HPE FlexNetwork 7500 Series Command Reference Manual page 139

type and number. If you do not specify this option, the device searches the routing table for the
outgoing interface and uses the primary IP address of the outgoing interface as the source IP
address of the NTP messages.
version number: Specifies the NTP version. The value range for the number argument is 1 to 4. The
default value is 4.
Usage guidelines
When you specify an NTP server for the device, the device is synchronized to the NTP server, but the
NTP server is not synchronized to the device.
To synchronize the PE to a PE or CE in a VPN instance, provide vpn-instance vpn-instance-name in
your command.
If you include the vpn-instance vpn-instance-name option in the undo ntp-service unicast-server
command, the command removes the NTP server in the specified VPN instance. If you do not
include the vpn-instance vpn-instance-name option in the command, the command removes the
NTP server on the public network.
After you specify an NTP server for a device, the device polls and synchronizes its time with the
server at the minimum polling interval. If the time discrepancy between the two maintains in the
acceptable range, the system gradually increases the polling interval until the maximum polling
interval is reached. If the time discrepancy exceeds the acceptable range repeatedly, the polling
interval decreases gradually.
The polling interval configuration takes effect from the next polling.
Examples
# Specify NTP server 10.1.1.1 for the device, and configure the device to run NTP version 4.
<Sysname> system-view
[Sysname] ntp-service unicast-server 10.1.1.1 version 4
Related commands
ntp-service authentication enable
ntp-service authentication-keyid
ntp-service reliable authentication-keyid
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