ѬOݨ즳BͦbWszGyڪqڡIz٦_ǪOyګɳqɤqzDA
oDDniHkwDPn]wDAw骺D·СA]ݭnzL@DZM˸mӤRwF
ܩn譱AjO]w~Ϊ̬O[~ӤwAnBzաI
OKIڭ̥Ӭݬݺb̥i|XDaI
wD
b
¦`ڭ̴ܦh¦A
HΤ@²檺w@DCH@²檺PγsuӻAڭ̥iH]L[cpPUϩҥܡG
Ϥ@BϰsuAܷN
bWϥܷA"Linux PC3" ns Internet WhܡAݭnzLuB
洫B NAT D (Linux A IP ɾ)BADSL ƾھAH
Internet WҦC] (]AѾBBLu)F
Ǧai|XDڡH
- uDG
bWϥܤAiHo{AP]ƤAϥγ̦hNOuաI
n`NuuPu (RJ-45Y)
AӨäOҦ]Ƴ䴩۰ʤuPu\I
ҥHAnAѨA] (Hub/Switch/ƾھ) Ҥ䴩uFt~A
pGAuOb_BΪ̬OeWBAܦi㦳QpA
ҥHzݭn`N@UoǨƱG
- uQI_F
- uLקᦱܧγyT}F
- ۻsY ( pRJ-45uY ) ~褣}F
- YP] ( p Hub )IJ}F
- dBHub Router ]ƪDG
t~A٦@Ǻ]Ƥ]|DA`DpUG
- díwB~褣ΡAΪ̻PtΪۮeפΡF
- U]ƪYΡAIJ}AyTIF
- ѩ]ƩҦbҴcH (ҦpL) ɭPDF
- U]ƨϥΤk}Ay]ƥ\IF
- ]ưtmWhG
bUӳ]ƪtmWO@wWhAӳ̮eoͪDNOӪu|yTIA
ɭPsuɶӪƦܵLksuCڭ̴b¦LAӺ̪䴩ZA
٦@ǨLCtmDzoG
- ϥο~uA̱`oͦbuPuOI
- []uLAɭPTIYCҦpAӺ CAT5e uzפjOb 90
إkAYӳ] (Hub/D) פj 90 خɡA۵MNeX{ToͰDFI
- LTzZA̱`oͦbuΪ̺]Ʈ𨷿ӱjϪiF
- ϰWA`IΪ̨L]ƤӦhALhڭ̱`Hҿת 543 hӻG
- 5Ӻq(segment)CҿsegmentNbzsW̱@չqA
b@BNCq̭̦hu30xqMBu`WL185mC
- 4ӼWq(repeater)C]NONHj˸mC
- 3ӹqs(population)CoӤnzѡM]NOeһ5segmentM
u3ӥiH˹qM䥦ӤC
WzO@dẕ`wDAMաAɭԬO]ƥNDA
ӧڭ̦b¦̭ͨ쪺ӫܭny
Gu
zpA]OyyγqP_n]oIҥHAwDP_xIC
n㧐Uڭ̦AӲ@n]wDC
nD
ҿתnDAjNO IP ]w~ڡAѤڡA٦ DNS IP ]w~A
oǰDOݩn]wաIunN]w@AQΤ@ǰnd@dA
NDDXb̤FIDG
- d IP ]w~G
ҦpGP@ IP bP@ӺqX{y IP ĬBlBn]w~BdXʵ{ϥο~B
d IRQB I/O Address ]wĬF
- ѪD (route table)G
̱`NOw] (default gateway) ]w~FIΪ̬OѤũҾɭPDA
ϱoƫʥ]SkQeXhC
- qTw۲G
̱`oͦbP@~tΤqTǿAҦp Windows 98 P Windows 2000 yڡz
YnFqAh Windows 98 n[ NetBEUI oӳqTw~CSҦpⳡ Linux
DnzL NFS qTwǿƮɡA䳣on䴩 portmap oӱҰ RPC w{~I
odzqTwڭ̳|b᭱`OЪաI
- tD (loading)G
Pɦjqƫʥ]i Server Ϊ̬O Hub Ϊ̬OP@Ӻ줤A
NiyyƦܱIIt~ApGϺHϥ BT (P2P n)
Ϊ̬OHrɭPįΥRӰϺA]|yyDF
- LDG
ҦpG@ port QצFAyLkYǺ귽Fε{ Bug
DFε{ϥΪ̪]w~FHΤP@~tΪۮeʰDC
DBz
JMDoͤFANnhBzLڡIpBzOHHWPγsuϥܬҡAⴤӭhG
- ѦۨҰ_AiHѦۨ PC Wdd_AuB Hub A ATU-R
wˬdCboӨBJA̦nΪnNO ping A
ӧA̦nⳡHWDӶisuաF
- TwwSDFAAӫҳn骺]wDI
ڤWApGqɡAAiḨdzo˳BzG
- AѰDGoӰDOo͡H٬O]eڰFʧ@ӾɭPLksuH
