[Bender]

Rather than money one can donate NTP servers to the pool. [1] It can be a fun learning exercise in setting up a stable stratum-2 time server. One can create graphs from the optional logs.

Why bother? Many of the rabbit holes one could venture down in learning to set up a stable time server can also benefit application servers in terms of latency, responsiveness, learning how to get clients to share resources and so much more. Rather than trying to find cooperative stratum-1 servers, one can start by using each of the Google, Facebook and Apple public stratum-1 servers [2] to get started. They get beat up a lot but most of them are stable most of the time.

Ask your favorite LLM how to set up a public NTP server using NTPD or Chrony. For extra credit play with each of them.

[1] - https://www.ntppool.org/en/join.html

[2] - # grep -E "facebo|goog|appl" /etc/hosts

    17.253.16.253   time.apple.com
    129.134.28.123  time1.facebook.com
    129.134.29.123  time2.facebook.com
    129.134.25.123  time3.facebook.com
    129.134.26.123  time4.facebook.com
    129.134.27.123  time5.facebook.com
    216.239.35.0    time1.google.com
    216.239.35.4    time2.google.com
    216.239.35.8    time3.google.com
    216.239.35.12   time4.google.com

[tonyarkles]

One of the really nifty things about having a stratum-1 time server on-site (because... reasons) is those graphs. You can very readily see the subtle temperature-dependence of timing crystals. At the facility I was at there was a large cycle every day during the week and then smaller cycle on each weekend day. Our HVAC system didn't heat/cool the building as much on the weekend when no one was there so the temperature swing -> frequency swing was smaller.

Really drives home one of my favourite half-jokes: every sensor is a temperature sensor; some of them measure other things too.

[bigstrat2003]

Yep, I encourage everyone to do this (though don't ask an LLM, actually put effort into learning). It's easy and cheap to do. I have been running a server in the NTP pool on a Digital Ocean droplet for years now, costs me only $6 a month.

[CamperBob2]

The people who learn to use LLMs effectively for learning will outcompete you handily. You understand that, right? Tool use is an important skill, arguably among the most important ones we have evolved.

[dboreham]

We ran a public NTP server for many years. Then, details hazy, but I think there was a UDP amplification vulnerability that was exploited which upset our transit provider so we took it down. Might be fun to try again though.

[Analemma_]

A fully-patched NTP server should be fine. A lot of tier-2 ISPs were treating their NTP servers as abandonware that never got updates, so they ended up being ripe for UDP amplification attacks, but that was a vulnerability in ancient software, not the protocol.