-
Linux Email: [email protected]:
[email protected]
-
LINUX
URL: ftp://ftp.dlut.edu.cn/pub/PEOPLE/albin/
[email protected],May 1999.
-
LinuxLinuxTCP/IPUNIXLinuxInternetDNSFTPWWW(HTTP)LAN
Router/FirewallSMTP()/POP3
-
LinuxLinuxLinuxPPPXFree86 Shell ScriptCGI
-
UNIXInternetLINUX
-
LINUX LINUX LINUX
-
LINUX1.1 LINUXInternetUNIXUNIXMS$ ISP POSIXBSDSYSVLinus B.
Torvalds([email protected])GPLIntell 80x86, Pentium MMX,
Pentium II, Pentium III, AMD
-
Sun Sparc, DEC, Power PCX Windows, GNU C/C++, Sybase, Oracle,
Netscape, StarOffice, DOS EMU, (PPP/HTTP/FTP/DNS
SMTP/POP3/Firewall/BBS/samba/mars).TCP/IP, Novell IPS/SPX, NetBEUI,
AppleTalk, X.25,ArcNet1.2 Linux1991.8 Linux 0.011991.10.5 Linux
0.02()0.03 ->0.10 1992Linux 0.95(0.99p114)1994.3.14Linux 1.0
2.2.3/2.0.36
-
1.3 Linux
1.3.1 UNIXUNIXCI/O(system call)fork()pipe()cc,troff,
grep,awkshell. 60 MULTICS(Multiplexed Information and Computing
Services)1969 Ken Thompson, Dennis Ritchie PDP-111971 V1
PDP-11/20FSfork,roff,ed1973 V4 C1975 V6 UNIX1.X BSD1778 BSD, Bill
Joy. Chuck Hally1979 V7 UNIXK&C Csh
-
UNIXSystem V(AT&T)BSD SVR4,OSF/1UNIXAIX: SVR2BSDSMITFreeBSD:
Intel 80x86Free1.X386BSD2.X4.4BSD
Lite2.2.8-RELEASE/3.1.0-RELEASEftp://ftp.dlut.edu.cn/pub/FreeBSD/HP-UX(HP):
S III(SVRX),SVR2 4.2BSD OSF/1IRIX(SGI): V4(SVR
3.2,BSD)V5(SVR4)Linux(x86):POSIX; SYSVBSDOSF/1DEC DECUNIXSCO
UNIX(x86): SVR 3.2, UNIX
-
SunOS(680x0,Sparc,i386)SunOS 4.x(BSD 4.1c)Solaris(SunOS 5.x,
SVR4)NFS, Openlookultirx(DEC):Xinux(x86): MicrosoftSVRBSD()
1.3.2 LinuxBuffer Overflow
-
SVRXBSD
SVRX
xBSD
Kernel
/unix
/vmunix(Linux)
/etc/inittab(Linux)
/etc/ttys
/etc/rc.d/*(linux)
/etc/rc.*
/etc/mntab
/etc/mtab(Linux)
shell
sh, ksh
csh
Lp,lpstat,cancel
Lpr,lpq,lprm,lpd
(Linux)
termio,terminfo,
svr4:termios
Termios,
termcap(Linux)
Ps ef
Ps aux
/proc
-
swap, swap128Mx16=2GBLD_PRELOADcore dump: (pseudo
terminal,pty)(Alt+F1~F6,Alt+Arrow)CPUIntelLinuxHD/FD/Mainboard/SCSI/Audio/CDROM/MO,
NIC,ZIP/MOVideext2fs2TB255umsdosDOSLinux
-
POSIXUNIXUNIXshell: news/mail
-
Xcxterm,crxvtwgce,chdrv,yactxa+xcainhzttycnprintdosemu,wine,WABI(SUN,)WWW
Browser: Netscape,Mosaic,lynx,ArenaFreeBSDUNIXPOSIXSystem
V,BSDUNIXiBCS2SCOUNIXTCP/IP(ftp,telnet,NFS)Linux
TCP,IPV4,IPV6,AX25,X.25,IPX, DDP(AppleTalk),NetBEUI
-
TCP,IPV4,IPV,DDP,AX25NetwaresambaLinuxWindowsWindows 9x/NT
1.3.3
Linux(kernel)(Distribution)Linus2.2.32.0.36Linuxslackware,RedHat,
DebianLinux Linus
-
Linux (1)Walnut Creek Slackwareftp://ftp.cdrom.com, Walnut Creek
CDROMSlackwareLinux/Redhat RedhatDebian, pkgtool, Latest Version:
Slackware 3.6ftp://ftp.dlut.edu.cn/pub/Linux/slackware/
