ɨpGAQnnAѼƳ]wA]A IP ѼơBѰѼƻPLuANonAѩUoǬO~I𫟺H
ifconfig route oOOnI ^_^IMAsA@kAiHϥ ip oӷJ㪺Oӳ]w IP ѼưաI
- ifconfig GdߡB]wdP IP
쵥ѼơF
- ifup, ifdownGoɮO
scriptAzL²檺觋ӱҰʺF
- route GdߡB]wѪ
(route table)
- ip GƦXOA
iHקWz쪺\F
5.1.1 /۰ʳ]wPҰ/ IP ѼơG
ifconfig, ifup, ifdown
oTӫOγ~ObҰʺALA ifup P ifdown ȯN /etc/sysconfig/network-scripts
ifcfg-ethX (X Ʀr) iҰʩʧ@AäઽקѼơADʽվ
ifcfg-ethX ɮפ~Cܩ ifconfig hiHʵYӤ IP νվѼơIUڭ̴NOӽͤ@͡I
- ifconfig
ifconfig DnOiHʪҰʡB[PקѼơAiHק諸ѼƫܦhڡA]A IP ѼƥH MTU
iHקALykpUG
[root@www ~]# ifconfig {interface} {up|down} <== [PҰʤ
[root@www ~]# ifconfig interface {options} <== ]wPק虜
ﶵPѼơG
interfaceGdNA]A eth0, eth1, ppp0
options GiHѼơA]ApUG
up, down GҰ (up) (down) Ӻ(AΥѼ)
mtu GiH]wP MTU ƭȡAҦp mtu 1500 (쬰 byte)
netmask GNOlBnF
broadcastGNOs}ڡI
# dҤ@G[Ҧ(J ifconfig)
[root@www ~]# ifconfig
eth0 Link encap:Ethernet HWaddr 08:00:27:F3:5D:23
inet addr:192.168.1.11 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::a00:27ff:fef3:5d23/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:485 errors:0 dropped:0 overruns:0 frame:0
TX packets:143 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:46082 (45.0 KiB) TX bytes:19559 (19.1 KiB)
|
@ӻAJ ifconfig N|CXثewgQҰʪdA׳oӥdO_
IPA|QܥXӡCpGOJ ifconfig eth0 Ah|qXoiơA
ӤӤO_ҰCҥHpGAQnDYid Hardware AddressAJy
ifconfig "N" zYiI ^_^IܩWX{UƬOo˪(ƱƦCѤWӤUBѥӥk)G
- eth0GNOdNA] lo o loopback F
- HWaddrGNOdw}AU٪ MAC O]F
- inet addrGIPv4 IP }A Bcast, Mask ONO
Broadcast P netmask I
- inet6 addrGO IPv6 IP Aڭ̨SϥΡAҥHLF
- MTUGNOĤGͨ쪺
MTU ڡI
- RXG@NOѱҰʨثeʥ]pA
packets Nʥ]ơBerrors Nʥ]oͿ~ƶqB dropped
Nʥ]ѩDӾDƶq
- TXGP RX ۤϡAѱҰʨثeǰepF
- collisionsGNʥ]IpApGoͤӦhA
ܧApӦnF
- txqueuelenGNΨӶǿƪwİϪxsסF
- RX bytes, TX bytesG`Bǰe줸`q
zL[WzơAjPWiHAѨApAרO RX, TX error ƶqA
HάO_oY collision pAOݭn`NI ^_^
# dҤGGȮɭקA eth0 @ 192.168.100.100/24 Ѽ
[root@www ~]# ifconfig eth0 192.168.100.100
# pG[LѼơAhtη|̷Ӹ IP Ҧb class dA
# ۰ʪpX netmask H network, broadcast IP ѼơF
# pGٷQn藍PѼơAiHo˰G
[root@www ~]# ifconfig eth0 192.168.100.100 \
> netmask 255.255.255.128 mtu 8000
# ]wPѼƪAPɳ]w MTU ƭȡI
[root@www ~]# ifconfig eth0 mtu 9000
# ȭקӤ MTU ƭȡALOʡI
[root@www ~]# ifconfig eth0:0 192.168.50.50
# JӬݨӤA eth0:0 INObӺWAA@ӺA
# YOb@idW]wh IP NաI
[root@www ~]# ifconfig
eth0 Link encap:Ethernet HWaddr 08:00:27:F3:5D:23
inet addr:192.168.100.100 Bcast:192.168.100.127 Mask:255.255.255.128
inet6 addr: fe80::a00:27ff:fef3:5d23/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:9000 Metric:1
RX packets:1305 errors:0 dropped:0 overruns:0 frame:0
TX packets:230 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:123306 (120.4 KiB) TX bytes:30671 (29.9 KiB)
eth0:0 Link encap:Ethernet HWaddr 08:00:27:F3:5D:23
inet addr:192.168.50.50 Bcast:192.168.50.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:9000 Metric:1
# JӬݡAO_Pw驰TۦPڡISI]OP@idI
# pGQnNإߪi eth0:0 NnAvT즳 eth0 OH
[root@www ~]# ifconfig eth0:0 down
# eth0:0 oӤCpGQιw]ȱҰ eth1Gyifconfig eth1 upzYiF
# dҤTGNʪBzAϥέ즳]wȭغѼơG
[root@www ~]# /etc/init.d/network restart
# ]wƥġA|H ifcfg-ethX ]wDI
|
ϥ ifconfig iHȮɤʨӳ]wέקYӤd\AåB]iHzL eth0:0
oصӳ]wn@idWh IP Iʪ觋uO²ڡIåB]w~]A]ڭ̥iHQ
/etc/init.d/network restart
ӭsҰʾӺAeʪ]wƷ|ijIt~A
nҰʬYӺASL㦳 IP ѼƮɡAL ifconfig eth0 up YiI
oӰʧ@g`bLud|iA]ڭ̥nҰʵLudLh AP
sbP_ڡI
- ifup, ifdown
Yɪʭק@ǺѼơAiHQ ifconfig ӹFApGOnH]wɡA
YOb /etc/sysconfig/network-scripts ̭ ifcfg-ethx ɮת]wѼƨӱҰʪܡA
NonzL ifdown ifup ӹFFC
[root@www ~]# ifup {interface}
[root@www ~]# ifdown {interface}
[root@www ~]# ifup eth0
|
ifup P ifdown uO²FIo{O script ӤwAL| /etc/sysconfig/network-scripts
ؿUjM]wɡAҦp ifup eth0 ɡAL|X
ifcfg-eth0 oɮתeAMӥ[H]wC
ifcfg-eth0 ]whаѦĥ|C
LAѩo{DnOjM]w (ifcfg-ethx) ӶiҰʻPA
ҥHbϥΫeнTw ifcfg-ethx O_usbTؿA_h|ҰʥѳI
t~ApGH ifconfig eth0 .... ӳ]wΪ̬OקFA
NLkAH ifdown eth0 觋FI] ifdown |RثeѼƻP ifcfg-eth0
O_۲šAŪܡAN|Ӧʧ@C]Aϥ ifconfig ק粒AӭnH
ifconfig eth0 down ~ӤI
5.1.2 ѭקG route
ڭ̦bĤG¦ɭԽLѪDA
ⳡD@wnѤ~q TCP/IP wA_hNLkisuڡI@ӻAunA
ӤN|ͤ@ӸѡAҥHڭ̦w˪D@ eth0 Aݰ_ӴN|OoˡG
[root@www ~]# route [-nee]
[root@www ~]# route add [-net|-host] [ΥD] netmask [mask] [gw|dev]
[root@www ~]# route del [-net|-host] [ΥD] netmask [mask] [gw|dev]
[ѼơG
-n GnϥγqTwΥDW١Aϥ IP port numberF
-ee GϥΧԲӪT
W[ (add) PR (del) ѪѼơG
-net Gܫ᭱Ѭ@ӺF
-host Gܫ᭱s泡DѡF
netmask GP즳AiH]w netmask Mw쪺jpF
gw Ggateway ²gAO IP ƭȳAP dev PF
dev GpGuOnwѨ@dsuXhAhϥγoӳ]wA᭱ eth0
# dҤ@Gª[ѪA
[root@www ~]# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
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
0.0.0.0 192.168.1.254 0.0.0.0 UG 0 0 0 eth0
[root@www ~]# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 * 255.255.255.0 U 0 0 0 eth0
169.254.0.0 * 255.255.0.0 U 0 0 0 eth0
default gateway.vbird 0.0.0.0 UG 0 0 0 eth0
|
ѤWҤlJ[ route P route -n XGAAiHo{[ -n ѼƪDnOܥX IP Aܩϥ
route ӤwܡAܪhOyDW١zI]NOAbw]pUA route |hX IP DW١ApG䤣OH
N|ܪww(IpC)AҥHAq`ϥ route -n աI
ѤWݰ_ӡAڭ̤]D default = 0.0.0.0/0.0.0.0 A
ӤWTǧAnDOH
- Destination, GenmaskGoӪNNOOO network P
netmask աIҥHoөNNNզX@ӧ㪺oI
- GatewayGӺOqL gateway sXhHpG 0.0.0.0
ܸӸѬOѥǰeAYiHzLϰ MAC ǰTFpG IP
ܡAܸӸѻݭngLѾ (qTh) ~ǰeXhC
- FlagsG`@hӺXСANNqpUG
- U (route is up)GӸѬOҰʪF
- H (target is a host)GؼЬO@D (IP) ӫDF
- G (use gateway)GݭnzL~D (gateway) ʥ]F
- R (reinstate route for dynamic routing)GϥΰʺAѮɡA_ѸTXСF
