1
00:00:00,000 --> 00:00:11,210
>> [Daqq tal-mużika]

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00:00:11,210 --> 00:00:14,640
>> SPEAKER 1: Kull dritt, merħba
lura għall-CS50.

3
00:00:14,640 --> 00:00:18,190
Dan huwa l-aħħar ta 'tmien ġimgħat,
u kważi Halloween.

4
00:00:18,190 --> 00:00:22,460
Ħinijiet tal-uffiċċju bil-lejl ta 'għada se jkunu
dawk scariest għadhom, u mhux minħabba

5
00:00:22,460 --> 00:00:23,460
ta 'Halloween.

6
00:00:23,460 --> 00:00:28,600
>> Imma fuq din in-nota, ma jirrealizzaw li
problema stabbiliti sitt, il-kontroll jespliċitaw

7
00:00:28,600 --> 00:00:32,340
problema sett, hija magħrufa li tkun, għal ħafna
istudenti, l-aktar sfida,

8
00:00:32,340 --> 00:00:36,010
ċertament fost l-settijiet problema C,
u verament, b'mod ġenerali.

9
00:00:36,010 --> 00:00:39,250
U nsemmi dan biss minħabba li din hija
il-ġimgħa fejn ħafna nies jiksbu

10
00:00:39,250 --> 00:00:42,840
enfasizzat b'mod partikolari ma 'biss tipprova
biex jiksbu l-jespliċitaw kkritikat biex jaħdmu.

11
00:00:42,840 --> 00:00:45,640
U l-ħaġa waħda nixtieq ninkoraġġukom
huwa li, kif tkun taf tara llum, u

12
00:00:45,640 --> 00:00:49,670
nhar it-Tnejn, aħna jibdew hit din quċċata
din il-ġimgħa fejn, issa, l-affarijiet saru

13
00:00:49,670 --> 00:00:52,370
ftit aktar familjari, ftit aktar
aċċessibbli, kif aħna transizzjoni minn

14
00:00:52,370 --> 00:00:56,120
ambjent linja tal-kmand fl C sa
web ambjent bbażata fil-PHP.

15
00:00:56,120 --> 00:00:59,805
>> U hekk I d ​​ninkoraġġukom, anki jekk int
verament fl-aħħar wit tiegħek fil-

16
00:00:59,805 --> 00:01:02,785
tipprova tikseb l-sett p għax-xogħol, jekk
dak l tabilħaqq il-post int fuq, jew

17
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issib ruħek fil, tipprova tagħmel
għall-enerġija permezz ta 'dan.

18
00:01:05,770 --> 00:01:08,280
Minħabba I do think inti ser tkun pjuttost
kuntent, u pjuttost kburi lilek innifsek,

19
00:01:08,280 --> 00:01:12,300
jekk int verament tispiċċa dik il-parti
Naturalment, il-porzjon C, fuq dik għolja,

20
00:01:12,300 --> 00:01:13,310
jekk stressanti, nota.

21
00:01:13,310 --> 00:01:14,120
Allura dak li ma biża.

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Li jinsab biss maħsub biex ninkoraġġukom biex
residenza sa dik is-siegħa żejda sabiex

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jiksbu l-jespliċitaw verifika ħidma.

24
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>> U jekk inti tagħmel, jirrealizzaw li dan
huwa fakultattiv, kompletament.

25
00:01:22,730 --> 00:01:25,720
Imma aħna għandna l-hekk imsejjaħ bord big
li marru jgħixu dalgħodu.

26
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Bħala ta 'dalgħodu, I kien atop-big
board, li huwa kejl ta 'kif

27
00:01:29,950 --> 00:01:34,450
RAM ħafna u kemm running time
speller program tiegħek jeħtieġ.

28
00:01:34,450 --> 00:01:35,890
Imma stajt sadanittant ġew spostati.

29
00:01:35,890 --> 00:01:37,910
Jien issa n-numru unlucky 13.

30
00:01:37,910 --> 00:01:41,460
U dak li inti ser tara hawnhekk huwa, David
Kaufman, u Lauren, u Adam, u

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JASON, u oħrajn huma issa
atop-bord big.

32
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>> Jekk inti tħares hemmhekk lejn il-lemin,
lkoll verament tajba

33
00:01:47,480 --> 00:01:49,890
implimentazzjonijiet ta 'daqs inqas -

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jirritorna l-għadd ta 'kliem
fid-dizzjunarju.

35
00:01:51,640 --> 00:01:54,690
U f'kull waħda minn dawn kolonni, inti ser
ara kemm RAM kull tagħna

36
00:01:54,690 --> 00:01:58,370
implimentazzjonijiet qed tuża, kemm
running time huwa jieħu biex tesegwixxi

37
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tagħbija, versus kontroll, versus daqs
u jħottu, u mbagħad, l-

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running time totali.

39
00:02:02,490 --> 00:02:05,990
Hekk biss biex iserraħ ras Elmer, u Patrick,
u Linda, u kulħadd

40
00:02:05,990 --> 00:02:09,210
li jiġi wara li inti, hemm assolutament
ebda mistħija li jkunu lejn

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00:02:09,210 --> 00:02:10,590
il-qiegħ tal-bord big.

42
00:02:10,590 --> 00:02:13,950
Jekk xejn, dan ifisser li inti ltqajna tax-xogħol,
u huwa korrett, imma hija

43
00:02:13,950 --> 00:02:18,480
mhux neċessarjament bħala effiċjenti, l-ispazju
jew iż-għaqli, kif jista 'jkun.

44
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>> Allura, totalment mhux obbligatorju.

45
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Iżda li jkun maħsub li jkun karrotta ta 'tipi tant
li meta inti qed jaħdmu fuq p tiegħek

46
00:02:22,630 --> 00:02:25,960
stabbiliti, int tant kburi ta 'lilek innifsek, inti
ltqajna tax-xogħol, inti post għall-big

47
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board, inti stajt ltqajna numru verament tajba,
inti tmur pranzu, inti taqa '

48
00:02:28,920 --> 00:02:31,810
lura, u roommates tiegħek telgħet
inti out fuq il-bord kbar.

49
00:02:31,810 --> 00:02:34,910
Ukoll, huwa żmien, f'dak il-punt, li jmorru
lura lill-bord ta 'tfassil sabiex

50
00:02:34,910 --> 00:02:36,160
mill-ġdid jikkontestaw il-bord kbar.

51
00:02:36,160 --> 00:02:39,330
Jekk inti tħares lejn l-spec, il-
istruzzjonijiet għall-interfacing ma 'l-

52
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board big issa huma stazzjonati.

53
00:02:41,480 --> 00:02:44,870
>> Allura koppja ta 'kapijiet ups -

54
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waħda, il-pre-proposta għall-finali
proġett huwa dovut dan it-tnejn li ġejjin.

55
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Ara dan spec fuq li l-kors
website għal dak li tfisser.

56
00:02:51,060 --> 00:02:54,450
Huwa verament ftit każwali iżda ħsibt
email pprovokat bejnek u tiegħek

57
00:02:54,450 --> 00:02:58,410
TF, verament ftit biex tikseb l-affarijiet bdew,
l-konversazzjoni bdiet, anki jekk

58
00:02:58,410 --> 00:03:02,110
ħafna minnkom qatt ma anki miktub
paġna web qabel, lanqas biss jafu liema

59
00:03:02,110 --> 00:03:04,850
inti tista ', kif inti tista', timplimenta
proġett finali tiegħek.

60
00:03:04,850 --> 00:03:07,250
Mur fuq il-fidi li inti ser tkun taf
kif jagħmlu pjuttost ftit aktar

61
00:03:07,250 --> 00:03:08,410
affarijiet fil-ftit ġimgħat.

62
00:03:08,410 --> 00:03:12,900
Hekk biss jibdew dan il-proċess kull l-
spec ta 'esplorazzjoni ideat possibbli.

63
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>> Ukoll, dak li aħna'd nistedinkom biex tagħmel huwa -
għandna tradizzjoni, għal ħafna snin

64
00:03:16,030 --> 00:03:18,840
issa, fil-kors, ta 'hosting
dan - store.cs50.net.

65
00:03:18,840 --> 00:03:20,010
Kollox mibjugħ bi prezz.

66
00:03:20,010 --> 00:03:23,460
U huwa verament biss l-opportunità li
jilbsu CS50, jekk inti tixtieq li tagħmel

67
00:03:23,460 --> 00:03:24,920
li, fil-kors tal-u.

68
00:03:24,920 --> 00:03:27,990
Per eżempju, hemm affarijiet bħal
lt-shirts li inti tista raw

69
00:03:27,990 --> 00:03:29,880
għaddejjin madwar kampus, sweatshirts.

70
00:03:29,880 --> 00:03:33,960
U allura, aħna wkoll jistieden istudenti biex
jissottomettu disinji li jiġu immortalizzata fl

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00:03:33,960 --> 00:03:35,330
-maħżen CS50.

72
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>> Per eżempju, wieħed mill-aħħar tas-sena
Favourites li se, forsi, issa

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00:03:39,910 --> 00:03:41,860
jinħassu miegħek huwa dan wieħed hawn.

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00:03:41,860 --> 00:03:45,390

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Oġġett popolari ħafna.

76
00:03:46,820 --> 00:03:51,020
Mela jekk inti tixtieq li tipparteċipa fl
dan, aħna ser imqiegħed f'forma malajr, fi

77
00:03:51,020 --> 00:03:54,240
cs50.net/design, li inti tista 'upload
immaġni li inti ħadna fl

78
00:03:54,240 --> 00:03:56,990
Illustrator, Photoshop jew,
jew xi programm simili.

79
00:03:56,990 --> 00:03:59,850
U jekk int familjari ma 'dawn it-tipi
ta 'speċifikazzjonijiet, irridu li

80
00:03:59,850 --> 00:04:05,010
jkun image PNG, mill-inqas 200 dots kull
pulzier, u inqas minn li ħafna pixels,

81
00:04:05,010 --> 00:04:07,680
u taħt l-10 megabytes.

82
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Għal aktar dettalji, biss email il-
kapijiet kors fiż heads@cs50.net jekk

83
00:04:11,260 --> 00:04:13,910
inti tixtieq biex ikollhom sehem f'dan.

84
00:04:13,910 --> 00:04:20,920
>> Kull dritt, hekk illum, mhux aktar C. Allura aħna
jibdew jiġbdu lura l-saffi tal-

85
00:04:20,920 --> 00:04:24,900
internet, il-web, u kif tista '
attwalment tibda bil-miktub software għal

86
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dan l-ambjent differenti.

87
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Allura b'mod partikolari, ejja jistaqsu,
ewwel, il-kwistjoni ta '-

88
00:04:31,420 --> 00:04:36,070
let me nikseb us lill familjari tagħna
tpinġija app hawn fuq.

89
00:04:36,070 --> 00:04:42,702
Let me joħolqu l-kwistjoni ta ',
Kif taħdem l-internet.

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00:04:42,702 --> 00:04:43,560
>> [? STUDENT: Magic. ?]

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00:04:43,560 --> 00:04:44,010
>> SPEAKER 1: Magic.

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00:04:44,010 --> 00:04:44,940
OK.

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00:04:44,940 --> 00:04:45,880
Tweġiba tajba.

94
00:04:45,880 --> 00:04:49,460
Allura aħna ser tibda hemmhekk illum, u ara jekk
aħna ma tistax tagħmel dan ftit inqas maġika

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00:04:49,460 --> 00:04:50,880
f'siegħa.

96
00:04:50,880 --> 00:04:53,850
Ejja nippruvaw li tgħid li fil-
kuntest ta 'storja.

97
00:04:53,850 --> 00:04:58,480
>> Allura int fannijiet tal ser facebook.com,
jew reddit.com, jew

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00:04:58,480 --> 00:04:59,780
x'ikun dawn il-jiem.

99
00:04:59,780 --> 00:05:02,590
U hekk dak li verament jiġri meta
inti tip fil xi ħaġa simili

100
00:05:02,590 --> 00:05:07,020
facebook.com, u hit Ikteb, fil Chrome,
jew Firefox, IE jew, jew Safari,

101
00:05:07,020 --> 00:05:09,050
jew kwalunkwe browser int
fil-fatt jagħmlu?

102
00:05:09,050 --> 00:05:11,500
Nistgħu tell din l-istorja, forsi
piena mill sentenza?

103
00:05:11,500 --> 00:05:14,770
X'hemm waħda mill-ewwel affarijiet li
jiġri meta inti hit Ikteb, wara

104
00:05:14,770 --> 00:05:15,876
ittajpjar facebook.com?

105
00:05:15,876 --> 00:05:17,780
>> [? STUDENT:?] Kompjuter tiegħek
jagħmel talba HTTP.

106
00:05:17,780 --> 00:05:18,260
>> SPEAKER 1: OK.

107
00:05:18,260 --> 00:05:21,900
Allura kompjuter tiegħek jagħmel - aħna ser
sejħa hija - talba HTTP.

108
00:05:21,900 --> 00:05:22,940
Issa dak ma jfisser?

109
00:05:22,940 --> 00:05:27,980
Ukoll, lkoll għandek probabbilment jidhru jew
ittajpjat, għas-snin issa, H-T-T-P spiss

110
00:05:27,980 --> 00:05:29,186
segwit minn kolon, mmejla, slash.

111
00:05:29,186 --> 00:05:30,340
Allura dak hu li?

112
00:05:30,340 --> 00:05:33,980
>> Ukoll, HTTP huwa HyperText
Transfer Protocol.

113
00:05:33,980 --> 00:05:37,360
U dan huwa biss mod fancy ta 'tgħid,
huwa l-lingwa li web browsers,

114
00:05:37,360 --> 00:05:42,460
bħal Chrome u oħrajn, u servers mill-web,
bħal facebook.com, kellem lit-

115
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xulxin.

116
00:05:43,100 --> 00:05:46,730
U huwa pjuttost sempliċi, l-Ingliż
lingwa orjentati.

117
00:05:46,730 --> 00:05:48,140
Huwa kważi simili kodiċi psewdo.

118
00:05:48,140 --> 00:05:51,820
>> U huwa mod ta 'klijent, kif
aħna ser sejħa hija - browser -

119
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komunikazzjoni mal-server.

120
00:05:53,150 --> 00:05:56,230
U biss bħal fil restorant, meta inti,
il-klijent, bilqegħda fuq mejda

121
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u mbagħad tordna xi ħaġa off ta 'l-
menu tal-server, li server huwa

122
00:05:59,630 --> 00:06:02,720
ser iġibu inti lura xi ħaġa,
kwalunkwe huwa inti mitlub.

123
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Istess fid-dinja tal-kompjuter.

