DNS 中的协议字段详细定义

1 概述

总结DNS协议中各字段的取值

2 DNS Classes

Decimal	Name	Reference
0	Reserved	RFC6895
1	Internet(IN)	RFC1035
2	Unassigned
3	Chaos(CH)
4	Hesiod(HS)
5-253	Unassigned
254	QCLASS NONE	RFC2136
255	QCLASS * (ANY)	RFC1035
256-65279	Unassigned
65280-65534	Reserved for Private Use	RFC6895
65535	Reserved	RFC6895

3 DNS OpCodes

OpCode	Name	Reference
0	Query	RFC1035
1	IQuery(Inverse Query)	RFC3425
2	Status	RFC1035
3	Unsassined
4	Notify	RFC1996
5	Update	RFC2136
6-15	Unassigned

4 DNS RCODEs

Rcode	Name	Description	Reference
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
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
10	NotZone	Not AUthorized	RFC2845
11-15	Unassigned
16	BADVERS	Bad OPT Version	RFC6891
16	BADSIG	TSIG Signature Failure	RFC2845
17	BADKEY	Key not revognized	RFC2845
18	BADTIME	Signature out of time window	RFC2845
19	BADMODE	Bad TKEY Mode	RFC2930
20	BADNAME	Duplicate key name	RFC2930
21	BADALG	Algorithm not supported	RFC2930
22	BADTRUNC	Bad Truncation	RFC4635
23-3840	Unassigned
3841-4095	Reserved for Private Use
4096-65534	Unassigned
65535	Reserved

5 DNS Label Types

DNS label的最高两位来标识该label的类型

Value	Type	Status	Reference
0 0	普通label. 低6位是该label的长度	Standard	RFC1035
1 1	压缩label. 低6位和接下来的8位标识它相对于包头的偏移量	Standard	RFC1035
0 1	扩展类型的label. 低6位表示label的类型那个	Standard	RFC1035
1 0	未分配

