b}l DHCP eAڭ̥ӽƲߤ@UebĤGB¦̭쪺XӺѼƧaI n]wn@ӺҡAϹqiHQsW Internet AAq̭@wnUXӺѼƤ~AOOG

• IP, netmask, network, broadcast, gateway, DNS IP

𫟺A IP, netmask, network, broadcast P gateway iHb /etc/sysconfig/network-scripts/ifcfg-eth[0-n] oɮ׸̭]wADNS A}hOb /etc/resolv.conf Y]wCunoXӶس]wTAqӴNSDiHWFI ҥHAAa̭ 3, 4 qAAiHʪӳ]wnAһݭnѼơA MQ NAT A\ANiHjnj\sW Internet FIuO ^_^AOܡH

nFA{bڭ̴@Ӥj@ǨǪaI]AOǮձJ٪޲zAҺ޲zǥ͹qj 100 nFAA]wno 100 qOH

1. C@qAnXʪh]wnH
2. NҦǥͳX_ӡAM믫V.....ᤣIOоɤ@U]wH٬O
3. ǥѤ@DӦ۰ʪtҦѼƵJ٤@qH

oTظѨMשһݭnɶۦPApGAܪO(1)A򳾭ӤH{AAOu@gNOƱFA ]ҭnOɶPAұo~PIXߤOOҪCpGܬO(2)AܥiA|QWW̡B S}ߪ޲zٸIpGO(3)OHߧAIoӤת޲zɶO̵uA]O̤·Ъ@kաI

IDnǤFܡHOIo DHCP (Dynamic Host Configuration Protocol) ḀDnu@ANObiWĤTӤסA]NO۰ʪNѼƥTt줤CqA ΤݪqiHb}ɭԴNߧY۰ʪ]wnѼƭȡAoǰѼƭȥiH]AF IPBnetmaskBnetworkBgateway P DNS }Cp@ӡA޲zAAun`No@ѺѼƪDSNnFA LPǭ̪ӤHqAIAQQnhI] DHCP DwgAdwաI ^_^I I޲z̤jִNOiHܳܯBѴN౱ަn@DOI

AݭnDOADHCP q`OΩϰ@ӳqTwALDnǥѥΤݶǰesʥ]ӪzqҦDA Yϰ DHCP AɡA~|^Τݪ IP ѼƭnDCҥHoADHCP APΤݬOӭnbP@ӪzqC ܩ DHCP ʥ]bAPΤݪӨӦ^^pIUoˡG(1)

12.1-1B

ݨo IP Ѽƪ{ǥiH²ƦpUG

1. ΤݡGQμsʥ]oej DHCP Aʥ]G
   
   YΤݺ]wϥ DHCP wo IP (b Windows y۰ʨo IPz)AhΤݶ}Ϊ̬OsҰʺdɡA ΤݥD|oeXjM DHCP A UDP ʥ]ҦzqqCʥ]ؼ IP |O 255.255.255.255A ҥH@Doӫʥ]|HAYϰ DHCP AɡAh|}li欰C
   
   
2. AݡGѥΤݺHѿܡG
   
   DHCP AboӥΤݪnDA|woӥΤݪw} (MAC) P]wƨӶiUCu@G
   
   
   • AnɤMӥΤᤧeO_gιLY IP AYB IP ثeLHϥΡAhѦ IP ΤݡF
   • Y]wɰw MAC B~Tw IP (static IP) ɡAhѸөTw IP ΤݡF
   • YŦXWzӱAhHΥثeSQϥΪ IP ѼƵΤݡAðOUӡC
   
   `AAݷ|wΤݪnDѤ@պѼƯΤݿܡAѩ󦹮ɥΤݩ| IP A]Aݦ^ʥ]TA DnOwΤݪ MAC ӵ^CɦAݷ|OdoӯM}lݥΤݪ^C
   
   
3. ΤݡGMwܪ DHCP AѪѼƯæ^AG
   
   ѩϰiëDȦ@ DHCP AAΤݶȯ౵@պѼƪC ]ΤݥݭnܬO_n{iӦAѪѼƪCMwnϥΦAѼƯA ΤݫK}lϥγoպѼƨӳ]wۤvҡC~AΤݤ]|oe@Ӽsʥ]ҦzqDA iwgӦACɭYĤGxHW DHCP AAhoǨSQA|^ IP CܩQ DHCP A|~i橳Uʧ@C
   
   
4. AݡGOӦ欰æ^ΤݤwT{^ʥ]TG
   
   AݦΤݪT{ܫAA|^ǽT{^ʥ]AåBiΤݳoӺѼƯA åB}lpɳIӦɷ|ӳQѬ (uiȪr) HAiHo˷QG
   
   
   • ΤuG׬O (ifdown)Bs} (reboot)B (shutdown) 欰AҺOuAAoӮɭ Server ݴN|N IP ^Aé Server ۤvƥΰϤAݥӪϥΡF
     
