-
Resource Record: structured data associated with names / nodes
- format: owner ttl class type rdata
- example: www.example.com 3600 IN A 192.0.2.127
-
owner / name:
- a node in the domain name tree
- for a specific RR, owner is the domain name where the RR is found. (RFC 1034 3.6)
- consists of a sequence of labels
- format: node.zone.tld.
- the right most label is null, aka the root
- the 2nd from right is the top level domain
- the 3rd from right is the [organizational] domain name (usually)
-
label: character strings between the dots in a domain name
-
ttl: time to live
- how long to cache this DNS resource record
-
class: IN, internet.
-
type: the type of rdata that follows
- examples: A, MX, SOA, PTR
-
rdata: resource data. The contents vary widely by RR type
- examples: A records have an address, CNAME records bear a cname target, NS records point to nameservers (nsdname).
-
domain: an administrative boundary within the domain name tree.
-
subdomain: a domain contained by another domain. (ex: c.b.a is contained by b.a.)
-
node: a leaf or interior node in the domain name tree. (RFC 1034, 3.1)
-
domain name: the domain name of a node is the list of labels from the node to the root of the tree. A domain name identifies a node. (RFC 1035 3.6)