NetWare Directory Services

5-4

Understanding Time Synchronization in NDS

Time Servers

There are four types of NDS time servers: Single Reference, Primary,

Reference, and Secondary. During the NDS installation process you are

prompted to designate the time server type.

You can also change the time server type after installation by using the

System Administration Manager (SAM) utility.

CAUTION: Sometimes the UNIX server is running another, presumably more authoritative, time

synchronization protocol (such as NTP).

In this case, the time server type should be set to Reference and the conﬁgured

sources parameters should be set to” On”). This allows the host time synchronization

services to update the UNIX system clock, and allows the NetWare time

synchronization services to advertise that clock value to the network.

Each time server type performs a particular time synchronization function,

as explained in the following sections.

Single Reference

Single Reference time servers provide time to Secondary time servers and to

their own client workstations.

This server determines the time for the entire network. The network

supervisor sets the time on the Single Reference time server. (It is possible

for the time to be synchronized to an external clock.)

Because the Single Reference time server is the source of time on the

network, all other servers must be able to contact it.

The following ﬁgure illustrates a Single Reference time server providing

time to Secondary time servers and to its own client workstations. The

Secondary time servers, in turn, provide time to their own client

workstations.