     
   • ΤݯGe DHCP server ݵo IP ϥΪAΤݨϥγo IP FWwɶAӥBSsX DHCP ӽЮɡANݭnN IP ú^hIoӮɭԴN|y_uCΤ]iHAV DHCP DnDAt IP oC

HWNO DHCP oӨwb Server ݻP Client ݪB@AAѤWoӹB@AӬݡAڭ̥iHoAun Server ݳ]wSDA[W Server P Client bwsuWTwO OK A Client NiHǥ Server ӨoWѼơAMաAunڭ̳oǺ޲znnBT޲znڭ̪ DHCP AA KKIW]w۵MNܦ@²檺ƱաILAWzy{٬O@ǻݭnB~աG

• ---

  DHCP AΤݪ IP ѼƬTwΰʺAG

bWBJ̭A`NĤGBJFܡHNOA|hΤݪ MAC w}AçP_ MAC O_ݭn@өTw IP OIҥHաAڭ̥iH]w DHCP AΤݪ IP ѼƥDnءG

• Tw (Static) IPG
  unӥΤݹqdA MAC ֩wN|ܡAѩ DHCP iHھ MAC ӵTw IP ѼƯAҥHӹqCH@өTw IP sW Internet II oرpAXoΤݹqݭnΨӰѰϰ줺@ǺAȪD (ҥH IP nTw)Cpb Linux WDd MAC OH²աIܦh觋A²檺觋NOϥ ifconfig arp ӶiG
  

  # 1. [ۤv MAC i ifconfigG [root@www ~]# ifconfig | grep HW eth0 Link encap:Ethernet HWaddr 08:00:27:D2:C5:A1 eth1 Link encap:Ethernet HWaddr 08:00:27:BA:54:ED # ]idAҥHӵw}I # 2. [OH MAC i ping tX arp [root@www ~]# ping -c 1 192.168.1.1 [root@www ~]# arp -n Address HWtype HWaddress Flags Mask Iface 192.168.1.1 ether 00:13:49:AF:BB:67 C eth0

  
  
• ʺA (dynamic) IPG
  Client ݨCsW DHCP AҨo IP OTwIg DHCP Hѩ|QϥΪ IP ѡI

DAϰqiΨӰDΡAҥHݭn]wTw IP A_hϥΰʺA IP ]w²AӥBϥΤW㦳ΪuʡC򻡩OHpAO@ ISP nFAӧAuӽШ 150 IP ӰAȤsuΡCAO_uuܶ 150 ϥΪ̡HIMoIڥiHܶ 200 ӨϥΪ̥HWOI

Ho˷QnFAڤѶ}F@a\]A̭u 20 ӮyAO_ڤ@\u浃 20 ӤHOHMOաI]ȤHOHӤHAHYHYAҥHPˬO 20 ӮyAOiH 40 ӤHӦYڪ²\A]Ӫɶ@˹IAѤFܡHIաIAo ISP Mu 150 IP iHoAO]AϥΪ̨ëD 24 pɳbuWAҥHAiHNo 150 IP }ntA 200 ӤHӡyyϥΡzo 150 IP I

ƹW{bDy ADSL eWW]ϥΨyRA IP zPyTw IP zI |ҨӻnFAhinet/seed net Dn ISP ѩҿתGy@өTw IP ft 7~8 ӯB IP z ADSL \A]NOP˳zL@qܽu ISP AO𫟺@ӼOiHoTw IP OI ӨLhODTw IP ADHCP static/dynamic oӪN঳IաI ^_^

• ---

  󯲬ҳyDPG

ǤFIpGڭ[W DHCP B@Ҧĥ|ӨBJAA|o{̫ DHCP Aٷ|@ӯI F٭no˪@ӴOH]w٬OuIաI̤juINOiHקK IP QYǨϥΪ̤@εۡAӨϥΪ̫oO Idle (ob) AI

|ӨҤlӻAڭ̭褣OAڦ 150 IP AOڦ 200 ӥΤܡHڭ̥H 2010 ~@ɬרyɨӻnFC]CӨϥΪ̳ۤWD@ɪA YǼԮɬqNiFϥΦypI]NOAo 200 ӤHPɭnӨϥγo 150 IP AiܡHMiI֩w| 50 ӤHLksuA]yܩpIثetΥbuAЧAyAIz

HoӮɭԯ觋NܦγBաIXӤwgsuiӫܤ[HA N|]ӳQuAoӮɭԸ IP N|QXӡAIjaַmrImĹI ҥHA 50 ӤH (]AQuӪB) un~򪺡BVOB[oӶi DHCP nDoI ^_^""