ftp://ftp.cdrom.com/pub/LinuxMirror: ftp://sunsite.ust.hk/pub/
(Free IP)
-
(2)RedHat Linux: (Latest is Redhat 5.2)Redhat
Softwareslackware/debiandebianslackware(informix,
sybase,oracleIntel).RPM/GNU
shareware,PAMRPMURLftp://ftp.redhat.com/ftp://ftp.dlut.edu.cn/pub/Linux/redhat/redhat-5.2/
-
Redhatmandrake: ftp://ftp.dlut.edu.cn/pub/Linux/mandrake
Plinux:Linux,KDE(3)Debian
Linux:GNULinuxFTPLINUXshadowRedhatdebRPM
-
(,),dselect(4)Craftworks Linux: (5)Linux Pro:
WGS(6)Linux:TurboLinux, TurboLinuxCaldera OpenLinux
1.4 Linuxftp://ftp.dlut.edu.cn/pub/Linux/CDROM: FAQ:
Redhat/usr/doc/* LinuxFAQBBSbbs.dlut.edu.cnbbs.tsinghua.edu.cn
-
1.5 LINUX LinuxLinuxInternet Redhat LinuxLinuxGNU
-
Linux
-
UNIX
-
TCP/IPIP
-
(Internetworking)(The Internetworking model)(Applications and Up
Layers)(Physical and data link layers)(Network layer and path
determination)
-
(The Internetworking Model)ISO/OSI
-
60-70: 70-80: 80-90: 90:
-
60-70:(),.IBMSNAX.25,,,,,.,,(addressing), ,.
-
70-80:PCLAN,LAN,,EMAIL,LAN,WAN,(),,. DEC VAXDECnet.
-
80-90:,,,,,,(flexible),(scalable),(,)LAN/WAN/,.
-
90:,,bandwidth on demand, ,,: ,,C/S.,,.
-
LAN:(control the network privately under local administration)
24(connect physically adjacent devices)
-
:,,(PC),,,.,DOWN,: (To be continued)
-
()::,,,.. .;Token-Ring;.(HUB): ,,.,LAN,,HUB.:,,,VLAN.
-
()::,, ,,.ATM(Asynchronous Transfer Mode): (high-speed cell
switching).(repeater):,..,,,.,(),,.: 100Mbps.
-
WAN:24:,WANWANWANDOWN,,,(To be continued)
-
(),:(router)::X.25, Frame Relay, , .,,.Modem, CSU/DSU(channel
service units/digital service units)T1/E1,TA/NT1(Terminal
Adapters/Network Termination 1)ISDN(Integrated Services Digital
Network)(): /(Multiplexes):WAN(share a WAN facility among several
demand channels)ATM:
-
:(design)(operations)(troubleshooting)
-
:(connectivity): ,,(reliable performance):.(management control):
,.,.(flexibility): ,.
-
(The Layered Model)Why a Layered Network Model?Layer
FunctionsPeer-to-Peer CommunicationsData Encapsulation()Data
Encapsulation Example
-
Why a Layered Network Model?,,plug-and-play,,.(accelerates
evolution), ,(Simplifies teaching and learning),,.OSI
-
Layer FunctionsNetwork processes to applications,
,,telnetFTPData representation, ,Interhost communication,
,,()End-to-end connections,;Address and best path, ,,Access to
media,,,Binary transmission,
-
PDU: protocol data units, PDU,TCPsegment,;PDU,TCP segment.
-
(frame):.(),..(packet):
.(),..(datagram):.(segment):.(message):().(cell):,.ATMSMDS.
-
;PDU,();.
-
1.2.,,(segment)Email.3.segmentpacket,packet,.4.,,.5.()(a pattern
of ones and zeros), .*,.
