:


Original of this document is at Open Systems. Nets #2/97
http://www.osp.ru/nets/nt_2_97/source/88.htm





 · # 2/97
· . 88-99 










  TCP/IP



  ?



   



 



    ?



  



  



  



  -  






" "



 



 " "
 IntranetWare



    
 Internet  Novell



 





   .    World Wide
Web (WWW),       , 
   ,  ,     .
,    ,     , : ",
     ?"    
      -     ,
  Web-    , 
 .



 ""  ,  , ,
      . , ,
     MCI,   50 . 
 .  Digital Equipment Corporation (DEC) ,
         
 .    ,   ""
 .      
CERT Coordination Center,   ""  
 Internet   130 ,   1990 .,  2400 
1995 .



  TCP/IP



   ( ,   )
 ,  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.








  OSI





 Internet 





 














Telnet, FTP, DNS, NFS, PING, SMTP, HTTP





  ,   









 














TCP





  














TCP














IP





   


























         
,        .  
,    ,  (, 
)      :





        
,   -     , 
      .      
 ,      .



   



       
   ,   , 
    .    
    ,   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.

  .


















 





Web-









ANS, Inc





ANS InterLock





  *





http://www.ans.net









Check Point Software Technologies, Ltd.





FireWall-1





  





http://www.checkpoint.com









CyberGuard Corporation





CyberGuard Firewall





  





http://www.cyberguardcorp.com









Digital Equipment Corporation (DEC)





AltaVista Firewall





  





http://altavista.software.
digital.com









Global Internet





Centri Firewall





  





http://www.globalinternet.com









Milkyway Networks Corporation





Black Hole





  





http://www.milkyway.com









NEC Technologies, Inc.





PrivateNet





  





http://www.privatenet.nec.com









ON Technology





ON Guard





  





http://www.onguard.on.com









Raptor Systems, Inc.





Eagle





  





http://www.raptor.com









Secure Computing Corporation





BorderWare Firewall Server, Sidewinder Security Server





  





http://www.sctc.com









Trusted Information Systems, Inc.





Gauntlet Internet Firewall





  





http://www.tis.com








*      
       
  TCP/IP,   - .




, 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%- .
     ?      
,         , 
 ,         . 
   ,     .  
" ,  ...". 





     ""
     NetWare Connection, 
  NetWare Users International.







   (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-,  
,  ,    (address
translation).



   (STATEFUL INSPECTION FIREWALL) 
       OSI - , 
 .       
 ,        
  .




" "



    "" 
     Internet.



   (Domain Name System - DNS)   
 ,        IP-
 . DNS       , 
   IP-   .   
DNS  ,       "" 
 .  , DNS   
      .



FTP (File Transfer Protocol)     
,      Internet   
  .  FTP-  , , 
    .  FTP-  
       ,   
  (   FTP-).   
  FTP   ,    ,  
   ,    .



Sendmail -   Internet   , 
     ,   IP- .
 ,    Sendmail,   
   ,    ( ).



SMTP (Simple Mail Transfer Protocol) - ,  
   Internet.    , 
  ,   ,      
     .   
        ,  
       .



Telnet -  Internet,     
   Telnet,     .  
       ""
,    .    
  ,        
 .    Telnet,   
   ,       .



TCP/IP -  ,   Internet   
   .     ,
    . ,   
    "" ,   
   ,   .



World Wide Web (WWW) - ,    , 
      
 Internet  .    WWW  
 ,       
 Web-,        
  .         
 WWW,    Web-,   
,      ,   
  .   ,   
Web-         .





 



      (NCSA)
,        
 :        
.



         
 Internet,       .
     ,   
 SLIP (Serial Line Internet Protocol)  PPP (Point-to-Point Protocol).
     ,   
   ""  Internet 
. ,      Internet  
 ,       
 WWW,     Web- PPP- 
 .



         
 .





       
     .    ,
 ""  "" 
  .  ,     
      .





