Apple manual Network Setup Database Fundamentals, Database Structure

C H A P T E R 1

About Network Setup

Network Setup Database Fundamentals

This section describes the fundamental structure of and operations on the Network Setup database.

Database Structure

The Network Setup database consists of multiple areas. There are two types of areas: named areas store preferences, while temporary areas are used as part of the preference modification process. The system currently uses a single named area, known as the default area (sometimes referred to as the current area) to store all network preferences. While it is possible to create and manipulate other named areas within the database, doing so does not affect any network settings. Areas are identified by a unique area ID.

Each area contains a number of entities having the following properties:

■entity reference. An entity reference uniquely identifies an entity. The entity reference contains an area ID, which identifies the area in which the entity resides.

■entity name. A user-visible name for the entity that need not be unique.

■entity class and type. These values, both of type OSType, determine the type of data contained within an entity. There are three entity classes:

■network connection entity. A network connection entity contains information about a single instance of a network protocol on a port. Typically there is one active network connection entity per protocol stack, but on a multihomed computer there can be more. The entity type for an network connection entity indicates the network protocol of the connection.

■global protocol entity. A global protocol entity contains configuration for a protocol stack on a computer. There is only one active global protocol entity for each protocol stack. The entity type for a global protocol entity indicates the network protocol whose configuration it contains.

■set entity. A set entity groups global protocol and network connection entities into a set. The set entity contains entity references to each entity in the set. An area can contain multiple set entities, but there is one and only

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