Reference: Policy Pages Reference : System settings policies : NTP settings
  
NTP settings
You configure NTP setting in the NTP Settings page.
For details, see the SteelHead User Guide.
These configuration options are available:
Use NTP Time Synchronization
Enables NTP time synchronization.
Add a New NTP Server
Displays the controls to add a server.
Hostname or IP Address
Specifies the hostname or IP address for the NTP server. For IPv6 specify an IP address using this format: eight 16-bit hexadecimal strings separated by colons, 128-bits. For example: 2001:38dc:0052:0000:0000:e9a4:00c5:6282
You don’t need to include leading zeros. For example: 2001:38dc:52:0:0:e9a4:c5:6282
You can replace consecutive zero strings with double colons (::). For example: 2001:38dc:52::e9a4:c5:6282
Version
Specifies the NTP server version from the drop-down list: 3 or 4.
Enabled/Disabled
Specifies Enabled from the drop-down list to connect to the NTP server. Select Disabled from the drop-down list to disconnect from the NTP server.
Key ID
Specifies the MD5 key identifier to use to authenticate the NTP server. The valid range is from 1 to 65534. The key ID must appear on the trusted keys list.
Add a New NTP Authentication Key
Displays the controls to add an authentication key to the key list. Both trusted and untrusted keys appear on the list.
Key ID
Specifies the secret MD5 key identifier for the NTP server. The valid range is from 1 to 65534.
Secret (Text)
Specifies the shared secret. You must configure the same shared secret for both the NTP server and the NTP client to use MD5-based cryptography. The shared secret:
is limited to 16 characters or fewer
can’t include white space or #s
can’t be empty
is case sensitive
The secret appears in the key list as its MD5 hash value.