- D (dynamically installed by daemon or redirect)GwgѪAȩ port \]wʺA
- M (modified from routing daemon or redirect)GѤwgQקFF
- ! (reject route)GoӸѱN|Q(ΨөפwI)
- IfaceGoӸѶǻʥ]C
~A[@UWѱƦCdzA̧ǬOѤp
(192.168.1.0/24 O Class C)Avj (169.254.0.0/16 Class B) ̫hOw] (0.0.0.0/0.0.0.0)C
Mڭ̭nP_YӺʥ]ӦpǰeɭԡAӫʥ]|gѳoӸѪL{ӧP_I
|ҨӻAڤWYȦTӸѡAYڦ@Ӷǩ 192.168.1.20 ʥ]nǻA| 192.168.1.0/24
oӺ쪺ѡAFIҥH eth0 ǰeXhF
pGOǰe Yahoo DOH Yahoo D IP O 119.160.246.241Aڭ̳qLP_ 1)O 192.168.1.0/24A
2)O 169.254.0.0/16 GF 3)0/0 ɡAOKIǥXhFAzL eth0 Nʥ]ǵ 192.168.1.254
gateway DڡIҥHAѬOǪC
]AƳ]whӦP˪ѮɡA
ҦpbADWid]wۦP쪺 IP ɡA|X{pH|X{pUpG
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
|
]NOAѩѬO̷ӶǨӱƦCPǰeA
ҥHʥ]OѨӤ (eth0, eth1) ұA|ѤWz eth0 ǰeXhA
ҥHAb@DW]wӬۦP쪺 IP SNqIIh@|NOFC
DOD (Xen, VMware n) Ҭ[]hDɡA~|oӥn
# dҤGGѪW[PR
[root@www ~]# route del -net 169.254.0.0 netmask 255.255.0.0 dev eth0
# WoӰʧ@iHR 169.254.0.0/16 oӺI
# Ъ`NAbRɭԡAݭnNѪWX{TgJ
# ]A netmask , dev ѼƳI`N`N
[root@www ~]# route add -net 192.168.100.0 \
> netmask 255.255.255.0 dev eth0
# zL route add ӼW[@ӸѡIЪ`NAoӸѪ]wnPAqC
# |ҨӻApGڤUFUON|ܿ~G
# route add -net 192.168.200.0 netmask 255.255.255.0 gw 192.168.200.254
# ]ڪDȦ 192.168.1.11 o IP AҥHઽP 192.168.200.254
# oӺqϥ MAC qIo˻AiHzѶܡH
[root@www ~]# route add default gw 192.168.1.250
# W[w]ѪkIЪ`NAun@ӹw]ѴNFI
# P˪A 192.168.1.250 IP ]ݭnPA LAN q~I
# boӦapGAHK]wAOoϥΩUOs]wA
# /etc/init.d/network restart
|
pGOniѪRPW[ANonѦҤWҤlFAAϥ man route ̭ƴN״IFIJӬd\@UoI
AunOoAX{ySIOCADDRT: Network is unreachablez
oӿ~ɡA֩wOѩ gw ᭱ IP LkPA췾q (Gateway äbA줺)A
ҥHAˬd@UO_J~ڡI
@ӻApGIJ@ӷsҤDAbQnʭtΪ]wɱpUAMwpϥΥѪҳ]wɡA
ʪBzNܦGy
ifconfig eth0 192.168.1.11;
route add default gw 192.168.1.254zo˴NdwFI
pPաC짹իAAo /etc/init.d/network restart _tΪYiC
5.1.3 ѼƺXOG ip
ip OӫOIäO TCP/IP IP աIo ip O\ihFIWALNOXF ifconfig P route
oӫOo㤣LA ip iHF\oShhIuOӬ۷F`OCpGA쪺ܡAЦۦ
vi /sbin/ifup AND ifup NOQ ip oӫOӹFCnFApϥΩOHڭ̨@@@I
[root@www ~]# ip [option] [ʧ@] [O]
ﶵPѼơG
option G]wѼơADnG
-s GܥXӸ˸mέpƾ(statistics)AҦp`ʥ]ƵF
ʧ@GYOiHwǺѼƶiʧ@A]AG
link G˸m (device) ]wA]A MTU, MAC }
addr/address GB~ IP wAҦph IP FF
route GPѦ]w
|
ѤWykڭ̥iHDA ip FiH]w@ǰѼƤ~AٯiB~ IP wA]Ah IP
FAuOӧFIUڭ̴NTӳ (link, addr, route) Ӥгo ip OaI
- ˸m (device) ]wG ip link
ip link iH]wP˸m (device) ѼơA]A MTU HθӺ MAC AM]iHҰ (up)
(down) YӺաIӻykOo˪G
[root@www ~]# ip [-s] link show <== ªd\Ӹ˸mT
[root@www ~]# ip link set [device] [ʧ@PѼ]
ﶵPѼơG
showGܥXoӸ˸meApG[W -s |ܧhέpƾڡF
set GiH}l]wءA device O eth0, eth1 NF
ʧ@PѼơG]AUoǰʧ@G
up|down GҰ (up) (down) YӤALѼƨϥιw]AӺF
address GpGoӸ˸miH MAC ܡAγoӰѼƭקI
name GoӸ˸m@ӯSWrF
mtu GNO̤jǿ椸ڡI
# dҤ@GܥXҦT
[root@www ~]# ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
link/ether 08:00:27:f3:5d:23 brd ff:ff:ff:ff:ff:ff
3: sit0: <NOARP> mtu 1480 qdisc noop
link/sit 0.0.0.0 brd 0.0.0.0
[root@www ~]# ip -s link show eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
link/ether 08:00:27:f3:5d:23 brd ff:ff:ff:ff:ff:ff
RX: bytes packets errors dropped overrun mcast
438038 4511 0 0 0 0
TX: bytes packets errors dropped carrier collsns
104983 769 0 0 0 0
|
ϥ ip link show iHܥXӸ˸mwTApWҥܡA]Ad}(MAC)BMTUA
쪺ӬO sit0 FA sit0 OΦb IPv4 IPv6 ʥ]ഫWA
ڭ̶Ȩϥ IPv4 OS@ΪC lo sit0 ODҦۦ]wC
ӦpG[W -s ѼƫAhoӺdέpTN|QCXӡA
]A (RX) ζǰe (TX) ʥ]ƶqAԲӪeP ifconfig ҿXGۦPC
# dҤGGҰʡBP]w˸mT
[root@www ~]# ip link set eth0 up
# Ұ eth0 oӸ˸mF
[root@www ~]# ip link set eth0 down
# NڡI²檺nR
[root@www ~]# ip link set eth0 mtu 1000
# MTU ȡAF 1000 bytesANO bytes ڡI
|
sd MTU ϥ ifconfig ]iHFڡISԣF_ALApGOnydNB
MAC }TzܡAiNoϥ ip o㤣LA]weonӺdA_h|\C
pUҥܡG
# dҤTGקdNBMAC Ѽ
[root@www ~]# ip link set eth0 name vbird
SIOCSIFNAME: Device or resource busy
# ]Ӹ˸mثeOҰʪAҥHo˰]wCAӭno˰G
[root@www ~]# ip link set eth0 down <==
[root@www ~]# ip link set eth0 name vbird <==s]w
[root@www ~]# ip link show <==[@U
2: vbird: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
link/ether 08:00:27:f3:5d:23 brd ff:ff:ff:ff:ff:ff
# ȤFaIsdNiHܡILAOo^ӰڡI
# ]ڭ̪ ifcfg-eth0 ٬Oϥέ쥻˸mNIקKDAn^
[root@www ~]# ip link set vbird name eth0 <==^
[root@www ~]# ip link set eth0 address aa:aa:aa:aa:aa:aa
[root@www ~]# ip link show eth0
# pGAd䴩w} (MAC) iH諸ܡA
# WoӰʧ@NiHAd}FIF`aI
# LA٬OyѸܡAէХߨ^ӰڡI
|
boӸ˸mwT]wWA]A MTU, MAC Hζǿ骺ҦAiHbo̳]wC
쪺O address ءAӶث᭱iOw} (MAC) ӤO IP I
ܮedڡIOOIhwѼƥiHϥ man ip d\@UP ip link ]wC
- B~ IP ]wG ip address
pG ip link OP OSI Chw
ĤGhƳshܡA ip address (ip addr) NOPĤThhѼưաI
DnOb]wP IP UѼơA]A netmask, broadcast C
[root@www ~]# ip address show <==NOd\ IP ѼưڡI
[root@www ~]# ip address [add|del] [IPѼ] [dev ˸mW] [Ѽ]
ﶵPѼơG
show GªܥX IP TڡF
add|del GiѼƪW[ (add) ΧR (del) ]wADnG
IP ѼơGDnNO쪺]wAҦp 192.168.100.100/24 ]wF
dev Go IP ѼƩҭn]wAҦp eth0, eth1 F
ѼơGDnUoǡG
broadcastG]ws}ApG]wȬO + ܡytΦ۰ʭpz
label GYOoӸ˸mOWAҦp eth0:0 NOFI
scope GoӤAq`OoXӤjG
global G\Ӧ۩ҦӷsuF
site GȤ䴩 IPv6 AȤ\DsuF
link GȤ\˸mۧڳsuF
host GȤ\DsuF
ҥHMOϥ global oIw]]O global աI
# dҤ@GܥXҦ IP ѼơG
[root@www ~]# ip address show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
link/ether 08:00:27:f3:5d:23 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.11/24 brd 192.168.1.255 scope global eth0
inet6 fe80::a00:27ff:fef3:5d23/64 scope link
valid_lft forever preferred_lft forever
