Technical data

Configuring and Managing NTP
12.3 Configuring Your NTP Host
12.3.1 Creating the Configuration File
To create a configuration file for your local host, edit a copy of the file
TCPIP$NTP.TEMPLATE (located in SYS$SPECIFIC:[TCPIP$NTP])
to add the names of participating hosts, then save the file as
SYS$SPECIFIC:[TCPIP$NTP]TCPIP$NTP.CONF. This file is not overwritten
when you install subsequent versions of TCP/IP Services.
Note
If you had a previous version of NTP configured on your system, your
TCPIP$NTP.CONF file is created automatically and is populated with
entries from the file UCX$NTP.CONF when you run the TCPIP$CONFIG
procedure.
12.3.2 Configuration Statements and Options
NTP configuration statements are formatted as follows:
• peer address [key ID] [version number] [prefer] [minpoll interval]
[maxpoll interval]
server address [key ID] [version number] [prefer ]
broadcast address [key ID] [version number] [ttl nn]
The following table describes the options to these statements:
Option Description
key ID For all packets sent to the address, includes authentication
fields encrypted using the specified key identifier, an
unsigned 32-bit integer. The default is no encryption.
version number Specifies the version number to be used for outgoing NTP
packets. Versions 1, 2, and 3 are the choices. The default
is 3.
prefer Marks the server as preferred. This host will be chosen for
synchronization among a set of correctly operating hosts.
minpoll interval Specifies the minimum polling interval for NTP messages,
in seconds to the power of two. The allowable range is 4
(16 seconds) to 14 (16384 seconds), inclusive. This option
is not applicable to reference clocks. The default is 6 (64
seconds).
maxpoll interval Specifies the maximum polling interval (in seconds), for
NTP messages. The allowable range is 4 (16 seconds)
to 14 (16384 seconds) inclusive. The default is 10 (1024
seconds). (This option does not apply to reference clocks.)
ttl nn Specifies the time-to-live for multicast packets. Used only
with broadcast mode.
• broadcastclient address
This statement directs the local server to listen for broadcast messages at
the broadcast address of the local network. The default address is the subnet
address with each host file bit set to 1. Upon hearing a broadcast message
for the first time, the local server measures the nominal network delay
using a brief client/server exchange with the remote server, then enters the
broadcastclient mode, in which it listens for and synchronizes to succeeding
broadcast messages. Note that, to avoid accidental or malicious disruption in
Configuring and Managing NTP 12–5