IP TTL ( IP)
19.
( )
( )
O ospf
SPF shortest path first ( )
QoS
OSPF
OSPF (. Open Shortest Path First) ,
(link-state technology)
(Dijkstras
algorithm).
OSPF
(Interior Gateway Protocol IGP). OSPF
.
OSPF :
( RIP2,
- 30);
(VLSM);
( ,
);
(.
);
.
1. hello- ,
OSPF. ,
, ,
, hello-.
2.
,
( ).
, hello-
, , hello-. OSPF
.
, ,
.
3.
, .
4. , ,
|
|
|
.
5. ,
.
6. ,
,
. .
7.
.
20. OSI
( ) , :
: TCP, UDP, SPX
/ ( datagram)
TCP/IP
Transmission control protocol (TCP)
User datagram protocol (UDP)
( : USB, COM, PS/2 ..)
IP-
TCP UDP (): TCP1750 ≠ UDP1750
2 :
TCP (UDP) , ( ),
TCP (UDP) ,
Transmission Control Protocol (TCP)
- ( )
User Datagram Protocol (UDP)
- best effort
21.
DNS ( ) IP ( IP- )
:
a.
b.
c.
d.
e.
, - //
- ( )
- 127 63 , 255
DNS- DNS-. DNS- / .
DNS- , DNS-
|
|
|
DNS- (query) ( )
o
o
o ( )
o ( )
22.
SMTP (Simple mail transfer protocol)
Pop (Post office protocol)
IMAP (Internet message access protocol)
SMTP (Simple Mail Transfer Protocol)(25TCP) , TCP/IP
SMTP
HELO
MAIL FROM
RCPT TO
DATA
QUIT
POP3 (110TCP) ,
POP3
n USER []
n PASS []
n APOP [] [digest]
n STAT
n LIST [ ]
n RETR [ ]
n DELE [ ]
n QUIT
IMAP4 ,
n 2 : online offline
n 1
n
23. http
HTTP (HyperText Transfer Protocol ) ( ).
n
n
n
n
n
n
n
n
n Hypertext markup language ( ) WWW.
n HTML , .
URI (Uniform Resource Identifier ) , : , , , , .. ( )
n URI:
<>:<>
n :
n http://www.stankin.ru
n mailto:[email protected]
file://C:\Windows\system32\drivers\etc\hosts
URL (Uniform Resource Locator ) .
n URL:
<>://<>:<>@<>:<>/<URL->
n :
n ftp://User1@Pass:www.stankin.ru:8080/index.php?at=12
n http://www.stankin.ru/news/index.html
24.
(, circuit switching) ( ) (/ , , , , . ., ).
25.
(. packet switching) , , . , , .
( ) (packet). , , , - . . , . (datagram), .
|
|
|
, , . ( ) , . , , , , .
26.
Wi-Fi
Ad Hoc
Infrastructure
Ad Hoc Wi-Fi ( )
:
()
/
:
:
256
:
( .. )
2048
(Wireless access point) ,
(SSID)
, broadcast
MAC-
MAC
(WEP, WPA, WPA2)
WEP
WPA
n 802.1x Extensible Authentication Protocol (EAP) -
n Temporal Key Integrity Protocol (TKIP)
n
n
n Message Integrity Check (MIC)
WPA
n 48
n 128
n (Per Packet Keying, PPK)
n MIC, Message Integrity Check
n , forgery attack (bit-flip attack)
WPA2
n 256
n AES
n WPA
n Per Packet Keying
n Message Integrity Check
n 802.1x (EAP RADIUS)
| WEP | RC4 , | |
| WPA | TKIP , 802.1x (EAP Radius) | |
| WPA2 | AES, 802.1x | , |
Wi-Fi:
()
(AP/AP)
WEP
|
|
|
IrDA (Infrared Data Association) ,
:
() ()
IrLAP :
IrLMP LM-MUX :
/
IrLMP LM-IAS :
Bluetooth .
n Bluetooth PIN ( )
n PIN
n E0
n :
n
n
n
n
n Bluejacking
General packet radio service (GPRS)
n GSM
n IP, PPP, X.25
