, Original of this document is at Open Systems. Nets #2/97 http://www.osp.ru/nets/nt_2_97/source/88.htm http://www.osp.ru/nets/nt_2_97/source/88.htm
. World Wide Web (WWW), , , , . , , , : ", ?" - , Web- , .
"" , , , . , , MCI, 50 . . Digital Equipment Corporation (DEC) , . , "" . CERT Coordination Center, "" Internet 130 , 1990 ., 2400 1995 .
( , ) , Internet , . , TCP/IP - , Internet , - "" . TCP/IP, FTP Domain Naming System (DNS).
, TCP/IP, Internet , . , (, ), (, ). , , TCP/IP. - , .
(firewall) , . , - , , , . , .
, , . "" Internet, "", , , . , , , , TCP/IP, "". , , TCP/IP, , . , , , (. " ").
OSI ( 1). OSI, (International Standards Organization - ISO), , , - , . , OSI, , .
1.
OSI.
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, . , , (, ) :
, - , . , .
, , . , IP- . , , ( ), :
( , ), , , . , , , .
, , . , , , , . , .
, "" , , . , , , ( Internet-), IP- . , , , , , - "" .
, , TCP UDP (User Datagram Protocol). (, Telnet FTP), ( Telnet FTP). , , TCP/IP: TCP/IP ( , .. ), .
, Telnet TCP/IP 23. Telnet , , "" , 23 123.45.6.7 (IP- Telnet), - , .
, , . , , Cisco, Internet.
. IP-, (, Cisco Systems, Bay Networks Novell), ( , ).
, , , , " " . , , .
, , . "" () . , "", . , , "address-spoofing" ( ), Internet , , .
(Open Systems Interconnection - OSI) , IP- , "" : , . , .
() ( ), , . , TCP, . . , .
, , . , , , (, DNS- IP- ). , , TCP. TCP-, SYN () ACK ().
TCP, SYN , 1000, . , , , ACK , , ( 1001), , , SYN . : SYN (, 2000), ACK, 2001. .
"" , SYN ACK, , TCP-, .
"", TCP, , . , . , , , . , , .
, (pipe proxies), , , ( TCP/IP) .
TCP/IP, , - . , . Gauntlet Internet Firewall Trusted Information Systems, AltaVista Firewall DEC ANS Interlock ANS ( 2).
2.
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, AltaVista Firewall TCP/IP, , , FTP, HTTP (HyperText Transport Protocol) Telnet. , DEC , TCP/IP, Gopher SMTP (Simple Mail Transfer Protocol), .
: - (proxy server). , - ( ), . - , (address translation), IP- "" IP-. , .
, () . IP- IP-, . , - spoofing ( ), .
"" , OSI, . . , . "", , , "" "" . Web-, .
, , "" . , , .
, , -, , -, . , , : -, , -, OSI.
, , , . , - Telnet , , . , , . , - FTP Telnet, , .
, "" , ( OSI) . , .
, Eagle Raptor Systems, ANS InterLock ANS Sidewinder Security Server Secure Computing Corporation, - FTP, HTTP Telnet. , . , , FTP Put, , FTP-, . , FTP- , .
, , . , BorderWare Firewall Server Secure Computing , , , . Black Hole Milkyway Networks , . Eagle Sidewinder Security Server.
UNIX. Black Hole Milkyway Networks, SPARC- SunOS Solaris. , BorderWare Firewall Server Secure Computing Gauntlet Internet Firewall Trusted Information Systems Pentium , . Centri Firewall Global Internet Eagle Raptor Systems SunOS, Solaris Windows NT.
NetWare, TCP/IP. TCP/IP , IPX, IPX/IP TCP/IP NetWare, (, LAN WorkPlace LAN WorkGroup Novell).
, , , - "" . "", .. , Internet. Internet .
, "", , (.. , "" ). , Black Hole Milkyway Networks , , . Milkyway Networks , , . Gauntlet Internet Firewall Trusted Informa-tion Systems.
"" (, Telnet) , . , . "" , .
, , "" . , CyberGuard NEC Technologies - SOCKS , TCP/IP, Cyber-Guard Firewall PrivateNet . SOCKS , IETF (Internet Engineering Task Force) "" , . SOCKS "" , , . , SOCKS (, ), . , SOCKS, , .
. , OSI, IP- . , , . , , , .
, , , Put Get FTP. , , - .
: - , - . . , , . . OSI. -, . , , , .
- , , , . .
Internet , "" , OSI . FireWall-1 Check Point Software Techno-logies . 1993 ., 40%.
- ON Guard ON Technology. NetWare 3.11, 3.12 4., ON Guard Intel 486 . ON Guard IP-, IPX-, NetWare IP-, Internet , NetWare "" IPX-. ON Guard 32- Secure32OS, ON Technology . , , UNIX Windows NT.
ON Guard, , spoofing, IP- (denial-of-service). , .
, , , . , , 100%- . ? , , , . , . " , ...".
(APPLICATION-LEVEL GATEWAY) . OSI. - , TCP/IP.
- (BASTION HOST) - -, . - , .
(CIRCUIT-LEVEL GATEWAY) . , , . , .
(DUAL-HOMED GATEWAY) - , : , - . , . .
(FIREWALL) , (, , ). . , .
(PACKET-FILTERING FIREWALL) , , , . , TCP- IP- ( , .).
(PROXY) - , , . Internet, , (.. ), . -. , , TCP/IP.
- (PROXY SERVER) - , IP- IP-,