istess mod tista 'tkun data
niżel fuq l-internet mill-routers.

355
00:15:16,930 --> 00:15:18,680
Allura biex inaqqsu l-
odds ta 'dan, jien ser

356
00:15:18,680 --> 00:15:21,980
biex jieħdu sigurtà tiegħi ftit
imqassijiet hawn u maqtugħin Rob

357
00:15:21,980 --> 00:15:26,140
fis, ejja ngħidu, erba
biċċiet, erba segmenti.

358
00:15:26,140 --> 00:15:27,210

359
00:15:27,210 --> 00:15:33,350
>> U issa, jien ser jimxi 'l quddiem u
jitqiegħdu waħda biċċa aktar informazzjoni

360
00:15:33,350 --> 00:15:34,610
fuq dan l-envelop.

361
00:15:34,610 --> 00:15:39,630
Jien se ngħid xi ħaġa simili, 1 ta '4.

362
00:15:39,630 --> 00:15:43,370
Allura issa, pakkett finali tiegħi, fil
inqas l-ewwel, tidher bħal dan.

363
00:15:43,370 --> 00:15:45,500
Jien ser jimxi 'l quddiem
u tpoġġi dan wieħed fil hawn.

364
00:15:45,500 --> 00:15:47,070

365
00:15:47,070 --> 00:15:53,430
U għall-finijiet ħin, il jien ser
tikketta l-oħrajn identiku bħala 2 ta '4,

366
00:15:53,430 --> 00:15:57,760
3 ta '4, 4 ta' 4.

367
00:15:57,760 --> 00:16:02,170
>> Għal darb'oħra, bl Dan l-indirizz IP fil-
quddiem ta 'dan u bl-indirizz IP tiegħi

368
00:16:02,170 --> 00:16:06,660
fuq id-dahar xellug, iżda I
ma tistax tibgħat lilhom għadha biss.

369
00:16:06,660 --> 00:16:08,930
Għaliex jirriżulta
li fuq l-internet,

370
00:16:08,930 --> 00:16:10,980
servers tista 'tagħmel affarijiet multipli.

371
00:16:10,980 --> 00:16:14,300
Fil-fatt, aħna kollha jistgħu jużaw il-web
pjuttost ftit, il-web dinjija,

372
00:16:14,300 --> 00:16:16,139
http: // x'ikun.

373
00:16:16,139 --> 00:16:17,930
Iżda hemm ieħor
servizzi fuq l-internet.

374
00:16:17,930 --> 00:16:21,760
Liema huma xi servizzi oħra, sort
ta 'utent, servizzi faċli għall-konsumatur

375
00:16:21,760 --> 00:16:25,020
li rebbiegħa f'moħħna minbarra
programm tat-tip browser web?

376
00:16:25,020 --> 00:16:26,724

377
00:16:26,724 --> 00:16:27,390
UDJENZA: Email.

378
00:16:27,390 --> 00:16:28,180
DAVID Malan: Email.

379
00:16:28,180 --> 00:16:28,410
OK.

380
00:16:28,410 --> 00:16:28,630
Tajba.

381
00:16:28,630 --> 00:16:29,446
X'hemm wieħed ieħor?

382
00:16:29,446 --> 00:16:30,070
UDJENZA: Chat.

383
00:16:30,070 --> 00:16:32,780
DAVID Malan: Allura chat, kemm jekk
huwa Skype, jew Gchat, jew xi ħaġa

384
00:16:32,780 --> 00:16:33,992
bħal dik.

385
00:16:33,992 --> 00:16:34,817
>> UDJENZA: Ħażna.

386
00:16:34,817 --> 00:16:37,150
DAVID Malan: Allura xi tip ta '
ħażna tas-servizz, ċertament.

387
00:16:37,150 --> 00:16:39,004
Xi ħaġa bħal Dropbox,
jew Kaxxa, jew bħalhom.

388
00:16:39,004 --> 00:16:40,920
Allura hemm differenti
servizzi fuq l-internet.

389
00:16:40,920 --> 00:16:44,090
U jirriżulta li Dan,
jekk huwa tabilħaqq kompjuter,

390
00:16:44,090 --> 00:16:46,520
ma għandhom jiġu dedikati
li ħaġa waħda fil-ħajja.

391
00:16:46,520 --> 00:16:49,650
Huwa jista 'attwalment tagħmel affarijiet multipli.

392
00:16:49,650 --> 00:16:51,740
U fil-fatt, huwa jista 'jkun server email.

393
00:16:51,740 --> 00:16:53,270
Huwa jista 'jkun web server.

394
00:16:53,270 --> 00:16:55,120
Huwa jista 'jkun chat server.

395
00:16:55,120 --> 00:16:57,600
>> Iżda li jidher li tissuġġerixxi
li Dan jeħtieġ li tkun taf

396
00:16:57,600 --> 00:17:01,010
minn qabel liema huma l-
kontenut ta 'dawn il-messaġġi.

397
00:17:01,010 --> 00:17:02,830
Huwa dan ta 'paġna web jien jibgħat lilu?

398
00:17:02,830 --> 00:17:04,140
Huwa email jien jibgħat lilu?

399
00:17:04,140 --> 00:17:05,930
Huwa instant
messaġġ Jien jibgħat lilu?

400
00:17:05,930 --> 00:17:08,630
Allura għandna bżonn wieħed biċċa aktar
informazzjoni dwar dawn envelop

401
00:17:08,630 --> 00:17:10,930
b'tali mod li Dan, meta hu
jirċievi dan il-pakkett,

402
00:17:10,930 --> 00:17:13,119
jaf liema programm għall-użu li juri dan.

403
00:17:13,119 --> 00:17:14,200
>> Huwa ta 'browser?

404
00:17:14,200 --> 00:17:15,170
Huwa Google?

405
00:17:15,170 --> 00:17:16,170
Huwa Skype?

406
00:17:16,170 --> 00:17:19,760
Jew hija Outlook jew xi
programm ieħor għal kollox?

407
00:17:19,760 --> 00:17:23,740
U hekk, ma TCP taqa
biss konvenzjoni tal-bniedem.

408
00:17:23,740 --> 00:17:26,930
Id-dinja iddeċieda xi snin
ilu biex interi uniċi jassoċjaw

409
00:17:26,930 --> 00:17:28,520
mas-servizzi l-aktar popolari.

410
00:17:28,520 --> 00:17:31,920
>> One sejjaħ Protokoll File Transfer,
FTP, għalkemm huwa ftit datata issa.

411
00:17:31,920 --> 00:17:34,150
Iżda identifikatur uniku tagħha huwa 21.

412
00:17:34,150 --> 00:17:39,020
SMTP għall email ħerġin, uniku tagħha
identifikatur huwa 25 biss għaliex.

413
00:17:39,020 --> 00:17:43,616
DNS, il-ħaġa tkellimna dwar preċedenti,
juża n-numru 53 għall-mistoqsijiet tagħha.

414
00:17:43,616 --> 00:17:45,365
Bħal dak li huwa l-PI
indirizz tal google.com?

415
00:17:45,365 --> 00:17:46,580

416
00:17:46,580 --> 00:17:49,790
>> U issa, l-aktar familjari għalik
jista 'jkollhom x'imkien f'xi punt

417
00:17:49,790 --> 00:17:52,620
raw in-numru 80 u forsi 443.

418
00:17:52,620 --> 00:17:55,822
Dawk huma l-uniċi
identifikaturi għall HTTP,

419
00:17:55,822 --> 00:17:57,530
li hija l-lingwa
Ser naraw użati dalwaqt

420
00:17:57,530 --> 00:18:00,000
għal traffiku web bejn
browsers u s-servers.

421
00:18:00,000 --> 00:18:02,740
U 443 huma l-
Verżjoni sigur tagħha.

422
00:18:02,740 --> 00:18:05,530
>> Allura l-wieħed dettall aħħar jien
se jitqiegħdu fuq envelop tiegħi

423
00:18:05,530 --> 00:18:08,530
hija li jien mhux ser
tibgħat din biss biex IP Dan l.

424
00:18:08,530 --> 00:18:13,630
Jien ser jibgħatha lill ngħid,
: 80, jekk dak li jien jippruvaw jibagħtu

425
00:18:13,630 --> 00:18:16,862
lilu hija paġna web, web page
li fih stampa Rob Boden tal.

426
00:18:16,862 --> 00:18:19,320
Hekk jien ser jagħmlu l-istess
ħaġa fuq dawn pakketti oħra.

427
00:18:19,320 --> 00:18:23,620
>> U mbagħad finalment, jien ser qatra
dawn off mal-eqreb router,

428
00:18:23,620 --> 00:18:26,300
jirrikonoxxi li dan
router mhux bilfors

429
00:18:26,300 --> 00:18:28,210
tieħu l-istess triq kull darba.

430
00:18:28,210 --> 00:18:30,900
Fil-fatt, I jista 'jkollhom l-
ewwel pakkett jmorru b'dan il-mod.

431
00:18:30,900 --> 00:18:32,670
Tieni pakkett jista 'jmur il-mod.

432
00:18:32,670 --> 00:18:34,250
Tielet packet-- tibda routing.

433
00:18:34,250 --> 00:18:35,420
--might jmorru fuq hawn.

434
00:18:35,420 --> 00:18:36,440

435
00:18:36,440 --> 00:18:39,530
U fil theory-- ma tistax jżommha.

436
00:18:39,530 --> 00:18:43,660
Fit-teorija, l-erba 'dawn pakketti
għandhom eventwalment rotta mod tagħhom,

437
00:18:43,660 --> 00:18:46,940
madankollu effiċjenti jew ineffiċjenti,
it-triq kollha għall-dahar.

438
00:18:46,940 --> 00:18:51,560
>> F'liema punt, Dan, malli
irċevuta, jista reassemble minnhom

439
00:18:51,560 --> 00:18:55,735
ibbażata on-- l-ħaġa umoristiċi hija,
nafu lkoll dak l-eżitu hawn

440
00:18:55,735 --> 00:18:56,360
se tkun.

441
00:18:56,360 --> 00:18:57,600
Dan għaddej biex tikseb stampa ta 'Rob.

442
00:18:57,600 --> 00:18:58,974
Imma ejja ara kif taħdem din out.

443
00:18:58,974 --> 00:18:59,664

444
00:18:59,664 --> 00:19:02,080
Ukoll, pjuttost, Dan għaddej biex
jiksbu parti minn stampa ta 'Rob.

445
00:19:02,080 --> 00:19:04,286

446
00:19:04,286 --> 00:19:04,785
Tajba ħafna.

447
00:19:04,785 --> 00:19:06,200

448
00:19:06,200 --> 00:19:07,580
Kulħadd illum parteċipanti.

449
00:19:07,580 --> 00:19:09,200

450
00:19:09,200 --> 00:19:09,910
Kull dritt.

451
00:19:09,910 --> 00:19:13,870
Allura kif Dan jibda biex jirċievu dawn
pakketti, ejja jistaqsu mistoqsija waħda.

452
00:19:13,870 --> 00:19:18,820
X'jiġri jekk wieħed minnkom gets għażżien,
mgħobbijin, malizzjużi, jew biss powered

453
00:19:18,820 --> 00:19:22,570
off, u wieħed jew aktar mill-
pakkett ma tagħmel lill Dan?

