DNS message format

Source: Internet
Author: User
Tags rfc

The following is a brief description of each column:
Qid
The number of the DNS query package, which is used as the confirmation basis.
Qr
The query packet is 0 bytes and the response is 1. The length is 1 byte.
Opcodes
Encapsulation type (query, IQUERY, status, reserved ). The length is 4 bytes.
Flags
A total of 4 bytes, each representing: AA (authoritative answer), TC (truncation), RD (recursion desired), and RA (recursion avalable ).
Reserved
Reserved unused.
Rcodes
Response Message, 4 bytes long, except 0 and 6-15 Reserved unused, 1-5 are: Format error, Server failure, name error, not implemented, refused, respectively.
Question section, answer section, authority section, additional Records Section
Each section is divided into three sub-columns: name, type, and class, which are used as the information of the query, response, authorization, and additional records, and their respective lengths.
Well, the discussion about the DNS protocol will be introduced here for the time being. I believe the above is enough for you to digest it.
RFC file for DNS protocol
RFC-822, RFC-883, RFC-920, RFC-973, RFC-974, RFC-1032, RFC-1033, RFC-1034, RFC-1035, RFC-1101

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