Network Time Protocol (NTP) and Simple Network Time Protocol (SNTP) are client-server protocols that are used to synchronize time on IP networks. NTP provides greater accuracy and better error checking capabilities than SNTP does, but requires more resources.
For many applications, it is not necessary to modify the NTP factory default configuration settings. It is possible, however, to change most of the settings in order to support specific NTP applications which may require a non-standard configuration:
These features include the ability to use either MD5 authentication or NTP Autokey, to block NTP access to parts of the network and to broadcast NTP data to the network’s broadcast address. NTP and SNTP are used to synchronize time on any computer equipment compatible with the Network Time Protocol. This includes Cisco routers and switches, UNIX machines, and Windows machines with suitable clients. To synchronize a single workstation, several freeware or shareware NTP clients are available on the Internet. The software running on the PC determines whether NTP or SNTP is used.
When the NTP service is enabled, NetClock will “listen” for NTP request messages from NTP clients on the network. When an NTP request packet is received, NetClock will send an NTP response time packet to the requesting client. Under typical conditions, NetClock can service several thousand NTP requests per second without MD5 authentication enabled, and at a somewhat lower rate with MD5 authentication enabled.
You can either enable or completely disable the NTP Service. When NTP is disabled, no NTP time packets will be sent out to the network. When enabled, by default, the NTP Service operates in Unicast mode, i.e. the NTP Service responds to NTP requests only.
Note: In order to configure NTP, you need to access the NTP Setup screen which requires ADMINISTRATOR rights.