124
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A browser -

125
00:06:04,970 --> 00:06:05,610
klijent -

126
00:06:05,610 --> 00:06:07,890
hija ser tagħmel talba, u
allura, nisperaw nikseb lura

127
00:06:07,890 --> 00:06:09,120
xi ħaġa mill-server.

128
00:06:09,120 --> 00:06:11,660
U li xi ħaġa hija, fi
livell għoli, il-paġna web.

129
00:06:11,660 --> 00:06:15,040
F'livell kemmxejn aktar baxx, huwa
fajl miktuba ieħor

130
00:06:15,040 --> 00:06:17,160
lingwa imsejħa HTML -

131
00:06:17,160 --> 00:06:18,920
HyperText Markup Language.

132
00:06:18,920 --> 00:06:20,720
Iżda aktar fuq li fi ftit mument.

133
00:06:20,720 --> 00:06:22,470
>> Allura HyperText Trasferiment Protokoll -

134
00:06:22,470 --> 00:06:23,450
HTTP -

135
00:06:23,450 --> 00:06:26,050
dak l-protokoll li
browser u l-użu server.

136
00:06:26,050 --> 00:06:27,830
Ukoll, dak huwa protokoll, eżattament?

137
00:06:27,830 --> 00:06:29,280
Ukoll, inti tista 'taħseb
bħala lingwa.

138
00:06:29,280 --> 00:06:32,580
Imma jekk I jilħqu udjenza tagħna hawn,
ħaġa normali għalina bnedmin għal

139
00:06:32,580 --> 00:06:35,928
do huwa, meta aħna insellem xi ħadd,
I say, hi, jien jisimni David.

140
00:06:35,928 --> 00:06:37,320
>> [? STUDENT: Hi,] jisimni Dipty?.

141
00:06:37,320 --> 00:06:39,000
>> SPEAKER 1: "Hi, jien jisimni
Dipty, "hi risposti.

142
00:06:39,000 --> 00:06:43,530
U hekk aħna kellna din pjuttost arbitrarja
interazzjoni ta 'l-idejn tħawwad, kif

143
00:06:43,530 --> 00:06:45,730
spiss il-konvenzjoni tal-bniedem
f'ħafna pajjiżi.

144
00:06:45,730 --> 00:06:47,380
U li l-protokoll, id-dritt?

145
00:06:47,380 --> 00:06:50,680
I sort tal nidihom billi testendi tiegħi
idejn, pjuttost awkwardly, fuq il-palk

146
00:06:50,680 --> 00:06:51,610
tal Sanders hawn.

147
00:06:51,610 --> 00:06:54,670
Hi induna, oh, stajt gotten
jitlob għal idejn apparentement.

148
00:06:54,670 --> 00:06:58,170
U hekk hi wieġbet għal din it-talba
billi fil-fatt jirrikonoxxi dan.

149
00:06:58,170 --> 00:07:01,860
An jirrikonoxxi, ACK, huwa attwalment
frażi komuni ħafna fid-dinja ta '

150
00:07:01,860 --> 00:07:04,060
networking, għal server li
jirrikonoxxu l-klijent.

151
00:07:04,060 --> 00:07:07,720
Imbagħad, aħna tip ta mimlija li
transazzjoni, u awkwardness fuq.

152
00:07:07,720 --> 00:07:10,010
Allura li verament dak li qed jiġri
taħt il-barnuża kif ukoll.

153
00:07:10,010 --> 00:07:13,450
>> Let me jagħmlu dan ftit aktar
teknikament taħt il-barnuża.

154
00:07:13,450 --> 00:07:16,900
Jien se jmorru fuq hawn
għal tieqa terminal.

155
00:07:16,900 --> 00:07:19,950
Dan tieqa terminal jiġri li jkun fuq tiegħi
Mac, iżda inti tista 'tagħmel l-istess tip

156
00:07:19,950 --> 00:07:21,760
ta 'ħaġa fil CS50 Appliance.

157
00:07:21,760 --> 00:07:24,750
U jien fil-fatt se tuża programm
li aħna mhux se verament użati għal

158
00:07:24,750 --> 00:07:26,300
ħafna fil-livelli kollha-semestru.

159
00:07:26,300 --> 00:07:27,430
Iżda huwa msejjaħ telnet.

160
00:07:27,430 --> 00:07:31,880
>> Lura fil-ġurnata, telnet kien il-programm
li inti użati biex jgħaqqdu l-

161
00:07:31,880 --> 00:07:34,910
server remot, biex jiċċekkjaw mail tiegħek
jew li jagħmel xi ħaġa bħal dik.

162
00:07:34,910 --> 00:07:38,460
Għal issa, aħna qed tmur biex tuża din qodma
programm skola, telnet, li nippretendu li

163
00:07:38,460 --> 00:07:39,830
tkun browser.

164
00:07:39,830 --> 00:07:41,550
U jien ser jimxi 'l quddiem u
tagħmel dan li ġej - let me

165
00:07:41,550 --> 00:07:42,800
jiżdied id-daqs tat-tipa tiegħi.

166
00:07:42,800 --> 00:07:48,080
>> U jien se ngħid, telnet għall-
server imsejħa www.facebook.com, iżda

167
00:07:48,080 --> 00:07:50,980
speċifikament, telnet-port 80.

168
00:07:50,980 --> 00:07:52,070
Aħna ser terga 'lura għal dan.

169
00:07:52,070 --> 00:07:56,630
Iżda għal issa, jafu li ħafna mis-servizzi
fuq l-internet huma identifikati

170
00:07:56,630 --> 00:07:58,170
unikament minn xi numru.

171
00:07:58,170 --> 00:07:59,460
F'dan il-każ, huwa 80.

172
00:07:59,460 --> 00:08:02,910
Issa ħafna għandek probabbilment
qatt ittajpjat 80 qabel.

173
00:08:02,910 --> 00:08:08,540
Iżda fir-realtà, jekk immur għal browser
u iġbed up, per eżempju,

174
00:08:08,540 --> 00:08:16,500
http://www.facebook.com/--

175
00:08:16,500 --> 00:08:18,460
li l-awto-sħiħ, li l-
mhux l-istorja tiegħi -

176
00:08:18,460 --> 00:08:23,070
id-dritt, hekk issa, immorru
kolon 80 slash.

177
00:08:23,070 --> 00:08:26,270
>> So I jsostnu li anki jekk inti ħadthom
probabbilment qatt ittajpjat dan qabel, ma

178
00:08:26,270 --> 00:08:30,310
l-kolon 80 wara facebook.com,
nisperaw, huwa għadu sejjer jaħdem.

179
00:08:30,310 --> 00:08:32,220
U fil-fatt, din tmur għall facebook.com.

180
00:08:32,220 --> 00:08:34,860
Għalhekk jirriżulta li 80
kien impliċitu.

181
00:08:34,860 --> 00:08:36,690
Xejn minna bnedmin kellhom
it-tip li għal snin.

182
00:08:36,690 --> 00:08:41,350
Minħabba browsers, awtomatikament, just
jassumi li n-numru inti tixtieq li tuża

183
00:08:41,350 --> 00:08:44,620
meta jċemplu up a server hekk
li jitkellmu huwa, fil-fatt, 80.

184
00:08:44,620 --> 00:08:47,340
Minħabba qosra Long storja, servers
tista 'tagħmel mod aktar milli sempliċiment

185
00:08:47,340 --> 00:08:48,320
iservu up paġni web.

186
00:08:48,320 --> 00:08:50,030
>> Huma jistgħu jirrispondu għall-messaġġi instantanji.

187
00:08:50,030 --> 00:08:51,230
Huma jistgħu jibgħat emails.

188
00:08:51,230 --> 00:08:54,410
Hemm lottijiet ta 'servizzi li
tista 'taħdem fuq server wieħed.

189
00:08:54,410 --> 00:08:57,590
Allura dawn in-numri - f'dan il-każ, 80 -
unikament jidentifika wieħed minn dawk

190
00:08:57,590 --> 00:09:01,830
servizzi, li huwa HTTP, il-
protokoll web minn server

191
00:09:01,830 --> 00:09:03,210
jistgħu attwalment appoġġ.

192
00:09:03,210 --> 00:09:07,250
Imma nista jissimulaw din it-talba issa,
testwalment, jużaw din l-iskola antika

193
00:09:07,250 --> 00:09:08,240
Programm telnet.

194
00:09:08,240 --> 00:09:12,940
Hekk jien ser essenzjalment issa nippretendu
li jkun browser u jitkellmu HTTP

195
00:09:12,940 --> 00:09:16,620
billi jibgħat, mal keyboard tiegħi, eżattament
l-kmandi li Chrome biss kienu jafu

196
00:09:16,620 --> 00:09:18,260
tibgħat għalija magically.

197
00:09:18,260 --> 00:09:19,910
>> Hekk jien ser jimxi 'l quddiem
u hit Ikteb.

198
00:09:19,910 --> 00:09:22,000
Avviż li huwa jippruvaw 31.13.69.32.

199
00:09:22,000 --> 00:09:26,110
13 X'inhu dan?

200
00:09:26,110 --> 00:09:27,440
Allura huwa l-indirizz IP.

201
00:09:27,440 --> 00:09:30,790
Issa anki jekk int ma wisq familjari
mal-intricacies ta 'dawk, inti

202
00:09:30,790 --> 00:09:33,420
probabilment jkollhom sens ġenerali
li jeżistu dawn l-affarijiet.

203
00:09:33,420 --> 00:09:34,650
U l-indirizz IP -

204
00:09:34,650 --> 00:09:36,620
Indirizz tal-Protokoll Internet -

205
00:09:36,620 --> 00:09:40,970
huwa biss identifikatur uniku għal
kompjuter fuq l-internet.

206
00:09:40,970 --> 00:09:43,040
Dan huwa daqsxejn ta 'oversimplification
għall-mument.

207
00:09:43,040 --> 00:09:47,490
>> Iżda kull kompjuter fuq l-internet
uniku indirizz IP, ħafna bħal kull

208
00:09:47,490 --> 00:09:53,600
house fi, ngħidu aħna, l-Istati Uniti għandha unika
indirizz postali, xi ħaġa bħal 123

209
00:09:53,600 --> 00:09:55,820
Main Street, fl Anytown, USA.

210
00:09:55,820 --> 00:09:56,540
Allura xi ħaġa bħal dik.

211
00:09:56,540 --> 00:09:58,330
U li, wisq, huwa oversimplification.

212
00:09:58,330 --> 00:10:01,470
Iżda dawn l-indirizzi li għandna fil-
dinja postali u dawn l-indirizzi

213
00:10:01,470 --> 00:10:04,940
li għandna fid-dinja tal-kompjuter
jidentifika unikament servers hekk li meta

214
00:10:04,940 --> 00:10:09,030
inti tibgħat messaġġ lill magħhom matul l-
internet, jew meta inti tpoġġi ittra

215
00:10:09,030 --> 00:10:10,500
mailbox iskola antika -

216
00:10:10,500 --> 00:10:12,100
posta -

217
00:10:12,100 --> 00:10:16,940
is-servizz jaf kif tikseb dan
talba, jew l-ittra, il-

218
00:10:16,940 --> 00:10:18,110
riċevitur intenzjonat.

219
00:10:18,110 --> 00:10:21,390
>> Issa kompjuter tiegħi, b'xi, għandha biss
dehret li IP uniku Facebook

220
00:10:21,390 --> 00:10:23,820
huwa 31.13.69.32.

221
00:10:23,820 --> 00:10:25,170
Fil-fatt, li probabbilment jistgħu jinbidlu.

222
00:10:25,170 --> 00:10:27,780
Facebook probabbilment ikun IP multipli
indirizzi, għaliex assolutament

223
00:10:27,780 --> 00:10:29,150
jkollhom aktar minn waħda server.

224
00:10:29,150 --> 00:10:30,810
Imma dak li ġara għalina magically.

225
00:10:30,810 --> 00:10:35,070
Fil-fatt, l-isem sigriet interna tal-
server Stajt apparentement konnessi

226
00:10:35,070 --> 00:10:40,270
li huwa msejjaħ star.c10r.facebook.com,
x'ikun li hu.

227
00:10:40,270 --> 00:10:42,960
Huwa biss x'ikun is-sistema
amministratur fil Facebook iddeċieda li

228
00:10:42,960 --> 00:10:46,510
sejħa dan server partikolari li I
kien kemmxejn saltwarjament mibgħuta lill.

229
00:10:46,510 --> 00:10:48,630
>> Mela issa jekk konnessjoni tiegħi ma tkunx
ttajmjati out, jien ser

230
00:10:48,630 --> 00:10:50,210
jippretendux li dak browser.

231
00:10:50,210 --> 00:10:54,590
Jien se ngħid tikseb ispazju
quddiem mmejla ispazju.

232
00:10:54,590 --> 00:10:58,220
U jien ser nippretendu li jitkellem
HTTP verżjoni 1.1, li huwa

233
00:10:58,220 --> 00:10:59,880
il-wieħed li ħafna browsers użu.

234
00:10:59,880 --> 00:11:03,980
U jien speċifikament ser isemmu
l-server, mill-mod, I jridu li l-

235
00:11:03,980 --> 00:11:06,280
website magħrufa mad-dinja
kif facebook.com.

236
00:11:06,280 --> 00:11:09,000
Ikteb, Ikteb.

237
00:11:09,000 --> 00:11:11,390
U issa, avviż dak li ġara.

238
00:11:11,390 --> 00:11:16,400
>> Il-server, l-wejter, wieġbet
għall-ordni tiegħi, jew it-talba tiegħi, ma

239
00:11:16,400 --> 00:11:17,720
messaġġ ieħor testwali.

240
00:11:17,720 --> 00:11:20,720
Issa mill-ġdid, fid-dinja ta 'browsers bħall
Chrome u Safari, inti ma tkunx

241
00:11:20,720 --> 00:11:21,990
tara dan, bħala l-bniedem.

242
00:11:21,990 --> 00:11:24,770
Microsoft u Google biss jaħbu
dawn id-dettalji minna.

243
00:11:24,770 --> 00:11:29,580
Iżda Facebook wieġbet bl-
tweġiba, ukoll fil-lingwa HTTP.

244
00:11:29,580 --> 00:11:33,250
Avviż hemm kodiċi hawn, 302, li
attwalment għandha sinjifikat partikolari billi

245
00:11:33,250 --> 00:11:34,110
konvenzjoni.

246
00:11:34,110 --> 00:11:36,030
Misjuba, b'tali mod li mill-inqas promettenti.

247
00:11:36,030 --> 00:11:39,160
>> Imma apparentement Facebook huwa javżak
me, mm-mm, ma tridu

248
00:11:39,160 --> 00:11:40,190
dak li inti mitlub.

