HP ProCurve 6120G/XG Configuration Manual page 224

Time Protocols
SNTP: Viewing, Selecting, and Configuring
Disabling Time Synchronization Without Changing the SNTP
Configuration. The recommended method for disabling time synchroniza­
tion is to use the timesync command.
Syntax: no timesync
For example, suppose SNTP is running as the switch's time synchronization
protocol, with Broadcast as the SNTP mode and the factory-default polling
interval. You would halt time synchronization with this command:
ProCurve(config)# no timesync
If you then viewed the SNTP configuration, you would see the following:
Figure 9-10. Example of SNTP with Time Synchronization Disabled
Disabling the SNTP Mode. If you want to prevent SNTP from being used
even if selected by timesync (or the Menu interface's Time Sync Method param­
eter), configure the SNTP mode as disabled.
Syntax: no sntp
For example, if the switch is running SNTP in Unicast mode with an SNTP
server at 10.28.227.141 and a server version of 3 (the default), no sntp changes
the SNTP configuration as shown below, and disables time synchronization
on the switch.
9-16
Halts time synchronization without changing your SNTP
configuration.
Disables SNTP by changing the SNTP mode configuration to
Disabled.