454
00:19:22,570 --> 00:19:26,920
>> Kif huwa Dan ser tkun taf huwa ma
tirċievi waħda mill-segmenti ta 'l-erba

455
00:19:26,920 --> 00:19:28,040
I bagħtet lilu?

456
00:19:28,040 --> 00:19:30,040
Just intuwittivament, x'nistgħu nagħmlu?

457
00:19:30,040 --> 00:19:30,540
Yeah?

458
00:19:30,540 --> 00:19:31,456
>> UDJENZA: [inaudible].

459
00:19:31,456 --> 00:19:35,885

460
00:19:35,885 --> 00:19:36,760
DAVID Malan: Eżattament.

461
00:19:36,760 --> 00:19:40,250
Għaliex stajt unikament nnumerati lilhom, u
Kif stajt speċifikat segmenti hemm ħafna

462
00:19:40,250 --> 00:19:44,030
għandu jkun, huwa jista 'jiddeduċi minn dik
liema, jekk hemm, mill-segmenti

463
00:19:44,030 --> 00:19:45,070
hu attwalment nieqes.

464
00:19:45,070 --> 00:19:48,770
U dak TCP jgħidlekx kompjuters biex
do, jekk il-kompjuters, bħal Mac OS,

465
00:19:48,770 --> 00:19:52,510
u Windows, Linux u appoġġ
u jifhmu TCP, li jagħmlu,

466
00:19:52,510 --> 00:19:57,010
Dokumentazzjoni TCP essenzjalment
jgħid li Dan għandu tibgħatli

467
00:19:57,010 --> 00:20:00,580
messaġġ lura qal, ħej, David,
Jien nieqsa packet numru 1 ta '4,

468
00:20:00,580 --> 00:20:02,290
jew 3 ta '4, skond liema huwa.

469
00:20:02,290 --> 00:20:06,016
>> U mbagħad, xogħol tiegħi huwa li jieħdu
ieħor stampa ta Rob,

470
00:20:06,016 --> 00:20:09,140
li għandna ekstras ta 'għal aktar tard lum
jekk inti tixtieq li tieħu waħda miegħek,

471
00:20:09,140 --> 00:20:13,550
u allura nista resend dak is-segment
tal Rob-triq kollha għall-dahar.

472
00:20:13,550 --> 00:20:16,380
>> Allura kif simplistiku kif
dan il-mekkaniżmu huwa, li

473
00:20:16,380 --> 00:20:20,310
huwa dak li qed jiġri kważi kwalunkwe ħin
inti tagħmel xi ħaġa fuq l-internet,

474
00:20:20,310 --> 00:20:22,530
partikolarment għal dawn
aktar popolari ta 'servizzi.

475
00:20:22,530 --> 00:20:26,500
Hemm protokolli oħra,
teknoloġiji oħra minbarra TCP

476
00:20:26,500 --> 00:20:27,880
li jaħdmu ftit differenti.

477
00:20:27,880 --> 00:20:33,040
Imma hekk ħafna mis-servizzi aħna tipikament
jużaw attwalment jiddependu fuq dawn il-protokolli.

478
00:20:33,040 --> 00:20:35,720
>> Allura Dan, ma ikollok l-
stampa sħiħa lura hemmhekk?

479
00:20:35,720 --> 00:20:36,220
Iva.

480
00:20:36,220 --> 00:20:37,840
Aħna assemblati mill-ġdid Rob fid-dahar.

481
00:20:37,840 --> 00:20:39,610
Grazzi tant għall-routers.

482
00:20:39,610 --> 00:20:43,260
Suppose, I attwalment tixtieq l-
tara l-routers bejni

483
00:20:43,260 --> 00:20:46,400
u MIT, simili ħafna inti guys kienu
l-routers bejni u Dan.

484
00:20:46,400 --> 00:20:49,500
>> Ukoll, pjuttost milli nslookup
għall-isem server Lookup,

485
00:20:49,500 --> 00:20:53,150
I jistgħu minflok tip traċċa rotta, li
huwa attwalment għaddejjin biex jagħmlu dak li jgħid.

486
00:20:53,150 --> 00:20:55,240
U jien ser tagħmel u
modalità kwieta bil sing 1.

487
00:20:55,240 --> 00:20:57,448
Huwa argument linja tal-kmand
li biss jgħid, ipprova din

488
00:20:57,448 --> 00:20:58,740
darba u mhux iktar minn darba.

489
00:20:58,740 --> 00:21:02,210
>> U issa, jien ser tip www.mit.edu.

490
00:21:02,210 --> 00:21:05,660
Issa, l-output huwa
pjuttost malajr u cryptic.

491
00:21:05,660 --> 00:21:08,300
Imma x'hemm pulita dwar dan
huwa li kull wieħed minn dawn ringieli

492
00:21:08,300 --> 00:21:10,750
essenzjalment jirrappreżenta
student f'dan l-udjenza

493
00:21:10,750 --> 00:21:13,870
jekk inti kienu l-passaġġ bejn lili u MIT.

494
00:21:13,870 --> 00:21:17,930
Dak li tara up here, l-ewwel, huwa
l-isem tad-dominju li jien ittajpjat fil,

495
00:21:17,930 --> 00:21:20,500
jew domain kompletament ikkwalifikat
isem kif huwa msejjaħ kif suppost.

496
00:21:20,500 --> 00:21:24,420
>> U dan apparentement huwa l-
Indirizz IP ta www.mit.edu.

497
00:21:24,420 --> 00:21:26,260
My kompjuter dehret li għalija.

498
00:21:26,260 --> 00:21:29,170
Dan hawnhekk hija wegħda
li aħna qed biss se

499
00:21:29,170 --> 00:21:31,490
sabiex jippruvaw jilħqu MIT fi żmien 30-ħops.

500
00:21:31,490 --> 00:21:34,180
Aħjar ikun hemm aktar minn
30 student bejn lili u daN.

501
00:21:34,180 --> 00:21:37,870
U issa, kull wieħed minn dawn ringieli
tirrappreżenta litteralment router

502
00:21:37,870 --> 00:21:40,280
bejni u Dan,
litteralment wieħed minnkom guys.

503
00:21:40,280 --> 00:21:42,950
>> U hekk dan wieħed ma jidhirx
li jkollu isem, isem ta 'dominju.

504
00:21:42,950 --> 00:21:44,150
Hija biss għandha IP.

505
00:21:44,150 --> 00:21:49,439
U hija ħadet biss 0.662 millisekondi
biex jiksbu mill me għal dak l-ewwel router.

506
00:21:49,439 --> 00:21:51,230
Il-wieħed li jmiss ma kienx
li ħafna farther bogħod.

507
00:21:51,230 --> 00:21:53,560
Hija biss ħa wieħed
millisekonda biex naslu s'hemm.

508
00:21:53,560 --> 00:21:56,280
U issa, Thankfully, l-affarijiet
jiksbu ftit aktar faċli għall-utent

509
00:21:56,280 --> 00:21:58,860
ma 'ismijiet li huma cryptic
iżda ftit aktar javżak.

510
00:21:58,860 --> 00:22:03,440
>> Dan apparentament huwa router fil-
qalba ta 'netwerk Harvard miżmuma,

511
00:22:03,440 --> 00:22:06,330
biss għaliex in-nies kienu qalulna
dan, fl-Ċentru tax-Xjenza, SC.

512
00:22:06,330 --> 00:22:11,720
U GW huwa biss notazzjoni shorthand għal
portal li huwa sinonimu għal router.

513
00:22:11,720 --> 00:22:14,630
Allura dan huwa xi sistema
mod superscript amministratur

514
00:22:14,630 --> 00:22:17,230
tal tismija wieħed mis-servers
fil-Center Xjenza.

515
00:22:17,230 --> 00:22:20,360
>> Sadanittant, li server hija apparentement
konnessi minn xi tip ta 'cable

516
00:22:20,360 --> 00:22:24,760
router ieħor thats nicknamed
l-portal fruntiera sing wieħed

517
00:22:24,760 --> 00:22:26,770
xi ħaġa, tkun xi tkun dawn in-numri jfisser.

518
00:22:26,770 --> 00:22:29,230
U mbagħad, apparentement,
Harvard għandu konnessjoni

519
00:22:29,230 --> 00:22:31,340
li l millisekonda ieħor
bogħod għal xi ħaġa

520
00:22:31,340 --> 00:22:35,590
imsejjaħ salib it-toroq tat-Tramuntana
li huwa punt peering komuni

521
00:22:35,590 --> 00:22:38,430
bejn postijiet kbar bħal Harvard
fejn il-lottijiet ta 'cabling tmur

522
00:22:38,430 --> 00:22:40,870
u tippermetti interkonnessjonijiet
fost entitajiet differenti.

523
00:22:40,870 --> 00:22:43,700
>> Pass sitt, sfortunatament,
ma jkollux isem validu.

524
00:22:43,700 --> 00:22:45,370
U pass seba gets interessanti.

525
00:22:45,370 --> 00:22:46,820

526
00:22:46,820 --> 00:22:49,260
Għandi l-ebda idea dak li ħafna minn dawn jfisser.

527
00:22:49,260 --> 00:22:50,875
Iżda NY ma jaqbżu fil lili.

528
00:22:50,875 --> 00:22:52,375
U dak li ma probabbilment turi?

529
00:22:52,375 --> 00:22:54,810

530
00:22:54,810 --> 00:22:56,520
Mhuwiex anki tekniku.

531
00:22:56,520 --> 00:22:57,400
Just New York.

532
00:22:57,400 --> 00:23:00,510
Allura fil-fatt, x'hemm bniedem komuni
konvenzjoni mhuwiex garantit

533
00:23:00,510 --> 00:23:04,730
iżda konvenzjoni komuni hija li routers isem
min-natura tal-belt jew l-ajruport

534
00:23:04,730 --> 00:23:05,960
kodiċi li dawn qed eqreb.

535
00:23:05,960 --> 00:23:08,630
>> Allura b'xi probabbilità,
dan in-numru router seba

536
00:23:08,630 --> 00:23:10,270
huwa probabbilment, tabilħaqq, fi New York.

537
00:23:10,270 --> 00:23:13,020
U dan jidher li jikkorroboraw
din il-preżunzjoni, għaliex dan huwa

538
00:23:13,020 --> 00:23:16,700
sitt millisekondi minflok waħda biss
jew hekk għal xi ħaġa hawn fuq il-kampus.

539
00:23:16,700 --> 00:23:19,900
Imma issa tieħu dan in kunsiderazzjoni,
dritt fuq Megabus jew whatnot,

540
00:23:19,900 --> 00:23:23,810
jista 'jieħu erba, ħames, sitt sigħat
biex tikseb bniedem minn hawn lejn New York.

541
00:23:23,810 --> 00:23:28,040
>> Biex tikseb biċċa ta 'data,
jieħu biss sitt millisekondi

542
00:23:28,040 --> 00:23:31,020
biex tikseb packet mill me għal Dan jekk
kien il-triq kollha fi New York.

543
00:23:31,020 --> 00:23:36,832
Mbagħad finalment, dan apparentement huwa l-
isem tad-dominju attwali għall www.mit.edu.

544
00:23:36,832 --> 00:23:38,790
Huma ħadthom apparentement
esternalizzati servers web tagħhom

545
00:23:38,790 --> 00:23:42,030
lil kumpanija msejħa Akamai li jfisser
xi kumpanija oħra runs servers tagħhom.