MOuIAOpGbϥΪ̪רӬݡA٬Oi|yI̤ja@_A ڥsuiӴNݭnQXhHIҥHoApGn ISP A٬OonWnAȪw~I o˧AiHAѯ欰FܡHI ^_^

JMɶAO_Nڥ DHCP o IP NonyʡzbYӮɶIhsos IP OHݭnաI]ثe DHCP Τݵ{jh|Dʪ̾گɶhsӽ IP (renew) I]NObeA DHCP Τݵ{NwgSsӽЧsɶFCҥHD DHCP DIA _hAҨo IP ӬOiH@ϥΤUhI

• ---

  h DHCP AbP@zqp

γ\Ago{L@ƱANOڪ̭ⳡHW DHCP AɡA 쩳@A|ѧڪoΤݹqҵoX DHCP nDHIܩpAͤ]oI ]bWAܦhɭԳOymĹzA DHCP ^]OpI Server1 ^ɡAAϥΪNO Server1 ҴѪѼƤeApGO Server2 ^AANOϥ Server2 Ѽƨӳ]wAΤ PC ILAeUMOoǹqyzsuzOb@_ڡI

]oӯS⪺YAҥHAbm DHCP A]weA nbwg`B@ϺUաA_h|ܺGC|ӳҤlӻnFAY@LtsͦbպwɡA b즳ϺWF@ IP ɾAGAqۡHɤjӪqFI]ɾɤjӪO걵b@_A ӧڭ̾ǮլOϥ DHCP ΤݤWCѩ IP ɾ]wäsW Internet AzIjaLkWFաI AoFܡHnHKհճo DHCP AI

JM DHCP nBOyKΤݳ]wzAӥBʸ˸mW譱D`KIO_NANon[]@ DHCP OHi@wIUӭnijaOXӷʪDA Aˤ@wyݡzuU@ǷOIϥAۤvۤvynzNnաI

• ---

  ϥ DHCP XӮɾ

bYDZpUAˬOjPij[] DHCP DI򱡪pOHҦpG

• 㦳۷hʸ˸mXG
  ҦpAqܦhOqϥΪXI]oصqNOʩʪ˸mA pGC@Ӧa卖nhݤHayޡIAo䪺ѼƬOHzٱon߬O_|Ha IP ۽Ĭ𵥵DIoӮɭԡADHCP iNOAϬPoI
  
  
• ϰ줺qƶq۷hɡG
  t~@ӱpNOAҭtd줺qƶq۷ejɡA jASk@Ӥ@Ӫi满ӳ]wL̦ۤvѼơAoӮɭԬFٳ·СA٬O[] DHCP ӪKoIpBA@@Ax DHCP DAnyXXQӤqHn²檺hI^_^

• ---

  ijϥ DHCP Dɾ

M DHCP ܦhnBAOASo{@ӨBJǩǪrI^Yݤ@UBJ@A Τݦb}ɭԷ|DʪoeTWҦAoӮɭԡApGWNOS DHCP DOHܩpAAoΤݹqAyM|򪺵oeTIz uɶPƤo|h[ALA֩w|WL 30 HWA ƦܥiHF@HWIzIoqɶAFHIFB٬OI ҥHoApGqƤhA٬OϥΤʪ觋ӳ]w@UNnFIKI

• bA줺qAܦhODγ~Aܤ֥ΤݨDAGNSn[] DHCP F
• 󷥺ݪpOA@a̡Au 3 ~ 4 qAoӮɭԡA[] DHCP uளӽmm\OAƹWAèShjįqF
• A޲zAjhdݩªAä䴩 DHCP wɡF
• ܦhϥΪ̪TѳܰA]Sݭn[] DHCP աC

peҭzAWOʪkAƹWA@ƱѨMDOܦhתA SҿתyTzסAuy۹iBåBŦXgٮįqP\zסI ҥHoA[]eAХhoI

DHCP nݨD²ANOunAݳnYiAb CentOS 5.x WAoӳn骺WٴNO dhcp oIpGOw]wˡAoӳnO|w˪AЦۦϥ yum h˦noӳnaIw˧A AiHϥΡy rpm -ql dhcp zӬݬݳoӳn鸪ѤFɮסA򥻤WAnɮ׸ƦpUG