-
Applications and Upper LayersSections:Application, Presentation,
and Session LayersTransport Layer
-
Objectives: Upon completion of this chapter, you will be able to
:Name and describe computer,network,and internetwork
applicationsDescribe the OSI presentation-layer functions and
identify common standardsDescribe the OSI session-layer functions
and identity common standardsDescribe the OSI transport-layer
functions for end-to-end network servicesIdentify common processes
for establishing connections, flow control, and windowing
-
Application, Presentation, and Session Layers
-
Application LayerSelect network application to support users
application
-
OSI,OSI.OSI
-
Application Layer(Cont.).Internetwork applications can extend
beyond the enterprise
-
EDIWWWX.400SMTPBBSInternet
-
Presentation Layer
-
(data transfer syntax)EBCDICASCII
-
Session Layer
-
NFS(Network File System)SUNUNIXTCP/IPSQL(Structured Query
Language)IBMRPC(Remote Procedure Call)(build)X
Windows:UNIXASPAppleTalk Session ProtocolDNA SCPDigital Network
Architecture Session Control Protocol
-
(Transport Layer)
-
()(segment)bufferbuffer(acknowledge back)
-
OSI(is accomplished segment by segment)
-
(originating)
0 1024UNIXroot/etc/services
-
(Connection-Oriented Sessions)
-
(peer system)OS(authorized)
-
(Flow Control)
-
()(not ready)
-
(Reliability with Windowing)
-
Reliability with
Windowing(Cont.)Window.(Windowing)(packet)TCP/IP
-
(Positive Acknowledgment)
-
Positive Acknowledgment (Cont.)(positive)55 5ACK 7 7
-
(Transport to Network Layer)
-
Physical and Data-Link Standards
-
()()()()RS-232C/DLANWAN
-
LAN Data Link Sublayers
-
OSIIEEELLCLLCMACLLCIEEE 802.2, MAC
-
LANLAN,/(CSMA/CD,carrier sense multiple access collision
detect)(Token Passing)CSMA/CD,,,CSMA/CD(contention access).
LAN/IEEE802.3,100BaseT.,.LAN/IEEE802.5FDDI.LAN(unicast),(multicast)(broadcast).
-
LLCLLC802MACLLC802MACLLCLLC/
-
Physical and Logical Address,IPAppleTalk,
-
MAC Address
-
MAC()MACMAC(OUI,Organization Unique
Identifier)IEEEMACARPMACTCP/IPHelloMACMACMACXeros(XNS)Novell
IPXDECnet Phase IV
-
Finding the MAC Address
-
MAC
-
AMACB 0000.0c12.2222 D 0000.0c12.3333BMACA 0000.0c12.1111 D
0000.0c12.3333DMACA 0000.0c12.5555 B 0000.0c12.5555CMACA
0000.0c12.1111 B 0000.0c12.2222D 0000.0c12.4444
-
LAN Technology Overview
-
(Ethernet):XeroxXerox,Intel,DECLANCSMA/CD10Mbps,;IEEE802.3(Token-Ring):
IBM416MbpsIBM;IEEE802.5FDDI(Fiber Distribution Data
Interface)100Mbps2
-
Ethernet and IEEE 802.3
-
Physical Layer: Ethernet/802.3
-
: Ethernet/802.310Mbps.10Base2: 185m10Base5: 500m10BaseT:
100m
-
IEEE802.3
IEEE 802.3
10Base5
10base2
10baseT
10baseFL
100BaseT
10
10
10
10
10
100
(m)
500
500
185
100
2000
100
50
50
50
-
Ethernet/802.3 Operation
-
CSMA/CD,.,(terminator).100PC,100A,BC,;D,
-
Ethernet/802.3 Broadcast:.1(FFFF:FFFF:FFFF).,AB/C/D.(multicast
address):,group address();.
-
8Bytes
6
6
2
46~1500
FCS
4
Ethernet
7
SOF
6
6
802.2
FCS
4
IEEE802.3
1. (preamble);SOF,
2. ;802.3,802.2
3. FCS,CRC,,.
-
Ethernet/802.3
-
100BaseFX:62.5/125,400M,MAC802.3MAC,100Mbps100BaseT4:43/4/5,100M,200M,MAC802.3MAC,100Mbps
100BaseTX:(1,2,3,6)51/2STP,200M,MAC802.3,100Mbps100VG-AnyLan:43245,(UTP),HPCSMA/CD,,100BaseT;,CSMA/CD.
(100/150, 600/900).:IEEE802.3,1000Mbps.
-
Token-ring FDDIToken-ring: IEEE802.5, MSAU(Multistation access
Unit)FDDIANSI X3T9.5100Mbps(),
-
:(Path Determination),,():(best effort end-to-end packet
delivery),.
-
:,,,,,
-
: : :
-
TCP/IP
-
TCP/IP
-
TCP/IP(Universal),LANWAN.
-
TCP/IPIP(MTU)
-
(Transport Layer)
-
():(1)(sliding windows);(2)(sequence numbers):TCPUDPTCP,,,.