546
00:23:42,030 --> 00:23:44,380
U hu għalhekk li aħna qed jaraw
li ħaġa stramb hemmhekk.

547
00:23:44,380 --> 00:23:45,720
>> Well, ejja tagħmel dan darba aktar.

548
00:23:45,720 --> 00:23:49,150
Ejja imorru quddiem u tagħmel traċċa
rotta lill ħabib tagħna Professur Nick

549
00:23:49,150 --> 00:23:52,955
Parlante fil Stanford li għandu
server imsejħa nifty.stanfor.edu.

550
00:23:52,955 --> 00:23:55,870

551
00:23:55,870 --> 00:23:56,980
Ikteb.

552
00:23:56,980 --> 00:23:59,460
U issa, aħna ser tara probabbilment
triq kemmxejn itwal

553
00:23:59,460 --> 00:24:00,960
li tmur permezz ta 'ftit iżjed ibliet.

554
00:24:00,960 --> 00:24:03,160
Allura hawn dawn nameless
Servers Harvard hawn.

555
00:24:03,160 --> 00:24:05,660
Aħna fil-qalba ta 'Harvard,
l-portal tal-fruntiera ta 'Harvard,

556
00:24:05,660 --> 00:24:08,081
salib it-toroq tat-Tramuntana,
kull fejn dan huwa.

557
00:24:08,081 --> 00:24:10,080
U issa, huwa jkollna a
ftit aktar interessanti.

558
00:24:10,080 --> 00:24:12,960
Jien guessing li router
numru tmienja hija fil dak belt?

559
00:24:12,960 --> 00:24:14,210
UDJENZA: [INTERPOSING VOICES]

560
00:24:14,210 --> 00:24:18,570
DAVID Malan: Chicago probabbilment, ibbażata
fuq dan, ibbażata fuq din il-ħaġa hawn.

561
00:24:18,570 --> 00:24:25,220
U issa għandna Salt Lake City forsi,
forsi Los Angeles hawn, u mbagħad LAX,

562
00:24:25,220 --> 00:24:27,690
Yep, dan probabbilment LA mill-qiegħ.

563
00:24:27,690 --> 00:24:29,940
Sakemm finalment, din tmur
mill-California nofsinhar

564
00:24:29,940 --> 00:24:34,420
it-triq kollha sa California Tramuntana
fejn Stanford hija fil Palo Alto.

565
00:24:34,420 --> 00:24:35,299
So pretty jibred.

566
00:24:35,299 --> 00:24:36,840
U ejja tieħu dan il-pass wieħed ulterjuri.

567
00:24:36,840 --> 00:24:39,000
Hija apparentement kieku
tieħu inti 82 millisekondi

568
00:24:39,000 --> 00:24:42,360
biex jibgħat messaġġ lill Dan jekk inti kienu
fil-California minflok ta 'New York.

569
00:24:42,360 --> 00:24:45,090
Ejja nagħmlu xi ħaġa
bħal traċċi-rotot, wieħed

570
00:24:45,090 --> 00:24:51,350
tentattiv biex www.cnn.co.jp għall-
Verżjoni Ġappuniż tal-websajt CNN.

571
00:24:51,350 --> 00:24:52,540

572
00:24:52,540 --> 00:24:54,910
U issa, aħna qed għadhom fl
Boston jidher fil-mument.

573
00:24:54,910 --> 00:24:56,050

574
00:24:56,050 --> 00:24:58,165
>> A servers koppja sitt u
tmienja mhumiex jirrispondu

575
00:24:58,165 --> 00:24:59,790
għaliex qed tkun ftit privat.

576
00:24:59,790 --> 00:25:04,970
Iżda eventwalment, jidher li hemm
xi ħaġa interessanti għaddejjin bejn,

577
00:25:04,970 --> 00:25:08,395
ejja ngħidu, pass seba u disa.

578
00:25:08,395 --> 00:25:09,800

579
00:25:09,800 --> 00:25:12,610
X'inhu probabbilment bejn
seba u disa ', u ċertament

580
00:25:12,610 --> 00:25:14,610
bejn seba u pass 17?

581
00:25:14,610 --> 00:25:18,090

582
00:25:18,090 --> 00:25:20,210
Hemm qabża enormi
fl-ammont ta 'ħin

583
00:25:20,210 --> 00:25:23,540
huwa teħid għal data li jmorru minn wieħed
ta 'dawn ħops, wieħed minn dawn routers

584
00:25:23,540 --> 00:25:24,060
għall-ieħor.

585
00:25:24,060 --> 00:25:27,310
>> Allura odds huma, x'imkien fil-
hawn, hemm probabilment,

586
00:25:27,310 --> 00:25:31,440
speċjalment dritt hawn, hemm probabilment
korp kbir ħafna ta 'ilma li

587
00:25:31,440 --> 00:25:35,320
għandha xi trans Paċifiku jew trans
Cable Atlantiku li attwalment teħtieġ

588
00:25:35,320 --> 00:25:37,710
aktar żmien għad-data għall-
jiksbu minn punt għall-ieħor.

589
00:25:37,710 --> 00:25:40,690
Iżda għal darb'oħra, jimmaġina l-sigħat
hija kienet ser tieħu l-fly għall-Ġappun.

590
00:25:40,690 --> 00:25:45,786
Hawnhekk, f'xi 200 millisekondi,
boom, il-messaġġ tiegħek huwa attwalment hemm.

591
00:25:45,786 --> 00:25:48,160
Allura inti tista 'tilgħab madwar ma'
dan fuq l-appliance jew saħansitra

592
00:25:48,160 --> 00:25:50,940
fil-Windows jew Mac OS ma
jikkmanda kemmxejn differenti.

593
00:25:50,940 --> 00:25:53,860
Kultant, inti se tikseb dawn l-istilel,
bħal fir-ringieli sitta u tmienja, li

594
00:25:53,860 --> 00:25:55,300
ifisser biss l-routers
huma konfigurati mhumiex

595
00:25:55,300 --> 00:25:57,120
li jtik risposta
f'ġieħ privatezza tal.

596
00:25:57,120 --> 00:26:00,210
Iżda ġeneralment, din it-teknika
kieku, fil-fatt, ix-xogħol.

597
00:26:00,210 --> 00:26:03,730
>> Għalhekk jirriżulta li wisq hemm ieħor
informazzjoni mmerraq lurking fl-għodod

598
00:26:03,730 --> 00:26:05,610
li tieħu għall mogħtija kull jum.

599
00:26:05,610 --> 00:26:08,560
Allura per eżempju, jekk inti tirċievi
email, franchement kif xi wħud minnkom

600
00:26:08,560 --> 00:26:11,270
jista 'jkollhom reċentement, ta dubjuż
oriġini, jekk inti stajt qatt

601
00:26:11,270 --> 00:26:13,330
ħares lejn interface Gmail
qabel, kemm jekk huwa

602
00:26:13,330 --> 00:26:15,560
għall-interface kulleġġ
jew waħda personali tiegħek,

603
00:26:15,560 --> 00:26:17,620
inti tista 'tara tiegħek
inbox tfittex bħal dan.

604
00:26:17,620 --> 00:26:20,910
>> U fil-fatt, dan huwa email
I bagħtet, malan@harvard.edu,

605
00:26:20,910 --> 00:26:24,620
li jharvard@cs50.harvard.edu
dalgħodu biss

606
00:26:24,620 --> 00:26:26,070
so I tista 'tieħu screenshot.

607
00:26:26,070 --> 00:26:28,149
Iżda jirriżulta, kollha
din id-darba fil-Gmail,

608
00:26:28,149 --> 00:26:30,190
hemm dik trijangolu ftit
lejn il-lemin ta 'fuq

609
00:26:30,190 --> 00:26:34,080
hemm jmiss għall-crest Harvard li jekk
tikklikkja, inti tista 'ikklikkja Show Original.

610
00:26:34,080 --> 00:26:35,160

611
00:26:35,160 --> 00:26:39,260
U jekk inti tagħmel dan, inti ser attwalment ara
mazz ta 'informazzjoni esoteric ħafna

612
00:26:39,260 --> 00:26:43,360
bħall timestamps, u IP
indirizzi, u ismijiet tad-dominju.

613
00:26:43,360 --> 00:26:46,990
>> Imma inti taf tara, fil-qosor, il-
headers li dan il-ħin jkollu

614
00:26:46,990 --> 00:26:50,430
intlaqtu fl kull
email inti tibgħat u tirċievi.

615
00:26:50,430 --> 00:26:54,130
U huwa dawn headers in-nies jistgħu
użu, xjentist kompjuter jew b'xi mod ieħor,

616
00:26:54,130 --> 00:26:56,670
li attwalment jiddeduċu ma
xi probabbiltà fejn

617
00:26:56,670 --> 00:26:59,290
u minn min email attwalment daħal.

618
00:26:59,290 --> 00:27:01,830
>> Fil-fatt, aħna ser nitkellmu fil
ġimgħat wara dwar kif email

619
00:27:01,830 --> 00:27:04,100
innifsu jista 'jiġi ġġenerat
programmatically li

620
00:27:04,100 --> 00:27:07,100
hija ħaġa tajba ħafna għal websajt
li irid jibgħat emails lill-utenti.

621
00:27:07,100 --> 00:27:12,020
Iżda aħna ser tara, wisq, kemm trivjali
huwa li ssawwar emails minn xi ħadd

622
00:27:12,020 --> 00:27:15,380
lil xi ħadd ieħor, sakemm inti fil-fatt
taf kif biex jivverifikaw l-headers.

623
00:27:15,380 --> 00:27:18,670
U anki li huwa jitilfu
proposition dawn il-jiem.

624
00:27:18,670 --> 00:27:22,220
>> Allura ma 'dak imsemmi,
ejja go wieħed saff up.

625
00:27:22,220 --> 00:27:25,100
Bdejna bil IP li
tindirizza pakketti għalina,

626
00:27:25,100 --> 00:27:26,470
tagħtihom indirizzi uniċi.

627
00:27:26,470 --> 00:27:29,770
TCP, li, fil-qosor,
garanziji ta 'kunsinna jew għall-inqas

628
00:27:29,770 --> 00:27:34,002
jżid il-probabbiltà tiegħu billi
żżid affarijiet simili segmenti, 1 jew 4,

629
00:27:34,002 --> 00:27:36,740
2 ta '4, 3 ta' 4, u 4 ta '4.

630
00:27:36,740 --> 00:27:40,710
>> U issa, ejja saff fuq nett
ta 'dan il-protokoll ieħor.

631
00:27:40,710 --> 00:27:44,550
Kollha ta 'dawn l-affarijiet huma
protokolli, konvenzjonijiet kompjuter

632
00:27:44,550 --> 00:27:47,670
li jiddettaw kif tnejn
kompjuters jitkellmu ma 'xulxin.

633
00:27:47,670 --> 00:27:52,030
HTTP, finalment illum, huwa
protokoll ta 'trasferiment Portugues.

634
00:27:52,030 --> 00:27:54,100
U dan huwa l-protokoll
li web browsers

635
00:27:54,100 --> 00:27:56,410
użu meta jitkellem servers mill-web.