249
00:11:40,190 --> 00:11:42,810
Inti minflok tixtieq lum
speċjali, li jkun

250
00:11:42,810 --> 00:11:45,680
facebook.com / unsupportedbrowser.

251
00:11:45,680 --> 00:11:50,350
Allura fuq livell għoli, dak ma Facebook
jidhru li tagħmel hawn?

252
00:11:50,350 --> 00:11:51,410
Huwa ridirezzjonar me.

253
00:11:51,410 --> 00:11:53,420
Allura Facebook ma bħall-
fatt li jien feint

254
00:11:53,420 --> 00:11:54,770
jkun dan browser oħra.

255
00:11:54,770 --> 00:11:57,700
U għalhekk huwa ridirezzjonar
me għal xi websajt.

256
00:11:57,700 --> 00:11:59,820
>> Jien fil-fatt kurjuż, issa, dak li
dan il-ħaġa tidher qiesha.

257
00:11:59,820 --> 00:12:04,420
Let me go fuq dak fil Chrome hekk aħna
tista tara dak li trid lili biex tara.

258
00:12:04,420 --> 00:12:07,060
Allura issa li ħadthom attwalment mibgħuta lili lura
Facebook minħabba li ħadthom realizzati,

259
00:12:07,060 --> 00:12:08,360
oh, inti do jkollhom browser appoġġjati.

260
00:12:08,360 --> 00:12:10,260
Aħna lanqas se
nuruk dik il-paġna.

261
00:12:10,260 --> 00:12:12,920
Mela ejja imorru quddiem u ara
jekk ma nkunux nistgħu jiffissaw dan.

262
00:12:12,920 --> 00:12:14,280
>> Jien ser ikollhom
iqarrqu ftit.

263
00:12:14,280 --> 00:12:16,350
U aktar fuq dan fil-ġimgħat li ġejjin.

264
00:12:16,350 --> 00:12:18,120
Imma jien ser tagħmel ħaġa waħda hawn.

265
00:12:18,120 --> 00:12:20,590
U jien ser jispjegaw dan qabel twil.

266
00:12:20,590 --> 00:12:24,320
Agħti me ftit mument li
iqarrqu, u naqra inti.

267
00:12:24,320 --> 00:12:28,190
So let me nikseb dan.

268
00:12:28,190 --> 00:12:29,110
OK.

269
00:12:29,110 --> 00:12:30,690
I ser jispjegaw dak li qed nagħmel
fi ftit mument.

270
00:12:30,690 --> 00:12:32,810
Jien ser jimxi 'l quddiem u tikkanċella din
konnessjoni, u jippruvaw dan jerġa.

271
00:12:32,810 --> 00:12:38,440
>> Get mmejla HTTP 1.1 www.facebook.com ospitanti
utent aġent.

272
00:12:38,440 --> 00:12:43,880

273
00:12:43,880 --> 00:12:44,560
OK.

274
00:12:44,560 --> 00:12:46,820
Issa jien preti li jkun Chrome.

275
00:12:46,820 --> 00:12:50,920
Għalhekk jirriżulta li meta browser
jibgħat talba għal server, huwa biss

276
00:12:50,920 --> 00:12:51,595
is-sistema unur.

277
00:12:51,595 --> 00:12:54,840
Jekk ngħid jien Chrome, Facebook
se tassumi jien Chrome.

278
00:12:54,840 --> 00:12:58,560
U l-mezzi li permezz tagħhom I identifikati
lili nnifsi bħala Chrome huwa b'dan

279
00:12:58,560 --> 00:13:00,360
atrociously sensiela twila.

280
00:13:00,360 --> 00:13:03,240
Essenzjalment, il-browser
manifatturi fid-dinja jkollhom

281
00:13:03,240 --> 00:13:06,470
iddeċieda, ukoll, din il-verżjoni ta 'din
browser fuq din is-sistema operattiva se

282
00:13:06,470 --> 00:13:09,740
jkollhom string utent aġent li jistenna
bħal dik mess crazy hemmhekk.

283
00:13:09,740 --> 00:13:12,110
U Mozilla huwa hemm għal
raġunijiet storiċi.

284
00:13:12,110 --> 00:13:15,160
>> Imma avviż kemm l-informazzjoni jien
jqattar facebook.com anki mingħajr

285
00:13:15,160 --> 00:13:16,030
qtugħ pulzieri

286
00:13:16,030 --> 00:13:18,910
Jien javżak Mark li huwa
Mac li jien jużaw.

287
00:13:18,910 --> 00:13:23,590
Jien javżak lilu li huwa ta 'Intel
ibbażata Mac running Mac OS 10.8.5.

288
00:13:23,590 --> 00:13:27,870
Bħala twarrib, din l-informazzjoni se
għal kull website li inti żjara ma

289
00:13:27,870 --> 00:13:28,500
browser tiegħek.

290
00:13:28,500 --> 00:13:31,360
Pretty innokwa s'issa imma
jiġrilha juicier ftit.

291
00:13:31,360 --> 00:13:33,920
>> Avviż li, jekk naqraw bogħod biżżejjed,
Jien jużaw verżjoni Chrome

292
00:13:33,920 --> 00:13:38,060
30.0.1599.101.

293
00:13:38,060 --> 00:13:42,410
Imma issa, avviż li r-rispons
huwa mhux ħażin kif kienet qabel.

294
00:13:42,410 --> 00:13:44,840
Fejn Facebook javżak
me biex tmur issa?

295
00:13:44,840 --> 00:13:49,140
Huwa javżak me, għal darb'oħra, il-websajt -

296
00:13:49,140 --> 00:13:50,720
huwa javżak me huwa
mċaqalqa b'mod permanenti.

297
00:13:50,720 --> 00:13:54,200
Ukoll, fejn l-Heck ma Facebook imorru?

298
00:13:54,200 --> 00:13:56,100
>> Yeah, dan huwa differenza sottili.

299
00:13:56,100 --> 00:14:01,680
Iżda avviż, hawnhekk, li l-websajt
fil-fatt rilokati HTTPS.

300
00:14:01,680 --> 00:14:05,210
Allura storja twila fil-qosor, dan huwa mod wieħed
li Facebook huwa li tinforza I

301
00:14:05,210 --> 00:14:08,890
attwalment jispiċċaw fil-verżjoni sigur ta '
websajt tagħhom, il-wieħed li l-użu

302
00:14:08,890 --> 00:14:09,660
encryption -

303
00:14:09,660 --> 00:14:12,730
aktar kumplessi minn l-encryption we
tkellem dwar għal p sett tnejn, iżda

304
00:14:12,730 --> 00:14:14,520
encryption xorta.

305
00:14:14,520 --> 00:14:17,110
>> Issa f'dan il-punt jiġrilha diffiċli
għalija li spoof web tagħhom

306
00:14:17,110 --> 00:14:18,230
jitlob tuża telnet.

307
00:14:18,230 --> 00:14:20,210
Għaliex jekk dawn qed javżak
nagħmel użu SSL -

308
00:14:20,210 --> 00:14:23,050
il-prefiss HTTPS huwa dak
li jimplika -

309
00:14:23,050 --> 00:14:25,590
jekk dawn qed javżak me li tuża
kriptografija, hemm ebda mod jien ser

310
00:14:25,590 --> 00:14:28,610
li manwalment kriptaġġ messaġġ tiegħi quddiem
ta 'kollha inti hawn, u jippruvaw

311
00:14:28,610 --> 00:14:29,770
figura kif tagħmel dan.

312
00:14:29,770 --> 00:14:31,150
Huwa biss se tikseb
ferm aktar kumplessa.

313
00:14:31,150 --> 00:14:33,150
Imma dak hu l-browser
qed tagħmel għalik.

314
00:14:33,150 --> 00:14:36,230
>> Ejja naraw jekk aħna ma tistax tagħmel dan ftit
aktar sempliċi, imbagħad, permezz ta 'websajt

315
00:14:36,230 --> 00:14:38,700
li mhux jistennew
li nkunu l-aktar siguri.

316
00:14:38,700 --> 00:14:43,310
Ejja ħa mmorru għal, per eżempju, harvard.edu
fuq il-port 80.

317
00:14:43,310 --> 00:14:44,550
Ikteb.

318
00:14:44,550 --> 00:14:48,170
Kull dritt, sabiex jiksbu slash HTTP 1.1.

319
00:14:48,170 --> 00:14:49,730
U dak ma dan l-ewwel linja mmejla jfisser?

320
00:14:49,730 --> 00:14:53,120
Just biex ikunu ċari, għaliex do
I iżommu ittajpjar li?

321
00:14:53,120 --> 00:14:54,790
>> Ukoll normalment, meta inti tip URL -

322
00:14:54,790 --> 00:14:57,610
u sfortunatament, browsers normalment
jaħbu dan dawn il-jiem -

323
00:14:57,610 --> 00:15:00,850
normalment, meta inti tmur harvard.edu,
li URL uffiċjalment

324
00:15:00,850 --> 00:15:02,560
ma għan slash.

325
00:15:02,560 --> 00:15:07,350
Minħabba linja waħda mmejla tindika
liema parti tal-hard drive?

326
00:15:07,350 --> 00:15:08,990
L-għerq tal-hard drive.

327
00:15:08,990 --> 00:15:11,260
Aħna fil-Appliance ma jkunux verament kellhom
biex jaħsbu dwar dan, għaliex aħna qed

328
00:15:11,260 --> 00:15:12,930
dejjem fil-folder John Harvard.

329
00:15:12,930 --> 00:15:14,690
Imma folder tiegħu huwa fil-folder ieħor.

330
00:15:14,690 --> 00:15:17,980
U li folder fil-għerq tal-
Hard drive appliance, biex ngħidu hekk,

331
00:15:17,980 --> 00:15:18,980
anki jekk huwa virtwali.

332
00:15:18,980 --> 00:15:21,660
Allura linja waħda mmejla bħal dan ifisser
l-għerq tal-hard drive.

333
00:15:21,660 --> 00:15:25,650
Huwa simili backslash kolon C, jew huwa
l-għerq tal-volum tiegħek, fuq Mac OS.

334
00:15:25,650 --> 00:15:28,740
>> Iżda Chrome, u browsers oħra dawn
jiem, gotten faċli għall-utent, u

335
00:15:28,740 --> 00:15:30,300
huma jinħbew li mmejla għal kollox.

336
00:15:30,300 --> 00:15:32,620
Imma dak li kollha dak il-mezz
fil-messaġġ testwali tiegħi -

337
00:15:32,620 --> 00:15:36,570
agħtini l-għerq ta '' s harvard.edu
homepage, jiġifieri, l-

338
00:15:36,570 --> 00:15:38,120
paġna default innifsu.

339
00:15:38,120 --> 00:15:39,900
So let me go quddiem u hit Ikteb.

340
00:15:39,900 --> 00:15:43,650
Ħalluni nfakkarkom-ospitanti li nixtieq
www.harvard.edu, biss fil-każ hemm

341
00:15:43,650 --> 00:15:45,880
websites oħra li jgħixu fuq il-
server fiżiċi istess.

342
00:15:45,880 --> 00:15:46,080
>> OK.

343
00:15:46,080 --> 00:15:47,700
Harvard ltqajna ftit
paċenzja miegħi.

344
00:15:47,700 --> 00:15:49,390
Mela ejja tagħmel dan mill-ġdid, aktar mgħaġġla.

345
00:15:49,390 --> 00:15:55,560
Get mmejla HTTP 1.1 www.harvard.edu ospitanti
user-aġent -

346
00:15:55,560 --> 00:15:58,080
Jien guessing servers tagħna ma
kura kemm dwar dan -

347
00:15:58,080 --> 00:15:59,566
Ikteb, Ikteb.

348
00:15:59,566 --> 00:15:59,962
Whew.

349
00:15:59,962 --> 00:16:01,700
Oh kkritikat dan, talba bad.

350
00:16:01,700 --> 00:16:02,080
OK.

351
00:16:02,080 --> 00:16:05,310
Allura x'inhu għaddej hawn -

352
00:16:05,310 --> 00:16:07,800
hello, harvard.edu.

353
00:16:07,800 --> 00:16:10,280
Għaliex huwa tagħmel l - interessanti.

354
00:16:10,280 --> 00:16:11,710
Oh, OK.

355
00:16:11,710 --> 00:16:14,830
>> Allura dak Harvard issa qed tagħmel - u aħna qed
ser malajr veer off ta '

356
00:16:14,830 --> 00:16:17,100
din it-triq, minħabba li għaddej
tikseb tedious malajr -

357
00:16:17,100 --> 00:16:21,270
avviż li Harvard huwa attwalment
kompressjoni risposta tagħha lili, li

358
00:16:21,270 --> 00:16:22,140
mhix ideali.

359
00:16:22,140 --> 00:16:25,780
Minħabba I, apparentement, bħala bniedem, ma
taf kif decompress bits li

360
00:16:25,780 --> 00:16:27,280
ġew mibgħuta lili kompressata.

361
00:16:27,280 --> 00:16:31,500
U dawn qed jiġu murija huwa żibel
hemm, għaliex qed żero u dawk,

362
00:16:31,500 --> 00:16:33,190
iżda dawn mhux qed karattri ASCII.

363
00:16:33,190 --> 00:16:36,090
Huma qed mudelli ta 'żero u dawk li
ġew kompressat li jibdew

364
00:16:36,090 --> 00:16:37,050
spazju inqas.

365
00:16:37,050 --> 00:16:39,010
>> Allura malajr ħafna, let me tara
jekk I jistgħu jirkupraw hawn.

366
00:16:39,010 --> 00:16:41,590
Ejja nippruvaw, forsi, ieħor
kampus għal kollox.

367
00:16:41,590 --> 00:16:50,450
mit.edu get slash HTTP slash 1.1 ospitanti
www.mit.edu user-agent kolon hemmhekk.

368
00:16:50,450 --> 00:16:51,600
Grazzi, MIT.

369
00:16:51,600 --> 00:16:52,630
OK.

370
00:16:52,630 --> 00:16:55,750
Allura hawnhekk għandna web page.

371
00:16:55,750 --> 00:16:58,840
>> Allura dan huwa l-lingwa
magħrufa bħala HTML -

372
00:16:58,840 --> 00:17:00,400
HyperText Markup Language.

373
00:17:00,400 --> 00:17:03,390
Jien sempliċiment scrolling back up
fil-ħin biex jiksbu l-ħafna

374
00:17:03,390 --> 00:17:04,810
ponta fuq ta 'din il-paġna.

375
00:17:04,810 --> 00:17:07,440
U avviż kif MIT wieġbet
għat-talba tiegħi.

376
00:17:07,440 --> 00:17:08,520
200 hija tajba.

