2

, , . , , .

.

5 . , 1, 2, 3, 4, 6, 7, 8 9 - . .

, . 2010 .

3

............................................................................................................................... 5 TCP/IP .............................................................................................. 7 1.1 TCP/IP ............................................................................................... 7 1.2 ................................................................................................. 11 1.3 .................................................................................. 18 1.3.1 TCP ................................................................... 19 1.3.2 UDP .................................................................. 43 ......................................................................... 48 2.1 ........................................................................................ 48 2.2 ..................................................................... 49 2.3 .................................................................................................. 62 ............................................................................. 79 3.1 ....................................................................... 79 3.2 .................................................................................... 87 3.3 .................................................... 93 ......................................................................................... 98 4.1 ................................................... 98 4.2 .................................................................. 117 4.3 ................................................................................... 124 4.4 ................................................................................ 136 4.5 ............................................................................................... 148 4.6 ................................................ 150 ......................................................................................... 158 5.1 .......................................................... 158 5.2 ............................................. 177 5.3 .......................................... 181 5.4 ............................................................................ 186 5.5 ................................................. 200 5.6. ... 206 ........................................................................................ 213 6.1 ..................................... 213

4

6.2 VPN ............................................................................................. 216 6.3 VPN .............................................................................................. 226 ............................................................................................... 232 7.1 ............................................................. 232 7.2 ........................................................................ 236 7.3 .............................................................................. 253 . ........................................... 274 8.1 .......................................... 274 8.2 ............................................................ 288 .................................................................... 300 9.1 SNMP ................................................................... 300 9.2 , . 312 ................................................................................................................ 327

5

,

. . .

, :

, , , ,

, .

(switches), (routers) (firewall) .

. : Scan Disk,

Defragment .

.

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. ,

.

.

, .

6

, TCP/IP.

, .

, .

, , .

, .

, , .

, Internet. (VPN), , . VPN .

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, . .

7

TCP/IP

TCP/IP (Transmission Control Protocol/Internet Protocol)

.

, . , , . , . () , - . .

, . , , . (, router). IP (IP ) , , , IP TCP/IP.

: ,

; , .

. ,

. , , IP . , .. , . IP . IP . , IP .

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.1.1 TCP/IP.

:

8

, TCP/IP . , . TELNET, FTP, SMTP . ;

, . . TCP UDP (User datagram protocol). UDP . , UDP , . UDP , .

. - . IP (Internet protocol) - . . , . - . , , . . IP . - ICMP, ARP RARP.

. . , , , , . - -. TCP/IP , - . IEEE 802.2, ATM, FDDI .

- TCP/IP . TCP/IP .

: , .

TCP/IP : TELNET ; FTP (File Transfer Protocol)

;

9

SMTP (Simple Mail Transfer Protocol) .

. 1.1

, . TCP/IP - - . TCP UDP . , UDP . . - , - . , , UDP - .

TCP/IP . , TCP/IP / (.1.2) . , ( ) . , . . () .

10

. 1.2 -

, , TCP/IP .

, , ( ) . .

, ( IP ), . , . , , , . , .

( ) (). (routers), (bridges) (gateways).

(bridge) . bridge MAC (Media Access Control) - , LLC (Logical Link Control). bridge IP. , IP , , , bridge .

(router) . , , .

11

- . IP . - , IP.

(gateways) gateway / IP . gateway / - . . / , . Gateway IP . gateway, , . , (firewall). .

1.2 IPv4

INTERNET, IP- - INTRANET .

TPC/IP , .1.3:

. 1.3

IP (Internet Protocol) e , . IP , - - , . ().

12

ICMP (Internet Control Message Protocol) e . .

ARP (Address Resolution Protocol) e IP . IP ( ) () (-).

RARP (Reverse Address Resolution Protocol) e MAC . () (-) IP- ( ).

.1.6

IP , .

. 1.6

, , .. . :

(Transmission Control Protocol) e :

, ;

.

IP - . TCP .

13

, TCP, UDP (User Datagram Protocol). , .. , .

IMCP

ICMP (Internet Control Message Protocol) ICMP DATA- IP-

.

, :

Destination Unreachable ( IP ); Time to Live Exceeded ( ); Parameter Problem ( ); Redirect ( ); Echo ( IP ); Echo Reply ( IP ); Timestamp ( ); Timestamp Reply ( ) Information Request ( ); Information Reply ( ); Address Request ( ); Address Reply ( ).

.

ARP RARP

, , . , , .

ARP IP- MAC-. , , IEEE 802.3 Ethernet. IP , ARP-, MAC-. ARP , IP- , , broadcast MAC-. MAC- , . , IP

14

IP . , , - MAC-. , ARP- MAC- MAC- .

RARP (Reverse Address Resolution Protocol) ARP. , MAC- IP-. , broadcast IP-, IP .

1.3 ,

, .

, . .