3: sit0: <NOARP> mtu 1480 qdisc noop
link/sit 0.0.0.0 brd 0.0.0.0
|
ݨWӯSrܡHSINO IP ѼưաI]O ip address ̥Dn\C
Uڭ̶i@BӷsWլݬݡG
# dҤGGsW@ӤAWٰ] eth0:vbird
[root@www ~]# ip address add 192.168.50.50/24 broadcast + \
> dev eth0 label eth0:vbird
[root@www ~]# ip address show eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
link/ether 08:00:27:f3:5d:23 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.11/24 brd 192.168.1.255 scope global eth0
inet 192.168.50.50/24 brd 192.168.50.255 scope global eth0:vbird
inet6 fe80::a00:27ff:fef3:5d23/64 scope link
valid_lft forever preferred_lft forever
# ݨWSrFaHhXF@sABW٬O eth0:vbird
# ܩ broadcast + ]iHg broadcast 192.168.50.255 աI
[root@www ~]# ifconfig
eth0:vbird Link encap:Ethernet HWaddr 08:00:27:F3:5D:23
inet addr:192.168.50.50 Bcast:192.168.50.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
# pGϥ ifconfig NݨoөǪFFIiRaI ^_^
# dҤTGN𫍧R
[root@www ~]# ip address del 192.168.50.50/24 dev eth0
# RN²ڡI ^_^
|
- Ѫ]wG ip route
oӶطMNOѪ[P]woIƹWA ip route \XGP route
oӫOthAOAL٥iHiB~ѼƳ]pAҦp MTU WA۷jڡI
[root@www ~]# ip route show <==ªܥXѪ]wӤw
[root@www ~]# ip route [add|del] [IPκ] [via gateway] [dev ˸m]
ﶵPѼơG
show GªܥXѪA]iHϥ list F
add|del GW[ (add) ΧR (del) ѪNC
IPκGiϥ 192.168.50.0/24 Ϊ̬Oª IP F
via Gq gateway XhA@wݭnF
dev GѨӸ˸msXhAoNݭnFI
mtu GiHB~]w MTU ƭȳI
# dҤ@GܥXثeѸ
[root@www ~]# ip route show
192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.11
169.254.0.0/16 dev eth0 scope link
default via 192.168.1.254 dev eth0
|
pWҥܡA²檺\NOܥXثeѸTA route oӫOۦPաI
ܥn`NXӤpFG
- protoGѪѨwADn redirect, kernel, boot, static, ra A
𫟺 kernel OѮ֤ߧP_۰ʳ]wC
- scopeGѪdADnO link AYOP˸msuC
AӬݤ@UpiѪW[PRaI
# dҤGGW[ѡADnOiq
[root@www ~]# ip route add 192.168.5.0/24 dev eth0
# w糧q]wnѡAݭnzL~Ѿ
[root@www ~]# ip route show
192.168.5.0/24 dev eth0 scope link
....(HUٲ)....
# dҤTGW[iHq~ѡAݳzL router I
[root@www ~]# ip route add 192.168.10.0/24 via 192.168.5.100 dev eth0
[root@www ~]# ip route show
192.168.5.0/24 dev eth0 scope link
....(Lٲ)....
192.168.10.0/24 via 192.168.5.100 dev eth0
# JӬݳA]ڦ 192.168.5.0/24 Ѧsb (ڪdpô)A
# ҥH~iHN 192.168.10.0/24 ѥᵹ 192.168.5.100
# DǻIPe쪺 route OO@˪I
# dҥ|GW[w]
[root@www ~]# ip route add default via 192.168.1.254 dev eth0
# 192.168.1.2 NOڪw]Ѿ (gateway) NڡI ^_^
# uOoAun@ӹw]ѴN OK I
# dҤGR
[root@www ~]# ip route del 192.168.10.0/24
[root@www ~]# ip route del 192.168.5.0/24
|
ƹWAo ip ObOӳդj`FI𫎆IJ Linux B͡Ai|ݨ즳Iw
nաIA|ϥ ifconfig, ifup , ifdown P route YiA
HᦳgFAA~^Ӫ ip oӦnOaI ^_^
쪺ܡA]iHۦѦ ethtool oӫOI (man ethtool)C
5.1.4 LuG iwlist, iwconfig
oӫOAnLud~iIoӫOγ~Oo˪G
- iwlistGQεLudiLu AP PoơF
- iwconfigG]wLudѼơC
oӫOΧڭ̦be@̭Lud]wͤFܦhFA
ҥHo̧ڭ̤AԽ͡A쪺Bӥϥ man iwlist P man iwconfig AѤ@UykA
MAe@Lup`d@dΪkANAѤFաI ^_^
5.1.5 ʨϥ DHCP ۰ʨo IP ѼơG
dhclient
pGAOϥ DHCP wbϰo IP ܡAO_@wnhs ifcfg-eth0 BOOTPROTO OH
KKIӧֳt@kANOQ dhclient oӫO]oӫO~Ouoe dhcp
nDu@{ڡInpϥΩOH²IpGҼ{LѼơAϥΩUkYiG
[root@www ~]# dhclient eth0
|
²aIo˴NiHߨsڭ̪dH dhcp whըo IP I
bU¤A̱`ť쪺@yܴNOGyDϡIڪ
Linux sWFIzڪѧoIW]hܡIӭnd]O@²檺ƱOI
LAƹWڭ̥iHۤvϥδճnӰlܥi~]AӫܦhOb
Linux Ywgw]sbFAunAnnǤ@ǰOA@ǪBͦbiDApɭԡA
AӴNߨiHDpӷdwLoI
ڭ̦bĥ|ͨ쪺ˬdBJwgO۷ԲӪy{FI
uO٦ǭnO]onAѤ@U~nI
5.2.1 ⳡDIqG ping
o ping OܭnOAping DnzL ICMP ʥ]
ӶiӺpiAMաA̭nNO ICMP type 0, 8 oA
OOnD^PDʦ^AO_sbSʡCnSO`NOA ping ٬OݭnzL
IP ʥ]Ӷǰe ICMP ʥ]A
IP ʥ]̭Ӭ۷n TTL ݩʡAoOܭn@ӸѯSʡA
ԲӪ IP P ICMP YƽаѦĤG¦ԲӤСC
[root@www ~]# ping [ﶵPѼ] IP
ﶵPѼơG
-c ƭȡG᭱O ping ơAҦp -c 5 F
-n GbXƮɤi IP PDW٪ϬdAϥ IP X(t)F
-s ƭȡGoeXh ICMP ʥ]jpAw] 56bytesALAiHj@ƭȡF
-t ƭȡGTTL ƭȡAw]O 255ACgL@Ӹ`IN|֤@F
-W ƭȡGݦ^DơC
-M [do|dont] GDnb MTU ƭȤjpAӱ`جOG
do GNǰe@ DF (Don't Fragment) XСAʥ]୫s]P]F
dontGNnǰe DF XСAܫʥ]iHbLDW]P]
# dҤ@G@U 168.95.1.1 o DNS DO_sbH
[root@www ~]# ping -c 3 168.95.1.1
PING 168.95.1.1 (168.95.1.1) 56(84) bytes of data.
64 bytes from 168.95.1.1: icmp_seq=1 ttl=245 time=15.4 ms
64 bytes from 168.95.1.1: icmp_seq=2 ttl=245 time=10.0 ms
64 bytes from 168.95.1.1: icmp_seq=3 ttl=245 time=10.2 ms
--- 168.95.1.1 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2047ms
rtt min/avg/max/mdev = 10.056/11.910/15.453/2.506 ms
|
ping ²檺\NOǰe ICMP
ʥ]hnDD^O_sbҤAW^TAXӭnجOo˪G
- 64 bytesGܳoǰe ICMP ʥ]jp 64 bytes ojAoOw]ȡA
bYǯSXAҦpnjӺ̤j MTU ɡAiHϥ -s 2000 ƭȨӨNF
- icmp_seq=1GICMP Ұi檺ơAĤ@s 1 F
- ttl=243GTTL P IP ʥ] TTL OۦPACgL@ӱa MAC
`I (node) ɡAҦp router, bridge ɡA TTL N|֤@Aw] TTL 255 A
AiHzL -t 150 kӭs]ww] TTL ƭȡF
- time=15.4 msG^ɶA즳 ms(0.001) us(0.000001)A
@ӻAVp^ɶAܨⳡDsuV}nI
pGAѰO[W -c 3 o˪WwơANonϥ [ctrl]-c NLFI
|
DG
g@}{ ping.sh AzLo}{AAiH ping Ӻ쪺DO_^C~ACDȵݤ@A]Ȱ@C
G
ѩȰ@Bݤ@A] ping ﶵG -W1 -c1 AӦҦbϺ 192.168.1.0/24 AҥHiHo˼gG
#!/bin/bash
for siteip in $(seq 1 254)
do
site="192.168.1.${siteip}"
ping -c1 -W1 ${site} &> /dev/null
if [ "$?" == "0" ]; then
echo "$site is UP"
else
echo "$site is DOWN"
fi
done
|
SO`N@UApGADPݰDäbP@Ӻ줺A
TTL w]ϥ 255 ApGOP@Ӻ줺A TTL w]hϥ 64 I
- ping lܸ|̤j MTU ƭ
ڭ̥ѲĤG¦̭ͨ[jT (frame) ɡA
įOUA]ʥ]]Ʒ|֡A[WpGӶǿ骺C鳣o frame
Ӥݭnsiʥ]ѻPժܡAįM|nAӭק frame jpѼƴNO
MTU աI
nFA{bڭ̪Dd MTU קiHzL ifconfig Ϊ̬O ip
OӹFAlܾӺǿ骺̤j MTU ɡASӦpdߡHI²檺kMOzL ping ǰe@Ӥjʥ]A
åB\~Ѿ switch Nӫʥ]աANBzաISIiHo˪G
# dҤGGX̤j MTU ƭ
[root@www ~]# ping -c 2 -s 1000 -M do 192.168.1.254
PING 192.168.1.254 (192.168.1.254) 1000(1028) bytes of data.
