What is SOA (Start of Authority) record?

Every domain you register in ClouDNS must have a SOA (Start of Authority) record. It defines the global parameters for the domain. There is one SOA record in a zone file (domain).

The SOA record has the following structure:

Serial number - The revision number of this zone file. Increment this number each time the zone file is changed. It is important to increment this value each time when a change is made, so that the changes will be distributed to any secondary DNS servers.

Primary NS - The host name for the primary DNS server for the zone. The Primary NS, set by default, is If you enter an invalid primary name server, it will be changed back to

DNS admin e-mail - The e-mail address of the person, responsible for administering the domain's zone file. If you enter an invalid e-mail for DNS administrator, it will be changed back to

Refresh Rate - The time in seconds that a secondary DNS server waits before querying the primary DNS server's SOA record to check for changes. The refresh rate varies from 1200 do 43200 seconds.

Retry Rate - The time in seconds that a secondary server waits before retrying a failed zone transfer. Usually, the retry rate is less than the refresh rate. The default value is 1800 seconds. The retry rate varies from 180 to 2419200 seconds.

Expire time - The time in seconds that a secondary server will keep trying to complete a zone transfer. If this time expires prior to a successful zone transfer, the secondary server will expire its zone file. This means the secondary will stop answering queries, as it considers its data too old to be reliable. The default value is 1209600 seconds.

Default TTL - The minimum time-to-live value applies to all resource records in the zone file. This value is supplied in query responses to inform other servers how long they should keep the data in cache. The default value is 3600 seconds (1 Hour).

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