, , . , , , , .

:

;

, , , , ;

, .

, .

, , , ,

15

( ). .

, (Point to Point), .

. , . , - .

- , .

.

TCP/IP - , TCP (Transport Control Protocol) UDP (User Datagram Protocol) .1.7.

. 1.7

1.3.1 TCP (Transport Control Protocol) () TCP/IP

5 : - (

) , , 8- , . , ;

-

16

. , () . , "", . , (authorization), . , , . . (. ), . , , , , ;

- . , . , , . , . 3 , , . , , . , , - . , , , push , , . , . , push TCP . , push , . , , ;

- , TCP/IP . , . ,

17

;

- - , TCP/IP , . -. , - , , . , , -. - , , . .

.1.8 TCP- .

. 1.8 TCP

, IP- , . 1.9.

HTT

P

SMT

P

FTP

TE

LN

ET

SNM

P

UD

TP

..

TCP UDP Internet IP v 4.0

. 1.9

18

TCP: World Wide Web HTTP (Hiper Text Transfer Protocol) ; (MAIL) SMTP (Simple

Massage Transport Protocol); FTP (File Transfer Protocol) .

. UDP: SNMP (Simple Network

Management Protocol) ; UDTP (User Define Transport Protocol)

.

. :

255 ; 256 1023 ; 1023 .

. 1.11

, , (Dest. port) , 23 TELNET . 1.11.

TCP () , . 1.12.

19

. 1.12 TCP

, .

TCP .1.14

. 1.14 ( )

TCP

, , , .

, - . , . , ,

20

. , . -, .

" " -. , ", - , .

, , , . , .

, , , - , ( , ). . TCP . -, -, TCP -, TCP . TCP , , .

TCP , . , , .

1.3.2 UDP (User Datagram Protocol) TCP/IP

, (). UDP , -, . .., , UDP - -, UDP , .

UDP I , , IP. To (acknowledge) , , , . UDP ,

21

. - , . UDP I . I , .

, UDP, , , , , . , . , , , . , UDP, , TCP/IP .

.1.15 UDP-

. 1.15 UDP

TCP . .

SOURCE PORT ( ) DESTINATION PORT ( ) 16- UDP , , . . , . , 0.

LENGTH () , . , 8, .

22

. 0 , . , UDP . , , IP . UDP , , .

UDP , 0. , UDP , I: 16- . , , "" : 0 1. 0, UDP .

UDP , UDP . UDP - , 16- . - , . - 0 , - , .

- UDP . , . UDP . , , UDP , UDP I . UDP IP , IP , UDP . , .

, - . , - . - - . . UDP, UDP , IP -, , UDP IP -. , UDP -,

23

, UDP -.

:

IP npe ;

UDP .

IP ; UDP .

: ? ,

. , ,

. . . " " . . " " " ".

. . , , .

" ?" , .

, , , .

/I , , . , - .

TCP

, . , .

, TCP . , ,

24

. , .

, TCP , . (, TCP ). , .

TCP . push.

TCP , , . , TCP

25

2.1

. . , . , ", .

. , ". , .

- , - - . ..

. :

?

, . . , , :

, ; , ; .

. - . , . .

: ,

; ; , ;

26

, ;

, , ;

, ; ,

. : , , ,

,

.

.

, ( ) .

, - , . ", , .

. .

(Distributed Denial of Service, DDoS) , , . . , , .

2.2 ,

. , .

27

, , . .

, , .

- - .

, . , , (VPNs), dial-in. , , , , .

.

, - . - - . . , , , .

, .

, - . , , - .

, .

:

(LAN). LAN

28

. , , .

. - ( , ), (, " ", ) . , ; .

:

; Denial of Service (DOS); IP ; ; .

. . . , ".

:: ( )

,

. , . , . , , . . 2.1 .

29

. 2.1

, -

: 1 - DNS , . 2 - ing, . 3 - , . .

Internet Control Message Protocol (ICMP) , ping , . ping; , IP , .

(IDS) , . - (ISP), , .

(

) , . , .

, , ( FDDI, 10BASE-T 100-Mbps Ethernet), .

30

2.2, Ethernet , Wireshark TCPDump, Ethernet .

. 2.2 Wireshark/TCPDump

/ Ethernet Wireshark. , Wireshark; , . , , , . , , , .. .

2.3 , .

.2.3 Ethernet

31

100BASE-T Ethernet . (Content Address Memory, CAM), . , , . , , .

. -

, . (Access Point, ) 150 . , , . . . , , . Service Set Identifier (SSID) IP , , , , .

802.11 , Wired Equivalent Protocol (WEP), . WEP , . - - Temporal Key Integrity Protocol (TKIP), Light Extensible Authentication Protocol (LEAP), Protected Extensible Authentication Protocol (PEAP) .. , . .

2.4 , . - , , , dial-in - - , , , , .

