Novell Doc: NW 6.5 SP8: NTP Administration Guide

4.1 Manual Configuration

Manual configuration is easy to plan, configure, and debug. This type of configuration is best suited in a setup where there are fewer than 15 servers and the servers are in the same geographical location and do not span across a large WAN.

You can manually configure a time synchronized setup by completing the following tasks:

4.1.1 Planning the Setup

You should plan the setup before configuring the time provider and time consumers. The setup consists of a time group, which is a set of servers synchronized for time.

The plan should include the following:

Identify the most reliable server in the subnet and make it the time provider.
Identify the other servers in the subnet be the time consumers.

4.1.2 Configuring the Time Providers

In manual configuration, a time provider can get time from the following:

From another time provider Client-Server Mode
From its local clock Self-Synchronized Mode

Client-Server Mode

In this mode, a time consumer takes time from a time provider. The time provider can be a time consumer in another setup or can take time from an external time provider as shown in the figure below.

Figure 4-1 Time Group Taking Time from a Time Provider

To configure the time provider:

Add a line similar to the following to the time provider's ntp.conf file:
```
server IP_address_of_time_provider prefer
```
The prefer parameter marks the server as preferred. All other things being equal, this time provider is chosen for synchronization among a set of correctly operating providers.

ntp.conf file is the configuration file for NTP. This file is located in sys:\etc. For more information, see The Configuration File.
Load XNTPD for the changes to take effect.

To do this, enter the following at the command prompt:

Load XNTPD

For more information, see Section 3.1, Client-Server Mode.

Self-Synchronized Mode

In this mode, the server takes time from its own local clock as shown in this figure.

Figure 4-2 Time Group with Self-Synchronization

To configure the time provider:

Add lines similar to the following to the time provider's ntp.conf file:
```
server 127.127.1.0 prefer
```
```
fudge 127.127.1.0 stratum 3
```
Load XNTPD for the changes to take effect.

To do this, enter the following at the command prompt:

Load XNTPD

4.1.3 Configuring the Time Consumers

Add a line similar to the following to the time consumer's ntp.conf file:
```
server IP_address_of_time_provider prefer
```
Load XNTPD for the changes to take effect.

To do this, enter the following at command prompt:

Load XNTPD

4.1.4 Sample Scenario

This sample scenario in Figure 4-3 demonstrates how to configure a time-synchronized setup in the manual mode.

Figure 4-3 Sample Scenario for Manual Configuration

In this scenario:

C1 and C2 are time consumers that obtain time from the time provider C3.
C3 is also a time consumer that obtains time from the time provider C4.
C4 is self-synchronized.

To use manual configuration to configure the setup explained in the scenario:

In the ntp.conf files of C1 and C2, add a line similar to the following:
```
server IP_address_of_C3 prefer
```
In the ntp.conf file of C3, add a line similar to the following:
```
server IP_address_of_C4 prefer
```
In the ntp.conf file of C4, add a line similar to the following:
```
server 127.127.1.0 prefer
```
```
fudge 127.127.1.0 stratum 3
```
Load XNTPD for the changes to take effect.

To do this, enter the following at the command prompt:

Load XNTPD