• /etc/dhcpd.conf
  oӴNO dhcp ADn]wɫIbY Linux WYoɮץiणsbAҥHpGATww dhcp no䤣oɮ׮ɡAФʦۦإߥYiC
  dhcp nbXɭԳ|W@ӽdɮסAAiHϥΡy rpm -ql dhcp zӬdߨ dhcpd.conf.sample oӽdɮסAMNɮ׽ƻs /etc/dhcpd.conf AAʥhקYiAo˳]weաI
• /usr/sbin/dhcpd
  Ұʾ dhcp daemon ɰڡI̸ԲӪ觋ӭnϥΡy man dhcpd zӬd\@fOI^_^
  
  
• /var/lib/dhcp/dhcpd.leases
  oɮ׻ᦳ쪺Iڭ̫ezOyzܡHDHCP AݻPΤݯإߪҩlPNOOboɮ׷I

NA²aIӳnƤ]L~pӤwOI

DHCP ]w²ڡAunN dhcpd.conf ]wnNiHҰʤFCLsoɮ׮ɧAndNUWdG

• y # zѲŸF
• FkA ")" ᭱~ALC@]w᳣̫nHy ; zInI
• ]wػykDnGy <ѼƥN> <]we> zAҦpG
  default-lease-time 259200;
• Ydz]wإH option ӳ]wA򥻤觋y option <ѼƥNX> <]we> zҦpG
  option domain-name "your.domain.name";

򥻤WAڭ̭eLA DHCP IP tiʺA IP PTw IP A𫟺SݭnAѪOA pGݭn]wTw IP ܡANnDn]wTw IP qw} (MAC) ~AШϥ arp ifconfig ӬdA MAC aInFAݭn]wئǩOH dhcpd.conf Y]wDnjءA@ӬOAB@]w (Global) @ӬO IP ]wҦ (ʺAΩTw)A CӶت]wȤjUoXG

• ---

  ]w (Global)

]A dhcpd u޲z@ӰϬqϺA򰣤F IP ~\hѼƴNiHb]wϰ줤Ao]ABDNS D IP }BѾ IP }٦ʺA DNS (DDNS) sCTw IP ΰʺA IP SWdYdz]wɡAhH]wȬǡCoǰѼƪ]wW٬G

• default-lease-time ɶG
  ϥΪ̪q]nD@qSwתɶAYϥΪ̨SSOnDɶܡA NHw]ɶC᭱ɶѼƹw]쬰F
  
  
• max-lease-time ɶG
  PWw]ɶALAoӳ]wȬObWdϥΪ̩үnD̤jɶC]NOA ϥΪ̭nDɶYWL]wȡAhHȬǡF
  
  
• option domain-name "W"G
  pGAb /etc/resolv.conf ̭]wF@ӡy search google.com zܡAoܷAnjMDWٮɡA DNS tη|DA[WoӻW٪NC
  
  
• option domain-name-servers IP1, IP2G
  oӳ]wѼƥiHקΤݪ /etc/resolv.conf ɮסINO nameserver ᭱ DNS IP oISO`N]wѼƳ̥yserversz ( s )F
  
  
• ddns-update-style G
  ] DHCP ΤݩҨo IP q`O@ܰʪAҥHYDDWٻP IP NBzC DHCP iHzL ddns (аѦĤQP DNS `) ӧsDWP IP CLڭ̳o̤ͳoFAҥHAiHNL]w none C
  
  
• ignore client-updatesG
  PW@ӳ]wȸAΤݥiHzL dhcpd Aӧs DNS TCLAo̧ڭ̤]ͳoӡA ]NN]w ignore () FC
  
  
• option routers Ѿ}G
  ]wѾ IP ҦbAOoӡy routers zn[ s ~I
  
  

• ---

  IP ]wҦ (ʺAΩTw)

ѩ dhcpd DnOwϰӵ IP ѼƪA]b]w IP eAڭ̱onw@ӰϺ~C wϺ觋ϥΦpUѼơG

ڭ̪DϺn network / netmask IP oӰѼƤ~AҦpe͹LG 192.168.100.0 / 255.255.255.0 o˪]wȡC WY]wȷA subnet P netmask OrAӤjgNWAϺѼoCbA٦Ѽƻݭn]wH NO쩳 IP OTw٬OʺA]wڡG

• range IP1 IP2G
  boӰϺA@ӳs IP sΨӵo񦨰ʺA IP ]wA IP1 IP2 O} IP dC |ҨӻAAQn} 192.168.100.101 192.168.100.200 o 100 IP Ψӧ@ʺAtANOG range 192.168.100.101 192.168.100.200;
  
  
• host DW { ... };
  o host NOwTw IP Tw MAC ]wȡAӥDW٥iHۤvQQAYiC LbjANonw MAC PTw IP oIoӳ]wȫ]wOHݬݩUoG
  