2.1 .

32

. 2.4

(IP , Spoofing) , .

IP () . , IP , . , , .

(replay) , - , . , . , - .

. . , .

, . , -. , , . , , , - .

33

, , . . , - .

, , - ". , , . .

(DoS) -

, . , .

DoS , - IP.

DDoS , DoS

. (DDoS), DoS . DDoS 2.5.

. 2.5 DDoS

DDoS , , . , . . ,

34

. , .

. DDoS , . - , - . - , . , , , , , .

2.3 .

. , .

. , . .

IP , ( TCP, ICMP, UDP, DNS, NNTP, HTTP, SMTP, FTP, NFS/NIS X Windows).

TCP/IP ,

. 2.6 .

. 2.6 TCP/IP

35

( -), - , .

TCP RFC 1948, . . , , .

- . (, ), , . (, ), .

TCP/IP TCP/IP

- . , , . , .

. - , .

SYN TCP , SYN

(/) - SYN/ACK ( ) . () SYN/ACK . TCP .

SYN/ACK, - , . , SYN/ACK.

TCP SYN - TCP SYN . - SYN/ACK . SYN/ACK , - . TCP SYN IP , TCP

36

( email, WWW ) .

UDP TCP, User Datagram Protocol (UDP) -

. UDP . , . UDP , , .

, UDP , UDP - , TCP . , UDP- .

ICMP Internet Control Message Protocol (ICMP) IP

. ICMP - , ping traceroute.

ICMP IP . RFC 791, IP

65 535 (216 - 1) ; ( 20 , IP ). , - (MTU), - , .

MTU ( 2.3). Ping of Death Ping of Death ,

ICMP echo (.. ping"). ICMP echo

ICMP , ping . , :

, ICMP echo 65 507 , . , .

Ping of Death ping - . TCP/IP IP .

37

email email . Email , email . Email ; email ( , ). Email , email, .

email , , :

. ,

W32.Sobig.F, 2003 . SMTP , . From Send To , .

-

. , , . " , , , , .

.

DoS . , , - . LAN.

, , , , ,

38

. , .

WEP 802.11 WEP

LAN (NIC). WEP RC-4 . , , IEEE 802.11b 40- , 128- . WEP , 40- , 128- , .

, , , .

, DoS. , .

- , . , , - .

39

, .

() . ( () () . . , . .

, .

- 3.1. , , , . "" , iptables.

Internet.

. 3.1

, . . " " (Access Control List, ACL). , .

-, , , , IP-

40

, "" ().

, -. 3.2 /.

.3.2

. , , , . , :

,

, -, - . ( , ).

,

.

41

, .

.

, , , - .

- : , . , , : 10 100 Mbps 1000 Mbps, 800 Mbps. .

, (, , ..), , ( , ..), , -.

, ,

. , ,

. ( )

. , , .

,

( 3.4). , . , IP- , , "" , ( ), "" .

:

Check Point.

42

TCP,

" " (SYN, SYN/ACK, ), , (FIN RST).

: IP- , IP- TCP .

. : , ( ) () . , TCP c , .

Stateful Inspection Check Point

. , Stateful Inspection - , - (.. ).

Stateful Inspection Check Point, ( PIX Cisco iptables Linux) .

. , , ( ), , (. 3.6).

. 3.6.

43

" ", , , , , .

(" ") " ".

, . " " ( , SOCKS) , , .

, ,

, , , , .

, - ( ), - . , - .

(.. ), . . - ( ) Linux FreeBSD

- , - - . - - , - , . - -, - .

, ,

, . ; ; , , ( chroot); . - (

44

), tripwire AIDE.

. - , .

, , , , , . wheel root (.. su root).

IP IP-

, . , ..

IP- . - (Denial of Service - DoS), , () . , .

iptables IP- : iptables -I INPUT 1 -i eth0 -s 192.168.0.0/16 -j DROP iptables -I INPUT 2 -i eth0 -s 10.0.0.0/8 -j DROP iptables -I INPUT 3 -i ethl -s ! 192.168.100.0/24 -j DROP iptables -I INPUT 4 -i eth2 -s ! 10.0.0.0/8 -j DROP

, iptables Linux 2.4, .

( , Dropping) "", .. .

( , Rejecting) TCP c RST, TCP, "Port Unreachable" ICMP, UDP.

, ,

. ,

. -

HTTP 80, TCP 80 . Code Red (), Code Red

45

.

. , .

, DNS, DNS- ( ), DNS-.

.

,

. ,

. , , TCP 80, , .

( ), , , ( , ).

, " " - - .

.

.

,

. .

-.

, , . .

46

4.1. ,

, . (network operating system NOS) , .

, . , . , NetWare NT Server, .

- . ( ) - , RAM - , , .

- (peer-to-peer) .

- , , . . , , , , .

4.1 , / .

47

/ , Access ( ), . , . , / .

