PC

NIC (Network Interface Card)PC LAN Interface Card .PCI, 10/100Base-T, Ethernet 3COM, Intel, Realtk

( ROUTER ) LAN . OSI (LLC) (MAC) LAN . . .

. . . . .

(Repeater) . , . . . . .

(SWITCH) . .LAN PC . , .OSI 2 , . 3 , IP .

(Bridge) OSI MAC . Broadcasting .LAN WAN LAN . . .

(HUB) . 1 . . () , .

. . .

! 10Mbps 5 2Mbps 10Mbps .

Ethernet(IEEE802.3),10base-X 10Base5 : Thick Cable, , 500m10Base2 : Thin Cable, , 185m10BaseT : UTP, 100m, Cat.3, 4, 510BaseF : Fiber Optic Cable, 2Km

Fast Ethernet,100base-X 100Base-T4 : UTP, 4Pair , Cat.3, 4, 5100Base-Tx : UTP, 2pair , Cat.5100Base-Fx :

1. 2. 3. 4. 5.

(PROTOCOL) . (Syntax) : , , (Semantic) : , (Timing) :

OSI(Open Systems Interconnection) 7 Layer ?1984 ISO (International Standard Organization) OSI . . .

(Physical layer)OSI . . , , . . .

(Data link layer) , . . , . .

(Network layer) . . , , . , . .

(Transport layer) . , . . , , . () TCP, UDP .

(Session layer) . , . (checkpoint) . .

(Presentation layer) . , . , , , .

(Application layer)OSI . , e-mail . ( http, ftp, telnet, smtp)

IP(Internet Protocol) , , .

OSI 7 Network Layer . TCP . . IP . 65,535. . , .

TCP(Transport Control Protocol) (TCP) . TCP , . TCP . , , .

TCP . (Virtual Circuit) .OSI 7 (Transport Layer) . FTP, HTTP, Telnet.

TCP/IP

TCP/IP Hardware Interface(Ethernet, PPP )IPICMPARPRARPTCPUDPUser Application(HTTP, FTP, Telnet )

TCP/IP Network Layer( )OSI 48bit MAC(Media Access Control) Address IP ARP/RARP

Internet Layer( )IP(Internet Protocol)TCP, UDP, ICMP ICMP(Internet Control Message Protocol) ARP(Address Resolution Protocol)IP Hardware RARP(Reverse ARP)Hardware IP

Transport Layer( )TCP(Transmission Control Protocol) full-duplex, byte stream TCP .UDP(User Data Protocol) UDP datagram

Application Layer( ) HTTP, Telnet, FTP, SMTP, POP3

IPX (Internetwork packet exchange) (NetWare) 386 . (XNS) , OSI 3 (CL) . (IP) , .

SPX (sequenced packet exchange) (Novell, Inc.) (NetWare) . (XEROX) XNS(XEROX Network System) , OSI 4 (connection oriented) .

IPX / SPX ( Internetwork Packet Exchange / Sequenced Packet Exchange ) 1980 Novell . Novell Netware Protocol. IPX/SPX IPX SPX , IPX TCP/IP IP , SPX TCP .

NetBIOS MS IBM PC-LAN (API). API (LAN) , NetBEUI(NetBIOS extended user interface) . (PC) NetBIOS .

NetBIOS . 1. NAMING: . 2. Session: . 3. Datagram: Datagram .4. 5. () .

TCP/IP (Transmission Control Protocol/Internet Protocol) , . TCP/IP , TCP/IP , . TCP , .

IP , . , . TCP , .

HTTP , Telnet, FTP SMTP . , , , 4

. .2 . , . , , . , , .

IP : : 32bit 8bit 4 , (.) 10 NIC(Network Information Center) , IP 4bytes(32bits) (.) 10 . 203.172.112.72 10 . IP Class A, B, C, D, Class E. Class A, B, C IP 4Bit .