636
00:27:56,410 --> 00:27:59,970
>> Allura meta inti pull up browser bħal
Chrome, jew IE, Firefox jew, jew Safari,

637
00:27:59,970 --> 00:28:04,230
jew kwalunkwe, u inti tip fil xi ħaġa
bħal facebook.com u hit Ikteb,

638
00:28:04,230 --> 00:28:08,390
mhux biss ma kompjuter tiegħek l-ewwel
tittraduċi facebook.com fil dak?

639
00:28:08,390 --> 00:28:10,590

640
00:28:10,590 --> 00:28:11,770
Indirizz IP.

641
00:28:11,770 --> 00:28:17,420
Imbagħad converts-- imbagħad jibgħat
messaġġ għal dan l-indirizz IP qal,

642
00:28:17,420 --> 00:28:21,360
tagħti me homepage lum jew jagħtu
lili l-iskrin login ta 'Facebook.

643
00:28:21,360 --> 00:28:25,290
>> Jew jekk int diġà illoggjat, jagħtu
me-opinjoni default ta kronoliġika tiegħi.

644
00:28:25,290 --> 00:28:26,820
Allura dak hu HTTP jgħid.

645
00:28:26,820 --> 00:28:30,055
U aktar colloquially, jekk I am a web
server u inti are-- x'hemm isem tiegħek,

646
00:28:30,055 --> 00:28:30,180
mill-ġdid?

647
00:28:30,180 --> 00:28:30,920
>> UDJENZA: Margot.

648
00:28:30,920 --> 00:28:34,250
>> DAVID Malan: Margot huwa web
server, u jien web browser,

649
00:28:34,250 --> 00:28:37,610
u I sempliċement jixtiequ li tkun irkuprata tiegħi
kalendarju minn Margot, margot.com,

650
00:28:37,610 --> 00:28:39,640
Jien ngħid, hello, jien David.

651
00:28:39,640 --> 00:28:40,870
>> UDJENZA: Hi, jien Margot.

652
00:28:40,870 --> 00:28:43,570
>> DAVID Malan: U inti mbagħad twieġeb
b'informazzjoni addizzjonali lili.

653
00:28:43,570 --> 00:28:45,890
Allura aħna għandna dan uman stupid
konvenzjoni għall instance-- nirringrazzjak.

654
00:28:45,890 --> 00:28:47,510
--Ta tħawwad idejn xulxin.

655
00:28:47,510 --> 00:28:51,670
U kompjuters għandhom l-istess idea
Meta klijent, bħal browser,

656
00:28:51,670 --> 00:28:55,600
jitlob server biex tagħmel xi ħaġa
f'isem tiegħu jew tagħha.

657
00:28:55,600 --> 00:28:57,540
>> U hekk hawn stampa, per eżempju.

658
00:28:57,540 --> 00:29:01,120
Fuq ix-xellug huwa kompjuter laptop,
desktop, ikun x'ikun, jew saħansitra telefon.

659
00:29:01,120 --> 00:29:03,890
U dwar id-dritt huwa ħafna
datat ħsieb ta 'server.

660
00:29:03,890 --> 00:29:06,460
Huma tipikament jistenna iżgħar
u sexier dawn il-jiem.

661
00:29:06,460 --> 00:29:09,570
Imma l-punt huwa sempliċement li
hemm xi tip ta 'komunikazzjoni

662
00:29:09,570 --> 00:29:11,800
bejn klijent u server.

663
00:29:11,800 --> 00:29:14,080
>> U l-klijenti fis-sens
ta 'xi ħadd fil-restorant

664
00:29:14,080 --> 00:29:16,620
u l-wejter jew wejtress,
istess idea ma 'kompjuters.

665
00:29:16,620 --> 00:29:19,340
Klijenti u servers, wieħed
jitlob għall-informazzjoni,

666
00:29:19,340 --> 00:29:21,560
wieħed jirrispondi b'informazzjoni.

667
00:29:21,560 --> 00:29:23,920
Issa, kif ma dak
informazzjoni terga 'lura?

668
00:29:23,920 --> 00:29:25,890
Ukoll, jikkunsidraw dan.

669
00:29:25,890 --> 00:29:30,360
Get huwa tip ta 'l-inadempjenza way--
u huwa terminu super sempliċi.

670
00:29:30,360 --> 00:29:34,530
--that biss tiddetta kemm browser
gets informazzjoni minn server.

671
00:29:34,530 --> 00:29:38,270
>> Fi kliem ieħor, aktar milli biss
goof-ily testendi idejn tiegħi biex Margot,

672
00:29:38,270 --> 00:29:42,100
jekk I really kienu browser, I
kieku Jittieħed ġewwa ta 'pakkett,

673
00:29:42,100 --> 00:29:46,580
kif għamilt bir-ritratt Rob qabel, a
messaġġ testwali li litteralment tgħid

674
00:29:46,580 --> 00:29:53,084
xi ħaġa bħal din,
get / http / 1.1hostwww.google.com

675
00:29:53,084 --> 00:29:56,670
jew margot.com jew ikun x'ikun l-
isem server jista 'jiġri li jkun.

676
00:29:56,670 --> 00:29:58,540
U mbagħad, dot dot dot, xi għalf ieħor.

677
00:29:58,540 --> 00:30:00,310
>> Iżda litteralment, ġewwa
ta 'pakkett kieku

678
00:30:00,310 --> 00:30:03,290
jkun testwali pjuttost sempliċi
messaġġ bħal dik.

679
00:30:03,290 --> 00:30:05,990
Li malli jirċevuhom, Margot kieku
jiftħu, taqra l-kontenut,

680
00:30:05,990 --> 00:30:07,640
u jirrispondu kif xieraq.

681
00:30:07,640 --> 00:30:12,000
Issa, huwa ftit
mhux ovju b'dan l-eżempju.

682
00:30:12,000 --> 00:30:16,130
Iżda jiksbu /, liema huwa l-mmejla
probabbilment li jirreferu għal, biss ibbażat

683
00:30:16,130 --> 00:30:20,470
fuq familjarità tiegħek mal-
browsing il-web fil-ħajja ta 'kuljum?

684
00:30:20,470 --> 00:30:22,206
X'hemm-mmejla?

685
00:30:22,206 --> 00:30:23,147
>> UDJENZA: [inaudible].

686
00:30:23,147 --> 00:30:24,480
DAVID Malan: An sekwenza ħarba.

687
00:30:24,480 --> 00:30:27,280
Mhux idea ħażina iżda ġeneralment
jaħarbu sekwenzi jmorru l-mod ieħor.

688
00:30:27,280 --> 00:30:28,760
Li tkun backslash normalment.

689
00:30:28,760 --> 00:30:29,560
Iżda mhux maħsub ħażin.

690
00:30:29,560 --> 00:30:30,060
Yeah?

691
00:30:30,060 --> 00:30:31,190

692
00:30:31,190 --> 00:30:31,830
A pointer.

693
00:30:31,830 --> 00:30:35,100
Wkoll ħsieb tajjeb iżda
saħansitra aktar sempliċi minn dik.

694
00:30:35,100 --> 00:30:36,250
Il-direttorju dar.

695
00:30:36,250 --> 00:30:38,380
L-għerq ta 'hard drive, biex ngħidu hekk.

696
00:30:38,380 --> 00:30:39,890
Ħafna minna ma tip dan.

697
00:30:39,890 --> 00:30:43,150
Iżda teknikament, jekk int riedu
li tkun super xierqa dawn il-ġranet,

698
00:30:43,150 --> 00:30:50,056
inti tmur għal xi ħaġa
bħal http://www.facebook.com/.

699
00:30:50,056 --> 00:30:52,580
>> Issa, I said ħafna minna se le
jolqot ttajpjati l-mmejla.

700
00:30:52,580 --> 00:30:54,770
U franchement, ħafna
browsers, Chrome inklużi,

701
00:30:54,770 --> 00:30:57,019
lanqas biss jitħajru juru
lilna l slash dawn il-jiem

702
00:30:57,019 --> 00:30:59,060
sempliċiment minħabba li jixtiequ
tkun sempliċi u konċiża.

703
00:30:59,060 --> 00:31:02,920
Iżda l-slash ifisser biss jmorru
biex www.facebook.com u jiksbu

704
00:31:02,920 --> 00:31:08,076
mmejla, l-għerq tal-hard drive,
il-paġna default fil facebook.com.

705
00:31:08,076 --> 00:31:09,240
Użu ta 'dak il-protokoll?

706
00:31:09,240 --> 00:31:14,910
Ukoll, bl-użu verżjoni 1.1 tal
dan il-ħaġa magħrufa bħala HTTP.

707
00:31:14,910 --> 00:31:16,750
>> Il-server, jew Margot--
u mill-mod, do

708
00:31:16,750 --> 00:31:17,920
inti f'moħħu li jien jużaw int fl dawn?

709
00:31:17,920 --> 00:31:18,419
OK.

710
00:31:18,419 --> 00:31:19,430
Allura aħna qed tajba issa.

711
00:31:19,430 --> 00:31:23,910
Allura rispons Margot issa ma '
pakkett tal tagħha stess, ġewwa li minnhom

712
00:31:23,910 --> 00:31:26,040
huwa messaġġ simili testwali.

713
00:31:26,040 --> 00:31:30,640
L-ewwel linja ta 'liema hija,
Yep, I jitkellmu verżjoni HTTP 1.1.

714
00:31:30,640 --> 00:31:34,930
200 huwa l-kodiċi istatus
li ifisser biss kollox huwa OK.

715
00:31:34,930 --> 00:31:37,440
Għandi l-paġna li qed tfittex.

716
00:31:37,440 --> 00:31:44,040
>> Sadanittant, Kontenut-Tip: test / html, dan
huwa mod semi-arcane Margot ta 'tgħid,

717
00:31:44,040 --> 00:31:46,190
dak li talbu hija paġna web.

718
00:31:46,190 --> 00:31:50,530
U huwa tip, hekk li speak--
kważi simili sens varjabbli,

719
00:31:50,530 --> 00:31:52,060
iżda dan huwa livell ħafna ogħla issa.

720
00:31:52,060 --> 00:31:55,380
Tip tad-data tiegħu huwa test
imma speċifikament HTML.

721
00:31:55,380 --> 00:31:57,210
Il-lingwa aħna ser dalwaqt tara.

722
00:31:57,210 --> 00:31:58,700
>> U allura, hemm xi għalf ieħor.

723
00:31:58,700 --> 00:32:02,060
Allura Jittieħed oħra hija litteralment dak
Facebook qed tirrispondi bil.

724
00:32:02,060 --> 00:32:03,400
Mela ejja ara dan, wisq.

725
00:32:03,400 --> 00:32:05,380
Let me imorru quddiem u tiftaħ
up Chrome fuq laptop tiegħi

726
00:32:05,380 --> 00:32:07,980
li inti tista 'tagħmel fuq tiegħek
kompjuter stess ukoll.

727
00:32:07,980 --> 00:32:12,035
U jien ser jimxi 'l quddiem
u jiftħu www.facebook.com.

728
00:32:12,035 --> 00:32:12,535
Ikteb.

729
00:32:12,535 --> 00:32:13,590

730
00:32:13,590 --> 00:32:16,264
U jien nikseb dan l-iskrin familjari hawn.