/ . / , SQL Server Oracle, - , .

/ /

: . (distributed), ,

. 4.2 .

. 4.2

.

(data warehouse) ,

.

48

, PC- . , , (server farm).

. , Windows, no . , , (creating a share).

, NetWare, - .

Windows , File and Print Sharing . Windows 2003, server.

(share-level security) (peer-to-peer) , Windows. , , , . , , .

, , (.4.3)

. 4.3

Ivan

Ivo

Maria

Ana

Ivan, Maria

Ivan, Ivo

Ivo, Maria

Ana, Maria S4d2f5

1q2w3e

3q4w5e

5f6g7y

4

3

4 - S4d2f5

1

2 4 - S4d2f5 3 - 5f6g7y 1 - 1q2w3e

1- 1q2w3e

2 - 3q4w5e 3 - 5f6g7y

2 - 3q4w5e

49

(user-level security) - , . (user account), . ( ) . , . , (access control list), . , . , , , .

.

- . , , ( ). .

: , .

Windows XP Windows ,

. .

, , .

, .

, ,

. , . Local Users And Groups.

- , Active Directory,

-. Single Sign-On ( ) . - Active Directory Users and Computers.

50

logon- (, ).

:

, Windows,

. , , : Administrator Administrator ,

, , . . Active Directory Administrator . Administrator .

Guest Guest , . , , , . , , Windows.

HelpAssistant Windows , . , , HelpAssistant. , Terminal Services.

Support Support Help And Support. HelpServicesGroup Log On As Batch Job ( ). Support . Support_, , Support_388945aO.

, Windows .

. , . , .

, .

Active Directory , \, \

51

Windows XP : (local groups)

. Local Users And Groups.

(security groups) . Active Directory Users and Computers.

(distribution groups) . . Active Directory Users and Computers.

Local Users

And Groups. Control Panel. Administrative Tools Computer Management (.4.7).

.4.7

, , , .

Local Users And Groups :

.

, , . , SID .

52

,

, , . Windows , Windows NT Windows 2003, .

, , .

,

Windows, , Everyone, . , .

(share names), - - . , , salesdocs, Sales Documents; .

, .

4.2 (NOS)

. NOS , - ( , , ), .

, , :

Windows NT Windows 2000(2003,2008) NetWare UNIX/Linux

Windows NT 4.0 Microsoft , User Manager

for Domains, , . : Start, Programs, Administrative Tools, User Manager for Domains.

User Manager for Domains ; , ; ; ; . , .

53

. Windows NT 4.0 .

Administrator () Guest ().

Windows 2000 Windows 2000 -

Microsoft Management Console (), snap-in - , . snap-in , Active Directory Users and Computers. , Start, Programs, Administrative Tools, Active Directory Users and Computers .

Windows 2000, Windows NT 4.0, , , , (organizational units - OUs).

OU.

- , Windows NT 4.0.

Windows Windows .

: Windows Explorer net use

Windows Explorer Windows Explorer,

Windows Explorer. ,

Tools, Map Network Drive .

Explorer, , CD .

Windows Explorer, My Computer, , shortcut.

net use Windows

, (Universal Naming Convention - UNC).

: \ \ __\ ___

, :

54

net use __: \ \ __ \ ___

Windows Windows

. , ,

Printers and faxes, Control Panel, .

Sharing, Shared as .

, : Add Printer Wizard, net use .

Microsoft (wizards), .

, Printers and Faxes, , .

( ) " . (print spool).

UNIX Linux UNIX . (.., ,

) , , .

UNIX , Silicon Graphics Sun. UNIX (graphical user interface - GUI), X Window.

UNIX Linux (Network Information System - NIS),

Sun Microsystems, UNIX . NIS , , ( ), .

, UNIX, Windows, (case-sensitive); . MyDocs" mydocs." .

55

Web , Web , UNIX-, . Web WebSite.html", Website.html", file not found" ( ).

UNIX Linux,

adduser . root supervisor

. : ___: /# adduser

/etc/passwd. UNIX/Linux , ,

, (vi, Pico Emacs UNIX/Linux.)

. , , , , passwd. UNIX/Linux Windows.

4.3 (network

operating systems NOS) e . (directory service)

, .

, : , .

, . (). , () .

, , .

, , . () . . , .

- , . , , . , , , .4.8.

56

, ,

. (.., ) (.. ). , .

: . .

. ,

.

, . , .

. , , .

- PC Novell NDS

Microsoft Active Directory.

NDS 4, NetWare NDS - ,

. , , .

NDS . : (container objects) (leaf objects). , ; " - . . OU .

Microsoft Active Directory C Windows 2000 Server, Microsoft

, - , Novell NetWare 3 4. Active Directory . NDS

57

Novell , , Active Directory Microsoft , .

Active Directory Active Directory :

Active Directory Active Directory Shared System Volume .

