146_______________________________________ Internet

ID (16 ).   -. ID   
  , ,   ,    -
   .

QR (1 ).     (0 / 1).

OPCODE (4 ).   ( /  /  ).

 (1 ).   .

RCODE (4 ).   .

QDCOUNT (16 ).     .

ANCOUNT (16 ).     .

NSCOUNT (16 ).       NS.

ARCOUNT (16 ).     .

( ^)

       .

  ( Query)   ,  
    (QNAME),   (QTYPE),  
(QCLASS).   Query  DNS- 
 . 3.15.  QTYPE  QCLASS  16  ,   
   RR,      .

                                           15

QNAME                 1

QTYPE

QCLASS

. 3.15.   Query  DNS-

    (),   ,  
      .

,           -
 ISI.EDU  , ,      -
.        :  QNAME=ISI.EDU,
QTYPE=MX, QCLASS=IN.     ,   -
  (Answer)   RR (  . ),
,   :

ISI.EDU. MX 10 MARS.ISI.EDU.
MX 10 POMPA.ISI.EDU.

   (Additional)  , , IP-
  :