Looks like ntp-b.nist.gov authenticated ntp server went off line at approximately 06:09 UTC on 2026-09-19
In fact, it appears all servers at Boulder, Colorado site might be offline, even though the status page lists them as online.
Thankfully, I only monitor NIST and USNO servers as backup.
I see this too. I’ll also mention that the USNO Washington servers were unavailable for several hours due to networking issues starting 13:36 2026-09-17
I also noticed the USNO servers were breifly sporadic this morning. I didn’t know whether it was related to the NIST Boulder server outage. USNO offsets/jitter seemed to have increased in recent days to the point I had to mark them as no select.
I have been advised, all services will be back online by midnight MDT.
The NIST Boulder, CO NTP severs are back online