, . Shared System Volume ( Sysvol) (group policy objects) Windows 2000 . , Windows 2000 , .

Active Directory DNS Active Directory DNS

DNS, . DNS Windows 2000 . DNS Active Directory, - DNS.

Windows 2000 Dynamic DNS (DDNS), DNS .

Active Directory Active Directory

(access control list - ACL), , . .

: -

, - ,

,

. Windows 2000

, . .

4.4

.

58

, Windows NT, Windows XP Linux, , . , .

,

, . :

. ,

. (

), .

, (wallpaper).

, , . . , . , , , .

,

. , , , . .

, . Windows NT Windows 2000 Server, , , . NetWare - .

, , , , , , .

59

, , , . - ". , , . .

. , . , , . -, .

, .

,

. ,

, , . , Windows 2000, . , .

, , . , , .

, , .

, , .

, .

, , .

, .

Active Directory.

.

60

, .

:

.

.

,

, (administrative templates). , , Windows .

Administrative Templates Group Policy. , , , . Computer Configuration User Configuration . , - Group Policy, Windows.

, , . HKEY_LOCAL_MACHINE, - HKEY__CURRENT_USER. - , - , , Administrative Templates Group Policy.

: Not Configured

. Enabled

. Disabled .

. 4.5

(). , , .

61

. . . (log ).

.

.. , .

- , . , . ( ) , .

, .

, , . MB (Mega Bytes) GB (Giga Bytes).

4.6. 4.6.1

. ,

.

, , , , , , , .

. , , .

62

- , .

, , , .

4.6.2

. ,

, .

.

:

()

4.6.3

, : , , . .

, .

.

, , .

. ( ):

- , , .

- , .

- ,

63

( ).

4.6.4

. .

, .

( ) {redundant array of independent (inexpensive) disks - RAID).

- : (RAID

level 1) - , . . . , . , .

Windows NT boot.ini.

(RAID level 1) - , , . , , , .

() (RAID level 3) - , . ( , , ). , .

() (RAID level 5) - , RAID 3, , ( ) , . . , .

RAID , . RAID - -, -

64

. , Windows NT Windows 2000 Server, RAID.

65

,

. , .

(authentication), (authorization) (access control) . , - , . , , , . , , .

( , , -, , ..}.

, ; . , .

, (, ) . (integrity) , ; (confidentiality) , .

5.1

, " . ( ) , . .

. .

66

" .

. 1, 2 .., " :

4-9-14-14-5-18 9-19 18-5-1-4-25 "

: Dinner is ready ( ) , ()

. -. - (key), ,

, . . , .

- , - . 40- 56- , 128- .

: / .

, , . , .

/

, - / (public/private key encryption), - , . . . , , .

, ; .

67

, , . .

/ . , , , , . ( ), . , , , .

.

,

. , , . , .

.

( ), (message digest). ", () , .

,

, {certificate authority). , . , , .

,

. . , . , , , . . , , . ,

68

, . () . , , .

- , (local control), , (trusted third party).

IP point-to-point -

. IP , (/) - , , , , . Link Control Protocol (LCP) Network Control Protocols (NCPs) . , , , .

(PDR) High-Level

Data Link Control (HDLC), ISO 3309-1979 ( I5O3309-1984/PDAD1).

LCP NCP . LCP , . , LCP :

1 2 3 4

point-to-point , LCP , . , . NCP , IP.

69

NCP . , . , dialup , . .

Password Authentication Protocol (PAP)

. .

, . .

. , . . ". .

PPP Challenge Handshake Authentication Protocol Challenge Handshake Authentication Protocol (CHAP), RFC

1994, . CHAP .

HAP . .

. , . , . , .

CHAP . . .

CHAP .

70

P Extensible Authentication Protocol PPP Extensible Authentication Protocol ()

, . . , .

; , . , , - , , . , .

- .

, -

. TACACS+, RADIUS, Kerberos, DCE FORTEZZA. TACACS+ RADIUS dial-in . Kerberos , , , , , , , .

5.2 , Telnet, FTP

HTTP, . end-to-end , . . , . . WWWeb - , : Secure HyperText Transport Protocol (SHTTP). Secure Multipurpose Internet Mail Extensions (S/I) MIME, - .

5.3

71

. , , . end-to-end , .

Secure Socket Layer/Transport Layer Security Secure Socket Layer (SSL)/Transport Layer Security (TLS)

, ( HTTP, Telnet, NNTP FTP) TCP/IP. , , , , .

SSL , - , , , , SSL TCP .

SSL . SSL , , , (handshake, alert, change cipher spec application).

SSL/TLS HTTP . SSL/TLS 5.2.

Secure Shell Secure Shell (SSH) (login)

. , X Window System . , . SSH SSH , ,

SOCKS Socket Security (SOCKS) e ,

. / TCP UDP .

5.4

IP TCP/IP.

