DNS

(Domain Name System )

 

0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
Identification
QR Opcode AA TC RD RA Z Rcode
QDCOUNT
ANCOUNT
NSCOUNT
ARCOUNT
Question Section
Answer Section
Authority Section
Additional Information Section

 

DNS Parameters


Query/Response
  0 Query
  1 Response
Opcode
  0 Standard query (QUERY)
  1 Inverse query (IQUERY)
  2 Server status request (STATUS)
AA  
  (1 = Authoritative Answer)
TC  
  (1 = TrunCation)
RD  
  (1 = Recursion Desired)
RA  
  (1 = Recursion Available)
Z  
  (Reserved; set to 0)
Response code
  0 No error
  1 Format error
  2 Server failure
  3 Non-existant domain (NXDOMAIN)
  4 Query type not implemented
  5 Query refused
QDCOUNT  
  (No. of entries in Question section)
ANCOUNT  
  (No. of resource records in Answer section)
NSCOUNT  
  (No. of name sever resource records in Authority section)
ARCOUNT  
  (No. of resource records in Additional Information section)