731
00:32:16,264 --> 00:32:17,930
Imma issa, jien se jagħmlu xi ħaġa oħra.

732
00:32:17,930 --> 00:32:21,670
Jien ser jimxi 'l quddiem u
mur View, Developer.

733
00:32:21,670 --> 00:32:24,190
U mur Developer
Għodod, li inti għandek

734
00:32:24,190 --> 00:32:27,377
jkollhom fil Chrome fuq il-kompjuter tiegħek,
inqas fi żmien appliance tiegħek.

735
00:32:27,377 --> 00:32:29,460
Jien ser tiskrollja din
Ħaġa up hawn, u int

736
00:32:29,460 --> 00:32:33,060
ser tara mazz sħiħ
ta 'test cryptic hawn.

737
00:32:33,060 --> 00:32:37,920
>> Jirriżulta li dak Margot tpoġġi ġewwa
ta 'dak il-pakkett bi tweġiba lili

738
00:32:37,920 --> 00:32:41,472
hija lingwa msejħa HTML,
HyperText Markup Language.

739
00:32:41,472 --> 00:32:43,680
Mhuwiex programmazzjoni
lingwa għaliex inti ma tistax, hija

740
00:32:43,680 --> 00:32:46,679
ma jkollux loops, u kondizzjonijiet,
u l-funzjonijiet, u affarijiet bħal dik.

741
00:32:46,679 --> 00:32:47,870
Huwa lingwa markup.

742
00:32:47,870 --> 00:32:52,110
F'dak, hija għandha sintassi speċjali
imsejħa tags u attributi

743
00:32:52,110 --> 00:32:57,120
li tg browser dak li juri
fuq l-iskrin u kif juru dan.

744
00:32:57,120 --> 00:32:57,920
Għandhom jiġu ċċentrata?

745
00:32:57,920 --> 00:32:58,920
Jekk ikun kuraġġużi-ffaċċjati?

746
00:32:58,920 --> 00:33:00,270
Aħmar, aħdar, blu?

747
00:33:00,270 --> 00:33:01,390
Huwa lingwa markup.

748
00:33:01,390 --> 00:33:04,970
F'dak, jirrakkonta l-browser
dak li juri fuq l-iskrin.

749
00:33:04,970 --> 00:33:10,530
Allura dan huwa, litteralment, kollha ta 'l-
HTML u aktar li Facebook server

750
00:33:10,530 --> 00:33:13,950
huwa tobżoq out u li
Chrome, u IE, Firefox u jkollhom

751
00:33:13,950 --> 00:33:17,820
ġew iddisinjati minn tagħhom
awturi rispettivi biex jifhmu.

752
00:33:17,820 --> 00:33:20,780
>> U fil-fatt, huwa
ftit Messier minn dak.

753
00:33:20,780 --> 00:33:24,290
Jekk inti, minflok, mur View,
Developer, View Sors,

754
00:33:24,290 --> 00:33:27,550
dan huwa fil-fatt dak
Facebook huwa out tqegħid.

755
00:33:27,550 --> 00:33:29,800
Tip ta 'żero għal ħamsa
għall-istil, id-dritt, jekk aħna

756
00:33:29,800 --> 00:33:31,479
jiddeduċu li dan probabbilment mhuwiex l-aħjar.

757
00:33:31,479 --> 00:33:34,270
Iżda franchement, huma jistgħu jiksbu bogħod ma
dan għaliex jekk int jservu up

758
00:33:34,270 --> 00:33:36,090
biljuni ta 'paġni tal-web
kuljum, int verament

759
00:33:36,090 --> 00:33:40,040
ma jridux iskart ħin, u bytes,
u flus finalment fit-trażmissjoni

760
00:33:40,040 --> 00:33:43,000
affarijiet simili linja ġdida
karattri, u spazji, u tabs

761
00:33:43,000 --> 00:33:46,870
għaliex int infiq għall-bandwidth
bla bżonn mal-ISP tiegħek.

762
00:33:46,870 --> 00:33:49,580
>> Allura fil-fatt, dan huwa maħsub
li jiġu minified b'dan il-mod.

763
00:33:49,580 --> 00:33:51,740
Imma dak Chrome qed tagħmel
għalina huwa, huwa jieħu

764
00:33:51,740 --> 00:33:56,310
dan HTML, li kompletament qisu
mess u mhux intelliġibbli għall-bniedem,

765
00:33:56,310 --> 00:33:57,580
u huwa biss ifformattjar.

766
00:33:57,580 --> 00:34:00,280
Huwa pretty istampar hekk li
nistgħu wrap imħuħ tagħna madwaru

767
00:34:00,280 --> 00:34:01,452
ftit aktar faċilment.

768
00:34:01,452 --> 00:34:02,660
Iżda aktar interessanti hija din.

769
00:34:02,660 --> 00:34:06,180
Jekk I issa ikklikkja fil Chrome,
mhux Elementi iżda network,

770
00:34:06,180 --> 00:34:08,520
Jien ser tara ftit
screen qtugħ thats

771
00:34:08,520 --> 00:34:11,040
ser jurik me kollha
tat-talbiet HTTP

772
00:34:11,040 --> 00:34:14,380
li huma attwalment għaddejjin lura u
lura bejn lili u Facebook jew me

773
00:34:14,380 --> 00:34:17,219
u Margot jekk nagħmel
aktar minn talba waħda.

774
00:34:17,219 --> 00:34:21,409
>> Hekk jien ser jimxi 'l quddiem u kklikkja
l-ikona rikarigu up hawn fil Chrome.

775
00:34:21,409 --> 00:34:23,850
U issa, mazz sħiħ ta '
Jittieħed tellgħu passat fil-qiegħ.

776
00:34:23,850 --> 00:34:25,710
Jien ser tiskrollja
lura sa l-quċċata ħafna.

777
00:34:25,710 --> 00:34:29,350
U issa, avviż dan, il-
ewwel titlob browser tiegħi

778
00:34:29,350 --> 00:34:31,340
sar kien li www.facebook.com.

779
00:34:31,340 --> 00:34:34,199
>> Huwa juża l-get
mekkaniżmu li ifisser biss

780
00:34:34,199 --> 00:34:37,810
huwa jitkellem il-lingwa testwali
li rajna eżempju ta 'mument ilu.

781
00:34:37,810 --> 00:34:41,909
U barra minn hekk, jirriżulta
li r-rispons li Facebook

782
00:34:41,909 --> 00:34:46,070
tatni huwa ta '200 OK, li jfisser I
sabu l-paġna web fil-kwistjoni.

783
00:34:46,070 --> 00:34:49,630
>> Jekk I ikklikkja fuq din il-filliera, nista attwalment
tara dawk headers ftit aktar

784
00:34:49,630 --> 00:34:50,800
b'mod ċar.

785
00:34:50,800 --> 00:34:52,810
Dawn se tagħmel aktar sens qabel twil.

786
00:34:52,810 --> 00:34:57,020
Iżda tinnota li browser tiegħi jibgħat
lott kollu ta 'informazzjoni bħall-ospitanti,

787
00:34:57,020 --> 00:34:59,320
u l-metodu, u l-cookies.

788
00:34:59,320 --> 00:35:00,879
Aħna ser terga 'lura għal dawk qabel twil.

789
00:35:00,879 --> 00:35:03,170
U tkun taf finalment jifhmu
liema cookie attwalment hija

790
00:35:03,170 --> 00:35:04,930
u kif inti dalwaqt se tkun qed tibgħat lilhom.

791
00:35:04,930 --> 00:35:06,900
>> U tista 'tara liema
Facebook hija li jibgħat lura,

792
00:35:06,900 --> 00:35:12,230
inkluż it-tip ta 'kontenut test
HTML, il-ħin data attwali, il-privatezza tiegħu

793
00:35:12,230 --> 00:35:15,530
politika, jew in-nuqqas tiegħu, u
allura, finalment, numru ta 'cookies

794
00:35:15,530 --> 00:35:18,050
li qed jiġu stabbiliti fuq
kompjuter tiegħek ukoll.

795
00:35:18,050 --> 00:35:20,140
Iżda aħna ser tease dawk apparti qabel twil.

796
00:35:20,140 --> 00:35:23,950
>> Iżda fil-qosor, kull darba li inti
żar web page, issa għas-snin,

797
00:35:23,950 --> 00:35:26,970
inti kont qed jibgħat messaġġi lil
il-wieħed I bagħtet f'envelop

798
00:35:26,970 --> 00:35:28,230
li Margot u Dan.

799
00:35:28,230 --> 00:35:31,210
U inti stajt ġiet jkollna lura
tweġibiet bħal dan mill Facebook.

800
00:35:31,210 --> 00:35:35,650
Iżda barraminhekk, raden dak li qed
żvelata lil Facebook, u Google,

801
00:35:35,650 --> 00:35:39,101
u kulħadd kull
darba li żżur il-web page?

802
00:35:39,101 --> 00:35:42,100
X'inhu fuq barra ta 'kull
pakkett kompjuter tiegħek tkun ġiet tibgħat?

803
00:35:42,100 --> 00:35:43,800

804
00:35:43,800 --> 00:35:45,590
Indirizz IP tiegħek, id-dritt?

805
00:35:45,590 --> 00:35:48,720
Forsi mhux l-isem tiegħek kull
se, iżda l-indirizz IP tiegħek.

806
00:35:48,720 --> 00:35:52,410
U biss, ejja jgħaqqdu l-tikek
aktar tard, jekk inti qed tuża s-servizzi

807
00:35:52,410 --> 00:35:54,430
bħall-web, jew
BitTorrent, u l-ħajja,

808
00:35:54,430 --> 00:35:56,860
u inti stajt irreġistrat kompjuter
f'post bħal Harvard,

809
00:35:56,860 --> 00:36:01,080
xi ħadd x'imkien jaf li John
IP indirizzi Harvard dan, dot dan,

810
00:36:01,080 --> 00:36:02,350
dot dan, dot dan.

811
00:36:02,350 --> 00:36:06,730
>> U fil-fatt, zkuk jistgħu ma żammx kemm fuq
kampus bħal dan, fuq netwerk Comcast,

812
00:36:06,730 --> 00:36:10,270
fuq Verizon, jew franchement, fil-
NSA kif aħna riċentament ħadthom tgħallmu,

813
00:36:10,270 --> 00:36:14,040
li zkuk kollox pretty ħafna
li inti tagħmel fuq l-internet.

814
00:36:14,040 --> 00:36:15,910
U aħna ser terga 'lura għal
dan il-klassi futur

815
00:36:15,910 --> 00:36:18,990
dwar l-implikazzjonijiet ta 'dawn
deċiżjonijiet tad-disinn u s-sigurtà.

816
00:36:18,990 --> 00:36:21,920
>> Imma l-verità hija, inti verament
ma jkollhomx dak kollu li l-privatezza ħafna.

817
00:36:21,920 --> 00:36:25,380
Kull darba li inti kont qed iżuru kullimkien
fuq il-web, inti qed turi naħa tiegħek

818
00:36:25,380 --> 00:36:28,720
u l-iżvelar tal-anqas l-indirizz IP tiegħek.

819
00:36:28,720 --> 00:36:35,930
Nota hekk scary aside, x'nistgħu nagħmlu biex
affarijiet simili qtates ssodata fil-paġna web?