377
00:17:08,520 --> 00:17:10,630
200 mezzi kollox huwa litteralment OK.

378
00:17:10,630 --> 00:17:13,390
U li l-kodiċi istat li
aħna bnedmin verament qatt

379
00:17:13,390 --> 00:17:14,670
ara, b'mod mod tajjeb.

380
00:17:14,670 --> 00:17:16,140
Għaliex dan ikun ifisser kollox huwa tajjeb.

381
00:17:16,140 --> 00:17:19,369
>> Avviż li MIT ikun qed jinforma lili, ħej,
l-server aħna qed taħdem tissejjaħ

382
00:17:19,369 --> 00:17:23,849
Apache, li hija popolari ħafna
sors miftuħ web server ħielsa.

383
00:17:23,849 --> 00:17:25,589
Huma qed taħdem, apparentement,
UNIX, li hija

384
00:17:25,589 --> 00:17:27,130
sistema operattiva bħal Linux.

385
00:17:27,130 --> 00:17:30,660
Avviż li huma apparentament aġġornati
paġna web tagħhom fil 04:00,

386
00:17:30,660 --> 00:17:32,400
Greenwich Mean Time.

387
00:17:32,400 --> 00:17:34,990
>> Avviż ftit dettalji oħra.

388
00:17:34,990 --> 00:17:37,910
Huma qed jirritornaw, lili, test / html.

389
00:17:37,910 --> 00:17:39,800
Allura aħna ser tara dak li jfisser
fi ftit mument.

390
00:17:39,800 --> 00:17:45,460
Huma ħadthom apparentement tani 14717
bytes li jiswew ta 'HTML.

391
00:17:45,460 --> 00:17:48,180
U xi oħrajn, aktar esoteric
informazzjoni hija fil hemmhekk.

392
00:17:48,180 --> 00:17:49,920
>> Iżda din hija fejn jiġrilha interessanti.

393
00:17:49,920 --> 00:17:52,580
Din hija kif inti tagħmel paġna web.

394
00:17:52,580 --> 00:17:57,860
Din hija kif inti tagħmel paġna web li
titolu fil-tab, fil-browser tiegħek, hija

395
00:17:57,860 --> 00:18:00,590
MIT sing Massachusetts Institute
tat-Teknoloġija.

396
00:18:00,590 --> 00:18:06,300
U fil-fatt, jekk immorru lura għall Chrome u
żur www.mit.edu, avviż li,

397
00:18:06,300 --> 00:18:09,680
tabilħaqq, fit-titolu up hawn,
huwa MIT sing Massachusetts

398
00:18:09,680 --> 00:18:11,260
Istitut dot, dot, dot.

399
00:18:11,260 --> 00:18:16,490
U issa avviż, wisq, jekk I ikklikkja dritt jew
jikkontrollaw ikklikkja fuq il-desktop hawn,

400
00:18:16,490 --> 00:18:17,960
u mur View Page Sors -

401
00:18:17,960 --> 00:18:20,870
inqas fil Chrome, għalkemm kull browser
ma dan permezz xi tfisser -

402
00:18:20,870 --> 00:18:22,140
hawnhekk huwa l-istess fajl.

403
00:18:22,140 --> 00:18:25,140
>> Dan jiġri li jkun kkodifikati kulur,
jew sintassi enfasizzati.

404
00:18:25,140 --> 00:18:28,590
Iżda biss bħal bil-kodiċi C tiegħek li
ma kienx colorized minnek, kien

405
00:18:28,590 --> 00:18:31,810
colorized mill gedit, bl-istess mod
qed Chrome biss tagħmel

406
00:18:31,810 --> 00:18:33,130
dan prettier biex jinqara.

407
00:18:33,130 --> 00:18:37,110
Iżda dan huwa l-għalf li
aħna ser dalwaqt tkun bil-miktub.

408
00:18:37,110 --> 00:18:38,840
Allura dak hu l-endgame.

409
00:18:38,840 --> 00:18:42,020
Il-server wieġbet ma 'dik
informazzjoni, bħad inti wieġbu

410
00:18:42,020 --> 00:18:43,660
bl-idejn tiegħek għall handshake tagħna.

411
00:18:43,660 --> 00:18:47,280
Imma dak li inkella trid tmur
fuq fl bejn dawk il-passi?

412
00:18:47,280 --> 00:18:53,430
>> Well, meta I tip, f'dan l-aħħar każ,
www.mit.edu u hit Ikteb, aħna

413
00:18:53,430 --> 00:18:56,390
taf li tkellem lill-port
80 awtomatikament, port

414
00:18:56,390 --> 00:18:57,780
biss qed dak in-numru.

415
00:18:57,780 --> 00:19:00,710
Iżda fejn ma-indirizz IP imorru?

416
00:19:00,710 --> 00:19:05,045
Kif huwa kompjuter tiegħi jidhru dak
l-indirizz IP ta 'mit.edu hu?

417
00:19:05,045 --> 00:19:07,720

418
00:19:07,720 --> 00:19:10,840
>> Ukoll, jirriżulta, f'din id-dinja, hemm
huma affarijiet imsejħa DNS servers.

419
00:19:10,840 --> 00:19:14,500
U let me imorru quddiem u tiġbed
stampa quick hawn fuq.

420
00:19:14,500 --> 00:19:17,680
U dan ser biss jfassal, fi
termini mhux maħduma, x'inhu għaddej.

421
00:19:17,680 --> 00:19:21,510
Allura aħna ser nippretendu bħal dan huwa
laptop tiegħi hawn, fil Sanders.

422
00:19:21,510 --> 00:19:24,650
U li tkun Wi-Fi, hekk huwa konness
wirelessly għal xi ħaġa.

423
00:19:24,650 --> 00:19:26,060
>> X'hemm fil-fatt konness ma?

424
00:19:26,060 --> 00:19:27,990
Ukoll, x'imkien fil hawn, hemm
xi ħaġa fuq il-

425
00:19:27,990 --> 00:19:29,240
ħajt ma 'xi antenni.

426
00:19:29,240 --> 00:19:30,725
U li sejjaħ punt ta 'aċċess -

427
00:19:30,725 --> 00:19:31,560
AP.

428
00:19:31,560 --> 00:19:34,190
Punt ta 'aċċess bla wajers, wireless router -
sejħa hija tkun xi tkun trid.

429
00:19:34,190 --> 00:19:36,230
Iżda dawn qed kollha fuq il-kampus,
ma 'dawk antenni ftit.

430
00:19:36,230 --> 00:19:38,100
Tagħna huma magħmula minn Cisco, tipikament.

431
00:19:38,100 --> 00:19:42,480
U għalhekk b'xi, kompjuter tiegħi qed jitkellem
dak il-punt aċċess bla wajer,

432
00:19:42,480 --> 00:19:45,580
x'imkien hawn fil Sanders, jew
downstairs, jew barra.

433
00:19:45,580 --> 00:19:50,030
>> Sadanittant, dan il-ħaġa għandha ħafna ta '
wajers fiżiċi ser, probabbilment, l-

434
00:19:50,030 --> 00:19:52,175
Science Center, li aħna ser
jiġbed bħal dan.

435
00:19:52,175 --> 00:19:54,200
Din attwalment ma look bħal dik.

436
00:19:54,200 --> 00:19:55,200
Li attwalment jistenna ħafna aħjar.

437
00:19:55,200 --> 00:19:59,170
Allura l-Center Xjenza għandha mazz sħiħ
ta 'kompjuters ġewwa ta' dan li

438
00:19:59,170 --> 00:20:02,320
b'xi mod huma fiżikament konnessi għal kull
ta 'dawn il-punti ta' aċċess fuq il-kampus.

439
00:20:02,320 --> 00:20:06,440
U dawn il-kompjuters fiżiċi, aħna ser
sejħa routers, gateways jew.

440
00:20:06,440 --> 00:20:09,450
>> A router, kif ismu jissuġġerixxi, huwa
skop fil-ħajja huwa li rotta

441
00:20:09,450 --> 00:20:10,310
informazzjoni.

442
00:20:10,310 --> 00:20:14,150
Huwa jieħu xi bits, minn kompjuter,
bħala input, u figuri barra ta 'fejn

443
00:20:14,150 --> 00:20:15,640
dawk bits għandhom jintbagħtu.

444
00:20:15,640 --> 00:20:19,910
Allura fil-każ ta 'talba tiegħi għal
mit.edu, huwa attwalment pjuttost faċli.

445
00:20:19,910 --> 00:20:24,620
Talba tiegħi tiġi fi mill-browser tiegħi,
fuq Wi-Fi, il-punt ta 'aċċess, allura,

446
00:20:24,620 --> 00:20:27,080
permezz xi cable, fi router
fl-Ċentru tax-Xjenza.

447
00:20:27,080 --> 00:20:29,810
U b'xi mod, l-router fil-
Science Center figuri barra

448
00:20:29,810 --> 00:20:31,510
li MIT hija li mod.

449
00:20:31,510 --> 00:20:34,080
U jien ser jimxu 'l quddiem dawk
bits, jien ser rotta dawk bits,

450
00:20:34,080 --> 00:20:36,670
fl-triq, down Massa Ave., biex MIT.

451
00:20:36,670 --> 00:20:42,030
Imma kif ma kompjuter tiegħi jafu liema
l-indirizz IP anke kien?

452
00:20:42,030 --> 00:20:45,660
>> Ukoll jirriżulta li x'imkien
fil hawn hemm servers -

453
00:20:45,660 --> 00:20:48,330
u jien ser tiġbed
pjuttost astratt -

454
00:20:48,330 --> 00:20:49,710
bħala server DNS -

455
00:20:49,710 --> 00:20:51,220
Domain Name System.

456
00:20:51,220 --> 00:20:51,960
Dawn mhumiex routers.

457
00:20:51,960 --> 00:20:56,050
Dawn huma tipi differenti ta 'servers
għan li fil-ħajja huwa li jittraduċu

458
00:20:56,050 --> 00:21:04,340
ismijiet ospitanti, bħal www.mit.edu, għall-IP
indirizzi, bħal 1.2.3.4 So DNS servers

459
00:21:04,340 --> 00:21:05,240
do eżattament dan.

460
00:21:05,240 --> 00:21:08,320
Inti tista 'taħseb minnhom bħala li big
database, jew verament, bħal Excel big

461
00:21:08,320 --> 00:21:09,750
fajl ma 'żewġ kolonni.

462
00:21:09,750 --> 00:21:12,120
Wieħed huwa host names, wieħed
huwa indirizzi IP.

463
00:21:12,120 --> 00:21:15,020
U huma biss jikkonvertu waħda għall-
oħra, f'xi direzzjoni.

464
00:21:15,020 --> 00:21:16,830
>> Issa fir-realtà, huwa ftit
aktar kumplessi minn dak.

465
00:21:16,830 --> 00:21:22,070
Imma dak li kif il-kompjuter tiegħi, każwali tiegħi
Mac jew PC fuq din it-tabella hawn, jaf

466
00:21:22,070 --> 00:21:27,590
dak l-identifikatur uniku hija għal
www.mit.edu, jew Facebook, jew

467
00:21:27,590 --> 00:21:29,680
harvard.edu, għal dik il-kwistjoni.

468
00:21:29,680 --> 00:21:33,520
Iżda naturalment, hemm il-intier
tal-Massa Ave hawn.

469
00:21:33,520 --> 00:21:37,390
U mbagħad, irridu jiksbu MIT, li dan
huwa attwalment aktar konvinċenti.

470
00:21:37,390 --> 00:21:39,230
Li ser ikunu MIT.

471
00:21:39,230 --> 00:21:41,580
U għalhekk huma, ukoll, għandhom xi servers.

472
00:21:41,580 --> 00:21:45,770
U huma b'xi mod jkunu ta 'fili, jew
wireless, konnessjoni ma Harvard.

473
00:21:45,770 --> 00:21:48,830
U ovvjament, nistgħu mmorru ħafna farther
fl-triq minn MIT, u kellem lit-

474
00:21:48,830 --> 00:21:50,470
aktar kwalunkwe kompjuter fid-dinja.

475
00:21:50,470 --> 00:21:52,060
>> Imma ejja ara jekk aħna ma tistax tara dan.

476
00:21:52,060 --> 00:21:54,810
Let me jmorru lura għall Terminal tiegħi
tieqa għal ftit mument.

477
00:21:54,810 --> 00:22:00,170
U ejja nassumu li I dehret
dak l-indirizz IP huwa għall mit.edu

478
00:22:00,170 --> 00:22:02,700
bħal Telnet dehret out qabel,
u browser tiegħi tista ċar

479
00:22:02,700 --> 00:22:03,960
figura hija out għalija.

480
00:22:03,960 --> 00:22:06,970
U jien ser imexxu programm ieħor,
F'dan il-tieqa Terminal, imsejħa

481
00:22:06,970 --> 00:22:10,320
traceroute, intraċċar
rotta minn hawn -

482
00:22:10,320 --> 00:22:13,760
litteralment, din it-tabella -
li www.mit.edu.

483
00:22:13,760 --> 00:22:14,750
Ejja naraw x'jiġri.

484
00:22:14,750 --> 00:22:16,690
Let me fatt tiċkien il-daqs tat-tipa.

485
00:22:16,690 --> 00:22:17,430
OOP.

486
00:22:17,430 --> 00:22:18,790
Le, jien ridt li sorpriża għalik.

487
00:22:18,790 --> 00:22:19,110
>> OK.

488
00:22:19,110 --> 00:22:20,870
So here we go.

489
00:22:20,870 --> 00:22:22,880
Let me imorru quddiem u run dan hawn.

490
00:22:22,880 --> 00:22:26,410
U dak I kien jara mument ilu, u
aħna qed tara mill-ġdid issa, hija din

491
00:22:26,410 --> 00:22:29,980
output - www.mit.edu traceroute.

492
00:22:29,980 --> 00:22:33,380
Avviż, fl-ewwel linja, dan il-programm
tabilħaqq dehret li MIT

493
00:22:33,380 --> 00:22:35,730
Indirizz IP huwa dan in-numru hawnhekk.

494
00:22:35,730 --> 00:22:38,060
U issa, dak li għaddej
bejnietna u minnhom?

495
00:22:38,060 --> 00:22:44,110
>> Allura din il-linja hawn, fir-ringiela waħda, u dan
linja hawn, fir-ringieli tnejn, u mbagħad,

496
00:22:44,110 --> 00:22:46,335
ringiela tlieta - dak do kull wieħed minn dawn
linji probabbilment jirrappreżentaw?

497
00:22:46,335 --> 00:22:49,010

498
00:22:49,010 --> 00:22:50,225
Lokalitajiet, punti, żgur.

