DNS SOA record
(also start of authority record)
DNS SOA record definition
A DNS SOA record is a type of DNS record that contains all the administrative data about your DNS zone. Every DNS zone is defined by the domain name system (DNS) and needs its own DNS SOA record to function properly. Every time you set up a new DNS zone in your system, you’ll need a new DNS SOA record. In addition, every time you transfer one DNS zone to another DNS zone, you’ll need a new DNS SOA record.
Some of the administrative data that a DNS SOA record stores include the administrator’s email address, the date and time when the domain was updated last, and how long a server should wait between each refresh. DNS SOA records are needed so that DNS zones can be in compliance with IETF standards. Also, you can’t make DNS zone transfers without DNS SOA records.
See also: DNS server, DNS record
Parts of a DNS SOA record
MNAME. An MNAME is the name of the primary nameserver of a certain DNS zone. It stores all of the zone’s DNS records.
REFRESH. REFRESH is the amount of time that secondary servers need to wait before requesting the DNS SOA records from the primary server. It is usually measured in seconds.
vRETRY. RETRY determines the amount of time that a server needs to wait before asking an unresponsive primary server for updates again.
EXPIRE. EXPIRE is part of a DNS SOA record that shows the amount of time a secondary server should wait for a response from a primary server before it stops responding to queries for a specific DNS zone.