72

, , . (, hop), IP . IETF, IP ; IPsec.

, / IP .

IP Security IP Security (IPsec) ,

IP .

IPsec includes , , , ( ), () . IP , - ( TCP, UDP, ICMP, BGP ..).

, IPsec ,

ESP, IP.

ESP , . IPsec ; , . , . - , .

: ,

; ( ) . IPv4, IP - ( TCP UDP).

, - , IPv4 , .

73

, . . . , " IP IPsec , " IP . " IP , ; " . " IP ; " .

IPsec /

. , .

- ( -) , SA , . , , . , IPsec , . . -, , . IPsec Internet Key Management Protocol (IKMP), Internet Key Exchange (IKE). IKE IPsec, .

5.5

. dialup (VPDN) dialup . , dialup .

74

:

Layer 2 Forwarding (L2F) Point-to-Point Tunneling Protocol (PPTP) Layer 2 Tunneling Protocol (L2TP)

Layer 2 Forwarding Layer 2 Forwarding (L2F) Cisco Systems. -

L2TP, , . L2F .. High-Level Data Link Control (HDLC), HDLC Serial Line Internet Protocol (SLIP) - - .

dialup , dialup . , IP, IPX AppleTalk dialup, SLIP/PPP .

oint-to-Point Tunneling Protocol Point-to-Point Tunneling Protocol () Microsoft

IETF, RFC 2637. / , IP , NAS.

NAS NAS : PSTN ISDN

LCP

IP , GRE PNS-PAC

. , PNS-PAC . , . , PNS. . , TCP, , , .

Layer 2 Tunneling Protocol L2F, , Cisco

Microsoft, , , Layer 2 Tunneling Protocol (L2TP). RFC 2661 L2TPv2. L2TP

75

, , L2TPv3, - - . L2TPv3 , L2TPv2.

L2TP : . ,

, .

, dialup CHAP, PAP, EAP ( V.120 ). TACACS+ RADIUS , , . , ISP.

, dialup . , ISP.

, dialup.

ISP ( ) ( ).

PPPoE over Ethernet (PPPoE) RFC 2516

. . ADSL , , .

: . Ethernet MAC . --, / . , . , , , Ethernet.

, . , ,

, . - , .

76

. () (, ). , , .

IPsec IP . - , IP , IP , . IPsec , TCP ( UDP). , ( QoS, TCP/UDP ), .

, . PKI . PKI - , .

77

.

7.1. 7.1.1 (Quality of Service, QoS)

, Frame Relay (FR), Asynchronous Transfer Mode (ATM), Ethernet 802.1 , SONET IP , .

QoS , () , . , . QoS , , WAN .

QoS . QoS , , .

QoS : - . ,

, , WAN . , FTP .

- - . , - .

- . QoS .

- . QoS , WAN , .

78

. , , .

- . QoS , .

// , . . , - , .

: - (Priority Queuing, PQ); - (Custom Queuing, CQ) - (Weighted Fair Queuing, WFQ) - (Class-Based

Weighted Fair Queuing, CBWFQ). ,

QoS , , . QoS , , , .

QoS , .7.2:

- (Best-effort service) QoS, - . FIFO (First In First Out) , .

(DiffServ), QoS - , - , - . , . QoS PQ (Priority Queuing), CQ (Custom Queuing), WFQ (Weighted Fair Queuing) WRED (Weighted Random Early Detection).

(Guaranteed service), QoS . (RSVP - Resource Reservation Protocol)

79

CBWFQ(Class-Based Weighted Fair Queuing).

,

. , - .

(ACL). PQ CQ. PQ CQ , . , QoS . CBWFQ . IP .

(CAR) , . , , ... - , , .

- (NBAR) -. URL HTTP . , .

QoS (Policy-Based Routing, PBR)

, . IP , - , QoS . , . , QoS .

, , , ACLs.

80

(Network Based Application Recognition, NBAR). NBAR , . , - . , NBAR . - , URL MIME HTTP . - , web-. . , NBAR , . , .

NBAR , . . NBAR , .

NBAR (Packet Description Language Module, PDLM), . Flash , RAM. .

, . . :

, (FIFO First-In, First-Out) (PQ Priority Queuing) (CQ Custom Queuing) (WFQ Weighted

Fair Queuing)

(CBWFQ Class-Based Weighted Fair Queuing).

. , , . , .

81

.

FIFO: - (.7.6), FIFO

, .

FIFO , .

: - FIFO

- . - FIFO

(delay) .

- , FIFO .

: FIFO

.

FIFO , . FIFO , - , FIFO.

FIFO UDP TCP . , TCP , UDP . TCP , FIFO , TCP FIFO.

PQ. .

- , .

, . PQ

82

(IP, IPX, AppleTalk), , , ..

PQ , , . , (.7.7). , - .

PQ , , , WAN , .

