Stratum 1 NTP-сервер на Raspberry Pi в 2026 году: DCF77 + GPS/PPS, chrony, libgpiod v2
Stratum 1 NTP-сервер на Raspberry Pi в 2025 году: DCF77 + GPS/PPS, chrony, libgpiod v2, когда все туториалы по «точному времени на Raspberry Pi» сломаны на современных системах. Разбираю почему — и показываю как сделать правильно.
Secure time synchronization with NTS
To set the correct time on computers, usually NTP (Network Time Protocol) is used. However NTP is an insecure time synchronization protocol and allows a man-in-the-middle to shift time on an NTP client. To tackle these issues, NTS (Network Time Security) was created which aims to solve these problems. In this article I show how you can configure ntpd-rs and Chrony to use NTS servers. systemd's timesyncd does not support yet NTS, but it's currently in development so hopefully this will be […]https://blog.frehi.be/2026/03/29/secure-time-synchronization-with-nts/
Needed an #NTP server on a Raspberry Pi. To keep it light, I chose #OpenNTPD.
Not a great idea.
If your clock is off by more than 180 seconds, it won't adjust it; logs say
adjtime failed: Invalid argument
Now, according to the man page, it will jump to adjust larger offsets on startup, but apparently #Debian has patched this to require adding `-s` to /etc/default/openntpd.
They also don't support `constraint from` config stanzas used to get a trusted date via HTTPS.
Trying #chrony now.
I configured #chrony shipped with #ProxmoxVE to operate as a server and set up #DNS records on my router to point ntp[1-4].aliyun.com to the local IP of the #Proxmox node with chrony.
According to the internet, ntp[1-4].aliyun.com are 4 of 8 NTP servers used by #PhilipsHue bridge.
Then I blocked internet access for the bridge.
Now we wait and see if it works.
#chrony #proxmoxve #dns #proxmox #philipshue #homelad #selfhost #selfhosted #selfhosting #offline
NTP in practice. Mostly it works. Time to time it's like 8 hours off. Internet connection is working.
I already debugged unreliable NTP once and replaced the unreliable "ntp" NTP daemon with much more reliable "chrony" NTP daemon. But still unreliable.
"Old people don't like computers" - because computers are unreliable! Why would I use something that's unreliable? A tuning fork ground out of quartz, invented by Seiko, connected to a battery, semiconductor amplifier, 15-bit counter, few logic gates, stepper motor, cogwheels, hands and a clock face is much more reliable!
#ntp #unreliable #linuxfail #linux #chrony #ntpd #reliability
Made progress on packaging #ntpd_rs by @trifectatech for @gentoo :
✅ proper hermetic Rust build
✅ cooked up OpenRC init scripts
✅ runs unprivileged as ntp:ntp
✅ operational #prometheus metrics exporter
✅ man pages
Still a few rough edges but getting there!
#chrony is currently still the better choice but alternatives are always good.
I’ve written before about building microsecond-accurate NTP servers with Raspberry Pi and GPS PPS, and more recently about revisiting the setup in 2025. Both posts focused on the hardware setup and basic configuration to achieve sub-microsecond time synchronization using GPS Pulse Per Second (PPS) signals. But there was a problem. Despite having a stable PPS […]
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