In large-scale networks, if you rely on the administrator to manually configure to modify the system time of each device in the network, not only the workload is huge, but also the accuracy of the time cannot be guaranteed. NTP (Network Time Protocol) can be used to synchronize time between distributed time servers and clients, so that the time of all devices in the network is consistent, and provides high time synchronization accuracy. The transport layer protocol adopted by NTP is UDP, and the UDP port number used is 123.
"Distributed" here refers to that the device running NTP can not only synchronize time with other devices, but also provide time synchronization for other devices as a time server.
NTP is mainly used in situations where the time of all devices in the network needs to be consistent, such as:
·A network management system needs to analyze the log information and debugging information collected from different devices based on time.
·A billing system that requires the consistency of equipment time.
·Where multiple systems work together to deal with the same complex event. At this time, in order to ensure the correct execution sequence, the time of multiple systems must be consistent.