Documentation for DNS.

DNS Class

Note

As noted in [RFC6762], Multicast DNS can only carry DNS records with classes in the range 0-32767. Classes in the range 32768 to 65535 are incompatible with Multicast DNS. But Multicast DNS uses the 32768(0x8000) as a special value to indicate a cache-flush request.

DNS Message

All communications inside of the domain protocol are carried in a single format called a message. The top level format of message is divided into 5 sections (some of which are empty in certain cases) shown below

DNS Domain

EDNS0 moudle

EDNS0 is defined in RFC6891

DNS EDNS0

EDNS0.Option.Chain RFC7901

EDNS0.Option.Cookie

EDNS0.Option.DAU RFC6975

EDNS0.Option.DHU RFC6975

EDNS0.Option.ECS RFC7871

EDNS0.Option.Expire RFC7314

EDNS0.Option.ExtendedDNSError RFC8914

EDNS0.Option.KeyTag RFC8145

EDNS0.Option.LLQ RFC8764

EDNS0.Option.N3U RFC6975

EDNS0.Option.NSID RFC5001

EDNS0.Option.Padding RFC7830

EDNS0.Option.TcpKeepalive RFC7828

EDNS0.Option.UpdateLease [RFC-ietf-dnssd-update-lease-08]

DNS EDNS0 Option Codes (OPT)

DNS Header

The header contains the following fields

DNS OpCode

OpCode  Name    Reference
0   Query   [RFC1035]
1   IQuery (Inverse Query, OBSOLETE)    [RFC3425]
2   Status  [RFC1035]
3   Unassigned
4   Notify  [RFC1996]
5   Update  [RFC2136]
6   DNS Stateful Operations (DSO)   [RFC8490]
7-15    Unassigned

Reference

• iana
• DOMAIN NAMES - IMPLEMENTATION AND SPECIFICATION
• Domain Name System (DNS) IANA Considerations

DNS Question

DNS RCode

DNS return code

Record is a struct that represents a DNS resource record.

DNS CAA Record (Type 257)

DNS DNSKEY Record (Type 48)

DNS DS Record (Type 43)

DNS HTTPS Record (Type 65)

DNS NSEC3 Record (Type 50)

DNS NSEC3PARAM Record (Type 51)

DNS OPT Record (Type 41)

DNS RRSIG Record (Type 46)

DNS SVCB Record (Type 64)

DNS TLSA Record (Type 52)

DNS RRTypes

DNS Resource Record Type

DNS Zone management and operations.

Zone caching system for DNS zones.

DNSSEC zone signing and validation functionality.

Zone editor interface for interactive zone management.

DNS Zone file parser and generator for standard BIND format zone files.

Zone loading and persistence system.

Zone management system for DNS zones.

DNS Zone Name

DNS Resource Record Set

DNS Zone Recursive

DNS Root Hint

Zone storage system for managing DNS zones in memory.

Zone transfer functionality for DNS zones (AXFR/IXFR).

Zone validation and diagnostics tools for DNS zones.

Fetch Root data from iana