  
  • hardware ethernet w}G
    QκdWTww}ӳ]wAYӳ]wȰwoӵw}ĪNF
    
    
  • fixed-address IP}G
    @өTw IP }NC

]ڪҷALinux DF NAT A~ٱontdLAAҦplA䴩C ӦbݰϰhQn DHCP AȡCӵwtmppPUϩҥܡG

12.2-1BϰspרҥܷN

pWϩҥܡA]ڪ Linux A𫟺 eth1 鷺 eth0 ~AܩLѼƳ]pG

• Linux D鷺 eth1 IP ]w 192.168.100.254 oӡF
• q]w 192.168.100.0/24 o@qABq router 192.168.100.254 A~ DNS D IP عqH 168.95.1.1 Seednet 139.175.10.20 oӡF
• ڷQnCӨϥΪ̹w] 3 ѡA̪ 6 ѡF
• uQnt IP u 192.168.100.101 192.168.100.200 oXӡAL IP hOdUӡF
• ٦@DAL MAC Oy 08:00:27:FD:34:71 zAڭnLDW٬ vbird-inside AB IP 192.168.100.5 oӡC

ڪ]wɴN|UoӼˤlFG

[root@www ~]# vim /etc/dhcpd.conf
# 1. 骺ҳ]w
ddns-update-style            none;            <==ns DDNS ]w
ignore client-updates;                        <==Τݪ DNS s\
default-lease-time           259200;          <==w] 3 
max-lease-time               518400;          <==̤j 6 
option routers               192.168.100.254; <==oNOw]
option domain-name           "centos.vbird";  <==@ӻW
option domain-name-servers   168.95.1.1, 139.175.10.20;
# WO DNS  IP ]wAoӳ]wȷ|קΤݪ /etc/resolv.conf ɮפe

# 2. ʺAt IP
subnet 192.168.100.0 netmask 255.255.255.0 {
    range 192.168.100.101 192.168.100.200;  <==t IP d

    # 3. Tw IP ڡI
    host vbird-inside {
        hardware ethernet    08:00:27:FD:34:71; <==Τݺd MAC
        fixed-address        192.168.100.5;     <==Tw IP
    }
}
# ]wѼƷNqAЬd߫e@p`СAΪ man dhcpd.conf

²aIo˴N]wnFIAiHƻsWYƵMק@UAY IP ѼƲŦXAҡA N]wnA DHCP AFCUӲzפWANҰ dhcp FCLAbYǦ Linux distribution WA A Linux D㦳hӤɡAA@ӳ]wi|hӤPɨӺťANi|oͿ~FC

|ҨӻAڭ̲{b]wO 192.168.100.0/24 oӦb eth1 WYA]A٦@Ӥ eth2 b 192.168.2.0/24 nFA U@A DHCP PɺťܡAQ@QApG 192.168.2.0/24 쪺ΤݵoeX dhcp ʥ]nDɡA L|o IP HMO 192.168.100.X IҥHoAڭ̴Nonw dhcpd oӰɳ]wLťA ӤOwҦťڡIAOaI^_^IpBzOHb CentOS (Red Hat t) iHo˰G

[root@www ~]# vim /etc/sysconfig/dhcpd
DHCPDARGS="eth0"

LoӰʧ@b CentOS 5.x WwgݭnFA]s dhcp |DʪRAqPڪ dhcpd.conf ]wA pG̵LkkXAN|~ܡAHʤƦhFC ^_^IUӧڭ̥iH}lҰ dhcp լݬoI

}lӱҰ dhcp aIbҰʫeAon`NXƱG

• A Linux AҤwg]wnAҦp eth1 wgO 192.168.100.254F
• AWhwgBznAҦp iptables.rule NAT AȤwg]wF

t~An`NOGdhcpd ϥΪfO port 67 AåBҰʪG|Ob /var/log/messages ɮפAA̦nh[@U /var/log/messages ܪ dhcpd T~nC

# 1. Ұʫ[@UfܤơG
[root@www ~]# /etc/init.d/dhcpd start
[root@www ~]# netstat -tlunp | grep dhcp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address PID/Program name
udp        0      0 0.0.0.0:67    0.0.0.0:*       15349/dhcpd
[root@www ~]# chkconfig dhcpd on

# 2. TwhݬݵnɪXT
[root@www ~]# tail -n 30 /var/log/messages
Mar  2 16:11:42 www dhcpd: Internet Systems Consortium DHCP Server V3.0.5-RedHat
Mar  2 16:11:42 www dhcpd: Copyright 2004-2006 Internet Systems Consortium.
Mar  2 16:11:42 www dhcpd: All rights reserved.
Mar  2 16:11:42 www dhcpd: For info, please visit http://www.isc.org/sw/dhcp/
Mar  2 16:11:42 www dhcpd: WARNING: Host declarations are global.  They are not 
limited to the scope you declared them in.
Mar  2 16:11:42 www dhcpd: Wrote 0 deleted host decls to leases file.
Mar  2 16:11:42 www dhcpd: Wrote 0 new dynamic host decls to leases file.
Mar  2 16:11:42 www dhcpd: Wrote 0 leases to leases file.
Mar  2 16:11:42 www dhcpd: Listening on LPF/eth1/08:00:27:f8:91:bd/192.168.100/24
Mar  2 16:11:42 www dhcpd: Sending on   LPF/eth1/08:00:27:f8:91:bd/192.168.100/24
....(HUٲ)....