1008 bytes from 192.168.1.254: icmp_seq=1 ttl=64 time=0.311 ms
# pG^ANOiHoӫʥ]ApGL^ANܳo MTU ӤjFC
[root@www ~]# ping -c 2 -s 8000 -M do 192.168.1.254
PING 192.168.1.254 (192.168.1.254) 8000(8028) bytes of data.
From 192.168.1.11 icmp_seq=1 Frag needed and DF set (mtu = 1500)
# oӿ~TOAaݪ MTU ~ 1500 ӤwAAn 8000 MTU
# ڥNOLkFInpOnHΫe@p`Ъ ip link Ӷi MTU ]waI
|
LAAݭnDOAѩ
IP ʥ]Y (t options) NwgΤF 20 bytes
AA[W ICMP Y 8 bytes AҥHMAbϥ -s size
ɭԡAӫʥ]jpNon (20+8=28) jpFC
]pGnϥ MTU 1500 ɡANonUFy ping -s 1472 -M do xx.yy.zz.ip z~I
t~Aѩaݪd MTU ]|vT찻AҥHpGQnӶǿC骺 MTU ƭȡA
CӥiHվ㪺DNonϥ ifcofig ip N MTU դjAMAhi氻A
_hN|X{WѪרҤ@ˡAi|X{~TI
Lo MTU nHKվڡIDuDCq`վ MTU ɶOboӮɭԡG
- ]DsObϺAҦpO[c (cluster) ҤUA
ѩ`IOڭ̥iHA]iHzLק MTU ӼWiįF
- ]@~tιw] MTU PA줣šAɭPYǺiHQsuAYǺhLksuC
H Windows @~tΧ@suɪDɡAb Client ݮeoͳoӰDF
pGOnsW Internet DA`NnHKվ MTU A]ڭ̵LkD Internet
WC䴩 MTU hjA]......Oڭ̯ު쪺 ^_^I
t~ACسsu觋P MTU ȡA`Uؤ MTU ȤOJ
| MTU |
| Ethernet | 1500 |
| PPPoE | 1492 |
| Dial-up(Modem) | 576 |
5.2.2 DU`IRG traceroute
ڭ̫eͨ쪺OjhƳOwDѼƳ]wһݭnA ping OⳡD^nP_P_A
SOiHlܨⳡDqLUӸ`I (node) qTpnaOH|ҨӻApGڭ̳su yahoo
tפ`CAAıoO (1)ۤvҦDH (2)٬O~ Internet DHpGO (1)
ܡAڭ̷MݭnˬdۤvҰڡAݬݬO_S֤rFHpGO Internet DOHuyzڡI
P_O (1) ٬O (2) Nonϥ traceroute oӫOաI
[root@www ~]# traceroute [ﶵPѼ] IP
ﶵPѼơG
-n GiHiDWٸѪRA¥ IP At֡I
-U Gϥ UDP port 33434 Ӷi氻AoOw]wF
-I Gϥ ICMP 觋Ӷi氻F
-T Gϥ TCP Ӷi氻A@ϥ port 80
-w GYDbXS^nNŧiv...w]O 5
-p GYQϥ UDP P TCP w]ӰAibܰC
-i ˸mGΦbҡApGAܦhܽɡA~|ΨoӰѼơF
|ҨӻAA ADSL iHs~AAD| pppA
AiHϥ -i ӿܬO ppp0 ٬O ppp1 աI
-g ѡGP -i ѼƬۥAuO -g ᭱O gateway IP NOFC
# dҤ@G yahoo hU`IsuA
[root@www ~]# traceroute -n tw.yahoo.com
traceroute to tw.yahoo.com (119.160.246.241), 30 hops max, 40 byte packets
1 192.168.1.254 0.279 ms 0.156 ms 0.169 ms
2 172.20.168.254 0.430 ms 0.513 ms 0.409 ms
3 10.40.1.1 0.996 ms 0.890 ms 1.042 ms
4 203.72.191.85 0.942 ms 0.969 ms 0.951 ms
5 211.20.206.58 1.360 ms 1.379 ms 1.355 ms
6 203.75.72.90 1.123 ms 0.988 ms 1.086 ms
7 220.128.24.22 11.238 ms 11.179 ms 11.128 ms
8 220.128.1.82 12.456 ms 12.327 ms 12.221 ms
9 220.128.3.149 8.062 ms 8.058 ms 7.990 ms
10 * * *
11 119.160.240.1 10.688 ms 10.590 ms 119.160.240.3 10.047 ms
12 * * * <==i˸mpoͩҭP
|
o traceroute N䪺AoӫO|wsتaҦ node i UDP OɵݡA
ҦpWҤlAѳDs Yahoo ɡAL|gL 12 Ӹ`IHWAtraceroute |Dʪo
12 Ӹ`I UDP ^nݡAð^ЪɶAC`ITA̲צ^ǹWYܪGC
AiHo{CӸ`I^Ъɶjb 50 ms HAO٥iH Internet ҤFC
SO 10/12 ӡA|^ǬPAN node i]YǨ@IAڭ̵oeʥ]TQҭPC
]ڭ̬OzLѾʥ]AèSiJѾhoѾϥθ귽AҥHYǸѾȤ䴩ʥ]A
ä|ӦۥΤݪUաIɴN|X{WzDC] traceroute w]ϥ UDP ʥ]ApGAQըϥΨLʥ]A
-I -T iHլݬoI
ѩثe UDP/ICMP hXaA]ܦhѾiNoӫʥ]^\CҥHڭ̥iHϥ TCP ӰI
ҦpϥΦP˪kAzLݮɶ 1 AH TCP 80 fpUAiHo˰G
[root@www ~]# traceroute -w 1 -n -T tw.yahoo.com
|
5.2.3 ݥsuPG netstat
pGAıoAYӺAȩNҰʤFAONOLkysuܡAӫH
Aӭndߤ@UۤvҺťf (port) ӬݬݬO_uҰʡA]ɭԿùWܪ [OK]
ä@wO OK ڡI ^_^
[root@www ~]# netstat -[rn] <==PѦѼ
[root@www ~]# netstat -[antulpc] <==PѼ
ﶵPѼơG
P (route) ѼƻG
-r GCXѪ(route table)A\pP route oӫOF
-n GϥΥDWٻPAȦW١Aϥ IP P port number ApP route -n
PѼơG
-a GCXҦsuAA]A tcp/udp/unix socket F
-t GȦCX TCP ʥ]suF
-u GȦCX UDP ʥ]suF
-l GȦCXb Listen (ť) AȤAF
-p GCX PID P Program ɦWF
-c GiH]wX۰ʧs@AҦp -c 5 Cs@AܡF
# dҤ@GCXثeѪAABH IP port number ܡG
[root@www ~]# netstat -rn
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
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
0.0.0.0 192.168.1.254 0.0.0.0 UG 0 0 0 eth0
# oӰѼƴN route -n @Ҥ@ˡAaIoO netstat Dn\աI
# dҤGGCXثeҦsuAAϥ IP P port number
[root@www ~]# netstat -an
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State
....(ٲ)....
tcp 0 0 127.0.0.1:2207 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:735 0.0.0.0:* LISTEN
tcp 0 0 :::22 :::* LISTEN
tcp 0 132 192.168.1.11:22 192.168.201.101:1865 ESTABLISHED
udp 0 0 192.168.1.11:137 0.0.0.0:*
udp 0 0 0.0.0.0:137 0.0.0.0:*
....(ٲ)....