820
00:36:35,930 --> 00:36:40,730
>> Allura aħna għandna mazz ta 'tweġibiet li
tista 'tigi lura mill-server.

821
00:36:40,730 --> 00:36:42,340
U aħna mhux se tara kollha ta 'dawn illum.

822
00:36:42,340 --> 00:36:43,800
Iżda 200 hija tajba.

823
00:36:43,800 --> 00:36:46,622
U int probabilment ma bbenefikawx
kollha ta 'dawn bħala bniedem qabel.

824
00:36:46,622 --> 00:36:48,580
Imma inti ħadthom probabbilment jidhru
mill-inqas wieħed minn dawn.

825
00:36:48,580 --> 00:36:50,204
Liema wieħed minn dawn tista 'tidher familjari?

826
00:36:50,204 --> 00:36:51,097
UDJENZA: 404

827
00:36:51,097 --> 00:36:51,930
DAVID Malan: Allura 404.

828
00:36:51,930 --> 00:36:52,695
Fajl ma nstabx.

829
00:36:52,695 --> 00:36:55,320
U fil-fatt, int ser tara
dan programmatically yourself.

830
00:36:55,320 --> 00:37:00,220
404 ifisser biss il-fajl inti mitlub,
mmejla jew mmejla xi ħaġa, sempliċement

831
00:37:00,220 --> 00:37:00,950
ma teżistix.

832
00:37:00,950 --> 00:37:04,380
U web server tipikament
jirrispondi 404 bħala riżultat

833
00:37:04,380 --> 00:37:09,680
>> Sadanittant, aħna ser dalwaqt naraw li
kontenuti ta 'dak il-messaġġ

834
00:37:09,680 --> 00:37:11,800
huma din il-lingwa magħrufa bħala HTML.

835
00:37:11,800 --> 00:37:15,070
U dan huwa super
snippet sempliċi tal HTML

836
00:37:15,070 --> 00:37:18,380
li ma tagħmel xejn għajr
display bonjour dinja fuq l-iskrin.

837
00:37:18,380 --> 00:37:21,830
Tabilħaqq, inti tara fil-quċċata ta 'din
xi ħaġa imsejħa tip ta 'dokument

838
00:37:21,830 --> 00:37:24,220
dikjarazzjoni li biss jgħid, ħej, dinja.

839
00:37:24,220 --> 00:37:25,964
Dan il-fajl fih HTML.

840
00:37:25,964 --> 00:37:28,380
U mbagħad, il-bit jmiss ta HTML
li int ser jikteb,

841
00:37:28,380 --> 00:37:30,930
huwa għandu parentesi miftuħa,
u mbagħad l-kelma HTML,

842
00:37:30,930 --> 00:37:33,670
imbagħad bracket magħluqa, u mbagħad
ras miftuħa, u parentesi qrib.

843
00:37:33,670 --> 00:37:36,000
Allura fil-qosor, ejja fil-fatt
tagħmel dan aktar mekkanikament.

844
00:37:36,000 --> 00:37:39,980
Let me go fis appliance tiegħi,
imma int tista 'tagħmel dan kullimkien

845
00:37:39,980 --> 00:37:42,110
li inti għandek editur test għall.

846
00:37:42,110 --> 00:37:45,105
>> Jien ser jimxi 'l quddiem u
ħlief fajl imsejjaħ hello.html.

847
00:37:45,105 --> 00:37:46,440

848
00:37:46,440 --> 00:37:49,640
Jien ser tpoġġi fuq id-desktop tiegħi biex
żżomm affarijiet sempliċi super dritt issa.

849
00:37:49,640 --> 00:37:51,760
U jien se tagħmel
eżattament dak I biss raw.

850
00:37:51,760 --> 00:37:55,452
Allura tip doc HTML, miftuħa parentesi HTML.

851
00:37:55,452 --> 00:37:57,910
U issa, avviż, jien ser
tagħmel l-oppost preemptively.

852
00:37:57,910 --> 00:38:01,000
U mill oppost, I jfisser
l-istess tikketta, biex ngħidu hekk,

853
00:38:01,000 --> 00:38:02,767
iżda li jibda bil slash quddiem.

854
00:38:02,767 --> 00:38:04,600
U mbagħad, minn hawn,
Jien se ngħid, ras,

855
00:38:04,600 --> 00:38:07,530
għaliex jirriżulta li kull
paġna web għandu l-hekk imsejħa ras li

856
00:38:07,530 --> 00:38:10,300
huwa Jittieħed li tmur fit-titolu
bar, fuq nett tal-paġna.

857
00:38:10,300 --> 00:38:13,026
Fit-titolu huwa biss
se tkun bonjour hawn.

858
00:38:13,026 --> 00:38:15,150
U issa, jien ser ikollhom
korp li din il-paġna web.

859
00:38:15,150 --> 00:38:18,130
Allura kull paġna tal-web għandu kemm
ras top up u korp

860
00:38:18,130 --> 00:38:19,522
li hija l-imsaren ta 'l-paġna.

861
00:38:19,522 --> 00:38:21,980
U hawn, jien biss ser
ngħid xi ħaġa simili bonjour dinja.

862
00:38:21,980 --> 00:38:23,440
U jien ser jiffranka dan il-fajl.

863
00:38:23,440 --> 00:38:26,150
Jekk I issa jimminimizzaw gedit,
ħarsa, hemm fajl ftit

864
00:38:26,150 --> 00:38:28,470
fuq id-desktop tiegħi imsejħa hello.html.

865
00:38:28,470 --> 00:38:30,820
Issa, li mhux fuq server
għadhom, per se, Tabilħaqq, huwa

866
00:38:30,820 --> 00:38:33,040
biss fuq tiegħi desktop personali stess hawn.

867
00:38:33,040 --> 00:38:36,910
Imma jekk jien jiftħu Chrome u hit Kontroll
O-- hemm il-qattus fil-kwistjoni.

868
00:38:36,910 --> 00:38:38,710
--and mmur desktop tiegħi.

869
00:38:38,710 --> 00:38:43,730
>> U jien jiftħu hello.html, hemmhekk, fil-
fatt, huwa page tiegħi web sempliċi super.

870
00:38:43,730 --> 00:38:45,490
Il-korp tal-paġna tiegħi
u dan il-tieqa abjad

871
00:38:45,490 --> 00:38:47,610
hawnhekk huwa l-korp ma Hello dinja.

872
00:38:47,610 --> 00:38:51,020
U t-titolu fil-kap ta '
il-paġna huwa fil-tab hemmhekk.

873
00:38:51,020 --> 00:38:53,020
U aħna qed tmur biex tara
Hekk li huwa super

874
00:38:53,020 --> 00:38:55,004
sempliċi biex jiftħu paġni oħrajn ukoll.

875
00:38:55,004 --> 00:38:57,670
Per eżempju, jien ser jmorru
uħud mill-kodiċi ta 'distribuzzjoni

876
00:38:57,670 --> 00:39:00,230
għal din il-ġimgħa, is-sors
seba ', u jien ser

877
00:39:00,230 --> 00:39:03,150
biex jiftħu mhux l-JPEG
li dan Guy huwa hawnhekk.

878
00:39:03,150 --> 00:39:08,430
Imma jien ser jiftħu image.html,
li finalment tidher bħal dan.

879
00:39:08,430 --> 00:39:15,140
Iżda let me issa jiftħu dan up fil gedit,
u jmorru fil-sors Dropbox seba,

880
00:39:15,140 --> 00:39:17,470
u image.html.

881
00:39:17,470 --> 00:39:19,430

882
00:39:19,430 --> 00:39:21,960
>> Ħafna minn dan huwa biss
Kummenti kif aħna ser malajr tara.

883
00:39:21,960 --> 00:39:25,210
Imma jekk jien tixtieq li tqiegħed Grumpy
Cat ġewwa ta 'din il-paġna web,

884
00:39:25,210 --> 00:39:29,890
huwa biżżejjed li tpoġġi parentesi ieħor miftuħa,
u mbagħad l-immaġni kelma prinċipali jew img

885
00:39:29,890 --> 00:39:33,080
għal żmien qasir, u mbagħad alternattiva
test għal raġunijiet ta 'aċċessibbiltà

886
00:39:33,080 --> 00:39:35,890
jekk xi ħadd ikollu screen
qarrej jew xi ħaġa bħal dik.

887
00:39:35,890 --> 00:39:38,260
Sors li huwa, x'inhu l-
isem tal-fajl, cat.jpeg.

888
00:39:38,260 --> 00:39:39,280

889
00:39:39,280 --> 00:39:41,400
>> U mbagħad, għaliex dan
tag l-ftit speċjali,

890
00:39:41,400 --> 00:39:44,140
nitfgħu l quddiem mmejla, kif
Ser naraw, ġewwa tal-lametta.

891
00:39:44,140 --> 00:39:47,180
Imma r-riżultat aħħari huwa web
paġna li tidher bħal dan.

892
00:39:47,180 --> 00:39:51,320
Għalhekk fil-qosor, dak li aħna qed tmur biex tkun
tagħmel bħalissa maż-żmien qed tuża l-web

893
00:39:51,320 --> 00:39:54,200
u ħolqien ta 'paġni tal-web għall-
finalment tkun kontenituri

894
00:39:54,200 --> 00:39:57,280
mhux biss għal affarijiet iblah simili
immaġini, u links, u tabelli,

895
00:39:57,280 --> 00:40:00,770
u listi bulleted, u simili,
iżda wkoll biex tagħtina lilna nfusna

896
00:40:00,770 --> 00:40:04,890
user interface grafika, GUI,
b'differenza ma dak li għamilna aħna tbegħid.

897
00:40:04,890 --> 00:40:08,330
>> Iżda f'dan l-ambjent, aħna qed
se tibda tuża lingwi bħal PHP,

898
00:40:08,330 --> 00:40:10,960
u JavaScript, id-database
lingwa imsejħa SQL,

899
00:40:10,960 --> 00:40:14,050
a scripting lingwa client-side
imsejħa JavaScript biex effettivament joħolqu

900
00:40:14,050 --> 00:40:18,760
l-interfaces aktar dinamiċi iżda
jitqies f'kuntest ferm aktar familjari ħafna.

901
00:40:18,760 --> 00:40:21,970
Iżda qabel dakinhar, ejja
jikkonkludi llum bil-ħarsa,

902
00:40:21,970 --> 00:40:25,280
kif imwiegħed, ta 'dak li verament għaddej
taħt il-barnuża bl-internet

903
00:40:25,280 --> 00:40:26,060
innifsu.

904
00:40:26,060 --> 00:40:28,400
>> Jistipulaw għal-lum
li l-internet jista '

905
00:40:28,400 --> 00:40:31,390
jintużaw għat-trasferiment affarijiet
bħal paġni web fuq HTTP

906
00:40:31,390 --> 00:40:33,150
ferm simili I waħxu idejn Margot aktar kmieni.

907
00:40:33,150 --> 00:40:36,470
Iżda hemm tant oħrajn
servizzi li jużaw TCP u IP

908
00:40:36,470 --> 00:40:39,800
li nieħdu għall mogħtija
li x-xogħol kif aħna ser tara hawn

909
00:40:39,800 --> 00:40:42,477
f'dan il-film li taf
jqarrbuna sa l-aħħar tal-lum.

