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#ntp

7 posts6 participants1 post today

des connaisseurs en #proxmox et #ntp ici ?
mon serveur proxmox n'est pas à l'heure

root@pve:~# timedatectl
Local time: Sat 2025-04-05 00:07:08 CEST
Universal time: Fri 2025-04-04 22:07:08 UTC
RTC time: Fri 2025-04-04 22:07:08
Time zone: Europe/Paris (CEST, +0200)
System clock synchronized: no
NTP service: active
RTC in local TZ: no

et pourtant NTP service est bien "active", qu'est ce qui ne va pas ?

Huh. Now that I have #otel traces on a bunch of things at home, it's pretty clear that my clocks aren't in sync on every system. They're maybe 1ms off, but it's enough that supposedly-nested trace spans aren't quite nested right.

Which is annoying since I have two local GPS #NTP receivers.

The two "bad" machines were using #systemd-timesyncd to talk to Ubuntu's pool clocks instead of the local clocks. The "good" machines are using #chrony and claim that they're ~2 us off of GPS time.

Now I'm curious -- is this a problem with network latency and Ubuntu's pool, or is that just as good as timesyncd gets?

Active Directory Domain Sercvies 컨트롤러 서버의 NTP 서버 켜기
Windows Server에 NTP 서버 켜는 설명할 때 누군가 레지스트리을 어렵게 하기 시작했다. KB 문서 만들 때 UI 접근 경로보다는 명령어를 치는 구성이 설명이 더 쉬워서겠지 싶다.
당연하게도 그룹 정책 편집기에서 편집할 수 있다. 특히 도메인 컨트롤러라면 서버마다 매번 수동으로 넣을 것이 아니라 한 번만 하면 될 일이다.
굳이 문서로 남기기에는 시간이 아까운 일인데, 오랜만에 최초 구성할 일이 생겨 간단히 스크린샷을 남긴다.

Let's take a moment to remember the guy who made sure we don't have to change Every Goddamn Clock today, David L. Mills, creator of Network Time Protocol (NTP) who passed last year.

My wristwatch is synced to my phone, which is synced to the internet, which knows that time it is right now thanks to David Mills. Cheers to his memory 🥃

cse.engin.umich.edu/stories/re

Computer Science and EngineeringRemembering alum David Mills, who brought the internet into perfect timeMills created the Network Time Protocol, which enables any device online to know precisely what time it is.

Hello, fediverse friends. I have been working on my time server, time.lettersblogatory.com, for several months and have gotten it in pretty good shape. It is now ready for primetime, I hope. If you have an NTP client and would like to give it a try, please add time.lettersblogatory.com to your list of time servers. Bonus: the server is NTS-enabled! It's located in the Netherlands and is a stratum 2 server.

So, mein Stratum 1 NTP-Server ist nun auch komplett installiert. Die GPS-Antenne liegt jetzt mehr auf der Fensterbank, sondern ist draußen auf dem Zwischendach. Damit sehe ich immer 6-12 Satelliten gleichzeitig und habe im Lokalen Netz eine supergenaue Zeit mit einer Abweichung im Nano-Sekundenbereich.

#NTP#Zeitserver#GPS

Did you know chrony, the #NTP implementation, sets up an administrative listener on the loopback interface using UDP/323 by default?

Unfortunately in the #RPKI rpki-rtr has TCP/323 registered with IANA (see IETF RFC 6810). UDP/323 is reserved. Reserving a transport that is unused by the assigned application is common practice these days.

chrony's choice can probably be chalked up to a historical accident since it came first and presumably picked 323 because it "looked" like 123 and was then unassigned.

Chrony should probably change their default imo, but maybe it's too late or not worth it now?

late to the party, but today i have successfully installed my first #ntp server based on:
- #raspberry pi 2 B
- #gps module gt-u7 (my first ali order)
- tutorial on the web

i took me around 4 hours longer than any regular person, because:
i lost some time on figuring out there is no WLAN on a raspi2.
lost loads of time because I flipped 2 wires 🙈
ntp01 does now deliver accurate time 👍

Habe mal wieder ein neues Nerd-Projekt: Ein eigener Stratum 1 NTP-Zeitserver. Warum? Weil es geht. Die Daten kommen per GPS und haben dadurch eine Genauigkeit im Bereich von Nano-Sekunden. Der Testaufbau läuft, jetzt muss ich nur noch ein passendes Gehäuse drucken und eventuell die Antenne noch draußen positionieren.

Continued thread

David Groves' (fibrecat.org/) talk at #NetMCR about measuring and calculating the current time was really interesting, explaining crazy timezones, how DST has changed over the years, leap years and seconds, and then how computers sync time to each other via #NTP and #PTP.

I learnt that you can even get expansion cards that have mini atomic clocks on them! (opencompute.org/products/319/o)

Sadly I couldn't stay and chat afterwards as I had to get my train ☹️