What is NTP - Network Time Protocol ?

What is NTP ?

In general, the Network Time Protocol (NTP) is a protocol for synchronized to system time (clock) on the computer to an accurate source, via intranet or internet network. There are several sites NTP "Stratum 1" (NTP sites with resources from the atomic clock time) and "Stratum 2" (NTP sites with NTP time sources from other sites, with a slightly reduced level of accuracy) that can be used by the public.

In its application, the network should have one (or more) local NTP servers (Stratum 2 or 3) for all work-station, which is synchronized to the NTP server outside the network. This configuration further ensure the correlation between related systems in the network is concerned.

NTP Server

NTP Server is the site of NTP Stratum 1, 2, .. etc.., The server that the system time is synchronized to an accurate time source, and to the transmission of timing information packets to the computers 'clients' who asks.

Firewalls / Proxy and NTP

NTP servers communicate with clients using UDP port 123, not like other UDP protocols that use a high port (greater than 1023). Therefore, Firewall / Proxy Server must be set to open the lines of traffic on UDP port 123, so that the NTP Server synchronization between the 'client' to do.