CQ - CQ (Custom Queuing) e

. , . CQ . , . , .

PQ, CQ .

WFQ:

, , , , .

WFQ , . , - , , - .

- , (. 7.9).

WFQ e . . , WFQ

83

, - E1 (2.048 Mb/s).

WFQ: . (CBWFQ)

, - . , CBWFQ. , , () CAR .

CBWFQ . , , . .

CBWFQ , - - .

CBWFQ . - , . , . , , .

, - (Low-Latency Queue, LLQ), . PQCBWFQ (Priority Queue Class-Based Weighted Fair Queuing).

LLQ . . .

CBWFQ IP RTP IP RTP (RTP Real Time Protocol).

.

, , . , . (Weighted Random Early Detection, WRED).

84

WRED: (Random Early Detection,

RED) . RED , . , . RED TCP IP .

WRED RED IP . - . - ,

RED WRED TCP ,

, . TCP , . RED.

, .

- RED :

, .

, .

- RED , . .

- RED : , . .

7.3 QoS 7.3.1 FIFO FIFO - ,

. , , , . FIFO FCFS First Come, First Served.

, , FIFO , (default). ,

85

. tc FIFO eth0. #tc qdisc add dev eth0 root pfifo linit 10

tc , . qdisc ( class filter, ); add ; dev eth0 , eth0; root , ( FIFO , ); pfifo , pfifo (packet-fifo); pfifo - limit 10, ( , ) 10 .

: #tc qdisc show dev eth0

: qdisc pfifo 8001: dev eth0 limit 10 p

tc , pfifo 8001: ( 8001:0) 10 . , - 32- 16- 16- . 0 .

pfifo , . tc 8001:0.

: #tc qdisc del dev eth0 root

86

.

8.1 ,

, -. - . , . , . , ( ), .

. , .

Linux syslog . syslog, , , . , , .

, - () . , .

, /etc/cron.daily/aaa_base_rotate_logs. T e ; /etc/logfiles, , , , ( ), .

/var , , - /var , .

, , . ,

87

, .

syslog syslog ( klogd),

. syslog , .

Unix Linux syslog . syslog , , , . , - .

, (- /etc/init.d/syslogd /etc/init.d/sysklogd Linux). klogd, Linux.

klogd . , syslogd.

klogd ; -. , klogd .

Syslog-ng TCP

stunnel, ssh . syslog UDP, " " stunnel ssh, syslog -, Syslog-ng.

Syslog-ng ("syslog ") syslog - , ( ) . Syslog-ng TCP UDP. Syslog-ng . ("") .

Syslog-ng , syslog, .

88

8.2 -,

, ( ). , , , . . , , , -, . , , ?

(, Intrusion Detection Systems, IDS).

(host-based IDS) .

(network IDS) , , , , ( , base line).

, , , Tripwite Open Source Snort.

:

. , , . , ( " ") , .

? ,

"" (.. , ) - , . - , - , "" .

89

, , .

. () ,

. :

, , .

.

- .

, .

, .

:

. - . ISS RealSecure Network Filght Recorder - ( ) .

, ( , ).

: , . , , , .

, , . - , - , .

, ( ). - .

90

, /bin/ls: , , ( ) ..

- . - . , , .

, , , ( " ", , . , !) , , . , .

, ! , , .

, , - . -, , .

, , , , - - .. .

:

( ), : , ( , ), , , . - - , .

. , "". , . ,

91

- .

, , , .

-

. , -:

, ( ).

, : , , .

, , , -, .

, " ", . : , , . , .

,

, -. , : ,

"" , , , , .

, : , "" , , . , ( ) .

, , (, ). .

92

Snort

. - , : , . , : , . - ( ) , , .

Snort. Snort .

, ( - " ") Snort tcpdump. Snort , ( ).

, Snort . Snort , .

, Snort 100% , (""), . Snort , - - . Snort e GIMP, Apache Nessus .

, Snort (" Snort").

, .

Snort - - , Snort, , Snort.

93

9.1 SNMP (Simple Network Management Protocol)

, , , (host) (, , , .)

, , , . :

(fault management); (performance management); (layer management); (security management) .

SNMP , , . SNMP TCP/IP

SNMP (manager process) , : (host), , ..

, , - MIB (Management Information Base)

SNMP UDP ASN.1.

.

SNMP , MIB.

ISO- CMIP (Common Management Information Protocol), .

9.1.2 (MIB) MIB ,

TCP/IP . : MIB-I MIB-II. MIB-I

94

RFC1156 .

(node) . (gateway), EGP. , .

, . , SMI , MIB .