ݨoǸƴNO\HxաIרOWzSr骺CߧAڡIuOy֮աIzLA U@Aݨ쪺nɬOUҼ˩OH

Mar  2 16:16:50 www dhcpd: /etc/dhcpd.conf line 7: unknown option dhcp.domain-
name-server
Mar  2 16:16:50 www dhcpd: option domain-name-server    168.
Mar  2 16:16:50 www dhcpd:        ^
Mar  2 16:16:50 www dhcpd: /etc/dhcpd.conf line 9: Expecting netmask
Mar  2 16:16:50 www dhcpd: subnet 192.168.100.0 network
Mar  2 16:16:50 www dhcpd:                      ^
Mar  2 16:16:50 www dhcpd: Configuration file errors encountered -- exiting

Wzƪܦb 7, 9 殣ȦI]w~A]w~ab渹U٦ƲŸ (^) SOеXӡI ѤWpӬݡA 7 檺aӬO domain-name-servers ѤF[ s FAӲ 9 hOѼƤUA ӬO netmask ӫD network IoAѥGHpGOX{pUҼ˩OH

** You must add a ddns-update-style statement to /etc/dhcpd.conf.
   To get the same behaviour as in 3.0b2pl11 and previous
   versions, add a line that says "ddns-update-style ad-hoc;"
   Please read the dhcpd.conf manual page for more information. **

oܧAѰOb /etc/dhcpd.conf ̭[J ddns-update-style ѼƫŧiաI @@@oӿXTANoA]w~ҦbAھڿ~ӳBzA dhcp ]wɧaI

pGAJӪ@LĤG¦ܡAٷ|Oo /etc/hosts (ĥ| 4.4.1) |vTqbsuqݮɶaHڲ{bϥ DHCP AV|Iګ򪾹D@ PC sWڪDAng /etc/hosts eOHouO²FINNҦi઺q IP [ihɮקrI ^_^ IHҡAboӨҤlAt IP ܤ֦ 192.168.100.5, 192.168.100.101 ~ 192.168.100.200 AҥH /etc/hosts iHgG

[root@www ~]# vim /etc/hosts
127.0.0.1@@ localhost.localdomain localhost
192.168.100.254   vbird-server
192.168.100.5 @  vbird-inside
192.168.100.101 @dynamic-101
192.168.100.102 @dynamic-102
....(ٲ)....
192.168.100.200   dynamic-200

oˤ@ӡAҦisiӪ IP wgFAIMSjDoI ^_^ILA nѨM׫hO[] DNS AAoˤ@ӡAL Linux A] /etc/hosts NoCD IP PDWٹA˴N[աI

Linux ѼƳ]wٰOoaHOoܴNonѤFIbĥ| (4.2.2) ڭ̽͹L۰ʨo IP 觋A]wu²G

[root@client ~]# vim /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
BOOTPROTO=dhcp  <==NOLIwo@ӴNFI
ONBOOT=yes

[root@client ~]# /etc/init.d/network restart

PɰOonw]Ѫ]wI粒ANNڭ̪ӺsҰʧYi (nϥ ifdown P ifup A]٦w]ѭn]wI)CЪ`NApGAObݶioӰʧ@A Asuy֩w|IzA]dQAFIIҥHЦbe~iIpG檺G쥿T DHCP DAXɮץi|QʳG

# 1. DNS  IP |QʩOId\@U resolv.conf G
[root@client ~]# cat /etc/resolv.conf
; generated by /sbin/dhclient-script
search centos.vbird      <==ٰOo]wL domain-name _H
nameserver 168.95.1.1    <==oNOڭ̦b dhcpd.conf]w
nameserver 139.175.10.20

# 2. [@UѰաI
[root@client ~]# route -n
Kernel IP routing table
Destination    Gateway         Genmask        Flags Metric Ref  Use Iface
192.168.100.0  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
0.0.0.0        192.168.100.254 0.0.0.0        UG    0      0      0 eth0
# ISIѤ]QTFIOKաI

