Accurate time synchronization is essential for log correlation, authentication protocols, database replication, and certificate validation. A misconfigured NTP setup can cause subtle failures that are extremely difficult to diagnose.
Designing an NTP Hierarchy
Deploy internal NTP servers that synchronize with multiple public stratum 1 or stratum 2 sources. All other servers in your infrastructure should synchronize with these internal NTP servers rather than directly with external sources, reducing external dependencies and network traffic.
Chrony has largely replaced ntpd as the preferred NTP implementation on modern Linux distributions. It handles intermittent network connectivity, rapid clock correction after boot, and environments with infrequent network access more gracefully than the traditional ntpd daemon.
Monitor NTP offset and jitter across your fleet. Alert when offset exceeds a few hundred milliseconds, as this can indicate hardware clock issues, network problems, or NTP misconfiguration. Kerberos authentication, for example, fails when clock skew exceeds five minutes between client and server.