Configuring NTP
Configuring Network Time Protocol (NTP)
page 3-10
OmniSwitch 6800/6850/9000 Switch Management Guide
December 2007
NTP Servers
An NTP client needs to receive NTP updates from an NTP server. Each client must have at least one
server with which it synchronizes (unless it is operating in broadcast mode). There are also adjustable
server options.
Designating an NTP Server
To configure an NTP client to receive updates from an NTP server, enter the
ntp server
command with
the server IP address or domain name, as shown:
-> ntp server 1.1.1.1
or
-> ntp server spartacus
It is possible to remove an NTP server from the list of servers from which a client synchronizes. To do
this, enter the
ntp server
command with the
no
prefix, as shown:
-> no ntp server 1.1.1.1
Enabling/Disabling NTP Server Synchronization Tests
To enable an NTP client to invoke NTP server synchronization tests as specified by the NTP protocol,
enter the
ntp server synchronized
command as shown:
-> ntp server synchronized
NTP synchronization is enabled by default.
Note.
The NTP protocol discards the NTP servers that are unsynchronized.
To disable an NTP client from invoking tests for NTP server synchronization, enter the
ntp server unsynchronized
command, as shown:
-> ntp server unsynchronized
Disabling peer synchronization tests allows the NTP client to synchronize with either an NTP peer that is
not synchronized with an atomic clock or a network of NTP servers that will finally synchronize with an
atomic clock.
Setting the Minimum Poll Time
The minimum poll time is the number of seconds that the switch waits before requesting a time synchroni-
zation from the NTP server. This number is determined by raising 2 to the power of the number entered
using the
ntp server
command with the server IP address (or domain name) and the
minpoll
keyword.
For example, to set the minimum poll time to 128 seconds, enter the following:
-> ntp server 1.1.1.1 minpoll 7
This would set the minimum poll time to 2
7
= 128 seconds.
