Time synchronization

Accurate time is important for secure connections, certificate validation, log correlation, and device attestation. Devices keep their clocks synchronized over the network using NTP.

Default behavior

Out of the box, a device synchronizes against public time sources, so a device with internet access keeps accurate time without any configuration.

Setting custom NTP servers

If your environment requires specific time sources — for example, internal NTP servers on an isolated network — you can provide your own NTP configuration. You can set it:

at image creation, so it applies from first boot, or
by placing an NTP configuration on the device’s configuration storage.

When custom NTP settings are provided, they take effect early in the boot process so the device’s clock is correct before it contacts the platform.

Recommendations

On networks without internet access, always configure reachable internal NTP servers; otherwise the device cannot correct its clock, which can cause secure connections and attestation to fail.
Make sure outbound UDP 123 to your time sources is allowed — see Connectivity & ports.

Clock errors and connectivity

A device whose clock is far off may be unable to establish TLS connections to the platform and may fail attestation. If a device cannot come online and you suspect time, verify it can reach an NTP source.