499
00:22:50,225 --> 00:22:53,520
Huma qed jissejjaħ ħops, kunċettwalment.

500
00:22:53,520 --> 00:22:56,230
Imma fiżikament, liema huma?

501
00:22:56,230 --> 00:22:57,130
Huma qed routers.

502
00:22:57,130 --> 00:22:59,820
>> Aħna biss, verament, biċċa waħda ta '
hardware hawn biex jitkellmu dwar s'issa.

503
00:22:59,820 --> 00:23:00,560
Huma qed routers.

504
00:23:00,560 --> 00:23:01,800
Allura dan il-ħaġa hawn -

505
00:23:01,800 --> 00:23:02,990
Isem crazy -

506
00:23:02,990 --> 00:23:06,700
iżda dan huwa probabbilment kamra tal-magni,
MR, fil-Center Xjenza.

507
00:23:06,700 --> 00:23:08,680
Huwa portal, router aka.

508
00:23:08,680 --> 00:23:11,160
Dan huwa biss xi numru unika li
xi ħadd ħareġ bi għaliha.

509
00:23:11,160 --> 00:23:13,120
U huwa fi ħdan harvard.edu.

510
00:23:13,120 --> 00:23:16,290
U dak l-indirizz IP ta 'dak router
li l-, għal darb'oħra, probabbilment fil-

511
00:23:16,290 --> 00:23:17,860
Science Center, ibbażata fuq l-isem tagħha.

512
00:23:17,860 --> 00:23:21,440
Dan it-tieni ringiela jirrappreżenta ieħor
router li ma jkollux nickname

513
00:23:21,440 --> 00:23:23,980
apparentement - isem ospitanti - huwa
biss għandu l-indirizz IP.

514
00:23:23,980 --> 00:23:28,070
>> Storja twila fil-qosor hekk, biex tinkiseb data minn
punti A sa B, hemm aktar minn sempliċiment

515
00:23:28,070 --> 00:23:31,400
Router Harvard, u router MIT,
u router Google,

516
00:23:31,400 --> 00:23:32,640
u router Facebook.

517
00:23:32,640 --> 00:23:37,300
Hemm għexieren, mijiet, eluf ta '
routers bejn kwalunkwe punt A u kull

518
00:23:37,300 --> 00:23:38,710
punt B fuq l-internet.

519
00:23:38,710 --> 00:23:41,710
Imma tipikament, inti tista 'tikseb data
minn punt għall-ieħor fil-

520
00:23:41,710 --> 00:23:43,210
inqas minn 30 hops.

521
00:23:43,210 --> 00:23:47,930
Fi kliem ieħor, inti biss għandek idejn
id-dejta u t-30 jew anqas routers bħal dawn.

522
00:23:47,930 --> 00:23:49,720
U huwa tipikament ħafna
inqas minn dik.

523
00:23:49,720 --> 00:23:50,970
>> Well, ejja naraw x'jiġri hawn.

524
00:23:50,970 --> 00:23:54,460
Fir-ringiela tlieta, aħna hit router imsejjaħ
qalba Science Center portal

525
00:23:54,460 --> 00:23:56,580
xi ħaġa jew oħra.

526
00:23:56,580 --> 00:23:58,970
Fir-ringiela 4, għandna portal fruntiera -

527
00:23:58,970 --> 00:24:00,670
dawn huma biss akronimi cryptic -

528
00:24:00,670 --> 00:24:02,530
wkoll fi ħdan harvard.edu.

529
00:24:02,530 --> 00:24:04,160
Hawn gateway ieħor fruntiera.

530
00:24:04,160 --> 00:24:09,070
U mbagħad, kollha f'daqqa, Whoa,
we jidhru li huma fi New York City.

531
00:24:09,070 --> 00:24:12,030
>> Għalhekk jirriżulta li - u jien meta ddeduċiet
biss mill-isem ospitanti.

532
00:24:12,030 --> 00:24:12,970
Dan jista 'jkun qarrieqi.

533
00:24:12,970 --> 00:24:13,830
Dan jista 'jkun fl-triq.

534
00:24:13,830 --> 00:24:15,030
Huwa iebsa biex jgħidu -

535
00:24:15,030 --> 00:24:21,960
iżda dan jista 'jintuża bħala rivelazzjoni
li l-iqsar distanza bejn żewġ

536
00:24:21,960 --> 00:24:25,730
punti fuq l-internet mhux
neċessarjament linja dritta.

537
00:24:25,730 --> 00:24:29,380
Jekk naħsbu ta 'iqsar bħala l-eħfef
triq, l-anqas ikkonġestjonat

538
00:24:29,380 --> 00:24:32,070
triq, huwa pjuttost possibbli -
jekk aħna ma jistgħux ikunu żguri -

539
00:24:32,070 --> 00:24:37,090
li d-data hija jivvjaġġaw deċenti
distanza bejn ringieli ħames u sitt.

540
00:24:37,090 --> 00:24:42,000
>> Issa sfortunatament MIT, jew xi ħadd, ltqajna
ftit awto-difiża, u li ħadthom

541
00:24:42,000 --> 00:24:43,700
beda jinjora talbiet tagħna.

542
00:24:43,700 --> 00:24:47,380
Dawk routers ġew kkonfigurat biex
jinjora t-talbiet tal-formola li huma

543
00:24:47,380 --> 00:24:48,900
inti, li inti, li inti.

544
00:24:48,900 --> 00:24:51,650
Mela ejja ara jekk aħna ma tistax tagħmel dan
ma 'xi ħadd iżjed kooperattiv.

545
00:24:51,650 --> 00:24:56,260
Allura Stanford għandha tradizzjoni sbieħ ta '
jkollhom ftit aktar ftuħ.

546
00:24:56,260 --> 00:24:57,820
Mela ejja naraw x'jiġri hawn.

547
00:24:57,820 --> 00:24:59,080
>> Għal darb'oħra, pretty cryptic.

548
00:24:59,080 --> 00:25:01,040
Iżda nibdew, għal darb'oħra, fil-magna
kamra fil-Xjenza

549
00:25:01,040 --> 00:25:01,990
Center, fir-ringiela waħda.

550
00:25:01,990 --> 00:25:02,660
Allura li tajjeb.

551
00:25:02,660 --> 00:25:05,240
Ħafna mill-servers ma risposta,
inklużi Stanford.

552
00:25:05,240 --> 00:25:07,940
Allura avviż aħna marru mill-kamra tal-magni
fil-Center Xjenza, sa ċertu

553
00:25:07,940 --> 00:25:11,770
router anonima x'imkien ieħor, għall-ieħor
Science Center portal, sa fruntiera

554
00:25:11,770 --> 00:25:13,970
portal, u mbagħad, għal xi ħaġa hawn -

555
00:25:13,970 --> 00:25:14,620
nox.org.

556
00:25:14,620 --> 00:25:19,330
Dan huwa l-Crossroads Tramuntana, ħafna
popolari punt peering fejn il-lottijiet

557
00:25:19,330 --> 00:25:21,080
ta 'kejbils, lottijiet ta' ISPs -

558
00:25:21,080 --> 00:25:23,220
fornituri tas-servizz internet -
qabbad fis.

559
00:25:23,220 --> 00:25:25,470
Hawn ieħor IP nameless hawn.

560
00:25:25,470 --> 00:25:27,530
Hawn server ieħor bħal dan.

561
00:25:27,530 --> 00:25:29,910
>> Iżda dan huwa interessanti.

562
00:25:29,910 --> 00:25:33,750
Fejn hi l-router fil
ringiela tmienja, probabbilment?

563
00:25:33,750 --> 00:25:36,030
Allura huwa probabbilment f'Washington, DC.

564
00:25:36,030 --> 00:25:40,290
U nista 'tip ta' jikkorroboraw
din l-ipoteżi dan iż-żmien.

565
00:25:40,290 --> 00:25:45,230
Minħabba kemm idum ma ħadet us biex tmur
mill-Center Science għal dan router

566
00:25:45,230 --> 00:25:46,370
fir-ringiela seba?

567
00:25:46,370 --> 00:25:49,820
Ukoll, kejl dawn millisekondi
fuq il-lemin hawn huma

568
00:25:49,820 --> 00:25:51,960
estimi ta 'dak iż-żmien.

569
00:25:51,960 --> 00:25:54,610
>> Hemm tlieta minnhom minħabba li l-
programm, traceroute, tipprova kull

570
00:25:54,610 --> 00:25:58,010
router tliet darbiet, biss sabiex inti tista 'tikseb
medja viżwali tan-numri.

571
00:25:58,010 --> 00:26:00,230
Iżda huwa apparentement tieħu sitt
millisekondi biex jiksbu

572
00:26:00,230 --> 00:26:01,840
għar-ringiela router Seba.

573
00:26:01,840 --> 00:26:05,470
Imma kif fast tista ', apparentement, inti
ivvjaġġar, jekk inti daqsxejn, bejn

574
00:26:05,470 --> 00:26:09,520
Boston u Washington DC?

575
00:26:09,520 --> 00:26:14,180
14 millisekondi huwa kif sakemm jieħu
għal dak il-messaġġ instant, għal dak

576
00:26:14,180 --> 00:26:18,870
email, għal dak web page talba għal
jivvjaġġaw bejn hawn u Washington DC.

577
00:26:18,870 --> 00:26:23,970
>> Jekk I tmur aktar lilhinn, li router numru 10,
dak belt am I apparentament issa?

578
00:26:23,970 --> 00:26:24,810
Allura, Houston.

579
00:26:24,810 --> 00:26:27,350
U dan huwa kkorroborat
billi l-qabża fil-ħin.

580
00:26:27,350 --> 00:26:28,730
Huwa verament bil-mod biex jiksbu Houston.

581
00:26:28,730 --> 00:26:33,960
Huwa jieħu 47 millisekondi li tikseb minn
Boston għal Houston f'dan il-każ.

582
00:26:33,960 --> 00:26:37,120
U jekk inħarsu aktar, LAX -

583
00:26:37,120 --> 00:26:41,430
qisu aħna jkollna l Stanford
tip ta 'dan il-mod, billi jmorru permezz LA.

584
00:26:41,430 --> 00:26:43,170
Imma jien jiddeduċi li mill LAX.

585
00:26:43,170 --> 00:26:46,390
Il-geeks għandhom tendenza li jużaw kodiċijiet ajruport
għall-ismijiet routers hawn.

586
00:26:46,390 --> 00:26:48,600
U dan huwa tip ta 'konsistenti
ma din il-preżunzjoni.

587
00:26:48,600 --> 00:26:50,260
82 millisekondi.

588
00:26:50,260 --> 00:26:54,720
>> Imbagħad, aħna apparentement jmorru fi LAX,
ieħor router LA u mbagħad, xi

589
00:26:54,720 --> 00:26:59,530
nameless waħda, u mbagħad finalment,
isem cryptic fuq in-netwerk Stanford, jew

590
00:26:59,530 --> 00:27:04,670
miegħu mill-qrib, stanford.edu, huwa
90 millisekondi bogħod, jew 6

591
00:27:04,670 --> 00:27:06,170
siegħa flimkien bl-ajruplan.

592
00:27:06,170 --> 00:27:09,360
Allura dan huwa kif veloċi tad-data jivvjaġġa
fuq l-internet.

593
00:27:09,360 --> 00:27:11,410
U huwa affarijiet aħna assolutament
jieħdu għal mogħtija f'dawn il-jiem.

594
00:27:11,410 --> 00:27:13,950
Meta int wara xi Gchat ma
xi ħadd, u l-messaġġi huma biss

595
00:27:13,950 --> 00:27:16,940
jidhru, tikkunsidra kemm
mgħaġġel li qed jiġri.

596
00:27:16,940 --> 00:27:21,540
U viżwalment, huwa tabilħaqq jiġri
f'dak it-tip ta 'rata.

597
00:27:21,540 --> 00:27:25,620
>> Allura bejn il-punti wieħed u 18,
f'dan il-każ, hemm

598
00:27:25,620 --> 00:27:26,890
affarijiet minbarra routers.

599
00:27:26,890 --> 00:27:30,140
Liema huma xi magni fuq l-internet
li jista 'jimblokka t-traffiku

600
00:27:30,140 --> 00:27:31,610
mill jkollna permezz?

601
00:27:31,610 --> 00:27:31,950
>> STUDENT: Firewalls.

602
00:27:31,950 --> 00:27:32,910
>> SPEAKER 1: Allura, firewalls.

603
00:27:32,910 --> 00:27:36,260
U aħna għandna firewalls personali bħal
li Mac tiegħek jew PC tista 'żżomm

604
00:27:36,260 --> 00:27:37,540
traffiku fil-jew barra.

605
00:27:37,540 --> 00:27:38,990
Harvard għandha firewalls.

606
00:27:38,990 --> 00:27:40,820
MIT huwa preżunt li għandu firewalls.

607
00:27:40,820 --> 00:27:44,400
U Stanford ma, kif jagħmlu kollha ta 'l-
fornituri tas-servizz internet li proprji

608
00:27:44,400 --> 00:27:49,260
dawn routers bejn il-punti A u B.
Imma inti qatt ma tieqaf biex jikkunsidraw,

609
00:27:49,260 --> 00:27:52,710
jew kura, kif firewall xogħlijiet.

610
00:27:52,710 --> 00:27:56,380
Well diġà, aħna għandna l-bini bażiku
blokki li ma għall-inġinerija

611
00:27:56,380 --> 00:27:57,700
din ir-risposta.

612
00:27:57,700 --> 00:27:59,090
>> Jekk inti kienu firewall -

613
00:27:59,090 --> 00:28:03,740
u ejja nassumu li inti x'imkien
bejn punt A u punt B.

614
00:28:03,740 --> 00:28:06,080
A cable huwa li ġejjin fis inti,
u li jmorru minn int.

615
00:28:06,080 --> 00:28:11,160
Allura inti għandek il-ħila teknoloġika
li tħares lejn kollha tal-pakketti ta '

616
00:28:11,160 --> 00:28:14,200
informazzjoni li huma jirriżultaw bejn
inti u l-persuna l-oħra.

617
00:28:14,200 --> 00:28:17,280
Fi kliem ieħor, dawk il-messaġġi Get I kien
manwalment ittajpjar, inti tista 'taħseb

618
00:28:17,280 --> 00:28:21,060
bħala kitba ta 'nota ta' malajr lil xi ħadd,
tqegħid-indirizz IP ta 'l-

619
00:28:21,060 --> 00:28:24,810
riċevitur, u n-numru tal-port
riċevitur, fuq din il-pakkett, allura,

620
00:28:24,810 --> 00:28:28,520
miktub indirizz IP tiegħek stess u tiegħek
numru tal-port fil-naħa tax-xellug ta 'fuq

621
00:28:28,520 --> 00:28:30,230
kantuniera bħal inti ittra.