910
00:40:42,477 --> 00:40:45,956
>> [Daqq ta 'video]

911
00:40:45,956 --> 00:41:31,710

912
00:41:31,710 --> 00:41:35,870
>> -Għall-Ewwel darba fl-
istorja, in-nies u makkinarju

913
00:41:35,870 --> 00:41:38,940
huma jaħdmu flimkien, jirrealizzaw ħolma.

914
00:41:38,940 --> 00:41:41,780
A forza tgħaqqad li jaf
ebda konfini ġeografiċi.

915
00:41:41,780 --> 00:41:45,010
Mingħajr rigward għall razza, twemmin, jew bil-kulur.

916
00:41:45,010 --> 00:41:49,130
A era ġdida fejn il-komunikazzjoni
verament jgħaqqad lin-nies.

917
00:41:49,130 --> 00:41:51,795
Dan huwa l-bidu tas-Net.

918
00:41:51,795 --> 00:41:54,920

919
00:41:54,920 --> 00:41:56,450
>> Tixtieq tkun taf kif taħdem?

920
00:41:56,450 --> 00:42:00,260
Ikklikkja hawn biex tibda tiegħek
vjaġġ fix-xibka.

921
00:42:00,260 --> 00:42:02,780

922
00:42:02,780 --> 00:42:05,380
Issa, eżattament dak li ġara
meta inti għafast fuq din ir-rabta?

923
00:42:05,380 --> 00:42:07,190
Bdejt fluss ta 'informazzjoni.

924
00:42:07,190 --> 00:42:09,790
Din l-informazzjoni jivvjaġġa isfel
fil-kamra tiegħek mail personali

925
00:42:09,790 --> 00:42:14,040
meta Mr IP pakketti li, tikketti
dan, u tibgħatha fi triqitha.

926
00:42:14,040 --> 00:42:16,030
>> Kull pakkett huwa d-daqs limitat.

927
00:42:16,030 --> 00:42:19,900
Il-kamra mail għandu jiddeċiedi kif jinqasmu
l-informazzjoni u kif pakkett li hija.

928
00:42:19,900 --> 00:42:23,400
Issa, il-pakkett teħtieġ tikketta
li jkun fih informazzjoni importanti,

929
00:42:23,400 --> 00:42:27,480
bħall-indirizz, riċevitur mittent
indirizz, u t-tip ta 'pakkett huwa.

930
00:42:27,480 --> 00:42:41,070

931
00:42:41,070 --> 00:42:43,700
>> Minħabba dan packet partikolari
huwa ser jispiċċaw fuq l-internet,

932
00:42:43,700 --> 00:42:46,240
jiġrilha wkoll indirizz
għall-proxy server, li

933
00:42:46,240 --> 00:42:47,990
għandu funzjoni speċjali
kif aħna ser tara aktar tard.

934
00:42:47,990 --> 00:42:49,080

935
00:42:49,080 --> 00:42:53,430
Il-pakkett huwa issa nediet fuq
network tiegħek żona lokali jew LAN.

936
00:42:53,430 --> 00:42:56,220
Dan in-netwerk huwa użat għall-konnessjoni
l-kompjuters lokali,

937
00:42:56,220 --> 00:42:58,760
printers routers, et cetera
għall-iskambju ta 'informazzjoni

938
00:42:58,760 --> 00:43:00,790
fi ħdan il-fiżika
ħitan tal-bini.

939
00:43:00,790 --> 00:43:04,840
Il-LAN huwa pretty mhux ikkontrollat
post u, sfortunatament, l-inċidenti

940
00:43:04,840 --> 00:43:05,828
jista 'jiġri.

941
00:43:05,828 --> 00:43:13,240

942
00:43:13,240 --> 00:43:16,020
>> L-awtostrada ta 'LAN huwa ppakkjat
mat-tipi kollha ta 'informazzjoni.

943
00:43:16,020 --> 00:43:19,270
Dawn huma pakketti IP, Novell
pakketti, pakketti Apple Talk.

944
00:43:19,270 --> 00:43:21,440
Huma qed tmur kontra t-traffiku bħas-soltu.

945
00:43:21,440 --> 00:43:24,040
Il-router lokali jaqra l-
jindirizzaw u, jekk ikun meħtieġ,

946
00:43:24,040 --> 00:43:25,935
tittella 'l-pakkett għal netwerk oħra.

947
00:43:25,935 --> 00:43:27,610

948
00:43:27,610 --> 00:43:28,810
Ah, il-router.

949
00:43:28,810 --> 00:43:31,990
Simbolu ta 'kontroll fil-
dinja apparentement diżorganizzat.

950
00:43:31,990 --> 00:43:41,050

951
00:43:41,050 --> 00:43:45,480
>> Hemm huwa, sistematiku,
uncaring, metodiku, konservattivi,

952
00:43:45,480 --> 00:43:48,100
u xi kultant ma pjuttost sa veloċità.

953
00:43:48,100 --> 00:43:50,430
Iżda mill-inqas, huwa
eżatti għall-parti l-kbira.

954
00:43:50,430 --> 00:44:03,090

955
00:44:03,090 --> 00:44:05,530
>> Peress li l-pakketti jħallu l-
router, dawn jagħmlu mod tagħhom

956
00:44:05,530 --> 00:44:08,780
fil-intranet ta 'kumpanija
u ras għall-bidla router.

957
00:44:08,780 --> 00:44:10,179

958
00:44:10,179 --> 00:44:12,470
A ftit aktar effiċjenti minn
l-router, il-bidla router

959
00:44:12,470 --> 00:44:16,700
jilgħab veloċi u maħlula ma pakketti IP,
deftly rotta minnhom tul it-triq.

960
00:44:16,700 --> 00:44:18,950
A Pinball Wizard diġitali jekk inti se.

961
00:44:18,950 --> 00:44:19,532
>> -Here Immorru.

962
00:44:19,532 --> 00:44:20,490
Hawnhekk tidħol ieħor.

963
00:44:20,490 --> 00:44:21,198
U huwa ieħor.

964
00:44:21,198 --> 00:44:21,886
Watch dan, omm.

965
00:44:21,886 --> 00:44:22,258
Hawnhekk huwa tmur.

966
00:44:22,258 --> 00:44:22,382
Whoops.

967
00:44:22,382 --> 00:44:23,126
Madwar id-dahar.

968
00:44:23,126 --> 00:44:23,374
Ħej.

969
00:44:23,374 --> 00:44:23,622
Fil hemmhekk.

970
00:44:23,622 --> 00:44:24,122
Fil hemmhekk.

971
00:44:24,122 --> 00:44:24,862
Matul ix-xellug.

972
00:44:24,862 --> 00:44:25,110
Matul il-lemin.

973
00:44:25,110 --> 00:44:25,358
Matul ix-xellug.

974
00:44:25,358 --> 00:44:26,350
Matul il-lemin.

975
00:44:26,350 --> 00:44:26,596
Inti ltqajna.

976
00:44:26,596 --> 00:44:26,846
Hawnhekk tmur.

977
00:44:26,846 --> 00:44:27,342
Huwa rimjiet.

978
00:44:27,342 --> 00:44:27,840
Hu punteġġi.

979
00:44:27,840 --> 00:44:28,100
Li għaddej.

980
00:44:28,100 --> 00:44:28,580
Ħej, stenna.

981
00:44:28,580 --> 00:44:28,940
Ħej, oqgħod attent.

982
00:44:28,940 --> 00:44:29,898
Hawnhekk tidħol ieħor.

983
00:44:29,898 --> 00:44:30,860
Oh, here we go.

984
00:44:30,860 --> 00:44:33,740

985
00:44:33,740 --> 00:44:35,930
>> Pakketti -Bħala jaslu
destinazzjoni tagħhom, dawn qed

986
00:44:35,930 --> 00:44:40,640
telgħet mill-interface network,
lest biex jintbagħat lill-livell li jmiss,

987
00:44:40,640 --> 00:44:42,000
f'dan il-każ, il-prokura.

988
00:44:42,000 --> 00:44:43,060

989
00:44:43,060 --> 00:44:46,210
Il-prokuratur huwa użat minn ħafna
kumpaniji bħal tip ta 'bniedem tan-nofs

990
00:44:46,210 --> 00:44:48,650
sabiex titnaqqas it-tagħbija
fuq konnessjoni bl-internet tagħhom

991
00:44:48,650 --> 00:44:50,040
u għal raġunijiet ta 'sigurtà kif ukoll.

992
00:44:50,040 --> 00:44:51,824

993
00:44:51,824 --> 00:44:55,310
Kif tistgħu taraw, il-pakketti
huma kollha ta 'daqsijiet differenti,

994
00:44:55,310 --> 00:44:56,650
jiddependi fuq il-kontenut tagħhom.

995
00:44:56,650 --> 00:45:10,750

996
00:45:10,750 --> 00:45:14,790
>> Il-prokura jiftaħ il-pakkett u
jistenna għall-indirizz tal-web jew URL.

997
00:45:14,790 --> 00:45:16,230

998
00:45:16,230 --> 00:45:18,707
Jiddependi fuq jekk
l-indirizz huwa aċċettabbli,

999
00:45:18,707 --> 00:45:20,290
il-pakkett huwa mibgħut fuq l-internet.

1000
00:45:20,290 --> 00:45:25,880

1001
00:45:25,880 --> 00:45:28,700
Hemm, madankollu, xi wħud
indirizzi li ma jagħmlux dan

1002
00:45:28,700 --> 00:45:31,440
jiltaqa bl-approvazzjoni ta '
il-prokura, jiġifieri,

1003
00:45:31,440 --> 00:45:33,305
linji gwida korporattiva jew maniġġar.

1004
00:45:33,305 --> 00:45:35,830

1005
00:45:35,830 --> 00:45:38,290
Dawn huma sommarjament ttrattati.

1006
00:45:38,290 --> 00:45:39,530

1007
00:45:39,530 --> 00:45:41,070
Aħna ser ikollhom xejn ta 'dak.

1008
00:45:41,070 --> 00:45:43,350
Għal dawk li jagħmlu dan,
huwa fuq it-triq għal darb'oħra.

1009
00:45:43,350 --> 00:45:52,740

1010
00:45:52,740 --> 00:45:54,695
>> Issa jmiss, il-firewall.

1011
00:45:54,695 --> 00:45:58,060

1012
00:45:58,060 --> 00:46:01,414
L-firewall korporattiva
iservi żewġ għanijiet.

1013
00:46:01,414 --> 00:46:03,580
Dan jipprevjeni xi wħud pjuttost
affarijiet koroh fuq l-internet

1014
00:46:03,580 --> 00:46:05,379
milli jidħlu fil-intranet.

1015
00:46:05,379 --> 00:46:07,670
U tista 'wkoll tipprevjeni
informazzjoni korporattiva sensittiva

1016
00:46:07,670 --> 00:46:09,900
milli jintbagħtu out fuq l-internet.

1017
00:46:09,900 --> 00:46:11,810

1018
00:46:11,810 --> 00:46:14,210
>> Ladarba permezz tal-firewall,
router jiġbor il-pakkett

1019
00:46:14,210 --> 00:46:18,290
u jpoġġih fuq ħafna aktar ristretti
triq jew bandwidth, kif ngħidu.

