The primary zone type makes Posadis the primary DNS server for the zone (see Authoritative DNS).

Posadis supports two ways of storing and changing the primary DNS zone data.

• The traditional way of editing master files. The master file is stored on the server and hand-edited, or edited with a master file editor such as Mfedit. Such a primary zone is added to the Posadis configuration by adding the master file, with the name .prm or db., to the Posadis configuration directory.

• Using DNS update. The zone is changed using DNS update messages, sent by DHCP servers, or DNS update clients such as zoneedit. This is the recommended method for Posadis.

Configuration settings are either specified the zone file in the usual way, or embedded in the master file, depending on the method you use. The following configuration options are available:

• slaves (list of IP numbers) - List of slaves for the zone. Slaves get notification when the zone changes, and zone transfers are always allowed to them.

• xfr_acl (access control list) - Determines who further to allow zone transfers to. By default, zone transfers are allowed to all listed nameservers that are in zone, i.e. all domain names in the zone NS record that are in the zone itself. You can revert this behavior by adding the special keyword nons to the address match list.

• update_acl (access control list) - Determines who to accept DNS update messages from. Defaults to none.

• file (file name) - If the zone is loaded from a zone file, this can be used to point to the location of the DNS master file for the zone. If no file is given, the zone is assumed to be a DNS update zone.

A simple example for the dynamically updated acdam.net.znf file, in which two slaves are listed, and we only allow updates from the local host and forwarded DNS update messages from both secondaries:

zone primary
  slaves , 
  update_acl 127.0.0.1, ,