1. Rationale and Scope

1.1. Slow propagation of new and changed data in a DNS zone can be due to a zone's relatively long refresh times. Longer refresh times are beneficial in that they reduce load on the master servers, but that benefit comes at the cost of long intervals of incoherence among authority servers whenever the zone is updated.

1.2. The DNS NOTIFY transaction allows master servers to inform slave servers when the zone has changed -- an interrupt as opposed to poll model -- which it is hoped will reduce propagation delay while not unduly increasing the masters' load. This specification only allows slaves to be notified of SOA RR changes, but the architechture of NOTIFY is intended to be extensible to other RR types.

1.3. This document intentionally gives more definition to the roles of "Master," "Slave" and "Stealth" servers, their enumeration in NS RRs, and the SOA MNAME field. In that sense, this document can be considered an addendum to [RFC1035].