- T{ IPGݬݦۤvdLXʡH_oT IP ӳsuH
- T{ϺsuGQ ping
ӷqⳡDATwuP~ hub/switch u@`F
- T{~suGݥD IP ɾ_̾
sW Internet @kQo IP ѼơAåH
ping kTw~suOiH\F
- T{ DNS dGQ nslookup
host dig ˬd www.google.com ݬݡF
- T{ Internet `IGiHQ
traceroute ˬdU`IO_SDH
- T{A`AGO_AuHΥLFH
- T{ڤAGO_YǪAȨSTҰʡHiQ
netstat ˬdA
O_YǦwMS}AҦp SELinux oF
- vDGO_ѩv]w~ҭPH
O_ѩzѰOҥΥisufҭPHoӥiHzL
tcpdump ӳBzI
zLodzBzʧ@A@ӻAӳiHѨMzLkWDFI
MաApGOw骺DA]LkAAAi̻ݭnO......
y
eקaĤlIz
JMDWwgͨ쪺XӤpIFAUӷMO@Ӥ@ӪLBzڡI
Uڭ̴Non@B@}L}lˬdy{ڡI
BJ@Gdu@T{
A@XDɭԡAzӱqۤviHˬdaˬd_A]A
̭naNOˬdzdO_u@DաIˬddO_`u@kpUG
- TwdwgXʦ\G
pGdSXʦ\ALAK͡IIҥHAMݭnXʧAd~I
T{dO_QXʡAiHQ lspci ݬݦS Ethernet r˪ܸTAAH dmesg
ˬdO_Q֤߰A̫ϥ lsmod ݬݦS۹ҲդwQJC
ӨBJiHѦҡysW Internet - Linux dz@Ӥp`A
o̳AFI ^_^ILAn`NOApGWz˴觋Lko{AdҲաA
֩wNO֤P֤Ҳդ䴩AdڡIӫHѦ
ysW InternetdsĶzNFI
- TwiHʪإ IP ѼơG
bQJdҲաAåByodNzAڭ̥iHQ
ifconfig
ip ӪӺd@Ӻ}լݬݡI
ݯ_ IP ]wOHҦpG
[root@linux ~]# ifconfig eth0 192.168.1.100
|
Ӫإ߸Ӻd IP AM᪽J ifconfig ݯ_d\]wnѼƧYiC
pGiHإ߰_ IP ANH ping ˴ݬݡG
[root@linux ~]# ping 192.168.1.100
|
pG^ܡAܳoӺd]wӬOSDFI
AӫhO}l˴@UϰUӳswաI
ƹWnAӡApGzDzDWd (q`Oت)A
̦nR@iKyɥdӴXۥΡAyDIADzA
n@}lNDԦۤv@߰ڡIUUI
BJGGϰUs]˴
bT{F̭nd]wAåBTwdO`A
AۤUӫhOϰspFI]zO
Ϥ@ҳ]wPγsuϰ[cAAnDӡyzI
- 쪺G
AoMDϤ@UDPAiH۷qO]L̦byP@Ӻ̭zA
ҥHAAnDҿת 192.168.1.0/24 oغ쪺F觋ҥNNqA
BlBn (Netmask) Nq]oAѡCpGѰOFAЦ^h¦A½@½C
- Gateway P DNS ]wG
Gateway P DNS (b /etc/sysconfig/network-scripts/ifcfg-eth0, /etc/resolv.conf ]w) ̮eQdV
oӨëDOgA Linux D IP IӬOng IP ɾ ( NAT D) IP b Gateway A
g 168.95.1.1 b DNS IP ]wIdڡIpG٬OMH^h¦ݬݧaI
- Windows ݪu@sջPqWG
pzٻݭn귽ɡAzNb windows tΤ}ɮפɡA
åBijҦqNyu@sաz]wۦPAyqW١zhۦPI
]AϺҦD IP ]wTFAUӧANiHϥ ping ӴըⳡϺDsuA
oӳsuʧ@iHAըⳡDU]ơA]AuBHub/Switch NNI
pGLkզ\ANAѤ@UG
- IP ѼƬO_]wTG
AjաAMw IP O諸IbWҪɭԱ``o{PǵLksڪDWA
@gϥ ifconfig ~o{L̻Pڪ IP bP@ӺqANO|o˪poͰڡI
- suuDG
]Aڭ̫e쪺ulBL¶yTIDA
