DNS SOA Records

The DNS ‘start of authority’ (SOA) record stores important information about a domain or zone such as the email address of the administrator, when the domain was last updated, and how long the server should wait between refreshes.

All DNS zones need an SOA record in order to conform to IETF standards. SOA records are also important for zone transfers.

Example of an SOA record:

name	example.com
record type	SOA
MNAME	ns.primaryserver.com
RNAME	admin.example.com
SERIAL	1111111111
REFRESH	86400
RETRY	7200
EXPIRE	4000000
TTL	11200

The 'RNAME' value here represents the administrator's email address, which can be confusing because it is missing the ‘@’ sign, but in an SOA record admin.example.com is the equivalent of admin\@example.com.