9.1 MIB

System

7

Interfaces 23 AT 3 IP 38 ICMP

26

TCP

19

UDP

7

EGP 18 SNMP SNMP 30

System group:

sysDescr - (, HW, OS); sysObjectID - ; sysUpTime - ; sysContact - ; sysServices - ; Interfaces group: ifIndex - ; ifDescr - ; ifType - ; ifMtu - - : ifAdminisStatus - : ifLastChange -

: ifINErrors - , ; ifOutDiscards - ,

:

95

Address Translation Table group:

atTable - ; atEntry -

; atPhysAddress - , ; atNetAddress - ,

atPhysAddress;

IP group:

ipForwarding - IP ; ipInHdrErrors - ,

; ipInAddrErrors - ,

IP ; ipInUnknownProtos - ,

; ipReasmOKs - ;

ICMP group:

icmpInMsgs - ICMP ; icmpInDestUnreachs - ICMP

; icmpInTimeExds - ICMP ; icmpInSrcQuenchs - ICMP source

quench; icmpOutErrors - ICMP ,

ICMP;

TCP group:

tcpRtoAlgorithm - ;

tcpMaxConn - , ;

tcpActiveOpens - SYN-SENT CLOSED;

tcpInSegs - , ; tcpConnRemAddress - IP ; tcpInErrs - ,

; tcpOutRsts - reset-;

UDP group:

udpInDatagrams - UDP , ;

96

udpNoPorts - UDP , ;

udpInErrors - UDP , , ;

udpOutDatagrams - UDP , ;

EGP group:

egpInMsgs - EGP ; egpInErrors - EGP ; egpOutMsgs - EGP , ; egpNeighAddr - IP EGP- .

MIB, , . Ipv4.

9.1.3 (SNMP-Simple Network Managing Protocol)

SNMP SGMP , MIB , SIM.

RFC 1157 (Network Management Station - NMS), (Network management applications - NMA), (network elements - NE), , . (Management agent - MA) , . SNMP .

(authentication protocol) ,

, , , .

(privacy protocol) , SNMPv2 . , , :

; ; ; .

: -

MD5 (message digest). SNMPv2

97

128 ( digest), ;

- , ,

- , ;

- (privacy protocol), , . , , (Data Encryption Standard - DES). SNMPv2 .

SNMPv2

- .

(peer), SNMPv2 . .., , , SNMPv1. SNMPv2 , , - , ( )

SNMP , . 3 2. , SNMP . , 1 2, .

9.2 ,

,

. , .

. -

98

. - . , , LAN WAN . /IP .

,

. , .

, , () ; .. , , .

, ( ) , . , , . , . , . .

:

(botlenecks) (Baselines)

(bottleneck) ,

, , . , .

( , , ) , -.

, . -

99

, , , .

, . .

, :

.. , .

,

,

" . :

,

-

- . , .

- . .

. - ( ), .

, , () , .

,

. , Web , .

100

()

.

. (.. ), . () , ( ), .

.

, " .

Network Associates Sniffer ( Sniffer Pro). .

, . .

, :

Microsoft Performance Monitor Microsoft System Monitor Performance Monitor Windows NT 4.0 ( System Monitor

Windows 2000) , .

, . , .

Performance Monitor System Monitor (alerts), , .

, , :

:

101

. , , , (media) , .

Sniffer

, : Sniffer Pro LAN Sniffer Pro WAN Sniffer Pro High-Speed Gigabit Sniffer Pro Sniffer Distributed Analysis Suite Sniffer ,

, IP/IPX DLC . Sniffer Pro ,

. (hops).

Sniffer TCP/IP , ping, tracert, DNS lookup .

Sniffer ( ).

Sniffer Expert Analyzer, .

. -

, .

. .

, -, , , .

:

,

102

,

,

,

, Microsoft, Novell, IBM Hewlett Packard, - , . Network Monitoring Suite (NMS) Lanware, Simple Networking Management Protocol (SNMP) , , . ViewLAN NuLink SNMP .

,

, ( ), .

. , ,

, .

, , .

TCP/IP, . , , .

- . , .

.

, , (

103

), .

". , , .

. , .

, .

, .

- . - . , . , . ( ) , . .

, , .

TCP/IP , , , , :

ping pathping ping packet internetwork grooper. , ,

Echo Request, Internet Control Message Protocol (ICMP), . ICMP .

ping- . , ping , www.yahoo.com.

, , .

104

ping IP , . IP .

ping IP , , ping- , , .

, DHCP DNS , /I. , DHCP , DHCP DNS .

ping time , (Echo Request) (Echo Replay). ping- .

ping /IP .

ping 127.0.0.1. , , . pathping ping c tracert

, . pathping .

.

Tracert Windows Traceroute - Linux

TCP/IP

- . :

Netstat Nbtstat - /IP NetBIOS .

ARP ( " Linux UNIX) - Address Resolution Protocol (ARP).

ROUTE ( route" Linux UNIX) - , .

105

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, 2000. 8. . TCP/IP . ., , 2002. 9. . . ,

. ., , 2003. 10. . . ., , 2004. 11. , . , , , 1999. 12. , ., ., .

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