start of authority (networking) (SOA) A type of resource record used by the Domain Name System (DNS) to give meta-data about a set of domain name data (the contents of a "zone file"). An SOA record has the following parameters:
Serial: the zone serial number - a version number for the zone file. Refresh: the number of seconds between update requests from secondary and slave name servers. Retry: the number of seconds the secondary or slave will wait before retrying when an attempt fails. Expire: (time to live - TTL) the number of seconds a master or slave will wait before considering cached data out-of-date. Minimum: previously used to determine the minimum TTL, this offers negative caching. Last updated: 2007-05-11
