Poll [How often] Do you use NTP to sync your devices time?

Networking Networking Software
1

For polls it’s enclosed square brackets, then each option starts with *

  • daily sync, for every individual device
  • daily sync, one device, to all devices from lan-based server
  • weekly
  • weekly, with single lan-based time server
  • two weeks
  • two weeks using server for single upstream sync
  • monthly
  • monthly with lan sync
  • two months
  • two month with lan sync
  • three
  • three with lan
  • four
  • four with lan
  • five
  • five with lan
  • six
  • six with lan
  • seven
  • seven with lan
  • eight (good option for DST shifts 8/4)
  • eight with lan
  • Only for DST changes
  • nine
  • nine with lan
  • ten
  • ten with lan
  • eleven
  • eleven with lan
  • once a year
  • yearly with lan server to all other devices
  • full manual time sync, using local, non-network based clocks.

0 voters

This poll may look a bit wild but I want to be as thorough as possible to implant the idea of how reliant we are or not reliant but how often we use these servers. I really want to force you to at least think about it. I want you to ask yourself if you really have to refresh your time, as often as you do–AND on top of that, if it’s necessary to use a time server to get a fairly accurate time.

I think we all have enough clocks in our homes to invalidate the need for hundreds of thousands of time servers. This would save an unbelievable amount of energy, and help keep our air cleaner.

2

Yes, most (Dare I say all?) of my devices point to internet NTP servers however I do like the idea of hosting my own with an atomic clock

I do have a Windows Server hosting up NTP specifically for my CCTV cameras which are completely blocked from the internet

I think we all have enough clocks in our homes to invalidate the need for hundreds of thousands of time servers.

Problem is, most clocks SUCK

1 Like
3

yes/option 1, I guess? I have one computer sync to external NTP servers, and most of the other computers in my house/network sync to that one computer.

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4

Yes.

I use sync my local NTP server via NTP, and then all my devices sync to my local NTP server.
For some services it’s essential to have time synced between different servers.

5

No, I have transitioned to PTP. NTP is considered legacy these days.

https://tsn.readthedocs.io/timesync.html

2 Likes
6

For any devices that do not sync locally, you could run a dns filter on your network when you are using these devices, amd block those specific ntp domains, for a month or so, and turn it back on for just half an hour, with a little script, then disable the domain again. Any small changes like this might end up making big differences.

7

Wow this looks very interesting, but also complicated. Have you really gone through all of that setup process? I’d be interested to know how many times (pun?) your clock has been stepped (time changed) vs whatever they called the speed adjustment, that certainly has my attention!

Very cool, and this would also significantly reduce our need to re-sync pur clocks as frequently, further reducing electricity demands for time servers and all the network hops in between.

8

Here’s how to create poll using post options.

9

I just clicked edit on one of my other polls. It’s really simple, just couldn’t remember whatsoever.

10

I sync “one machine” with chronyd to nist and all the rest of my internal stuff uses the “one machine” for ntp/chrony

11

To be honest… All of this is automatic for me, so I never bother to check. :sweat_smile:

If you are interested and think that is a lot of config, then I recommend this, it’s really not complicated at all and I skip the first few steps by just installing the linuxptp package in Ubuntu. I would say setting up Pipewire from scratch was harder than configuring this!

NTP is good enough for synchronising the clock to the current second but most of industry use PTP these days…

12

What do you use on Windows for a slave?

13

Where’s the “I have my own local NTP service option? :joy:

And yeah if you’re relying on time for things like logs, Kerberos tickets, etc time sync is essential. And as above most clocks suck and drift a heap.

1 Like
14

That’s what the “lan” option means. It indicates you run a local NTP server that gets time from some other upstream server, and that gets sent to all lan devices, or as many as easily configurable.

I can’t edit the poll after 15 minutes of making the post.

15

PTPSync, or the built in Windows PTP.

1 Like
16

The doc says this works best with a NIC supporting PTP at the firmware level. Are you using such hardware?

I’ve said it already, but the main reason why this is so interesting to me is PTP can adjust the clockspeed in order to keep time more accurately.

I think, if all computers would do this, and just do any necessary number of syncs via the network to get an average of the drift, this software could set the necessary offset and then never run for another year.

All those NTP servers could just go offline (except for services needing repeated accurwcy checking) and we could save a LOT of electricity.

Imagine if instead of only adjusting the OS clock, we could adjust the motherboard clock speed. Now there are NICs with their own clocks, and their own drift. Let’s get all this stuff synced, ONCE, and then eliminate the need of repeat time syncing.

So is it only possible to change the speed of the OS cloxk, or is there programs that can also properly adjust the speed of the motherboard clock speed?

17

Most NICs I’ve come in contact with since at least 2018 have had such hardware support. You set PTP at the port itself.

Easiest way to check it is to download ethtool and run ethtool -T <nic> - if your computer says something like this, you should be golden:

me@home:~$ ethtool -T enp11s0 
Time stamping parameters for enp11s0:
Capabilities:
	hardware-transmit
	software-transmit
	hardware-receive
	software-receive
	software-system-clock
	hardware-raw-clock
PTP Hardware Clock: 0
Hardware Transmit Timestamp Modes:
	off
	on
Hardware Receive Filter Modes:
	none
	all

As opposed to a non-supporting hardware (here, a wireless NIC):

me@home:~$ ethtool -T wlp9s0 
Time stamping parameters for wlp9s0:
Capabilities:
	software-receive
	software-system-clock
PTP Hardware Clock: none
Hardware Transmit Timestamp Modes: none
Hardware Receive Filter Modes: none

Just ran these two commands on a B450 integrated NIC card, so most if not all NICs should support this.

18

This has to be some of the absolute WORST documentation I’ve read so far. It doesn’t clearly describe any of the steps, especially the most critical:

Synchronizing the system clock

and just lists arbitrary numbers with no explanation on any single bit of it, and expects you to believe that what you put in will be accurate, and if it’s not applicable to your setup, well you are on your own. Whatever, who cares if it’s not accurate, which I believe, would be the entire purpose of this software.

What a joke!

Also, it doesn’t describe how to synchronize without PTP-hardware-support.

I bet the redhat docs you linked to are significantly better.

19

Eh, took the first tutorial that showed in my Google search, didn’t vet it enough apparently :slight_smile:

Apparently all you need to do for software mode is add the -S flag to the ptp4l command, or add time_stamping software in the config file.

20

NTP has always done that. it uses a “hybrid phase/frequecy-lock feedback loop”[1]

For a comparison between NTP and PTP, see Clock Discipline Algorithm here.

If you’re using an “NTP” program that doesn’t adjust the clock (like the Windows clock internet time sync) that’s actually SNTP, not NTP proper, and you should just change your client software.