Zones

$Id: zone,v 1.1 1999/02/25 05:15:42 marka Exp $

Overview

Zones are the unit of delegation in the DNS and may go from holding

RR's only at the zone top to holding the complete hierachy (private

roots zones). Zones are a container for the RRsets that make up the

zone.

Zone have certain properties associated with them.

* name

* class

* master / slave / stub

* serial number

* signed / unsigned

* update periods (refresh / retry)

* last update time (slave)

* access restrictions

* transfer restrictions

* expire period

* updatable

* children => bottom

* glue

* rrsets

* transfer "in" in progress

* transfers "out" in progress

* "current" check in progress

* our masters

Zones also have versions associated with them, each of which, with

the exception of the current zone, has an expiry date.

Zones need to have certain operations performed on them. The need to

be:

* loaded

* unloaded

* dumped

* updated

* copied out in full or as partial deltas

* read from

* validated

* generate a delta between two given versions.