Active UNIX domain sockets (servers and established)
Proto RefCnt Flags Type State I-Node Path
unix 2 [ ACC ] STREAM LISTENING 10098 /tmp/.X11-unix/X0
unix 2 [ ACC ] STREAM LISTENING 10571 @/tmp/fam-root-
....(Uٲ)....
|
netstat XDnjAOO TCP/IP AHζDzΪ Unix socket C
ٰOoڭ̦b¦g̭gͨɮתܡH socket P FIFO ɮٰOoaH
NOb Unix ΨӰ{ƥyFA]NOWY椺ݨ쪺 Active Unix domain sockets eo
q`Oij[Wy -n zoӰѼƪA]iHLDWٻPAȦW٪ϬdAH IP
ΰfX (port number) ܡAܪtפW|֫ܦhIܩbXTA
ڭ̥ӽͤ@suAXALDnOUXӤjG
- ProtoGӳsuʥ]wADn TCP/UDP ʥ]F
- Recv-QGDѨϥΪ̵{sҽƻsӨӪ` bytes ơF
- Send-QGѻݥDҶǰeӨӡA㦳 ACK лx` bytes ơA
NDʳsu SYN ΨLлxʥ]Ҧ bytes ơF
- Local AddressGaݪ}AiHO IP (-n ѼƦsb)A
]iHO㪺DW١CϥΪONOy IP:port zuO IP 榡 IPv4 IPv6 tC
pWҥܡAb port 22 AϥΪ :::22 NOw IPv6 ܡAƹWLNۦP 0.0.0.0:22 NC
ܩ port 2207 Ȱw lo }AN Internet WOLksڥ 2207 fաI
- Foreign AddressGݪD IP P port number
- statGACADnAtG
- ESTABLISEDGwإ߳suAF
- SYN_SENTGoXDʳsu (SYN лx) suʥ]F
- SYN_RECVG@ӭnDsuDʳsuʥ]F
- FIN_WAIT1GӴѪA(socket)w_Aӳsub_uF
- FIN_WAIT2Gӳsuw_AbݹD^_uT{ʥ]F
- TIME_WAITGӳsuw_A socket ٦bWݵF
- LISTENGq`ΦbAȪť port IiϥΡy -l zѼƬd\C
WAڭ̱``ͨ쪺 netstat \ANOb[suAFAӺsuAA
SH[yڥثe}Fh֪ port bݥΤݪsuzH
yثeڪsuAAhֳsuwإߩβͰDẕ`C
ApAѻP[OHq`Oo˳BzG
# dҤTGqXثewgҰʪA
[root@www ~]# netstat -tulnp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program
tcp 0 0 127.0.0.1:2208 0.0.0.0:* LISTEN 2029/hpiod
tcp 0 0 0.0.0.0:139 0.0.0.0:* LISTEN 2158/smbd
tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN 1792/portmap
tcp 0 0 127.0.0.1:631 0.0.0.0:* LISTEN 2056/cupsd
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 2088/sendmail:
....(Uٲ)....
# W̭nO -l ѼơA]iHȦCXb Listen port
|
AiHo{ܦhAȨȰw糧 lo }ӤwAںOsӰfPAȪC
ӥѤWzƧڭ̤]iHݨAҰ port 111 ANO portmap {ApGQnoӰfA
AiHϥ kill R 1792 A]iHϥ killall R portmap oӵ{ǧYiCp@ӡA
ܻPANાDӵ{ҰʤFǰfoI
# dҥ|G[WYҦsuA
[root@www ~]# netstat -atunp
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program
tcp 0 0 127.0.0.1:2208 0.0.0.0:* LISTEN 2029/hpiod
....(ٲ)....
tcp 0 0 :::22 :::* LISTEN 2047/sshd
tcp 0 148 192.168.1.11:22 192.168.201.101:1865 ESTABLISHED 13619/1
....(Uٲ)....
|
ݨWYSraHNثewgإ߳su@suALOѻݥD 192.168.201.101
Ұʤ@Ӥj 1024 fVaݥD 192.168.1.11 port 22 isu@suA
AnQ_ӪOGyClient ݬOH@Ӥj 1024 HW
port isuzA~yu
root iHҰʤp 1024 HU port zANݪWYsuoIpGosuAQn屼LܡA
ݨ̥k䪺 13619 FSH kill |ΧaI ^_^
ܩDzΪ Unix socket ơAOoϥ man netstat d\@UaI
o Unix socket q`OΦb@ǶȦbWB@{Ҷ}ҪѤɡA
Ҧp X Window ObWB@ӤwܡHҰʺ port OHMiHϥ Unix socket
oAt~AҦp Postfix o@AAѩܦhʧ@ObWYӧA
ҥHH|Ϋܦh Unix socket I
|
DG
лAȦWٻP port number b Linux AOΨɮרӳ]wH
G
/etc/services
|
5.2.4 DWٻP IP G
host, nslookup
DWٻP IP Aڭ̥DnЪO DNS Τݥ\ dig oӫOCLFoӫO~A
٦ӧ²檺OANO host P nslookup աIUڭ̨ӲoӫOaI
- host
oӫOiHΨӬdXYӥDW٪ IP I|ҨӻAڭ̷QnD tw.yahoo.com IP ɡAiHo˰G
[root@www ~]# host [-a] hostname [server]
ﶵPѼơG
-a GCXӥDԲӪUDWٳ]w
[server] GiHϥΫD /etc/resolv.conf DNS A IP ӬdߡC
# dҤ@GCX tw.yahoo.com IP
[root@www ~]# host tw.yahoo.com
w.yahoo.com is an alias for tw-cidr.fyap.b.yahoo.com.
tw-cidr.fyap.b.yahoo.com is an alias for tw-tpe-fo.fyap.b.yahoo.com.
tw-tpe-fo.fyap.b.yahoo.com has address 119.160.246.241
|
@IIP O 119.160.246.241 ڡI²NiHdߨ IP FIo IP OV֬dߪOHNOgb
/etc/resolv.conf
ɮפ DNS A IP աIpGQnϥθɮפDӬdߡA]iHo˰G
[root@www ~]# host tw.yahoo.com 168.95.1.1
Using domain server:
Name: 168.95.1.1
Address: 168.95.1.1#53
Aliases:
tw.yahoo.com is an alias for tw-cidr.fyap.b.yahoo.com.
tw-cidr.fyap.b.yahoo.com is an alias for tw-tpe-fo.fyap.b.yahoo.com.
tw-tpe-fo.fyap.b.yahoo.com has address 119.160.246.241
|
|iDڭ̩ҨϥΨӬdߪDO@oIo˴NMFaILAAM]L
dig oӫOAҥHoӫOȬOѦҰѦҰաI
- nslookup
oNγ~P host WO@˪ANOΨӧ@ IP PDWٹˬdA
PˬOϥ /etc/resolv.conf
oɮרӧ@ DNS AӷܡC
[root@www ~]# nslookup [-query=[type]] [hostname|IP]
ﶵPѼơG
-query=typeGdߪAFDzΪ IP PDWٹ~ADNS ٦ܦhTA
ҥHڭ̥iHd߫ܦhPTA]A mx, cname A
ҦpG -query=mx dߤkI
# dҤ@GX www.google.com IP
[root@www ~]# nslookup www.google.com
Server: 168.95.1.1
Address: 168.95.1.1#53
Non-authoritative answer:
www.google.com canonical name = www.l.google.com.
Name: www.l.google.com
Address: 74.125.71.106
....(Uٲ)....
# dҤGGX 168.95.1.1 DW
[root@www ~]# nslookup 168.95.1.1
Server: 168.95.1.1
Address: 168.95.1.1#53
1.1.95.168.in-addr.arpa name = dns.hinet.net.
|
pAݰ_ӻP host thaILAo nslookup ٥iH IP XDWٳI
ҦpӽdҤGALDW٬OG dns.hinet.net Iثejaijϥ dig
oӫOӨN nslookup Aڭ̷|b DNS A ɦAӦnnͤ@ͧaI
ԣOݳsuOHNObPqinJpաIڭ̥iHzL telnet, ssh Ϊ̬O ftp
wӶi卤ݥDnJCUڭ̴NOӤФ@UoǰOaIo̶ȬOͨΤݥ\A
Aڭ̫h|bi满C
5.3.1 ݾP BBS suG telnet
telnet Oڭ̦bӤHqWnsAu@ɡA̭n@ӳnFILiHsAWYA
٥iHΨӳs BBS OID`ΡILA telnet ƦbǰeɭԬOϥΩX (lơAS[K) A
ҥHƦb Internet W]ɭԡA|MI@I (NȳQOHť)C
ԲӪƧڭ̷|byݳsuAz`ЪC
[root@www ~]# telnet [host|IP [port]]
# dҤ@GsxW۷ PTT BBS ptt.cc
[root@www ~]# telnet ptt.cc
wӨ ~{ ثei93144jϥΪ̦buW
пJNAΥH guest [AΥH new U:
¿C~OjڦVpX|ijABɧUze!http://ppt.cc/s;Cy
PTTradio 8/31 (G)20:00 Ĭ-Q~@X hX,ФW http://pttradio.net
|
pWҥܡAڭ̥iHzL telnet s BBS WAӦpGAD} telnet
AAȪAP˪QΡy telnet IP zåBJbPKXANnJDFC
t~Ab Linux W telnet nٴѤF Kerberos {Ҥ觋A쪺ܽЦۦѾ\ man telnet C
FsAHγs BBS ~A telnet ٥iHΨӳsY port (A) WYoI
|ҨӻAڭ̥iH telnet s port 110 Aݬݳo port O_TҰʩOH
# dҤGGݪ 110 o port O_TҰʡH
[root@www ~]# telnet localhost 110
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused
# pGX{o˪TANo port SҰʩΪ̬OoӳsuDA
# ]Aݨ쨺 refused I
[root@www ~]# telnet localhost 25
Trying 127.0.0.1...
Connected to localhost.localdomain (127.0.0.1).
Escape character is '^]'.
220 www.centos.vbird ESMTP Sendmail 8.13.8/8.13.8; Wed, 1 Sep 2010 11:42:06 +0800
ehlo localhost
250-www.centos.vbird Hello localhost.localdomain [127.0.0.1], pleased to meet you
250-ENHANCEDSTATUSCODES
250-PIPELINING
250-8BITMIME
....(ٲ)....
250 HELP
quit
221 2.0.0 www.centos.vbird closing connection
Connection closed by foreign host.