# 3. ݤ@UΤݪOaI
[root@client ~]# netstat -tlunp | grep dhc
Proto Recv-Q Send-Q Local Address  Foreign Address State  PID/Program name
udp        0      0 0.0.0.0:68     0.0.0.0:*              1694/dhclient
# ASݿITOӤp{bʴ DHCP suAoI

# 4. ݤ@ݥΤݯҰOTaI
[root@client ~]# cat /var/lib/dhclient/dhclient-eth0.leases
lease {
  interface "eth0";
  fixed-address 192.168.100.5; <==V server jno IP ]w
  option subnet-mask 255.255.255.0;
  option dhcp-lease-time 259200;
  option routers 192.168.100.254;
  option dhcp-message-type 5;
  option dhcp-server-identifier 192.168.100.254;
  option domain-name-servers 168.95.1.1,139.175.10.20;
  option domain-name "centos.vbird";
  renew 4 2011/3/3 09:22:43; <==U@wps (renew) ɶI
  rebind 5 2011/3/4 15:32:28;
  expire 6 2011/3/5 00:32:28;
}
# oɮ׷|OӤdҴgnDL DHCP TInI
# SݥXӡALXGNPA]w /etc/dhcpd.conf H ^_^

So{AΤݨoƳQOb /var/lib/dhclient/dhclient-eth0.leases YڡH pGAhidACidۤv DHCP nDN|QgJ줣PɦWɮ׷hI [ɮ״NDAƬOpoIoi]OnI

b Windows U]w DHCP wHo IP bO²Iڭ̥Hثe̱`Ϊ Windows XP ӻܡA AiH̾ڡy}lz-->y]wz-->yxz-->yMںsuz-->ysuz-->yϰsuz Ӷ}l@B@BiUʧ@G

1. bIFWϰAAୱWӷ|X{pUϥܡG
   
   
   12.3-1Bϰ Windows XP tγ]w DHCP 觋
   
   
2. b 12.3-1 aUbYҫyezBAN|X{pUeoG
   
   
   12.3-2Bϰ Windows XP tγ]w DHCP 觋
   
   bWeAijAiHbbYҫ 1 BĿ墨ӶءAp@Ӧbୱ̩UkN|X{@ӺŸA HANiHIӹϥܨӶiJoӵeFIKաCMbbY 2 aĿ Internet Protocol (TCP/IP) ءA IyezANiiJ]weC
   
   
3. UӦpUϩҥܡAAunĿy۰ʨo IP }zӶءAMUyTwz}]weA p@ Windows N|}l۰ʨo IP u@FC
   
   
   12.3-3Bϰ Windows XP tγ]w DHCP 觋
   
   
4. ApT{A IP wgQQoOHpGOb Windows 95 AAiHϥΤ@ӦWy winipcfg z [A IP ]wCLb windows 2000 HAAiݭnϥΩROܦr[~CAiHϥΡG y}lz-->y{z-->yε{z-->yROܦrzӨX׺ݾAMo˳BzݬݡG
   

   C:\Documents and Settings\dmtsai> ipconfig /all ....(eٲ).... Ethernet adapter ϰsu: Connection-specific DNS Suffix . : centos.vbird Physical Address. . . . . . . . . : 00-D0-18-AF-6E-81 Dhcp Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes IP Address. . . . . . . . . . . . : 192.168.100.199 Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : 192.168.100.254 DHCP Server . . . . . . . . . . . : 192.168.100.254 <==o@ DHCP D DNS Servers . . . . . . . . . . . : 168.95.1.1 139.175.10.20 Lease Obtained. . . . . . . . . . : 2011~33 U 10:22:37 Lease Expires . . . . . . . . . . : 2011~36 U 10:22:37 C:\Documents and Settings\dmtsai> ipconfig /renew # o˥iHߧYnDs IP TI

   o˴N OK աI²aI

Τݷ|DʪTAAݧ󤣯ѰOOoIAݬOOboӦaG

[root@www ~]# cat /var/lib/dhcpd/dhcpd.leases
lease 192.168.100.200 {
  starts 4 2011/03/03 01:21:29;
  ends 0 2011/03/06 01:21:29;
  binding state active;
  next binding state free;
  hardware ethernet 08:00:27:fd:34:82;
}
lease 192.168.100.105 {
  starts 4 2011/03/03 01:22:45;
  ends 0 2011/03/06 01:22:45;
  binding state active;
  next binding state free;
  hardware ethernet 08:00:27:fd:34:71;

qoɮ׸̭ڭ̴NDh֥ΤݤwgVڭ̥ӽФF DHCP IP ϥΤFOIܮeAѧaI

Q@QApGA@ʥxqn޲zACqƱOTw IP pUAAnpBmH ²AzL DHCP fixed-address NաIOAo@ʥxq MAC poHAnաH DCqhۼgAMA^ӳ]w dhcpd.conf ܡHo]ӥiȤFaHJMCq̲׳on}A Ab}AQΤʪkӳ]wnCD IP AbھکU}ӳBznA dhcpd.conf oI

