 2.   TCP/IP_____________________________73_

PING (Packet Internetwork Groper,   ).  
 PING      -
  TCP/IP-.

     PING   ICMP
Echo-,       -
      ""    .

 PING        -
      TCP/IP.   -
        
PING.   ( )  ,  
 ,   , , 
 ,   ,   -
,     ,    -
          -
  .

      PING,  -
  -   thumper.bellcore.com,   64  .
     ICMP-:

C:\>ping -n 6 -1 64 thumper.bellcore.com
Pinging thumper.bellcore.com [128.96.41.1] with 64 bytes of data:

Reply from 128.96.41.1 bytes=64 time=380ms TTL=240

Reply from 128.96.41.1 bytes=64 time=361ms TTL=240

Reply from 128.96.41.1 bytes=64 time=400ms TTL=240

Reply from 128.96.41.1 bytes=64 time=371ms TTL=240

Reply from 128.96.41.1 bytes=64 time=351ms TTL=240

Reply from 128.96.41.1 bytes=64 time=561ms TTL=240

   TRACEROUTE   UDP  ICMP.
 TRACEROUTE     -
     .    
       -
      Internet.   
  .

 TRACEROUTE     
  UDP-.  , 
 ,      TTL = 1. -
  TTL   1     , -
        -
 .    ICMP- Time
Exceeded Message ()      UDP-
   .