       
 .  ,      ,
    ,   ,  
  .      
     ,   
     .




 " " 
IntranetWare



   Novell  IntranetWare 
 ,    Internet   
      . IntranetWare 
  NetWare 4.11, Novell Web Server, Netscape Navigator, NetWare MultiProtocol
Router (MPR)  IPX/IP Gateway. MPR   IPX/IP   
        Internet 
  .



NetWare MPR -     -  
      IntranetWare.   
FILTCFG.NLM (,    MPR),  
  ,       
   IP-      .
NetWare MPR    ,  FTP, HTTP  Telnet.



 IPX/IP -  ,    
  IntranetWare.       ,
   IPX-   Internet  ,
       TCP/IP.  
 WINSOCK.DLL    ""  TCP
  IPX (  IP).        IPX/IP
   IPX-    IP-. " 
"  ,  ,    , 
 IP- ,     
    IntranetWare.



"" .  WINSOCK.DLL   
IPX/IP ""  .    
Netscape Navigator     ,  www.novell.com.
       IP-  
IPX/IP  DNS,        
         IPX-
 IP  .



  .  IPX/IP    
 .      
   IP-      
Internet. ,      
   Web- ( HTTP,  80)  
 13:00  17:00 .



   IPX    .  IPX/IP ( 
IPX/IP Gateway  Novell, Iware Connect  Quarterdeck  NOV*IX
for Internet  FTP Software)   .
      ,  
 IP-,   ,       .
 -       
,        .





      Internet
 Novell



Novell       
  IntranetWare.   Novell,   IntranetWare
Border Services,  - (proxy cache),  
  (Virtual Private Network - VPN)   .



-    HTML-  
,      ,  
 ,    .  VPN  
     Internet,  
,    .  ,  
    ,   Internet.
 VPN    ,   40-
   RC2.   
    WAN-   
   ,    
 .       ,
  , - HTTP   
   .



 



 IntranetWare Border Service,    
 ,   :





  



   IPX-  IP-,  
 .       ,
       .  
     (NDS - Novell Directory Services),
 ,      .
   ,   
 ,       . 
  ,     NDS, 
  NDS       Internet
  ,      .    NetWare
Administrator,       
     Internet (, FTP, HTTP
 Telnet),   .      
,  ,   Everyone    
  ABCD  8   5 , . .    .



 HTTP



 HTTP    ,  
HTTP-.     ,   
    HTTP    NDS,  
     .  
  HTTP ,    
.          
 IP-, ""    ,
  .



 



IntranetWare Border Services     
  ,  Macintosh  UNIX,     
,        .
 ,      IPX-,    IP-.
  IPX    IPX- 
    IPX,     
 IPX-,     .



 IP-    ,   .
     IP-   
IP-,  ""  IP-  
  ,    Internet ( 
     HTTP).   
    IP-,   
  Internet   , ,  Web -  FTP-.





 



         
  Internet.



FTP://INFO.CERT.ORG  HTTP://WWW.CERT.ORG



 /pub/cert_advisories    
 CERT,      .
          
Internet.



HTTP://WWW.NCSA.COM



      
(NCSA)       (Firewall
Policy Guide).        , 
NCSA,     Web-,    
  . NCSA      
        .
 ,   NCSA,  FireWall-1  Check
Point Software Technologies, ON Guard  ON Technology  Gauntlet
Internet Firewall  Trusted Information Systems.



HTTP://WWW.OUTLINK.COM



Outlink -  ,   
    The Firewall Report,  
      ,      
.      
20    Internet  ,    
  .



HTTP://WWW.TELSTRA.COM.AU/PUB/DOCS/SECURITY



     ,   
   Internet.



FTP://FTP.GREATCIRCLE.COM/PUB/FIREWALLS



           
 .         ,
 .



HTTP://CS-WWW.NCSL.NIST.GOV



        
   Web-,     .






 · #2/97


Bottom Line


Last-modified: Sat, 12 Jul 1997 11:55:01 GMT

  :