NTP

In brief

The protocol that keeps all machines on the same time, to the millisecond. Without it, certificates, logs and transactions fall out of sync and break.

▶ Precise definition

Network Time Protocol: a protocol for synchronising the clocks of networked systems. An invisible but critical building block on which authentication, certificate validity, log timestamps and transaction consistency all depend. Its reference time sources are few in number and form a control point that is rarely monitored.