t~AǤª Hub/Switch Ϊ̬O ATU-R (ADSL ƾھAU٪pQtO]) ѩS
Auto MDI/MDIX \AҥHLk۰ʪuP_A
AuɭԡA]NLkqաIoAѥGHt~Aڭ̱``|A
²P_CDO_Qs Hub/Switch iHzLs Switch WOӧP_A
LAѩɭԺuT}AMO٬O|GALNOLks Switch p
(ۤvNoLڡI)AɡABͭɤ@ OK uӴլݬݧaI
- d Hub/Switch XDG
@Lkb~s쳾DAhìOIFAGĨDҦb줽ǹݡAxI
DOnnI|LksuOH]O.......Ǥҳq}A[W Switch ҦbBūLA
[Wª switch ynzaFAINoˡy switch z
bsҰ switch (ޱAWqu) N`FCҥHoAܦhpO|oͪA
ӰϰҤ]ܮevTsu~ڡI
TwۤvD IP PdSDA[WϺzL ping ]չLSDA
UӴNOnyoiH~su IP ѼơzաIoӭnI
BJTGoT IP Ѽ
syoT IP ѼơzڡHٰOoڭ̽LpGnQsW Internet ܡA
niH public IP i淾q~AӻP public IP oqkAbxW` ADSL,
Cable modem, dzN, qܼAb CentOS Aڭ̥iHzLק
/etc/sysconfig/network-scripts/ifcfg-eth0AΪ̬OQ rp-pppoe Ӷi漷A
LצpA
ANOonsY ISP hNOFbAT{ҦϺSDA
ѦҤ@U
sW Internet @СA
sWAߧYH ifconfig ݬݦS쥿T IP ڡH
bxWpGϥ ADSL suܡAAӥiHQo@եT Public IP ѼƪI
~ؤHBͨӫHAL̨ϥ ADSL ᳺMo@ Private IP A
`L̨Sk[IL̷Qаݳo˪pO_XzCpGzxѬA
M|DGyoMXzIzA]Ao IP uOFns ISP hӤwA
ISP PADMiHzL Private IP ӳsuڡIpGOo˪ܡAzN֩wLk[FI ^_^
t~A̱`o{LkQo IP ~NOyBOOTPROTOzoӳ]wȳ]wFI
] static P hdcp wҲͪ IP nDO@˪ڡIٰOoaI
nSOdb ifcfg-eth0 ̭]wѼƳIt~ApGAOϥ ADSL A
OѬOLk\AijAiHo˸լݬݡG
- N ADSL ƾھ (ATU-R) AN Switch/Hub ]qF
- RݤQAodz]ƤyD֡z@IAAsWqF
- N Linux s ADSL d (] eth0) b ifcfg-eth0 AyONBOOTz]w noA
sҰʺ (/etc/init.d/network restart)AMA adsl-start
- pG٬OLk\AåBAwgT{SDAФعqHu{HzBzaI
]ܦhɭԳOѩCLA]iD@ǺѼƦIDA
ҥHAܴNnҰʺdA adsl-start ۰ʥhҰʺdYiI
pGQo IP Ao٬OLkQs Internet WɡAAıo٦ǦaݭnBzOH
BJ|GT{ѪWh
pGAwgQoT IP ѼƪܡAUӴNOդ@UO_iHsW Internet ڡI
ijAiHըϥ ping ӳss Hinet DNS DA]NO 168.95.1.1 աI
[root@linux ~]# ping -c 3 168.95.1.1
|
pG^ANܧAyWwgSDAiHs Internet FIzA
pGS^OHoFT IP oLks~DA֩wIISI
ٰOoڭ̦b줺ƪǿiHzL
MAC ӶǰeA
pGbϺơAhݭnzLѡAרOӹw] (default route) ʥ]aI
ҥHA
pGA public IP Lks~ (Ҧp 168.95.1.1)
AiDNXbѻPWFC
]ASҰʨADNYpѤUo
ѪDpˬdHN
route -n ˬdڡI
DG]Өϥ ADSL Linux DALѪpUAAıoXFDH
Destination Gateway Genmask Flags Metric Ref Use Iface
