NTP
How to verify NTP stratum and offset on a LAN
Check reachability, LOCK, stratum, and offset so you do not mistake switch issues for a bad time server.
Confirm L3 reachability and that UDP 123 is allowed. QYTS-3000 factory default IP is 192.168.1.123 unless changed.
Ping the server and open its Web UI. Confirm GNSS LOCK and the NTP serve policy; warm-up may temporarily reply Stratum 2.
On Linux, use chronyc tracking / ntpq -p (or OS tools) to read reach, offset, and stratum. LAN NTP is typically millisecond-class—do not accept against GNSS nanosecond figures.
Respect recommended client counts and overload protection in the datasheet. Port scans or large Web exports can rate-limit replies.
If an NTP source ACL is enabled, allowlist client IPs or you will see “reachable but not syncing”.