[root@www ~]# vim setup_dhcpd.conf
#!/bin/bash
read -p "Do you finished the IP's settings in every client (y/n)? " yn
read -p "How many PC's in this class (ex> 60)? " num
if [ "$yn" = "y" ]; then
        for site in $(seq 1 ${num})
        do
                siteip="192.168.42.${site}"
                allip="$allip $siteip"
                ping -c 1 -w 1 $siteip > /dev/null 2>&1
                if [ "$?" == "0" ]; then
                        okip="$okip $siteip"
                else
                        errorip="$errorip $siteip"
                        echo "$siteip is DOWN"
                fi
        done
        [ -f dhcpd.conf ] && rm dhcpd.conf
        for site in $allip
        do
                pcname=pc$(echo $site | cut -d '.' -f 4)
                mac=$(arp -n | grep "$site " | awk '{print $3}')
                echo "  host $pcname {"
                echo "          hardware ethernet ${mac};"
                echo "          fixed-address     ${site};"
                echo "  }"
                echo "  host $pcname {"                         >> dhcpd.conf
                echo "          hardware ethernet ${mac};"      >> dhcpd.conf
                echo "          fixed-address     ${site};"     >> dhcpd.conf
                echo "  }"                                      >> dhcpd.conf
        done
fi
echo "You can use dhcpd.conf (this directory) to modified your /etc/dhcpd.conf"
echo "Finished."

oӸ}Qk²ApGA޲zqO Linux ܡA}ϥΡy ifconfig eth0 YOURIP z ӳ]w IP AboӨҤlAڨϥΪO 192.168.42.X/24 oӰϬqA IP N]wnFI MbzLW}]@ACq MAC P IP NQgJ dhcpd.conf oI MAbNKW /etc/dhcpd.conf YiIpGA޲zqO Windows ܡA ϥΤrUFy netsh interface ip set address xxx zOӭ׭qoI

JMwgDΤݪ MAC }FApGΤݪDŦX@ǹqзǡA åBӥΤݥDҨϥΤd[DO䴩\ɡAڭ̴NiHzLΤݹq}FC pGA@DQnLiHzLӱҰʮɡAAnboΤݹqWiG

1. Aonb BIOS ̭]wyz\A_hOSΪI
2. AӧAnoDWuAåBq]OqC
3. NoD MAC ۤUӡAMݺC

UӽШû}۪D DHCP AW (un@ Linux DiI) Aw net-tools oӳnA N|o ether-wake oӫOAoNODn\IӦpϥγoӫOOH]ΤݥD MAC 11:22:33:44:55:66 nFAAQnoDQANo˰aG

[root@www ~]# ether-wake 11:22:33:44:55:66

# h\iHoˬd\G
[root@www ~]# ether-wake -u

MAN|o{AIΤݥDQҰʤFIHpGAnsϰܡA unsWADAMzLo ether-wake nANAϰDҰʤFA ޤWN[KաIAOaI ^_^

ڭ̪DϰpGܦh Linux AɡAAonN private IP [JCD /etc/hosts ̭A o˦bsuqݮɶ~|OɩΪ̬OݤӤ[DCDOApGqƶqӤjASܦhվɡA oɧAon``hs@ǭL /etc/hosts AФЧoH

ɦbϺ[]@ DNS AtdDWٸѪRNܭnI]JMwg DNS AiDW٪ѪRAAڥݭn /etc/hosts IӪsΪ̬Os骺q]ݭngѼơAo˺@|PܦhC ]A@ӦnϺAzפWAڭӦb DHCP ADWbwˤ@ DNS AAѤqWٸѪRyC ]wNаѦҫ򳹸`oC

• ---

  DHCP ^t׻P switch ]wD

bXsTǼt (http://www.dic.ksu.edu.tw) tdqЫǪ@ACqЫǤ giga switch OCޥ\઺Iޥ\]wThA switch ]iʥ]`PסCDOApGת欰yӶWLzɡA]iy\hDC

޲zqЫǦbsҰʺo DHCP ɡA|ݴXGF 30 AM̲׬O\AOo[OI o IP At׫oSO`A@SDNOоɺѼƳ]wɡAǥͳ|zzsIHѤFA FN@~io IP B`...

ӰݤFg窥pùժA~o{iO switch DCjhb]wyL2 Featuresz-->ySpanning Treez-->ySTP Port SettingszlؤrAN STP f]w (Disabled) ݬݡA oӳ]wADHCP oNZFIsa}\]NSDo]ѵjaѦI