59.104.200.1 0.0.0.0 255.255.255.255 UH 0 0 0 ppp0
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
0.0.0.0 192.168.1.2 0.0.0.0 UG 0 0 0 eth0
G
JӬݨWѿXAĤ@O ppp0 ͪ public IP AĤGO eth0 줶A
bݨ̫@ 0.0.0.0/0.0.0.0 oӹw]ѡAMO쪺 eth0 gateway H
oXzA̤jDӬOXb ifcfg-eth0 ̭p߳]wFyGATEWAY=192.168.1.2z
ҭPAѨMkG
- ifcfg-eth0 GATEWAY=192.168.1.2 @A(ӦiX{b /etc/sysconfig/network )
- sҰʺ /etc/init.d/network restart
- si漷G adsl-stop; adsl-start
|
t~@ӥioͪpANOGyѰO]ww]ѡzաI
Ҧpϥ ifconfig ʭs]wLd IP AѳWhO|QsA
ҥHw]ѥiN|FIӮɭԧANonQ route add ӼW[w]oI
BJGDWٻP IP dߪ
DNS ~
pGAo{iH ping 168.95.1.1 o Internet WDAoLkϥsb}Cs
http://www.google.com ܡA֩w 99% HWDOӦ۩ DNS ѪRxZI
ѨMkNO /etc/resolv.conf hݬݳ]wȹ藍ڡI
@`eOo˪G
[root@linux ~]# vi /etc/resolv.conf
nameserver 168.95.1.1
nameserver 139.175.10.20
|
̱`~Oy nameserver rgFIzuO̱`Dt~ApG client ݬO
Windows tΩOH``Ǫ̷|daNOb windows ]wFIn`NG
Windows ݪ DNS ]wPD /etc/resolv.conf eۦPYiI
ܦhǪ̳H TCP/IP DNS DOWۤv Linux DAoO諸
(Dzۤv Linux W DNS A) IzunWz ISP z DNS D IP mNiHF
BJGLinux NAT
A IP ɾXD
NAT A²檺\NO IP ɾաINAT D@wOѾAҥHAnb Linux
W[nTѸTC_h֩wDCt~A NAT DW]wO_XzH
IP ɾWO_]wתA|vT~suO_\DIC
NAT Pڭ̷|b`~ЪաI
BJCGInternet D
Internet ]|XDIMաSFO|XDI
|ҨӻAnX~exW詤]IuYAɭPn_FluQ_A
GɭP Internet yqj먮IoNO Internet D٦AƦ~e
Study Area maIѩѾ]wXFItA
GɭPsutתwCCoODXDAӬO Internet WYӸ`IXFpC
QnT{O_DӦ Internet ܡANϥ
traceroute aI
dݰDOӦۨӦaAI
BJKGDD
pGWzBz OK AoLknJYDɡAڷQA̤jDNOX{bD]wաI
o]AG
- DèS}ӶAȡGҦpDF telnet AAϥ telnet hsuAOLksWաI
- Dv]w~GҦpANYӥؿ]w drwx------ Aӥؿ֦̬ root A
AoNӥؿ} WWW sAѩ WWW LkiJӥؿAҥHMLkTΤsڡI
oǪ嫬v]w~pڡI
- w]w~GҦp SELinux OΨӧӷLޥDs@خ֤߾A
pGAS]wnNҥΪܡADAȫܦhyLkQҥΡzA
SELinux NnFCӨLҦp /etc/hosts.deny, PAM ҲյA
iyϥΪ̵LknJDIoNODAӬODysuLk\I
- DG]w~]O@ӫܱ`DAAiHϥ
tcpdump Ӱlܫʥ]yVA
HQAѨO_]w~C
WA@ӺҪ˴u@iOTyNӥB``oAܦhg窥D
бz``@yXhťťݤjagAh google ݬݤHaѨMkA
UAѨMDI ^_^