6 DNS资源记录

TYPE	Value	Meaning	Reference
A	1	a host address	[RFC1035]
NS	2	an authoritative name server	[RFC1035]
MD	3	a mail destination(OBSOLETE - use MX)	[RFC1035]
MF	4	a mail forwarder(OBSOLETE - use MX)	[RFC1035]
CNAME	5	the canonical name for an alias	[RFC1035]
SOA	6	marks the start of a zone of authority	[RFC1035]
MB	7	a mailbox domain name (EXPERIMENTAL)	[RFC1035]
MG	8	a mail group member (EXPERIMENTAL)	[RFC1035]
MR	9	a mail rename domain name (EXPERIMENTAL)	[RFC1035]
NULL	10	a null RR (EXPERIMENTAL) [RFC1035]
WKS	11	a well known service description	[RFC1035]
PTR	12	a domain name pointer	[RFC1035]
HINFO	13	host information	[RFC1035]
MINFO	14	mailbox or mail list information	[RFC1035]
MX	15	mail exchange	[RFC1035]
TXT	16	text strings	[RFC1035]
RP	17	for Responsible Person	[RFC1183]
AFSDB	18	for AFS Data Base location	[RFC1183][RFC5864]
X25	19	for X.25 PSDN address	[RFC1183]
ISDN	20	for ISDN address	[RFC1183]
RT	21	for Route Through	[RFC1183]
NSAP	22	for NSAP address, NSAP style A record	[RFC1706]
NSAP-PTR	23	for domain name pointer, NSAP style	[RFC1348][RFC1637][RFC1706]
SIG	24	for security signature	[RFC4034][RFC3755][RFC2535][RFC2536][RFC2537][RFC2931][RFC3110][RFC3008]
KEY	25	for security key	[RFC4034][RFC3755][RFC2535][RFC2536][RFC2537]\\[RFC2539][RFC3008][RFC3110]
PX	26	X.400 mail mapping information	[RFC2163]
GPOS	27	Geographical Position	[RFC1712]
AAAA	28	IP6 Address	[RFC3596]
LOC	29	Location Information	[RFC1876]
NXT	30	Next Domain (OBSOLETE)	[RFC3755][RFC2535]
EID	31	Endpoint Identifier	[http://ana-3.lcs.mit.edu/~jnc/nimrod/dns.txt]
NIMLOC	32	Nimrod Locator	[http://ana-3.lcs.mit.edu/~jnc/nimrod/dns.txt]
SRV	33	Server Selection	[RFC2782]
ATMA	34	ATM Address
NAPTR	35	Naming Authority Pointer	[RFC2915][RFC2168][RFC3403]
KX	36	Key Exchanger	[RFC2230]
CERT	37	CERT	[RFC4398]
A6	38	A6 (OBSOLETE - use AAAA)	[RFC3226][RFC2874][RFC6563]
DNAME	39	DNAME	[RFC6672]
SINK	40	SINK	[http://tools.ietf.org/html/draft-eastlake-kitchen-sink]
OPT	41	OPT	[RFC6891][RFC3225]
APL	42	APL	[RFC3123]
DS	43	Delegation Signer	[RFC4034][RFC3658]
SSHFP	44	SSH Key Fingerprint	[RFC4255]
IPSECKEY	45	IPSECKEY	[RFC4025]
RRSIG	46	RRSIG	[RFC4034][RFC3755]
NSEC	47	NSEC	[RFC4034][RFC3755]
DNSKEY	48	DNSKEY	[RFC4034][RFC3755]
DHCID	49	DHCID	[RFC4701]
NSEC3	50	NSEC3	[RFC5155]
NSEC3PARAM	51	NSEC3PARAM	[RFC5155]
TLSA	52	TLSA	[RFC6698]
Unassigned	53-54
HIP	55	Host Identity Protocol	[RFC5205]
NINFO	56	NINFO	[Jim_Reid]
RKEY	57	RKEY	[Jim_Reid]
TALINK	58	Trust Anchor LINK	[Wouter_Wijngaards]
CDS	59	Child DS	[George_Barwood]
Unassigned	60-98
SPF	99	[RFC-ietf-spfbis-4408bis-21]
UINFO	100	[IANA-Reserved]
UID	101	[IANA-Reserved]
GID	102	[IANA-Reserved]
UNSPEC	103	[IANA-Reserved]
NID	104	[RFC6742]
L32	105	[RFC6742]
L64	106	[RFC6742]
LP	107	[RFC6742]
EUI48	108	an EUI-48 address	[RFC7043]
EUI64	109	an EUI-64 address	[RFC7043]
Unassigned	110-248
TKEY	249	Transaction Key [RFC2930]
TSIG	250	Transaction Signature	[RFC2845]
IXFR	251	incremental transfer	[RFC1995]
AXFR	252	transfer of an entire zone	[RFC1035][RFC5936]
MAILB	253	mailbox-related RRs (MB, MG or MR)	[RFC1035]
MAILA	254	mail agent RRs (OBSOLETE - see MX)	[RFC1035]
*	255	all records the server/cache has available	[RFC1035][RFC6895]
URI	256	URI	[Patrik_Faltstrom]
CAA	257	Certification Authority Restriction	[RFC6844]
Unassigned	258-32767
TA	32768	DNSSEC Trust Authorities
DLV	32769	DNSSEC Lookaside Validation	[RFC4431]
Unassigned	32770-65279
Private use	65280-65534
Reserved	65535

7 EDNS Version

Range	Description	Reference
0	EDNS version 0	RFC6891
1-255	Unassigned

8 DNS EDNS0 Option Codes (OPT)

Value	Name	Status	Reference
0	Reserved		[RFC6891]
1	LLQ	On-hold	[http://files.dns-sd.org/draft-sekar-dns-llq.txt]
2	UL	On-hold	[http://files.dns-sd.org/draft-sekar-dns-ul.txt]
3	NSID	Standard	[RFC5001]
4	Reserved
5	DAU	Standard	[RFC6975]
6	DHU	Standard	[RFC6975]
7	N3U	Standard	[RFC6975]
8	edns-client-subnet	Optional
9-65000	Unassigned
65001-65534	Reserved for Local/Experimental Use		[RFC6891]
65535	Reserved for future expansion		[RFC6891]

DNS 中的协议字段详细定义

DNS中的协议字段定义

Table of Contents

1 概述

2 DNS Classes

3 DNS OpCodes

4 DNS RCODEs

5 DNS Label Types

6 DNS资源记录

7 EDNS Version

8 DNS EDNS0 Option Codes (OPT)