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@IھڿXGAڭ̴NDoӳqTw (port number ѪqTw\) O_\ҰʧoI
ӦbC port ҺťAȳSOAҦpWz port 25 NObҴѪqllAȡA
ӪAȩҤ䴩ONpPWϥΪƤ@ˡAOL port No䴩oӡy ehlo zROA
]P port P{IҥHM䴩RONPoI
P mail server telnet ΪkAڭ̱NblAI
5.3.2 FTP sunG ftp, lftp
{bH̥ѩeq email iHΡA]ǰeɮץiHܻPzL email CL email ٬OʫHeqA
pGQn@fǰeӴX MB ɮסA٬OonzL FTP oӳqTw~ڡIr FTP nDn ftp,
lftp ӡAϧΤOHb CentOS Ww] gftp oӦnΪFFCbo̧ڭ̶ȤФrӫOӤwC
- ftp
ftp oӫO²AΦbBz FTP AUưաCѩҦbmbXsjA]ǫϥαXsj FTP
AҡG
[root@www ~]# ftp [host|IP] [port]
# dҤ@GsuXsjhݬ
[root@www ~]# ftp ftp.ksu.edu.tw
Connected to ftp.ksu.edu.tw.
220---------- Welcome to Pure-FTPd [privsep] ----------
220-You are user number 1 of 50 allowed.
220-Local time is now 12:02. Server port: 21.
220-Only anonymous FTP is allowed here <==TnݰڡIo FTP Ȥ䴩ΦW
220-IPv6 connections are also welcome on this server.
220 You will be disconnected after 5 minutes of inactivity.
Name (ftp.ksu.edu.tw:root): anonymous <==o̥ΰΦWnJI
230 Anonymous user logged in <==ITOΦWnJFI
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> <==̲nJGݰ_ӬOoˡI
ftp> help <==ѻݭnOAiH`ѦҡI
ftp> dir <==ܻݦAؿe (ɦWC)
ftp> cd /pub <==ܴؿ /pub
ftp> get filename <==U@ɮסAɦW filename
ftp> mget filename* <==UhɮסAiϥθUΦr *
ftp> put filename <==W filename oɮרAW
ftp> delete file <==RDW file oɮ
ftp> mkdir dir <==إ dir oӥؿ
ftp> lcd /home <==yaݥDzu@ؿ
ftp> passive <==Ұʩ passive Ҧ
ftp> binary <==ƶǿҦ]w binary 榡
ftp> bye <== ftp n骺ϥ
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FTP O@ӫܳ·ЪwA]LϥΨ port OiROPƪyAԲӪƧڭ̷|b FTP
AԽ͡Ao̧ڭ̥ªФ@Upϥ ftp oӳnCڭ̷MOݭnnJoA
ҥHbWYڭ̷MݭnJbPKXFCLѩXsjȴѰΦWnJAΦWnJ̪bNOy anonymous zҥHgӱbYiCpGOpH FTP
ɡA~ݭnѤ@է㪺bPKXաI
nJ FTP DANϥ ftp n骺\iWǻPUʧ@AXӱ`Ϊ ftp
OpWALAijAiHsjǪ FTP Aϥ help (ΰݸ ?)
ӰѦҥiΪOAMդUHըϥΤ@UoӫOaIo˥HSsɭԡAA]iH ftp
UFOIaIt~An`NOA} ftp nɡAonJy bye zIOy exit zաI
pGѩYDzzѡAA FTP D port }bDWfɡAANiHQΩU觋ӳsӳDI
[root@www ~]# ftp hostname 318
# ]D ftp Aȶ}Ҧb 318 o port ڡI
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- lftp (۰ʤƸ})
¨ϥ ftp `Oıoܳ·СASֳt ftp ΤnOHڭ̥iHϥ}C觋ӵnJ FTP
AڡHANO lftp \FI lftp w]ϥΰΦWnJ FTP AAiHϥ}C觋oơA
ϥΤWª ftp nnΨǡC~AѩibOCJb/KXAiHUi{}]pI
[root@www ~]# lftp [-p port] [-u user[,pass]] [host|IP]
[root@www ~]# lftp -f filename
[root@www ~]# lftp -c "commands"
ﶵPѼơG
-p G᭱iHW FTP DѪ port
-u G᭱hOWbPKXANsWݥDF
pGS[bKXA lftp w]|ϥ anonymous հΦWnJ
-f GiHNOgJ}Ao˥iHUi shell script ۰ʳBzI
-c G᭱[WһݭnOC
# dҤ@GQ lftp nJXsj FTP A
[root@www ~]# lftp ftp.ksu.edu.tw
lftp ftp.ksu.edu.tw:~>
# @I@UlNnJFIܧּ֧aI ^_^IAP˥iϥ help hd\O
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ܩnJ FTP DA@˥iHϥΡyhelpzܥXiH檺OAP ftp աILhFҪ\AӥB]D`
bash oIܤIFoӦnΪr FTP n𫗪~AƹW٦ܦhϧΤnγnOI
̱`NO gftp FAD`eWI CentOS N gftp FAAiHX쪩ШӦwˡAMiJ X Window A
Ұʤ@ shell AJy gftp zNo{LnΰաI
pGAQnwɪhUXsj FTP U /pub/CentOS/RPM-GPG* ɮɡAӸ}ӭngOH
ڭ̹ըӼggݧaI
# ϥɮװtX lftp hBzɡG
[root@www ~]# mkdir lftp
[root@www lftp]# vim lftp.ksu.sh
open ftp.ksu.edu.tw
cd /pub/CentOS/
mget -c -d RPM-GPG*
bye
[root@www lftp]# lftp -f lftp.ksu.sh
[root@www lftp]# ls
lftp.ksu.sh RPM-GPG-KEY-beta RPM-GPG-KEY-CentOS-3 RPM-GPG-KEY-centos4
RPM-GPG-KEY-CentOS-4 RPM-GPG-KEY-CentOS-5
# NnBzʧ@[J lftp O
[root@www lftp]# vim lftp.ksu.sh
lftp -c "open ftp.ksu.edu.tw
cd /pub/CentOS/
mget -c -d RPM-GPG*
bye"
[root@www lftp]# sh lftp.ksu.sh
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YDΦWnJɡAhiHϥΡy open -u username,password hostname zק lftp.ksu.sh Ĥ@I
pGANoӸ}gJ crontab AANiHwɪH FTP iW/U\oIoNOrOnBI
5.3.3 ϧΤYɳqTnG pidgin
(gaim )
{bӤjaDO MSN, YɳqHΨLqTnaHnsWoǦAɡAӫBzH²Ab
X Window Uϥ pidgin NnFI²²줣ХiJ X Window tΡAMgLyε{z-->
yںz-->yPidgin YɳqzҰʥLYi (Ъ`NAwgwˤF pidgin FAi yum install pidgin
Bz)CMN|X{pUաG
5.3-1Bpidgin we
bWϤUysWzAMA|ݨpUeG
5.3-2Bpidgin 䴩YɳqT
ܯ_OA pidgin 䴩qThIڭ̨ϥ MSN ӧ@ӸnFG
![]w MSN bܷN](/linux_server/0140networkcommand//pidgin-3.gif "]w MSN bܷN")
5.3-3B]w MSN bܷN
pWϡAbeJAbPKXApGObΪqWAdUnUyOKXzسIUsWA
pidgin w]N|յnJFInJ᪺epUҥܡG
5.3-4Bϥ pidgin MSN 觋iso
pGQnnXFANU 5.3-4 ̥k䨺ӵANyҰʡzӤؤĿAANnXoI
HrɭMsIOrFnnHI֦ӮɶbrAIuաIoӪFA
ObrɭUWsnuIOO links wget o_JAOAAݭnTwAwgwˤFoӮM~C
nΦbOACentOS w]oӪNೣw˳IUNڭ̨Ӳ@oӦnΪåaI
5.4.1 rsGlinks
ꦭ̱`ϥΪO lynx oӤrsAL CentOS q 5.x Hw]ϥΪrsO links
o@Ao䪺ϥΤ觋SD`A]Abo@Aڭ̴NȤ links oIY lynx 쪺ܡA
ۤv man @UaI
oӫOiHڭ̨sA{Aoɮ׳̤j\Oby
d\ Linux WH HTML ykg (document)z
OHpGAg Linux U /usr/share/doc oӥؿݹLƪܡA
N|``o{@ǺɮסAϥ vi hd\ɡAѬOݨ@ HTML ykIê\Ūڡ
oɭԨϥ links NOӦnkաIiHݪMMڡI ^_^
[root@www ~]# links [options] [URL]
ﶵPѼơG
-anonymous [0|1]GO_ϥΰΦWnJNF
-dump [0|1] GO_NƪX standard out ӫD links n\
-dump_charset G᭱QnzL dump XùytsXAbig5 ϥ cp950
# dҤ@Gs Linux kernel
[root@www ~]# links http://www.kernel.org
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ڪJ links }AN|X{pUϥܡG
5.4-1Bϥ links dߺƪܵG
WoӵepUG
- iJeAѩOrAAҥHsƥi|I첾ILI|vTڭ̬ݩNNI
- oӮɭԥiHϥΡyWUzЦbWﶵ(pHcBҵ)AU Enter NiJӭ
- iHϥΡykzӲʡyW@ΤU@z
- @DZ`\G
- hGhistory AgsL URL Nܨe
- gGGoto URLA g J}(URL) p :http://www.abc.edu/
- dGdownloadANӳsƤU쥻ɮסF
- qGQuitA} links oӳnF
- oGOptionAiJ\Ѽƪ]wȭק襤A̲ץigJ ~/.elinks/elinks.conf
- Ctrl+C Gj_ links C
- V:
- W GʴЦܥ "W@ӥisI" .
- U GʴЦܥ "U@ӥisI" .
- Gback. ^W@.
- k GiJϥմЩҳs.
- ENTER Pƹ "k" .