TCP.,,,.,TCP,,,TCP.TCP,.
-
()UDP,.UDP,.UDP,UDP,. UDP:DNS,SNMP, TFTP, BOOTP, SYSLOG,
RADIUS(Remote Authenticate DialIn User Server).
-
TCP
0 31
IHL
(Sequence Number)
(Acknowledgement Number)
HLEN
(Window)
I
-
TCP()/:TCP:;,(ACK.
No.):.HLEN:TCP,32bits(4).:0:,SYNACKFIN.Window:(octets),(checksum):Urgent:
:
-
TCPUDP(SOCKET).RFC1700Well Known Port
Number.256,2561023;1023UNIX,root1023.UNIX/etc/services
-
TCP
-
TCP:
-
()
-
TCP:
-
TCP:(Windowing)
-
TCP
-
UDP
Bits 16 16 16 16 .
-
(Internet Layer)
-
(Network Layer)OSITCP/IP
-
OSITCP/IPIPIP(TCP/UDP)ICMPARPIP(IP->MAC)RARPARPIP(MAC->IP),
-
IP
0 4 8 16 31
IHL
IP
IP
IP
-
IP(VERS):4(IPV4),IPV66HLEN():IP32IP+MTU(Ethernet/PPP/X.25)(allowing
differing MTUs in the internet)TTL:(Time To
Live),:(TCP/UDP)IPIPIP32IPIP
-
IP()IPTCPIPIP()IP
-
ICMP
-
ICMPTCP/IPICMPICMPIPICMP:Destination UnreachableTime
ExceededParameter ProblemSource QuenchRedirectEchoEcho
ReplyTimestampTimestamp ReplyAddress Request/Address
-
ICMP
-
ICMP()pingICMP Echo Request,ICMP Echo
-
ARPMap IP to EthernetLocal ARP
-
TCP/IPWWW(Acknowledged, TCP)(UDP)ICMP
-
TCP/IP
-
IP: 32(locationIPIP
-
IPIP32bits202.118.66.188(octet)bit
(128,64,,4,2,1)(octet)0255(1)IP(InterNIC)
-
IPIP254AA16777214 (256*256*256-2)64000BB640001600CC254IP
8 Bits 8 Bits 8 Bits 8Bits
A
B
C
D(multicast)224.x.x.x239.x.x.x
E,240.x.x.x
-
IPA01.0.0.0126.0.0.0,126A16,000,000B10,128.0.0.0191.255.0.0,
B65,000C110192.0.0.0223.255.255.0,C254D224.0.0.0239.255.255.0.
8 Bits 8 Bits 8 Bits 8Bits
A
0xxxxxxx
B
10xxxxxx
C
110xxxxx
-
IP
-
IP
Class
10.2.100.3
A
10.
2.100.3
128.63.4.100
B
128.63
4.100
201.225.9.8
C
201.225.9
8
192.6.142.9
C
192.6.142
9
130.113.64.16
B
130.113
64.16
256.241.201.10
IP
10.0.0.00.2.1.1
-
IP
-
()1IP0(202.118.66.0),TCP/IP()IP(Local
Address)()IP202.118.66.0IP202.118.66.1202.118.66.254, (IP
Forward).
-
IP:B65000;.
-
IP:IPIPIP32bit10
-
()IP
-
IP:32IP11202.118.66.8:255.255.255.0202.118.66.8/24
-
()C202.118.72.020,5(),255.255.255.248.202.118.72.0/255.255.255.248:
IP
202.118.72.0~202.118.72.7,202.118.72.0,202.118.72.7,202.118.72.1~202.118.72.6,IP.202.118.72.16/255.255.255.248:
IP: ?,?,?
-
()172.16.2.0172.16.2.1 -- 172.16.2.254172.16.2.255
- :202.112.30.65/255.255.255.252:202.112.30.64,:
202.112.30.65,202.112.30.66,
202.112.30.67,256-252=4,C256/(256-252)-2=62,202.112.30.4*n(0
-
() Internet+11172.163172.16.3.255,172.16172.16.255.255
Flooding:255.255.255.255,255.255.255.255172.16.1.255;
-
Class
201.2.10.60/29
255.255.255.248
26.4.3.18/21
255.255.248.0
172.16.32.4/30
255.255.255.252
159.226.4.1/25
255.255.255.128
-
IPIPID32 IDIPping
-
Email:[email protected];
BBSbbs.dlut.edu.cn(LINUX/UNIX/Networking)