622
00:28:30,230 --> 00:28:32,520
Imbagħad, inti tibgħat it out wirelessly.

623
00:28:32,520 --> 00:28:37,130
U qualche jivvjaġġa, permezz routers,
permezz wajers, wirelessly,

624
00:28:37,130 --> 00:28:39,190
fl-triq għall-MIT.

625
00:28:39,190 --> 00:28:43,520
>> Mela jekk int firewall, kif do
tieqaf dan ma jseħħx?

626
00:28:43,520 --> 00:28:49,710
What would you do jekk p jmiss tiegħek
tistabbilixxi kien timplimenta firewall?

627
00:28:49,710 --> 00:28:53,980
Kif nista stop kollha nies Harvard minn
qatt titkellem man-nies MIT-ġdid?

628
00:28:53,980 --> 00:28:55,870
>> [? STUDENT: You] ireġġgħu lura l-ittra?.

629
00:28:55,870 --> 00:28:56,450
>> SPEAKER 1: Inti liema?

630
00:28:56,450 --> 00:28:58,140
>> [? STUDENT:? Reverse]
l-ittra kmieni.

631
00:28:58,140 --> 00:28:59,290
>> SPEAKER 1: Reverse l-ittra -
X'tifhem?

632
00:28:59,290 --> 00:29:01,130
>> [? STUDENT:? Ibgħat] dan
lura lill-mittent.

633
00:29:01,130 --> 00:29:01,780
>> SPEAKER 1: Ibgħat lura.

634
00:29:01,780 --> 00:29:01,990
OK.

635
00:29:01,990 --> 00:29:05,720
Allura inti tista 'tirrifjuta l-virtwali
pakkett, it-tip ta billi tagħmel ritorn lejn

636
00:29:05,720 --> 00:29:06,660
mittent b'xi.

637
00:29:06,660 --> 00:29:08,370
Hekk żgur, dan huwa dak
li rridu niksbu.

638
00:29:08,370 --> 00:29:09,440
Imma ejja adsa ftit aktar profonda.

639
00:29:09,440 --> 00:29:10,460
Kif nista 'nagħmlu?

640
00:29:10,460 --> 00:29:13,950
>> Jekk l-input għal din il-problema - jekk jien
l-firewall, u jien effettiv

641
00:29:13,950 --> 00:29:18,020
permanenti bejn il-punti A u B, u
I am raġel nofs li gets li tħares

642
00:29:18,020 --> 00:29:21,240
ġewwa ta 'dan il-pakkett, u mbagħad jiddeċiedi
jekk jibgħatx lura lill

643
00:29:21,240 --> 00:29:25,030
Harvard jew li jippermettulha tkompli, liema
huwa dan I, l-firewall, vais

644
00:29:25,030 --> 00:29:26,280
tixtieq li tħares lejn?

645
00:29:26,280 --> 00:29:29,030

646
00:29:29,030 --> 00:29:29,975
>> I think I smajt hawnhekk.

647
00:29:29,975 --> 00:29:30,550
>> [? STUDENT: Fejn huwa] ġejjin minn?.

648
00:29:30,550 --> 00:29:32,360
>> SPEAKER 1: Fejn huwa ġejjin minn.

649
00:29:32,360 --> 00:29:36,410
Mela jekk l-indirizz IP sors -
in-numru ftit up here -

650
00:29:36,410 --> 00:29:38,430
huwa indirizz IP tappartjeni
li Harvard -

651
00:29:38,430 --> 00:29:40,220
u I jistgħu attwalment jafu li
bi probabbiltà għolja.

652
00:29:40,220 --> 00:29:45,540
Ħafna mill indirizzi IP Harvard nibdew
ma 140.247 dot dot xi ħaġa

653
00:29:45,540 --> 00:29:48,810
xi ħaġa, jew 128.103 dot
xi ħaġa dot xi ħaġa.

654
00:29:48,810 --> 00:29:51,450
Harvard tippossjedi dawk biċċiet
ta 'indirizzi IP.

655
00:29:51,450 --> 00:29:55,200
>> Ukoll, jekk nara li indirizzi IP bħala l-
mittent, I tista 'biss jibgħat lura.

656
00:29:55,200 --> 00:29:57,380
Fir-realtà, l-internet ma
jolqot ħela ta 'ħin

657
00:29:57,380 --> 00:29:58,460
jibgħat l-bits lura.

658
00:29:58,460 --> 00:30:02,480
Hija biss litteralment qtar-pakkett
billi jitħassru dan, b'mod effettiv.

659
00:30:02,480 --> 00:30:04,190
Allura dak li inkella jista I tħares lejn għalkemm?

660
00:30:04,190 --> 00:30:10,520
Ejja ngħidu li nixtieq biex in-nies fil-
Żjara Harvard mit.edu, u iġbed up

661
00:30:10,520 --> 00:30:13,230
websajts, u videos watch
fil-MIT, u simili.

662
00:30:13,230 --> 00:30:17,970
Imma ma rridx bnedmin fil-Harvard
email xi ħadd fi MIT.

663
00:30:17,970 --> 00:30:23,810
Kif jista I jippermettu traffiku minn Harvard
MIT, permezz tal-web, imma ma tippermettix

664
00:30:23,810 --> 00:30:24,700
xi ħaġa simili email?

665
00:30:24,700 --> 00:30:25,840
>> [? STUDENT:? Il-] numru tal-port.

666
00:30:25,840 --> 00:30:28,650
>> SPEAKER 1: Numru port - dak l-
uniku ingredjent oħra għandna.

667
00:30:28,650 --> 00:30:31,880
Għandna indirizz IP, li aħna biss
ingranati, jew għandna numru tal-port,

668
00:30:31,880 --> 00:30:34,870
fejn 80, għidna, unikament
jidentifika traffiku web.

669
00:30:34,870 --> 00:30:37,430
Issa I ma jistennew li inti tkun taf dan -
xi wħud minnkom jista 'diġà taf

670
00:30:37,430 --> 00:30:38,210
minn familjarità -

671
00:30:38,210 --> 00:30:41,860
x'hemm numru li użaw
għall-email, normalment?

672
00:30:41,860 --> 00:30:43,080
Huwa spiss 25.

673
00:30:43,080 --> 00:30:48,520
25 jirreferi għall SMTP, li hija mail
protokoll ta 'trasferiment li jista' jkollok

674
00:30:48,520 --> 00:30:51,270
kellha tistabbilixxi f'xi punt, jekk int
użu Eudora, jew Outlook, jew

675
00:30:51,270 --> 00:30:52,120
xi ħaġa bħal dik.

676
00:30:52,120 --> 00:30:53,190
Huwa biss numru ieħor -

677
00:30:53,190 --> 00:30:54,100
25.

678
00:30:54,100 --> 00:30:58,934
>> Telnet, li aħna kienu qed jużaw
qabel, tuża 23.

679
00:30:58,934 --> 00:30:59,770
FTP -

680
00:30:59,770 --> 00:31:03,750
protokoll ta 'trasferiment fajl, jekk inti stajt qatt
sema 'li wieħed - juża 21.

681
00:31:03,750 --> 00:31:07,430
HTTPS, il-verżjoni sigur ta 'HTTP,
li aħna ser terga 'lura

682
00:31:07,430 --> 00:31:10,130
qabel twil, użi 443.

683
00:31:10,130 --> 00:31:14,240
Allura l-dinja għandha mazz sħiħ ta '
numri li jikkorrelataw pakketti -

684
00:31:14,240 --> 00:31:17,760
pjuttost, jikkorrelataw is-servizzi
li dawn in-numri reali.

685
00:31:17,760 --> 00:31:19,400
Allura li kollox firewall qed tagħmel.

686
00:31:19,400 --> 00:31:23,330
Huwa jieħu ħarsa ġewwa dan virtwali
pakkett, u mbagħad jiddeċiedu Sen jew Nay

687
00:31:23,330 --> 00:31:26,230
sabiex jgħaddi tul, ibbażata
fuq dawk l-ingredjenti.

688
00:31:26,230 --> 00:31:29,720
>> Issa dak li jista Harvard b'mod ċar jagħmlu
biex tikseb passat dan firewall allura?

689
00:31:29,720 --> 00:31:33,620
Jekk inti tixtieq li tkun tista 'tibgħat messaġġ
MIT iżda mhux jinkixfu,

690
00:31:33,620 --> 00:31:38,050
ukoll, inti tista 'spoof indirizz IP tiegħek,
u biss b'xi mod ikunu fancy biżżejjed, tkun taf

691
00:31:38,050 --> 00:31:41,400
kif jiktbu kodiċi C, u jiktbu tiegħek
programm netwerk li tbiddel il-

692
00:31:41,400 --> 00:31:41,860
indirizz ditta.

693
00:31:41,860 --> 00:31:45,820
Il-problema hija li inti tista assolutament tibgħat
data anonimu, imma jekk inti tixtieq li

694
00:31:45,820 --> 00:31:49,850
jiksbu kwalunkwe tip ta 'tweġiba, bħall tara l-MIT
homepage, ovvjament, dan jindirizza

695
00:31:49,850 --> 00:31:50,870
jeħtieġ li jiġi korrett.

696
00:31:50,870 --> 00:31:52,780
Inkella, inti tista 'tgħid xejn
tixtieq, int mhux ser

697
00:31:52,780 --> 00:31:53,930
tisma lura minnhom.

698
00:31:53,930 --> 00:31:57,130
Iżda dawn huma biss wieħed mit-tipi
ta 'attakki li nistgħu jibgħat.

699
00:31:57,130 --> 00:31:59,240
>> Iżda jirriżulta meta aħna tibgħat dawn
messaġġi - u ejja jagħmlu

700
00:31:59,240 --> 00:32:00,485
eżempju ta 'dan.

701
00:32:00,485 --> 00:32:04,020
Jirriżulta, jekk ikolli messaġġ li
I trid tibgħat, huwa mhux biss mibgħuta

702
00:32:04,020 --> 00:32:04,920
pakkett wieħed.

703
00:32:04,920 --> 00:32:08,760
F'ġieħ l-effiċjenza tal, speċjalment meta
il-fajls int jitolbu jew il-

704
00:32:08,760 --> 00:32:13,570
tweġibiet int jkollna huma
partikolarment kbir, dak TCP/IP--

705
00:32:13,570 --> 00:32:16,330
Trażmissjoni Protokoll / Internet Kontroll
Protokoll - huwa biss fancy

706
00:32:16,330 --> 00:32:19,630
mod ta 'tgħid dak in-netwerking
software u kompjuters do - huma huma

707
00:32:19,630 --> 00:32:23,770
jieħdu messaġġ bħal dan, u dawn
taqtgħu up fi frak -

708
00:32:23,770 --> 00:32:25,540
ejja ngħidu erba frak.

709
00:32:25,540 --> 00:32:29,740
>> U jekk I issa maqtugħa dan up fis hawn,
maqtugħa dan up fis hawn, dak tiegħi

710
00:32:29,740 --> 00:32:34,270
kompjuter huwa mbagħad se tagħmel huwa huwa
ser jieħdu framment waħda u poġġih

711
00:32:34,270 --> 00:32:35,700
fl-istess pakkett.

712
00:32:35,700 --> 00:32:39,130

713
00:32:39,130 --> 00:32:41,100
Kull dritt, u let me nikseb a -

714
00:32:41,100 --> 00:32:41,630
ejja ara.

715
00:32:41,630 --> 00:32:43,150
Huwa ser jieħu waħda.

716
00:32:43,150 --> 00:32:46,490
Huwa ser jieħu pakkett ieħor, u
li għaddej biex tpoġġi t-tieni parti

717
00:32:46,490 --> 00:32:49,530
ta 'dan il-messaġġ fil hawn.

718
00:32:49,530 --> 00:32:51,370
Kull dritt.

719
00:32:51,370 --> 00:32:55,226
Huwa ser jieħu t-tielet
parti, poġġih fil hawn.

720
00:32:55,226 --> 00:32:57,410
Forsi ħin li jmiss aħna ser
biss tagħmel żewġ partijiet.

721
00:32:57,410 --> 00:33:00,010
U aħna ser jieħdu l-raba 'parti,
u poġġih fil hawn.

722
00:33:00,010 --> 00:33:02,140
>> U dak, issa, għandu jkun bil-miktub
fuq dawn pakketti -

723
00:33:02,140 --> 00:33:04,700
li aħna ser nippretendu li tagħmel, wasal iż-żmien għal
sake, u mhux fil-fatt jiktbu out.

724
00:33:04,700 --> 00:33:07,760
Liema jeħtieġ li tkun miktuba fuq kull
dawn l-erba pakketti, bil-messaġġ tiegħi

725
00:33:07,760 --> 00:33:08,320
lil xi ħadd?

726
00:33:08,320 --> 00:33:09,290
>> [? STUDENT: Il-] ordni?.

727
00:33:09,290 --> 00:33:10,270
>> SPEAKER 1: Allura, l-ordni.

728
00:33:10,270 --> 00:33:13,740
I bżonn mhux biss l-indirizz IP u l-
numri tal-port, kif aħna biss diskussi, I

729
00:33:13,740 --> 00:33:17,606
issa jeħtieġu numru ta 'sekwenza ta' xi tip
jiġifieri, dan huwa wieħed packet, dan

730
00:33:17,606 --> 00:33:19,840
huwa tnejn, dan huwa tlieta, dan huwa erbgħa.

731
00:33:19,840 --> 00:33:20,980
U dan huwa attwalment utli.

732
00:33:20,980 --> 00:33:23,690
Minħabba li l-internet, jirriżulta,
huwa attwalment pretty affidabbli.

733
00:33:23,690 --> 00:33:26,080
Routers jistgħu jiksbu konġestjonata.

734
00:33:26,080 --> 00:33:27,615
Kejbils tista 'tikseb megħlub -

735
00:33:27,615 --> 00:33:28,860
oversimplification -

736
00:33:28,860 --> 00:33:32,650
iżda, ma bits tali li dak routers
għandek tagħmel huwa biss qatra pakketti.

737
00:33:32,650 --> 00:33:35,540
>> Fi kliem ieħor, jekk l-internet huwa biss
verament kkonġestjonata, inti tista 'tikseb

738
00:33:35,540 --> 00:33:37,000
tlieta minn dawn l-erba pakketti.

739
00:33:37,000 --> 00:33:40,000
Imma jekk għandek identifikatur uniku fuq
kull wieħed minnhom, inti ser tkun taf li int

740
00:33:40,000 --> 00:33:42,510
nieqsa packet numru erbgħa ta 'erba.

