Starting with version 3.5, PresenTense Time Client includes a plug-in which supports NTP version 3 & 4 according to RFC 1305. This plug-in is distributed with PresenTense Time Client free of charge. If you require the newest, industry standard version of NTP, the
use of the NTP version 4 plug-in is recommended.
PresenTense Time Client generates the configuration file NTP.CONF for the NTP4 plug-In automatically from the settings you specify or you can edit this configuration file directly. The latter is only recommended for advanced users. Please refer to the parameter list shown below for a detailed
explanation of each parameter / setting.
Reference time Source
This option allows you to specify one primary and two redundant time servers to which PresenTense Time Client synchronizes. You may specify either an IP address, hostname, or DNS name for each server. If you elect to specify a hostname or DNS name, please ensure that name resolution is properly
configured on your TCP/IP network. If you decide to synchronize to a time server on the internet rather than a corporate time server, ensure also that firewall rules permit the network traffic for the protocol you select. Time servers specified here should support version 3 or 4 of the NTP
protocol. Click the key icon to select an encryption key to be used to authenticate each server if you require secure NTP. Authentication uses the MD5 secure hash algorithm. Ask your system administrator to furnish a key file "ntp.keys" for your time server(s).
This option allows you to specify the version for NTP. Possible values are version 3 and version 4.
This option allows you to specify an alternate NTP port. By convention, the NTP protocol operates on port 123 and in all but the most extraordinary circumstances you will want to use port 123 in order to retain compatibility with other NTP systems. Some circumstances, however, warrant changing
the default NTP port. If you operate PresenTense Time Client on a local area network behind a firewall which blocks incoming traffic to privileged ports (<1024) and are unable or not permitted to reconfigure your firewall to suit, you might wish to reconfigure the NTP4 plug-in to operate on an
alternate port. Be advised that you will need to adjust any time server software to use the new port settings also.
Minimum Poll Interval
This option allows you to specify the minimum poll interval for NTP messages. Typically the NTP4 plug-in will poll time servers at the rate specified as the minimum poll interval until the algorithm has achieved synchronization of the local system with its accurate time source(s).
Maximum Poll Interval
This option allows you to specify the maximum poll interval for NTP messages. After synchronization with its accurate time source(s) has been achieved, the NTP4 Plug-In may grow the interval between queries to its accurate time source(s) up to the maximum poll interval or as required to maintain
Use Burst Mode
This option tells the NTP4 plug-in to use eight packets instead of the usual one packet when polling a time server. When enabled, this option considerably increases timekeeping accuracy but may also increase network load where a large number of clients are located on the same network.