「refresh interval」を英語から日本語に翻訳する

An interval of time used by of a zone to determine how often to check if their zone data needs to be refreshed. When the refresh interval expires, the secondary master checks with its source for the zone to see if its zone data is still current or if it needs to be updated using a zone transfer. This interval is set in the SOA (start-of-authority) resource record for each zone.