741
00:33:42,510 --> 00:33:45,310
Allura inti tista 'titlob lill-Guy fil-
tarf l-ieħor biex jibgħathom.

742
00:33:45,310 --> 00:33:47,900
Iżda jekk wieħed jassumi li ma jseħħx,
ejja ara x'jista 'jiġri.

743
00:33:47,900 --> 00:33:50,780
>> Mela jekk jien tixtieq li jibgħat messaġġ lill - li
jixtieq jirċievi messaġġ tiegħi

744
00:33:50,780 --> 00:33:52,235
mill-internet?

745
00:33:52,235 --> 00:33:53,630
Kif dwar xi ħadd qrib bil-quddiem.

746
00:33:53,630 --> 00:33:55,490
Brian, huwa?

747
00:33:55,490 --> 00:33:56,430
Kull dritt.

748
00:33:56,430 --> 00:33:57,280
Inti toqgħod hemm.

749
00:33:57,280 --> 00:33:58,820
Jien ser tibgħat lill inti.

750
00:33:58,820 --> 00:34:01,100
U l-ħaġa dwar l-internet
hija li dawn jistgħu lanqas

751
00:34:01,100 --> 00:34:02,020
isegwu l-istess triq.

752
00:34:02,020 --> 00:34:02,990
>> So here I go.

753
00:34:02,990 --> 00:34:06,470
I am jibgħat messaġġ,
framment waħda minn erba.

754
00:34:06,470 --> 00:34:06,940
Be router.

755
00:34:06,940 --> 00:34:08,469
Just let nies oħra jittrattaw dan.

756
00:34:08,469 --> 00:34:10,310
Hemm inti tmur.

757
00:34:10,310 --> 00:34:12,790
Aħna ser jagħti dan lilek, u
aħna ser jagħti dan lilek.

758
00:34:12,790 --> 00:34:14,000
U aħna ser tara kif malajr -

759
00:34:14,000 --> 00:34:16,500
kemm millisekondi li tieħu
biex tikseb dan il-messaġġ Brian.

760
00:34:16,500 --> 00:34:20,820

761
00:34:20,820 --> 00:34:23,940
Kulħadd ikollu biex jipparteċipaw illum.

762
00:34:23,940 --> 00:34:25,130
Kull dritt.

763
00:34:25,130 --> 00:34:27,130
Brian għandha waħda, u tnejn.

764
00:34:27,130 --> 00:34:29,279
Jekk xi ħadd jixtieq li jkun -

765
00:34:29,279 --> 00:34:30,230
>> [? STUDENT: L-erba. ?]

766
00:34:30,230 --> 00:34:30,980
>> SPEAKER 1: Huwa għandu l-erba.

767
00:34:30,980 --> 00:34:32,480
Sabiex l-ebda wieħed għażel li tinżel pakkett.

768
00:34:32,480 --> 00:34:32,900
C'est jibred.

769
00:34:32,900 --> 00:34:33,330
Li l-multa.

770
00:34:33,330 --> 00:34:34,380
Allura Brian issa għandha l-erba.

771
00:34:34,380 --> 00:34:36,219
Jekk inti tixtieq li tmur quddiem u
reassemble dawk għalina.

772
00:34:36,219 --> 00:34:39,360

773
00:34:39,360 --> 00:34:40,320
I know, aħna qed feint.

774
00:34:40,320 --> 00:34:45,090
Allura f'ġieħ time tal -

775
00:34:45,090 --> 00:34:45,929
għandna erba.

776
00:34:45,929 --> 00:34:48,909
Allura, OK, miftuħa wieħed minnhom.

777
00:34:48,909 --> 00:34:49,360
OK.

778
00:34:49,360 --> 00:34:51,699
C'est kwart ta '
messaġġ tiegħi lilek.

779
00:34:51,699 --> 00:34:52,949
Issa, tiftaħ it-tieni.

780
00:34:52,949 --> 00:34:58,190

781
00:34:58,190 --> 00:35:01,985
Dan jista 'jkun umoristiċi, fl-aħħar,
biss lili u Brian.

782
00:35:01,985 --> 00:35:04,320
Kull dritt, inti ħadthom ltqajna tnejn.

783
00:35:04,320 --> 00:35:09,110
>> Allura fil-frattemp, aħna fiżikament ma
dan mal-imqass, iżda kollha huwa

784
00:35:09,110 --> 00:35:12,360
jieħu biex framment dawn l-affarijiet fil-
kompjuter huwa biss li tibgħat xi wħud mill-

785
00:35:12,360 --> 00:35:15,930
bits fil packet waħda, f'waħda virtwali
pakkett, xi wħud mill-bits fil-

786
00:35:15,930 --> 00:35:19,160
oħra, xi f'ieħor, u xi b'mod
raba, u mbagħad, let il-kompjuter

787
00:35:19,160 --> 00:35:21,570
tiddeċiedi, ibbażata fuq dawk in-numri,
f'liema ordni li għandek

788
00:35:21,570 --> 00:35:24,166
biex concatenate lilhom.

789
00:35:24,166 --> 00:35:26,270
U Brian, forsi, l-unika
wieħed li jista 'jara dan.

790
00:35:26,270 --> 00:35:29,010
Il-messaġġ I bagħtet lill Brain - minħabba
Naturalment, l-internet huwa mimli bl-

791
00:35:29,010 --> 00:35:30,260
dawn, hija -

792
00:35:30,260 --> 00:35:33,080

793
00:35:33,080 --> 00:35:34,500
iva.

794
00:35:34,500 --> 00:35:35,330
>> Allura dak hu l-messaġġ.

795
00:35:35,330 --> 00:35:36,700
U Brian jistgħu tistrieħ fuq dik issa.

796
00:35:36,700 --> 00:35:38,640
Għalhekk hija ħadet, ovvjament,
filwaqt li jagħmlu dan.

797
00:35:38,640 --> 00:35:41,680
Imma dan huwa dak li verament jiġri,
bħal routing data permezz tal-

798
00:35:41,680 --> 00:35:43,290
udjenza b'dan il-mod.

799
00:35:43,290 --> 00:35:47,320
Iżda hemm, għal darb'oħra, numru ta 'punti,
routers, firewalls, u oħrajn

800
00:35:47,320 --> 00:35:50,700
affarijiet bħal dawn bejn il-punti A u B. U
aktar milli biss tgħid l-istorja

801
00:35:50,700 --> 00:35:54,740
verbalment, ħsibt I d pull up dan
video li xi ħbieb ta 'tagħna, minn

802
00:35:54,740 --> 00:35:59,510
Erikson, snin lura, fil-fatt
jitqiegħdu flimkien li tispjega

803
00:35:59,510 --> 00:36:00,480
kif dan xogħlijiet kollha.

804
00:36:00,480 --> 00:36:02,380
U huwa madwar 10 jew hekk minuta fit-tul.

805
00:36:02,380 --> 00:36:04,065
Mela ejja jagħtuk, issa,
Ġellieda tal-Net.

806
00:36:04,065 --> 00:36:09,282

807
00:36:09,282 --> 00:37:09,720
>> [Daqq tal-mużika]

808
00:37:09,720 --> 00:37:14,990
>> Narrator: Għall-ewwel darba fl-istorja,
nies u makkinarju huma

809
00:37:14,990 --> 00:37:18,600
jaħdmu flimkien, jirrealizzaw ħolma -

810
00:37:18,600 --> 00:37:22,550
forza li jgħaqqad li jaf l-ebda
konfini ġeografiċi, mingħajr

811
00:37:22,550 --> 00:37:26,050
fir-rigward razza, twemmin, jew bil-kulur -

812
00:37:26,050 --> 00:37:31,000
era ġdida fejn il-komunikazzjoni tassew
jgħaqqad lin-nies.

813
00:37:31,000 --> 00:37:34,420
Dan huwa l-bidu tax-xibka.

814
00:37:34,420 --> 00:37:38,240

815
00:37:38,240 --> 00:37:40,070
Tixtieq tkun taf kif taħdem?

816
00:37:40,070 --> 00:37:44,605
Ikklikkja hawn biex tibda tiegħek
vjaġġ fix-xibka.

817
00:37:44,605 --> 00:37:47,930

818
00:37:47,930 --> 00:37:51,080
>> Issa eżattament dak li ġara meta
inti għafast fuq din ir-rabta?

819
00:37:51,080 --> 00:37:53,320
Bdejt fluss ta 'informazzjoni.

820
00:37:53,320 --> 00:37:56,950
Din l-informazzjoni jivvjaġġa isfel fil tiegħek
stess kamra mail personali, meta Mr

821
00:37:56,950 --> 00:38:01,805
Pakketti IP dan, tikketti dan,
u tibgħatha fit-triq tagħha.

822
00:38:01,805 --> 00:38:03,790
>> Kull pakkett huwa limitat fid-daqs tagħha.

823
00:38:03,790 --> 00:38:08,010
Il-kamra mail għandhom jiddeċiedu kif għandhom jinqasmu
l-informazzjoni, u kif

824
00:38:08,010 --> 00:38:09,170
pakkett li hija.

825
00:38:09,170 --> 00:38:13,390
Issa l pakkett teħtieġ tikketta li jkun fiha
informazzjoni importanti bħal

826
00:38:13,390 --> 00:38:19,492
bħala indirizz mittent, l-indirizz riċevitur,
u t-tip ta 'pakkett huwa.

827
00:38:19,492 --> 00:38:34,940

828
00:38:34,940 --> 00:38:38,680
>> Minħabba dan packet partikolari huwa se
barra fuq l-internet, huwa wkoll

829
00:38:38,680 --> 00:38:42,570
gets indirizz għall-proxy server,
li għandu funzjoni speċjali,

830
00:38:42,570 --> 00:38:44,410
kif Ser naraw aktar tard.

831
00:38:44,410 --> 00:38:50,070
Il-pakkett issa hija mnedija fuq tiegħek
netwerk ta 'żona lokali, jew LAN.

832
00:38:50,070 --> 00:38:53,990
Dan in-netwerk hija użata biex jgħaqqdu kollha
l-kompjuters lokali, routers,

833
00:38:53,990 --> 00:38:57,940
printers, eċċetera għall-informazzjoni
skambju fi ħdan il-ħitan fiżiċi ta '

834
00:38:57,940 --> 00:38:59,160
il-bini.

835
00:38:59,160 --> 00:39:04,130
Il-LAN huwa post pretty mhux kontrollat,
u sfortunatament, inċidenti

836
00:39:04,130 --> 00:39:05,425
jista 'jiġri.

837
00:39:05,425 --> 00:39:14,460

838
00:39:14,460 --> 00:39:18,050
>> L-awtostrada tal-LAN huwa ppakkjat
mat-tipi kollha ta 'informazzjoni.

839
00:39:18,050 --> 00:39:22,070
Dawn huma pakketti IP, pakketti Novell,
AppleTalk pakketti -

840
00:39:22,070 --> 00:39:24,500
dawn qed tmur kontra
traffiku, bħas-soltu.

841
00:39:24,500 --> 00:39:29,250
Il-router lokali taqra biex jindirizzaw u,
jekk ikun meħtieġ, tittella 'l-packet fuq

842
00:39:29,250 --> 00:39:31,710
network ieħor.

843
00:39:31,710 --> 00:39:33,570
Ah, il-router -

844
00:39:33,570 --> 00:39:37,490
simbolu ta 'kontroll fil apparentement
dinja diżorganizzat.

845
00:39:37,490 --> 00:39:38,480
>> ROUTER: Whoops, sorry dwar dan.

846
00:39:38,480 --> 00:39:39,965
Ejja tpoġġi dan wieħed hawn,
dan wieħed hawn.

847
00:39:39,965 --> 00:39:40,460
Dan jiċċaqlaq hawn.

848
00:39:40,460 --> 00:39:40,955
Dan wieħed jiċċaqlaq hawn.

849
00:39:40,955 --> 00:39:41,945
I ma bħal dan wieħed.

850
00:39:41,945 --> 00:39:42,935
Ejja jimxu dan wieħed.

851
00:39:42,935 --> 00:39:43,925
Dan wieħed imur hawn.

852
00:39:43,925 --> 00:39:45,410
[Inaudible]

853
00:39:45,410 --> 00:39:46,400
Poġġi jangle ieħor hawn.

854
00:39:46,400 --> 00:39:46,895
Ejja tpoġġi dan wieħed hawn.

855
00:39:46,895 --> 00:39:47,885
NaH, I ser imorru ma 'dak.

856
00:39:47,885 --> 00:39:48,700
Ejja tpoġġi dan wieħed hawn.

857
00:39:48,700 --> 00:39:49,930
>> Narrator: Hemm huwa -

858
00:39:49,930 --> 00:39:55,770
sistematiku, uncaring, metodiku,
konservattivi, u xi kultant, pjuttost mhux

859
00:39:55,770 --> 00:39:56,975
sa veloċità.

860
00:39:56,975 --> 00:40:00,090
Iżda mill-inqas huwa eżatt,
għall-parti l-kbira.

861
00:40:00,090 --> 00:40:01,243
>> ROUTER: Poġġi li wieħed hemmhekk.

862
00:40:01,243 --> 00:40:04,694
Li wieħed imur hemmhekk, li wieħed imur
hemm, u dan wieħed imur hemmhekk.

863
00:40:04,694 --> 00:40:05,680
Ukoll, ieħor imur hemmhekk.

864
00:40:05,680 --> 00:40:06,173
Li tmur hawn.

865
00:40:06,173 --> 00:40:07,423
[Inaudible]

866
00:40:07,423 --> 00:40:14,570

867
00:40:14,570 --> 00:40:18,670
>> Narrator: Peress li l-pakketti jħallu l-
router, dawn jagħmlu mod tagħhom fil-

868
00:40:18,670 --> 00:40:24,090
intranet ta 'kumpanija u ras
għall-bidla router.

869
00:40:24,090 --> 00:40:28,120
A ftit aktar effiċjenti mill-router,
l-iswiċċ router jilgħab veloċi u maħlula

870
00:40:28,120 --> 00:40:31,970
ma pakketti IP, deftly routing
minnhom flimkien mod tagħhom -

871
00:40:31,970 --> 00:40:34,720
Wizard pinball diġitali, jekk inti se.

872
00:40:34,720 --> 00:40:35,290
>> SWITCH ROUTER: Here we go.

873
00:40:35,290 --> 00:40:36,020
Hawnhekk tidħol ieħor.

874
00:40:36,020 --> 00:40:36,950
U huwa ieħor.

875
00:40:36,950 --> 00:40:37,406
Watch dan, mom.

876
00:40:37,406 --> 00:40:38,320
Hawnhekk tmur.

877
00:40:38,320 --> 00:40:39,235
Konvulżjonijiet, madwar id-dahar.

