Specifications

Chapter 5 Setting Up Open Directory Services 89
After you set up an Open Directory replica, other computers will connect to it as needed.
Computers with v10.3 or v10.4 of Mac OS X or Mac OS X Server maintain a list of Open
Directory replicas. If one of these computers can’t contact the Open Directory master
for directory and authentication services, the computer connects to the nearest replica
of the master.
You can congure Mac OS X computers to connect to an Open Directory replica
instead of the Open Directory master for directory and authentication services. On
each Mac OS X computer, you can use Accounts preferences to create an LDAPv3
conguration for accessing the replica’s LDAP directory.
You can also congure a DHCP service to supply the replica’s LDAP directory to
Mac OS X computers that get the address of an LDAP server from the DHCP service.
See “Using Advanced LDAP Service Settings” on page 133 and “Dening Automatic
Search Policies” on page 12 8 .
The Open Directory master updates the replica. You can congure the master to
update its replicas at a specic interval or whenever the master directory changes.
For more information, see “Managing Principals” on page 206.
Creating Multiple Replicas of an Open Directory Master
To make more than one server a replica of an Open Directory master, create the
replicas one at a time. If you try to create two replicas simultaneously, one attempt will
succeed and the other will fail. A subsequent attempt to establish the second replica
should succeed.
You can have up to 32 replicas of an Open Directory master. These direct members of
the Open Directory master server are known as relays. Each relay can have up to 32
replicas of itself, giving you 1056 replicas in a two-tier hierarchy.
Setting Up Open Directory Relays for Cascading Replication
Using Server Admin, you can set up Mac OS X Server to be a replica or relay of
an Open Directory master so it can provide the same directory information and
authentication information to other computers as the master.
A relay has the following conditions:
It is a replica of an Open Directory master (a direct member). Â
It has replicas (supports up to 32 replicas). Â
The process of conguring a replica of a relay is the same as conguring a replica of
an Open Directory master. For more information, see “Setting Up an Open Directory
Replica” on page 87.