(Subnet Mask) IP ID ID . IP . .(SubNetting)(Supernetting)

IP 4 , 4 ID/ ID . IP , ID ID .Class A 255.0.0.0 (Host 224 -2 )Class B 255.255.0.0 (Host 216 -2 )Class C 255.255.255.0 (Host 28 -2 )

IP VER 4 TCP/IP TCP, UDP, ICMP, IGMP IP . Internet . host 4 (32bit) dot(.) NIC (Network Information Center) /. Best effort (Connection-less) Hop by Hop . . (MTU Size) network IP : network routing / network 32bit IP

IP version 6 IP (Expanded Addressing) (Scalable Routing) IP V4 IP V6 Address size = 128bit(16 bytes)Header format . extension header: networking audio and video: flow labels and QoS

IPv6 address dotted hexadecinal notation or colon hex 104.230.140.100.0.0.0.0.0.0.0.5.150.10.255.255 68E6:8C64:0:0:0:5:96A:FFFF zero compression ( address ) 68E6:8C64::5:96A:FFFF IPv4 dotted 10 IPv6 68E6:8C64:0:0:0:5:150.10.255.255 zero compression 68E6:8C64::5:150.10.255.255

TOPOLOGY . , . , (Star), (Mesh), (Bus), (Ring), (Tree) .

BUS Topology : . . .

Ring Topology : . Ring , , .

(Tree Topology) (Head-and) (Branch) , ,

Star Topology: . .

(Mesh Topology) . Bus-Star ( ) star .

BUS . . XXXX .XXXX

IPCONFIG Ipconfig.exe DHCP( ) IP . IP /showclassID adapter DHCP ID ./setclassIDadapter [classidtoset]. classid classid . /all, /renew

PING ping IP ping IP ICMP . TCP/IP ping . ping . ping IP_address ping . Ping TCP/IP . PING IP

ping 127.0.0.1 IP IP . ping IP_address_of_local_host IP . ping IP_address_of_default_gateway IP .

TRACERT . (ICMP) . c:\>tracert www.empas.com

NSLOOKUP . , . IP . .Windows NT/2000

1. E-mail() . . POP3 ( )SMTP ( )

2. FTP() File Transfer Protocol ., , , , , , .

3. Gopher() .

4. Usenet() PC .

.

5. Telnet . .

6. (WWW : World Wide Web) , , , ., , , . (HTTP) .

HTTP (Hyper Text Transfer Protocol) , , , , . . HTTP(Hyper Text Transfer Protocol; ) (Daemon) . HTTP HTTP .

Fire-Wall()

PROXY SERVER ( ) . . (Firewall) , www FTP . , . .

File server (LAN) . LAN , .

DNS (Domain Name Server) SERVER IP . IP IP . IP 147.46.80.205 4 sis.snu.ac.kr

URL ( Uniform Resource Locator )? HTTP, FTP, , e-mail, , . URL .

, ( ), . (syntax) :// / / .URL . URL , , , , . Protocol://host.domain/directory/file URL http , ftp, news .

PC . e- , . PC . . , ID(e-mail address) . ID PC , .

POP, SMTP

SMTP(Simple Mail Transfer Protocol Server) .SMTP= =POP3-Post office Protocol 3 POP3 .POP3= =

SMTP POP3

IMAP(Internet Mail Access Protocol) , .IMAP , , , .

NNTP(Network News Transport Protocol)

SNMP simple network management protocol TCP/IP (RFC 1157). (Router), (Hub) (network agent) .

TCP/IP (SGMP:simple gateway management protocol) , (OSI) (CMIP) . 2 , . 1988 RFC 1157 (SNMP) , 1991 SNMP2 SNMP2 .

Watermarking . , .

. .

PGP (pretty good privacy) . , . 3 .

S-HTTP secure hypertext transfer protocol (HTTP) . SSL(secure sockets layer) .S-HTTP HTTP SSL HTTP (FTP) (Telnet) (TCP) .

1. 2. 3.