1. DNS/RCODE
https://tools.ietf.org/html/rfc2929 (BCP 42)
http://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml
http://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml#dns-parameters-6
https://www.icann.org/en/system/files/files/sac-032-en.pdf
- Preliminary Report on DNS Response Modification
2. 最初の 16 こ
0 NoError No Error [RFC1035] 1 FormErr Format Error [RFC1035] 2 ServFail Server Failure [RFC1035] 3 NXDomain Non-Existent Domain [RFC1035] 4 NotImp Not Implemented [RFC1035] 5 Refused Query Refused [RFC1035] 6 YXDomain Name Exists when it should not [RFC2136][RFC6672] 7 YXRRSet RR Set Exists when it should not [RFC2136] 8 NXRRSet RR Set that should exist does not [RFC2136] 9 NotAuth Server Not Authoritative for zone [RFC2136] 9 NotAuth Not Authorized [RFC2845] 10 NotZone Name not contained in zone [RFC2136] 11-15 Unassigned
-- ToshinoriMaeno 2015-05-05 22:53:21
4.1.1. ヘッダ節形式 Header section format
The header contains the following fields:
ヘッダーにあるフィールド：
1 1 1 1 1 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| ID |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|QR| Opcode |AA|TC|RD|RA| Z | RCODE |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| QDCOUNT |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| ANCOUNT |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| NSCOUNT |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| ARCOUNT |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+http://tools.ietf.org/html/rfc2136 Dynamic Updates in the Domain Name System (DNS UPDATE)
RCODE Response code - this 4 bit field is set as part of
responses. The values have the following
interpretation:
0 No error condition
1 Format error - The name server was
unable to interpret the query.
2 Server failure - The name server was
unable to process this query due to a
problem with the name server.
3 Name Error - Meaningful only for
responses from an authoritative name
server, this code signifies that the
domain name referenced in the query does
not exist.