
Concepts: About NetInfo Binding
When a Mac OS X computer starts up, it can bind its local directory domain to a shared NetInfo domain. The shared NetInfo domain can bind to another shared NetInfo domain. The binding process creates a hierarchy of NetInfo domains.
A NetInfo hierarchy has a branched structure. Local domains at the bottom of the hierarchy bind to shared domains, which can in turn bind to other shared domains, and so on. Each domain binds to only one shared domain, but a shared domain can have any number of domains bind to it. A shared domain is called a parent domain, and each domain that binds to it is a child domain. At the top of the hierarchy is one shared domain that doesn't bind to another domain; this is the root domain.
A Mac OS X computer can bind to a shared NetInfo domain by using any combination of three protocols: static, broadcast, or DHCP.
- With static binding, you specify the address and NetInfo tag of the shared NetInfo domain. This is most commonly used when the shared domain's computer is not on the same IP subnet as the computer that needs to access it.
- With DHCP binding, a DHCP server automatically supplies the address and NetInfo tag of the shared NetInfo domain. To use DHCP binding, the DHCP server must be configured to supply a NetInfo parent's address and tag.
- With broadcast binding, the computer locates a shared NetInfo domain by sending out an IP broadcast request. The computer hosting the shared domain responds with its address and tag.
For broadcast binding, both computers must be on the same IP subnet or on a network that is configured for IP broadcast forwarding.
The parent domain must have the NetInfo tag "network."
The parent domain must have a machine record for each computer that can bind to it with broadcast binding.
If you configure a computer to use multiple binding protocols and a parent is not located with one protocol, another one is used. The protocols are used in this order: static, DHCP, broadcast.