ܩpGOs Linux WɮסANiHϥΦpU觋G
[root@www ~]# cd /usr/share/doc/centos-release-notes-5.5
[root@www htmldocs]# links RELEASE-NOTES-en.html
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b CentOS 5.5 Ao@ɮסAڴNiHQ links ӨXݧoIܪGIUoˡG
5.4-2Bϥ links dߥ HTML ɮ
MաI]AҥiOb Linux tty1~tty6 AҥHLkܥXAoӮɭԧANon]wG
yLANG=en_USzyt]w~It~ApGYǮɨAWIYӺH۰ʨosɡC
|ҨӻA۰ʽuWsDW٨tΡAȤ䴩sAApisOHKKIiHϥ links IQ
-dump oӰѼƳBzG
# zL links N tw.yahoo.com eӧUxs
[root@www ~]# links -dump http://tw.yahoo.com > yahoo.html
# YӺzL GET \iHWDZb user KX pw AΤrBzG
[root@www ~]# links -dump \
> http://some.site.name/web.php?name=user&password=pw > testfile
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W᭱[Ӱݸ (?) aH᭱hOQκy GET z\oUܼƸơA
Qγoӥ\Aڭ̴NiHIӺWoID`KaIӥB|N檺GX testfile
ɮפALpGѪƬOHy POST zDܡANDpdwFC
GET P POST O WWW qTwAΨӱNƳzLsWǨAݪ@ؤ觋A
@ӻAثeQװϩγ浥AjhϥΥiH䴩hƪ POST 觋WǰաI
GET P POST Tڭ̷|b WWW AAΡI
5.4.2 rUG wget
pG links ObiyszA wget NObiyƪozC|ҨӻAڭ̪ Linux
֤߬Omb www.kernel.org ADnPɴ ftp P http ӤUCڭ̪DiHϥ lftp
ӤUơApGQnsӤUOHNQ wget aI
[root@www ~]# wget [option] [}]
ﶵPѼơG
YQnsuѱbPKXO@ɡAiHQγoӰѼƨӿJI
--http-user=usrname
--http-password=password
--quiet Gn wget bƮɭԪܰT
hѼƽЦۦѦ man wget aI ^_^
# dҤ@GФU 2.6.35.4 ֤
[root@www ~]# wget \
> http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.35.4.tar.bz2
--2010-09-01 17:36:24-- http://www.kernel.org/pub/linux/kernel/v2..
bdD www.kernel.org... 199.6.1.164, 204.152.191.37, 149.20.20.133, ...
bs www.kernel.org|199.6.1.164|:80... sWFC
weX HTTP nDAbԦ^... 200 OK
: 69259115 (66M) [application/x-bzip2]
Saving to: `linux-2.6.35.4.tar.bz2'
94% [====================================> ] 65,163,000 623K/s eta 7s
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A@@ܥiRaIzLsAunD}AߧYiHiɮתUA
SֳtSKA٥iHzL proxy UӤUOIzLק /etc/wgetrc ӳ]wANzAG
[root@www ~]# vim /etc/wgetrc
#http_proxy = http://proxy.yoyodyne.com:18023/ <==쩳UoXAjb 78
#ftp_proxy = http://proxy.yoyodyne.com:18023/
#use_proxy = on
# NL令UҼˡAOoAAni proxy D~I
http_proxy = http://proxy.ksu.edu.tw:3128/
use_proxy = on
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ܦhɭԥѩڭ̪suX{DAϥ ping n\oSLkXDIA̱`O]ѻP IP
Ҳͪ@ǧxZ (аѦҨP NAT D)AoӮɭԭnH²檺kNOyRʥ]yVzoIzLRʥ]yVAڭ̥iHAѤ@suӬOpiVsuʧ@A
]N|MAѨioͪDҦbFIUڭ̴Nӽͤ@ͳo tcpdump PϧΤʥ]RnaI
5.5.1 rʥ]^G tcpdump
bA tcpdump oӳnӻAAƦܥiHoӳnNObȳnA
]LiHRʥ]yVAsʥ]e]iHiyťzA
pGAϥΪǿƬOXܡAoFAb router hub WNiQHaťFI
ڭ̦bĤGͨ쪺 CSMA/CD
y{AOLҿתyťnzܡHo tcpdump NOաI
ܥiȧoIҥHAڭ̤]nAѤ@UoӳnڡI(Go tcpdump ϥ root )
[root@www ~]# tcpdump [-AennqX] [-i ] [-w xsɦW] [-c ] \
[-r ɮ] [ұ^ʥ]Ʈ榡]
ﶵPѼơG
-A Gʥ]eH ASCII ܡAq`ΨӮ WWW ʥ]ơC
-e GϥθƳsh (OSI ĤGh) MAC ʥ]ƨܡF
-nnGH IP port number ܡAӫDDWPAȦW
-q GȦCX²uʥ]TAC@檺e²
-X GiHCXQi (hex) H ASCII ʥ]eAťʥ]eܦ
-i G᭱nyťzAҦp eth0, lo, ppp0 F
-w GpGAnNťұoʥ]xsUӡAγoӰѼƴNFI᭱ɦW
-r Gq᭱ɮױNʥ]ŪXӡCӡyɮסzOwgsbɮסA
åBoӡyɮסzO -w һs@XӪC
-c Gťʥ]ơApGSoӰѼơA tcpdump |_ťA
ϥΪ̿J [ctrl]-c C
ұ^ʥ]Ʈ榡Gڭ̥iHMwYdzqTwΪ̬O IP ӷiʥ]^A
NiH²ƿXGAèo̦ΪTC`ܤkG
'host foo', 'host 127.0.0.1' Gw泡DӶiʥ]^
'net 192.168' GwYӺӶiʥ]^F
'src host 127.0.0.1' 'dst net 192.168'GPɥ[Wӷ(src)Υؼ(dst)
'tcp port 21'G٥iHwqTwAp tcp, udp, arp, ether
٥iHQ and P or Ӷiʥ]ƪXܩOI
# dҤ@GH IP P port number U eth0 oӺdWʥ]A 3
[root@www ~]# tcpdump -i eth0 -nn
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
01:33:40.41 IP 192.168.1.10.22 > 192.168.1.11.1190: P 116:232(116) ack 1 win 9648
01:33:40.41 IP 192.168.1.10.22 > 192.168.1.11.1190: P 232:364(132) ack 1 win 9648
<==U [ctrl]-c ᵲ
6680 packets captured <==UӪʥ]ƶq
14250 packets received by filter <==ѹLoұo`ʥ]ƶq
7512 packets dropped by kernel <==Q֤ߩҥʥ]
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pGAOĤ@ tcpdump man page ɡA֩w@YӤjA] tcpdump
XGORʥ]YơAϥΪ̦pGS²ʥ]¦AnoI
ҥHAܤ֧Aon^¦̭hN TCP
ʥ]YƲzѲzѤ~nڡI ^_^IܩӽdҤ@ҲͪXdҤAڭ̥iHϤƭA
ڭ̥HdҤ@ӯSrӻ@UG
- 01:33:40.41GoӬOʥ]Q^ɶAy::zF
- IPGzLqTwO IP F
- 192.168.1.10.22 > GǰeݬO 192.168.1.10 o
IPAӶǰe port number 22AAnAѪOAӤj (>) ŸOʥ]ǿVI
- 192.168.1.11.1190Gݪ IP O 192.168.1.11A
BӥD} port 1190 ӱF
- P 116:232(116)Goӫʥ]a PUSH ƶǿлxA
Bǿ骺Ƭƪ 116~232 byteAҥHoӫʥ]a 116 bytes ƶqF
- ack 1 win 9648GACKP Window size ơC
²檺kANOӫʥ]O 192.168.1.10 Ǩ 192.168.1.11AzL port O 22 1190 A
Ba 116 bytes ƶqAϥΪO PUSH XСAӤO SYN DʳsuлxC
IeݪaIҥHAWY~аȥ
TCP Yh@@@ڡI
AӡA@ӺAܦDWAAQnoYDAsuʥ]ƦӤwɡA
ϥ tcpdump tXuROPWܪk]iHALAnI
ڭ̥iHzL tcpdump ܪk\ANNһݭnƿWߪXӡC
bWdҤ@Aڭ̶Ȱw eth0 ťAҥH eth0 WƳ|QܨùWA
nRڡIڭ̥iH²ƶܡHҦpuX port 21 suʥ]AiHo˰G
[root@www ~]# tcpdump -i eth0 -nn port 21
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
01:54:37.96 IP 192.168.1.11.1240 > 192.168.1.100.21: . ack 1 win 65535
01:54:37.96 IP 192.168.1.100.21 > 192.168.1.11.1240: P 1:21(20) ack 1 win 5840
01:54:38.12 IP 192.168.1.11.1240 > 192.168.1.100.21: . ack 21 win 65515
01:54:42.79 IP 192.168.1.11.1240 > 192.168.1.100.21: P 1:17(16) ack 21 win 65515
01:54:42.79 IP 192.168.1.100.21 > 192.168.1.11.1240: . ack 17 win 5840
01:54:42.79 IP 192.168.1.100.21 > 192.168.1.11.1240: P 21:55(34) ack 17 win 5840
|
@Io˴NȴX port 21 TӤwABJӬݪܡAA|o{ʥ]ǻOVA
client ݵoXynDz server ݫhHy^zAҥHAMOh^ڡI
ӧڭ̤]NiHgLoӫʥ]yVAѨʥ]B@L{C|ҨӻG
- ڭ̥b@ӲݾJy tcpdump -i lo -nn z ťA
- At}@Ӳݾӹ糧 (127.0.0.1) nJyssh localhostz
XG|OpH
[root@www ~]# tcpdump -i lo -nn
1 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
2 listening on lo, link-type EN10MB (Ethernet), capture size 96 bytes
3 11:02:54.253777 IP 127.0.0.1.32936 > 127.0.0.1.22: S 933696132:933696132(0)
win 32767 <mss 16396,sackOK,timestamp 236681316 0,nop,wscale 2>
4 11:02:54.253831 IP 127.0.0.1.22 > 127.0.0.1.32936: S 920046702:920046702(0)
ack 933696133 win 32767 <mss 16396,sackOK,timestamp 236681316 236681316,nop,
wscale 2>
5 11:02:54.253871 IP 127.0.0.1.32936 > 127.0.0.1.22: . ack 1 win 8192 <nop,
nop,timestamp 236681316 236681316>
6 11:02:54.272124 IP 127.0.0.1.22 > 127.0.0.1.32936: P 1:23(22) ack 1 win 8192
<nop,nop,timestamp 236681334 236681316>
7 11:02:54.272375 IP 127.0.0.1.32936 > 127.0.0.1.22: . ack 23 win 8192 <nop,
nop,timestamp 236681334 236681334>
|
WܪYO tcpdump AMG
- 3 ܪOyӦ client ݡAa SYN Dʳsuʥ]zA
- 4 ܪOyӦ server ݡAF^ client ݤ~(ACK)Aٱa SYN DʳsuлxF
- 5 h client ݦ^ server Twsuإ (ACK)
- 6 Hh}liJƶǿ骺BJC
q 3-5 檺y{ӬݡAxڡHSINOTV洤¦y{աIaI
L tcpdump ҥHQ٬bȳn𫗪@iWYЪ\oI
WЪ\iHΨӧ@ڭ̥Dʥ]suPǿ骺y{RA
oNUڭAѨʥ]B@APAѨD]wWhO_ݭnqaC
_ϥέnӰաIpGڭ̨ϥ tcpdump b router WťyXzǿƮɡA
Ҧp FTP ǿwAAıo|oͤDOH
ڭ̥bDݤUFy tcpdump -i lo port 21 -nn -X zMAH ftp nJAÿJbPKXA
GANiHo{pUpG
[root@www ~]# tcpdump -i lo -nn -X 'port 21'
0x0000: 4500 0048 2a28 4000 4006 1286 7f00 0001 E..H*(@.@.......
