Network Time Protocol (NTP)
- is used to synchronize computer clocks over a network
NTP - Introduction
A computer that needs to synchronize its time will use the Network Time Protocol (NTP), which relies on UDP port 123 for communication. The computer (NTP client) sends a time-request packet to the NTP server, which then responds with its current time and timestamps of its own. The client uses these timestamps and Marzullo’s algorithm (or a variant) to calculate network delay and clock offset, then adjusts its local clock to match the server’s time.