A resource record
An A Resource Record is used to assign an IPv4 address to a DNS name . A resource records are the most common resource records in the DNS .
In addition to the host IP address assignment, A RRs are also used for DNSBLs or to specify subnet masks for backward resolutions in accordance with RFC 1101 .
The corresponding record type for IPv6 is AAAA .
construction
Name
- published name
TTL
- time to live : indicates how long in seconds this resource record may be valid in a cache (optional; if not specified, a previously explicitly defined default value is assumed - via a $ TTL statement at the beginning of the zone file )
IN
- class: Internet (optional; alternatives are the classes
HS
for HESIOD andCH
for CHAOS, two experimental network projects that have been obsolete for a long time;IN
assuming no information ) A
- Record Type
Length
- the length of the entry, in this case 4 for the 4 bytes of the IP address .
Adresse
- the IP address at which the searched server can be reached
example
www.example.com. 3600 IN A 172.27.171.106
Put equivalent:
$TTL 3600 $ORIGIN example.com. www A 172.27.171.106