878
00:40:39,235 --> 00:40:40,660
Ħej, fil hemm, fil hemmhekk.

879
00:40:40,660 --> 00:40:41,135
Matul ix-xellug.

880
00:40:41,135 --> 00:40:42,090
Matul il-lemin.

881
00:40:42,090 --> 00:40:42,480
Matul ix-xellug.

882
00:40:42,480 --> 00:40:42,820
Matul il-lemin.

883
00:40:42,820 --> 00:40:43,490
You ltqajna.

884
00:40:43,490 --> 00:40:43,800
Hawnhekk niġu.

885
00:40:43,800 --> 00:40:45,170
Huwa rimjiet, hu punteġġi.

886
00:40:45,170 --> 00:40:45,860
Huwa ser.

887
00:40:45,860 --> 00:40:48,270
Ħej Wayne, oqgħod attent, hawn
taqa 'xulxin.

888
00:40:48,270 --> 00:40:49,520
Oh, here we go.

889
00:40:49,520 --> 00:40:52,920

890
00:40:52,920 --> 00:40:56,330
>> Narrator: Kif pakketti jaslu tagħhom
destinazzjoni, dawn qed telgħet mill-

891
00:40:56,330 --> 00:41:01,250
interface network, lesti biex jiġu
mibgħuta lill-livell li jmiss -

892
00:41:01,250 --> 00:41:04,340
f'dan il-każ, l-prokura.

893
00:41:04,340 --> 00:41:08,750
Il-prokura hija użata mill-kumpaniji ħafna bħala
tip ta 'bniedem tan-nofs sabiex

894
00:41:08,750 --> 00:41:11,570
inaqqsu l-piż fuq l-internet tagħhom
konnessjoni, u għal

895
00:41:11,570 --> 00:41:15,350
raġunijiet ta 'sigurtà kif ukoll.

896
00:41:15,350 --> 00:41:19,420
Kif tistgħu taraw, il-pakketti
huma kollha ta 'daqsijiet differenti,

897
00:41:19,420 --> 00:41:21,770
jiddependi fuq il-kontenut tagħhom.

898
00:41:21,770 --> 00:41:37,960

899
00:41:37,960 --> 00:41:45,110
>> Il-prokura jiftaħ il-pakkett u jistenna
għall-indirizz web, jew URL.

900
00:41:45,110 --> 00:41:49,500
Skont jekk l-indirizz ikun
aċċettabbli, il-pakkett huwa mibgħut fuq

901
00:41:49,500 --> 00:41:50,750
l-internet.

902
00:41:50,750 --> 00:41:56,940

903
00:41:56,940 --> 00:42:01,970
>> Hemm, madankollu, xi indirizzi li
ma jissodisfawx bl-approvazzjoni ta '

904
00:42:01,970 --> 00:42:03,090
il-prokura -

905
00:42:03,090 --> 00:42:05,893
jiġifieri, korporattiva jew
linji ta 'gwida.

906
00:42:05,893 --> 00:42:09,100

907
00:42:09,100 --> 00:42:13,710
Dawn huma sommarjament ttrattati.

908
00:42:13,710 --> 00:42:15,620
Aħna ser ikollhom xejn ta 'dak.

909
00:42:15,620 --> 00:42:19,227
Għal dawk li jagħmlu dan, huwa
fuq it-triq mill-ġdid.

910
00:42:19,227 --> 00:42:29,950

911
00:42:29,950 --> 00:42:32,313
>> Up li jmiss, l-firewall.

912
00:42:32,313 --> 00:42:36,500

913
00:42:36,500 --> 00:42:40,225
Il-firewall korporattiva
iservi żewġ għanijiet.

914
00:42:40,225 --> 00:42:44,350
Dan jipprevjeni xi affarijiet pjuttost koroh
mill-internet mill ġejjin fil-

915
00:42:44,350 --> 00:42:48,460
intranet, u tista 'wkoll tipprevjeni
informazzjoni korporattiva sensittiva

916
00:42:48,460 --> 00:42:53,380
qed jintbagħtu fuq l-internet.

917
00:42:53,380 --> 00:42:57,340
>> Ladarba permezz tal-firewall, router
jiġbor il-pakkett u jpoġġih fuq

918
00:42:57,340 --> 00:43:01,216
triq ħafna aktar ristretti, jew
bandwidth, kif ngħidu.

919
00:43:01,216 --> 00:43:06,830
Ovvjament, it-triq mhix wiesgħa
biżżejjed biex teħodhom kollha.

920
00:43:06,830 --> 00:43:10,870
>> Issa inti tista wonder dak li jiġri kollha
dawn il-pakketti li ma jagħmluha

921
00:43:10,870 --> 00:43:11,950
tul it-triq.

922
00:43:11,950 --> 00:43:16,540
Ukoll, meta Mr IP ma tirċevix
rikonoxximent li pakkett kien

923
00:43:16,540 --> 00:43:22,940
irċevuti f'waqthom, huwa sempliċiment
jibgħat packet sostituzzjoni.

924
00:43:22,940 --> 00:43:29,360
Aħna issa huma lesti li jidħlu fid-dinja
tal-internet, web spider ta

925
00:43:29,360 --> 00:43:33,670
networks interkonnessi li
span globu kollu tagħna.

926
00:43:33,670 --> 00:43:39,360
Hawnhekk, routers u switches jistabbilixxu
kollegamenti bejn networks.

927
00:43:39,360 --> 00:43:42,740
>> Issa l-nett huwa kompletament differenti
ambjent minn inti ser issib fi

928
00:43:42,740 --> 00:43:44,900
il-ħitan ta 'protezzjoni ta LAN tiegħek.

929
00:43:44,900 --> 00:43:47,340
Hawn, huwa l-Wild West -

930
00:43:47,340 --> 00:43:50,540
ħafna spazju, ħafna ta '
opportunitajiet, ħafna ta 'affarijiet li

931
00:43:50,540 --> 00:43:53,130
jesploraw, u postijiet li jmorru.

932
00:43:53,130 --> 00:43:57,620
Grazzi għall kontroll ftit u
regolament, ideat ġodda issib fertili

933
00:43:57,620 --> 00:44:01,530
ħamrija biex timbotta l-pakkett
ta 'possibbiltajiet tagħhom.

934
00:44:01,530 --> 00:44:05,240
Iżda minħabba din il-libertà,
ċerti perikli lurk wkoll.

935
00:44:05,240 --> 00:44:10,860
Inti qatt ma taf taf meta inti ser jilħqu l-
ping dreaded tal-mewt, speċjali

936
00:44:10,860 --> 00:44:15,610
verżjoni ta 'ping normali talba li
xi idjota maħsub sa mess up

937
00:44:15,610 --> 00:44:18,500
hosts unsuspecting.

938
00:44:18,500 --> 00:44:23,760
>> Il-passaġġ pakketti tagħna tieħu jista 'jkun permezz
satellita, linji tat-telefon, wireless,

939
00:44:23,760 --> 00:44:25,650
jew saħansitra cable trans-oċeaniċi.

940
00:44:25,650 --> 00:44:29,860
Dawn mhux dejjem jieħdu l-iktar mgħaġġla,
jew iqsar, rotot possibbli.

941
00:44:29,860 --> 00:44:33,560
Imma dawn se naslu s'hemm eventwalment.

942
00:44:33,560 --> 00:44:38,410
Forsi hu għalhekk huwa kultant
imsejjaħ il-stenna dinja kollha.

943
00:44:38,410 --> 00:44:42,710
Iżda meta kollox qed taħdem tajjeb,
inti tista 'tevita l-globu

944
00:44:42,710 --> 00:44:47,110
ħames darbiet fuq fil-waqgħa
ta hat, litteralment -

945
00:44:47,110 --> 00:44:51,520
u kollha għall-ispiża ta '
sejħa lokali, jew inqas.

946
00:44:51,520 --> 00:44:55,260
>> Qrib it-tmiem tad-destinazzjoni tagħna,
aħna ser issib firewall ieħor.

947
00:44:55,260 --> 00:44:58,450

948
00:44:58,450 --> 00:45:02,740
Jiddependi fuq perspettiva tiegħek bħala
packet data, l-firewall jista 'jkun

949
00:45:02,740 --> 00:45:06,930
bastjun ta 'sigurtà, jew
avversarju dreaded.

950
00:45:06,930 --> 00:45:11,710
Dan kollu jiddependi fuq liema naħa int
fuq u liema intenzjonijiet tiegħek huma.

951
00:45:11,710 --> 00:45:15,590
>> Il-firewall hija mfassla biex
let biss f'dawk il-pakketti

952
00:45:15,590 --> 00:45:18,060
li jilħqu l-kriterji tagħha.

953
00:45:18,060 --> 00:45:22,450
Dan firewall qed topera
dwar il-portijiet 80 u 25.

954
00:45:22,450 --> 00:45:26,880
Tentattivi kollha biex jidħlu permezz ieħor
portijiet huma magħluqa għan-negozju.

955
00:45:26,880 --> 00:45:40,500

956
00:45:40,500 --> 00:45:48,470
>> Port 25 huwa użat għall-pakketti tal-posta, filwaqt li
port 80 huwa l-entratura għall-

957
00:45:48,470 --> 00:45:50,755
pakketti mill-internet
lill-web server.

958
00:45:50,755 --> 00:45:54,060

959
00:45:54,060 --> 00:45:58,230
Ġewwa l-firewall, pakketti huma
skrinjati aktar bir-reqqa.

960
00:45:58,230 --> 00:46:02,190
Xi pakketti jagħmilha faċilment permezz
doganali, filwaqt li oħrajn

961
00:46:02,190 --> 00:46:04,760
tfittex biss daqsxejn dubjużi.

962
00:46:04,760 --> 00:46:08,390
>> L-uffiċjal firewall mhix faċilment
imqarraq, bħal meta dan ping ta '

963
00:46:08,390 --> 00:46:14,430
packet mewt tipprova jaħbi ruħha
bħala packet normali ping.

964
00:46:14,430 --> 00:46:14,740
>> Firewall: Next.

965
00:46:14,740 --> 00:46:15,214
OK.

966
00:46:15,214 --> 00:46:15,688
Mur fuq.

967
00:46:15,688 --> 00:46:16,162
Li OK.

968
00:46:16,162 --> 00:46:16,636
Ebda problema.

969
00:46:16,636 --> 00:46:17,584
Jkollhom jum sabiħ.

970
00:46:17,584 --> 00:46:18,532
Kun hawn.

971
00:46:18,532 --> 00:46:20,315
Bye.

972
00:46:20,315 --> 00:46:23,870
>> Narrator: Għal dawk pakketti xxurtjati
biżżejjed li jagħmilha s'hawn, il-

973
00:46:23,870 --> 00:46:25,920
vjaġġ huwa kważi fuq.

974
00:46:25,920 --> 00:46:28,940

975
00:46:28,940 --> 00:46:35,380
Huwa biss lineup fuq l-interface li
jittieħdu fil-web server.

976
00:46:35,380 --> 00:46:40,700
>> Illum web server tista 'taħdem fuq ħafna
affarijiet, minn mainframe, għal webcam,

977
00:46:40,700 --> 00:46:41,910
għall-kompjuter fuq l-iskrivanija tiegħek.

978
00:46:41,910 --> 00:46:44,630
Jew għaliex ma friġġ tiegħek?

979
00:46:44,630 --> 00:46:48,750
Bl-setup xierqa, inti tista 'ssib
taf jekk inti għandek l-makings għal

980
00:46:48,750 --> 00:46:51,570
tiġieġ cacciatore, jew jekk
ikollok tmur shopping.

981
00:46:51,570 --> 00:46:54,870
Ftakar, dan huwa l-bidu tax-xibka.

982
00:46:54,870 --> 00:46:56,360
Possibbli kważi xejn.

983
00:46:56,360 --> 00:47:00,540

984
00:47:00,540 --> 00:47:05,540
>> Wieħed wieħed, il-pakketti jiġu riċevuti,
miftuħa, u tinfetaħ.

985
00:47:05,540 --> 00:47:09,550

986
00:47:09,550 --> 00:47:11,900
L-informazzjoni li jkun fihom -

987
00:47:11,900 --> 00:47:14,370
jiġifieri, it-talba tiegħek
għall-informazzjoni -

988
00:47:14,370 --> 00:47:17,520
tintbagħat fuq il-web
applikazzjoni server.

989
00:47:17,520 --> 00:47:24,650

990
00:47:24,650 --> 00:47:33,750
>> Il-pakkett innifsu huwa riċiklat, lesta li
jerġa 'jintuża, u mimlija bil tiegħek

991
00:47:33,750 --> 00:47:46,830
informazzjoni mitluba, indirizzati, u
tibgħat, fi triqtu lura lilek, lura

992
00:47:46,830 --> 00:47:56,950
passat il-firewall, routers, u fuq
permezz ta 'l-internet, lura permezz

993
00:47:56,950 --> 00:48:08,430
firewall korporattiva tiegħek, u fuq tiegħek
interface, lesti li jissuplixxu tiegħek

994
00:48:08,430 --> 00:48:11,060
web browser bl-informazzjoni
inti mitlub -

995
00:48:11,060 --> 00:48:14,320

996
00:48:14,320 --> 00:48:17,236
jiġifieri, dan il-film.

997
00:48:17,236 --> 00:48:22,870

998
00:48:22,870 --> 00:48:27,590
>> Kuntent bl-isforzi tagħhom u fidu
f'dinja aħjar, trusty tagħna

999
00:48:27,590 --> 00:48:33,840
pakketti tad-data ride off blissfully fis
l-estinzjoni ta 'jum ieħor, li jafu

1000
00:48:33,840 --> 00:48:37,135
kompletament, servew
kaptani tagħhom ukoll.

1001
00:48:37,135 --> 00:48:40,080

1002
00:48:40,080 --> 00:48:43,695
Issa mhux li jispiċċa kuntenti?

1003
00:48:43,695 --> 00:48:47,910

1004
00:48:47,910 --> 00:48:49,890
>> SPEAKER 1: Li, allura, huwa
kif l-internet jaħdem.

1005
00:48:49,890 --> 00:48:53,360
Permezz problema sett seba se inti
nifhmu aħjar dan u se inti

1006
00:48:53,360 --> 00:48:55,830
jitgħallmu daqsxejn ta HTML, PHP, u aktar.

1007
00:48:55,830 --> 00:48:58,590
Aktar dwar dan fl-ispeċifikazzjoni
li se jmorru fuq il-ġimgħa.

1008
00:48:58,590 --> 00:49:00,310
U aħna se tara inti nhar it-Tnejn.

1009
00:49:00,310 --> 00:49:02,763