1020
00:46:18,290 --> 00:46:21,505
Ovvjament, il-filliera mhuwiex
wiesgħa biżżejjed biex teħodhom kollha.

1021
00:46:21,505 --> 00:46:22,727

1022
00:46:22,727 --> 00:46:25,060
Issa, inti tista wonder, dak li
jiġri li dawn il-pakketti kollha

1023
00:46:25,060 --> 00:46:27,250
li ma jagħmlux dan matul it-triq.

1024
00:46:27,250 --> 00:46:29,880
Ukoll, meta Mr IP ma
jirċievi rikonoxximent

1025
00:46:29,880 --> 00:46:32,160
li packet kien
irċevuti f'waqthom,

1026
00:46:32,160 --> 00:46:34,060
huwa sempliċiment jibgħat packet sostituzzjoni.

1027
00:46:34,060 --> 00:46:36,040

1028
00:46:36,040 --> 00:46:40,510
>> Aħna issa huma lesti li jidħlu fil-
dinja ta 'l-internet, spider

1029
00:46:40,510 --> 00:46:44,656
web tan-netwerks interkonnessi
li jkopru globu kollu tagħna.

1030
00:46:44,656 --> 00:46:47,845
Hawnhekk, routers u switches
jistabbilixxu rabtiet bejn in-netwerks.

1031
00:46:47,845 --> 00:46:49,239

1032
00:46:49,239 --> 00:46:51,280
Issa, ix-xibka hija kompletament
ambjent differenti

1033
00:46:51,280 --> 00:46:53,740
milli inti ser issib ġewwa l-
ħitan protettivi tal LAN tiegħek.

1034
00:46:53,740 --> 00:46:56,510
>> Hawn, huwa l-Wild
Punent, ħafna spazju,

1035
00:46:56,510 --> 00:47:00,440
ħafna opportunitajiet, ħafna ta '
affarijiet li tesplora, u postijiet li jmorru.

1036
00:47:00,440 --> 00:47:02,790
Grazzi għal ftit ħafna
kontroll u regolazzjoni,

1037
00:47:02,790 --> 00:47:07,250
ideat ġodda jsibu ħamrija fertili biex timbotta
il-pakkett ta 'possibbiltajiet tagħhom.

1038
00:47:07,250 --> 00:47:10,590
Iżda minħabba din il-libertà,
ċerti perikli lurk wkoll.

1039
00:47:10,590 --> 00:47:14,230
>> Inti qatt ma taf taf meta inti
jilħqu l-ping dreaded tal-mewt,

1040
00:47:14,230 --> 00:47:18,040
verżjoni speċjali ta 'talba normali
ping li xi idjota ħasbu up

1041
00:47:18,040 --> 00:47:19,830
li mess up ospiti unsuspecting.

1042
00:47:19,830 --> 00:47:21,470

1043
00:47:21,470 --> 00:47:25,490
Il-passaġġ pakketti tagħna tieħu forsi permezz
satellita, linji tat-telefon, wireless,

1044
00:47:25,490 --> 00:47:27,340
jew saħansitra cable TRANSOCEANIC.

1045
00:47:27,340 --> 00:47:30,290
>> Huma ma dejjem jieħdu l-iktar mgħaġġla
jew iqsar rotot possibbli,

1046
00:47:30,290 --> 00:47:33,330
iżda dawn se naslu s'hemm, eventwalment.

1047
00:47:33,330 --> 00:47:37,255
Forsi hu għalhekk li huwa kultant
imsejjaħ il-stenna madwar id-dinja.

1048
00:47:37,255 --> 00:47:39,650
Imma meta kollox huwa
jaħdem mingħajr xkiel, inti

1049
00:47:39,650 --> 00:47:43,270
tista jevitaw il-globu ħamsa
drabi matul fil-waqgħa ta hat,

1050
00:47:43,270 --> 00:47:46,690
litteralment, u kollha għall-
ispiża ta 'telefonata lokali jew inqas.

1051
00:47:46,690 --> 00:47:47,970

1052
00:47:47,970 --> 00:47:51,025
>> Qrib it-tmiem tad-destinazzjoni tagħna,
aħna ser issib firewall ieħor.

1053
00:47:51,025 --> 00:47:53,710

1054
00:47:53,710 --> 00:47:56,160
Jiddependi fuq tiegħek
perspettiva bħala data packet,

1055
00:47:56,160 --> 00:48:00,520
l-firewall jista 'jkun Bastion
ta 'sigurtà jew avversarju dreaded.

1056
00:48:00,520 --> 00:48:04,420
Dan kollu jiddependi fuq liema naħa int
fuq, u liema intenzjonijiet tiegħek huma.

1057
00:48:04,420 --> 00:48:08,365
>> Il-firewall hija mfassla biex let biss
dawn il-pakketti li jissodisfaw il-kriterji tiegħu.

1058
00:48:08,365 --> 00:48:09,590

1059
00:48:09,590 --> 00:48:11,940
Dan firewall qed topera
fuq Portijiet 80 u 25.

1060
00:48:11,940 --> 00:48:13,250

1061
00:48:13,250 --> 00:48:16,380
Tentattivi kollha biex jidħlu permezz oħra
portijiet huma magħluqa għan-negozju.

1062
00:48:16,380 --> 00:48:27,690

1063
00:48:27,690 --> 00:48:30,600
>> Port 25 huwa użat għall-pakketti tal-posta.

1064
00:48:30,600 --> 00:48:32,750

1065
00:48:32,750 --> 00:48:35,791
Filwaqt Port 80 huwa l-entratura għall-
pakketti mill-internet għall-web

1066
00:48:35,791 --> 00:48:36,290
server.

1067
00:48:36,290 --> 00:48:38,880

1068
00:48:38,880 --> 00:48:42,540
Ġewwa l-firewall, pakketti
jiġu skrinjati aktar bir-reqqa.

1069
00:48:42,540 --> 00:48:44,660
Xi pakketti jagħmilha
faċilment permezz tad-dwana,

1070
00:48:44,660 --> 00:48:47,500
filwaqt li oħrajn tfittex biss daqsxejn dubjużi.

1071
00:48:47,500 --> 00:48:49,630
>> Issa, l-uffiċjal firewall
mhix faċilment imqarraq,

1072
00:48:49,630 --> 00:48:53,010
bħal meta dan ping
ta jipprova packet mewt

1073
00:48:53,010 --> 00:48:55,628
biex jaħbi lilu nnifsu bħala
pakkett normali ping.

1074
00:48:55,628 --> 00:48:56,128
-Move Flimkien.

1075
00:48:56,128 --> 00:48:56,606
Huwa OK.

1076
00:48:56,606 --> 00:48:57,106
Ebda problema.

1077
00:48:57,106 --> 00:48:58,040
Jkollhom jum sabiħ.

1078
00:48:58,040 --> 00:48:59,360
Let me outta hawn.

1079
00:48:59,360 --> 00:49:00,460
Bye.

1080
00:49:00,460 --> 00:49:02,990
>> -Għall-Dawn il-pakketti xxurtjati
biżżejjed li jagħmilha s'hawn,

1081
00:49:02,990 --> 00:49:04,860
il-vjaġġ huwa kważi fuq.

1082
00:49:04,860 --> 00:49:07,280

1083
00:49:07,280 --> 00:49:11,560
Huwa biss up linja fuq l-interface
li jittieħdu fil-web server.

1084
00:49:11,560 --> 00:49:12,610

1085
00:49:12,610 --> 00:49:16,850
Illum, web server tista 'taħdem fuq ħafna
affarijiet, minn mainframe, għal webcam,

1086
00:49:16,850 --> 00:49:18,430
għall-kompjuter fuq l-iskrivanija tiegħek.

1087
00:49:18,430 --> 00:49:20,220
Għaliex ma friġġ tiegħek?

1088
00:49:20,220 --> 00:49:22,140
>> Bl-sett xieraq
up, inti tista 'ssib out

1089
00:49:22,140 --> 00:49:24,330
jekk inti għandek l-makings
għall cacciatore tiġieġ

1090
00:49:24,330 --> 00:49:25,690
jew jekk ikollok tmur shopping.

1091
00:49:25,690 --> 00:49:28,625
Ftakar, dan huwa l-bidunett tal-Net.

1092
00:49:28,625 --> 00:49:29,850
Kważi xejn possibbli.

1093
00:49:29,850 --> 00:49:32,960

1094
00:49:32,960 --> 00:49:37,080
>> Wieħed wieħed, il-pakketti huma
riċevuti, miftuħa, u tinfetaħ.

1095
00:49:37,080 --> 00:49:40,350

1096
00:49:40,350 --> 00:49:44,280
L-informazzjoni li jkun fihom, li
hija talba tiegħek għal informazzjoni,

1097
00:49:44,280 --> 00:49:46,080
tintbagħat fuq il-web
applikazzjoni server.

1098
00:49:46,080 --> 00:49:52,670

1099
00:49:52,670 --> 00:49:54,345
>> Il-pakkett innifsu jiġi riċiklat.

1100
00:49:54,345 --> 00:49:57,280

1101
00:49:57,280 --> 00:50:06,770
Lesta biex tintuża mill-ġdid u mimlija bil
informazzjoni mitluba tiegħek, indirizzati,

1102
00:50:06,770 --> 00:50:08,680
u jibgħat fuq triqtu lura lilek.

1103
00:50:08,680 --> 00:50:10,430

1104
00:50:10,430 --> 00:50:14,700
Lura passat il-firewalls, routers,
u fuq permezz ta 'l-internet.

1105
00:50:14,700 --> 00:50:18,164

1106
00:50:18,164 --> 00:50:19,705
Lura permezz firewall korporattiva tiegħek.

1107
00:50:19,705 --> 00:50:24,461

1108
00:50:24,461 --> 00:50:26,295
U fuq interface tiegħek.

1109
00:50:26,295 --> 00:50:27,400

1110
00:50:27,400 --> 00:50:30,630
Lesti li jissuplixxu web browser tiegħek
bl-informazzjoni li inti mitlub.

1111
00:50:30,630 --> 00:50:33,010

1112
00:50:33,010 --> 00:50:34,538
Dan huwa dan il-film.

1113
00:50:34,538 --> 00:50:40,030

1114
00:50:40,030 --> 00:50:43,200
>> Kuntent bl-isforzi tagħhom u
fidu f'dinja aħjar,

1115
00:50:43,200 --> 00:50:45,960
pakketti tagħna data trusty
ride off blissfully

1116
00:50:45,960 --> 00:50:49,830
ġo l-estinzjoni ta 'ieħor
jum, jafu kollox huma

1117
00:50:49,830 --> 00:50:51,635
jkunu servew kaptani tagħhom sew.

1118
00:50:51,635 --> 00:50:54,030

1119
00:50:54,030 --> 00:50:57,209
Issa, mhuwiex li jispiċċa kuntenti.

1120
00:50:57,209 --> 00:50:58,042
[END daqq ta 'video]

1121
00:50:58,042 --> 00:50:59,533
DAVID Malan: Li lilha għall CS50.

1122
00:50:59,533 --> 00:51:01,521
Aħna se tara inti ġimgħa d-dieħla.

1123
00:51:01,521 --> 00:51:05,994

1124
00:51:05,994 --> 00:51:11,220
>> [MUSIC - KATY PERRY, "dlam"]

1125
00:51:11,220 --> 00:54:19,222