0x0010: 7f00 0001 0015 80ab 8355 2149 835c d825 .........U!I.\.%
0x0020: 8018 2000 fe3c 0000 0101 080a 0e2e 0b67 .....<.........g
0x0030: 0e2e 0b61 3232 3020 2876 7346 5450 6420 ...a220.(vsFTPd.
0x0040: 322e 302e 3129 0d0a 2.0.1)..
0x0000: 4510 0041 d34b 4000 4006 6959 7f00 0001 E..A.K@.@.iY....
0x0010: 7f00 0001 80ab 0015 835c d825 8355 215d .........\.%.U!]
0x0020: 8018 2000 fe35 0000 0101 080a 0e2e 1b37 .....5.........7
0x0030: 0e2e 0b67 5553 4552 2064 6d74 7361 690d ...gUSER.dmtsai.
0x0040: 0a .
0x0000: 4510 004a d34f 4000 4006 694c 7f00 0001 E..J.O@.@.iL....
0x0010: 7f00 0001 80ab 0015 835c d832 8355 217f .........\.2.U!.
0x0020: 8018 2000 fe3e 0000 0101 080a 0e2e 3227 .....>........2'
0x0030: 0e2e 1b38 5041 5353 206d 7970 6173 7377 ...8PASS.mypassw
0x0040: 6f72 6469 7379 6f75 0d0a ordisyou..
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WXGwgQ²ƹLFAAnۦbAXGjMr~C
qWXGSr餤Aڭ̥iHo{y FTP nϥΪO
vsftpd AåBϥΪ̿J dmtsai oӱbW١ABKXO mypasswordisyouz
KKIAiiȰڡIpGϥΪOX觋ӶǿAơH
ҥHڭ̤~``bڡAOܤwwI
t~AoAѡAFiH tcpdump ťAҥH tcpdump ɺ|Ұʦb
yüҦ (promiscuous)zAҥHA|b /var/log/messages ̭ݨܦhĵiTA
qAAdQ]wüҦIOߡAO`CܩhΡAаѦ man tcpdump oI
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DG
pϥ tcpdump ť (1)Ӧ eth0 dB (2)qTw port 22 A(3)ʥ]ӷ 192.168.1.100 ʥ]ơH
G
tcpdump -i eth0 -nn 'port 22 and src host 192.168.1.100'
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5.5.2 ϧΤʥ]^G wireshark
tcpdump Orʥ]^ASϧΤHڡINO wireshark
(1) oMnCoMn驭٬ ethereal AثePɴѤr tethereal HιϧΤ
wireshark өNNCѩڭ̷wˮɹw]èS˳oMA]pnϥ yum
hw˳I]iHXШӦw˰աIMݭnwˡAOOr wireshark
HιϧΤ wireshark-gnome nCwˤ觋pUG
[root@www ~]# yum install wireshark wireshark-gnome
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ҰʳoMn骺k²AAnb X Window UAzLyε{z-->yںz-->ywireshark
network analyzerzNiHҰʰաIҰʪepUҥܡG
5.5-1Bwireshark ϥΥܷN
o@Mn\D`jjIo̶²檺ΪkAYSݨDANonۤvoC
Qn}l^ʥ]eAon]w@UťA]I 5.5-1 edpϥܧaI
N|X{pUeAܤFC
5.5-2Bwireshark ϥΥܷN
bWϤAAoܷQnťAo̦]ߥ~ʥ]ӦhɭPeܶáA]ǫϥΤ lo
ӧ@dҡCAon`NA lo ɬOܦwRIҥHAbIFystartzA٦}ݾA
ϥΡy ssh localhost zӹյnJۤvAoˤ~oʥ]IpUϩҥܡG
5.5-3Bwireshark ϥΥܷN
YSDAA^Fʥ]QniRAU 5.5-3 epϥܡAʥ]^ʧ@N|פA
UӡANڭ̨Ӷ}lR@Uʥ]aI
5.5-4Bwireshark ϥΥܷN
ӤRepWҥܡAe`@Tj϶AAiHNƹвʨCӰ϶ʴΡA
NiHվCӰ϶djpFCĤ@϶DnܪOʥ]YơAeNI tcpdump
ܵGAĤG϶hOԲӪYơA]ATتeBqTweH socket pair TC
ĤT϶hO 16 iP ASCII XܵG (ԲӪʥ]e)C
pGAıoYӫʥ]DAbe 1 aIӫʥ] (ϨҤO 31 ӫʥ])Ae 2 P 3
N|ܰʡIѩժʥ]O[Kƪʥ]A]e 2 ܥXʥ]YAe 3 ʥ]eNOýXաI
zLo wireshark ANiH@foһݭnҦʥ]eաIӥB٬OϧΤAܤKaI
5.5.3 NҰ TCP/UDP ʥ]fsuG
nc, netcat
o nc OiHΨӧ@YǪAȪ˴A]LiHsY port Ӷi淾qA~A٥iHۦҰʤ@ port
ӶťLΤ᪺suoID`ΡIpGbsĶ nc n骺ɭԵyGAPING_SECURITY_HOLEzѼƪܡAKKI
oӳn٥iHΨӨoΤݪ bash IiȧaIڭ̪ CentOS w]èSWѼơA
ҥHڭ̤Ψӧ@bȳnO nc ΨӨN telnet ]OӫܴΪ\FI(tαN nc W
netcat աI)
[root@www ~]# nc [-u] [IP|host] [port]
[root@www ~]# nc -l [IP|host] [port]
ﶵPѼơG
-l G@ťΡAY}Ҥ@ port ӺťΤ᪺suF
-u Gϥ TCP ӬOϥ UDP @suʥ]A
# dҤ@GP telnet Asaݪ port 25 d\T
[root@www ~]# nc localhost 25
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oӳ²檺\P telnet XG@˧aIiHhˬdYӪAȰաILA_b᭱A
ڭ̥iHإߨӳsuӶǰTI|ӨҤlӻAڭ̥bAݱҰʤ@ port ӶiťG
# dҤGGҰʤ@ port 20000 ӺťϥΪ̪sunD
[root@www ~]# nc -l localhost 20000 &
[root@www ~]# netstat -tlunp | grep nc
tcp 0 0 127.0.0.1:20000 0.0.0.0:* LISTEN 14152/nc
# Ұʤ@ port 20000 bWI
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UӧAA}t~@ӲݾӬݬݡA]Q nc ӳsuAAåBJ@ǫOݬݳI
[root@www ~]# nc localhost 20000
<==o̥iH}lJrFI
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ɡAbΤݧڭ̥iHJ@ǦrAA|o{bAݷ|PɥX{AJroI
pGAPɵ@B~ѼơAҦpQμзǿJPX (stdout, stdin) ܡANiHzLoӳsuӧ@ܦhƱFI
M nc \णupAA٥iHo{ܦhγ~I
ЦۦAD /usr/share/doc/nc-1.84/scripts/ ؿUݬݳo script AUoI
LApGAݭnB~sĶXt GAPING_SECURITY_HOLE \A
HϨݳsuiHiB~OɡANonۦUlXӽsĶFI