Re: [ntp:questions] Time syncing with something other than ntpd

[Miroslav Lichvar]

On 2017-02-01, sean  wrote:
> On 2017-01-30, William Unruh  wrote:
>> You do not say which OS you use. Windows (which version?), Mac, linux,
>> BSD?
>
> Primarily FreeBSD and OpenBSD, but also Linux. Knowning that, what's
> that mean in terms of a ntp client?

IIRC openntpd runs on all these systems, but reference clocks are
supported only on OpenBSD. chrony supports FreeBSD and Linux (both with
refclocks), but not OpenBSD. ntpd supports everything.

>> chrony does not work on windows. ntpd is what what tends to ship with
>> linux distros. chrony gives better time discipline but has a smaller
>> user group. 
>
> Well if I use Chrony with a GPS unit on something like a raspberry pi,
> would I be able to be apart of the NTP pool or is it limited to NTPD
> users only?

Yes, you can do that. The pool project page recommends ntpd, but it's
not a requirement. There are quite a few openntpd and chrony servers in
the pool, including a couple of my own.

-- 
Miroslav Lichvar

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Re: [ntp:questions] Time syncing with something other than ntpd

[sean]

On 2017-01-30, William Unruh  wrote:
> On 2017-01-30, sean  wrote:
>> Hi All,
>>
>> I'm real interested in NTP and accurate time, hence why I'm on this
>> newsgroup. I would like to look into getting a time sensor and I hear
>> the Garmin GPS 18X is what some folks run unless they need much more
>> precision. Is this still a pretty well regarding GPS unit for pretty
>> accurate (I know that's highly subjective) time keeping? This would be
>> a hobbyist thing and I'm not running an important business, if you were
>> going to ask.
>>
>> Next question...Do most folks here use the NTPD client, or it is a
>> mixture of Chrony and openNTPD? Maybe some folks just go with what ships
>> with their OS?
>
> You do not say which OS you use. Windows (which version?), Mac, linux,
> BSD?

Primarily FreeBSD and OpenBSD, but also Linux. Knowning that, what's
that mean in terms of a ntp client?

>
> chrony does not work on windows. ntpd is what what tends to ship with
> linux distros. chrony gives better time discipline but has a smaller
> user group. 

Well if I use Chrony with a GPS unit on something like a raspberry pi,
would I be able to be apart of the NTP pool or is it limited to NTPD
users only?

Best,
Sean

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Re: [ntp:questions] Time syncing with something other than ntpd

[sean]

On 2017-01-30, Terje Mathisen  wrote:
> sean wrote:
>> Hi All,
>>
>> I'm real interested in NTP and accurate time, hence why I'm on this
>> newsgroup. I would like to look into getting a time sensor and I hear
>> the Garmin GPS 18X is what some folks run unless they need much more
>> precision. Is this still a pretty well regarding GPS unit for pretty
>> accurate (I know that's highly subjective) time keeping? This would be
>> a hobbyist thing and I'm not running an important business, if you were
>> going to ask.
>
> I have had a Garmin 18 as well as 3-4 SURE kits, the latter is half the 
> price, requires about the same amount of soldering, and has been 
> measured at the 20-30 ns level, so quite accurate.
>>

Do you have a URL to the sure kits? What do you have it hooked up to
that's running your NTP daemon?

>> Next question...Do most folks here use the NTPD client, or it is a
>> mixture of Chrony and openNTPD? Maybe some folks just go with what ships
>> with their OS?
>
> Since I've been on the NTP Hackers team for a couple of decades I'm 
> partial to the original ntpd. :-)
>

Yeah, hard to imagine you wanting to change from something you know so
very well. Thank you for your contributions to NTP!

> Terje

Best,
Sean

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Re: [ntp:questions] Time syncing with something other than ntpd

[sean]

On 2017-01-30, David Taylor  wrote:
> On 30/01/2017 04:13, sean wrote:
>> Hi All,
>>
>> I'm real interested in NTP and accurate time, hence why I'm on this
>> newsgroup. I would like to look into getting a time sensor and I hear
>> the Garmin GPS 18X is what some folks run unless they need much more
>> precision. Is this still a pretty well regarding GPS unit for pretty
>> accurate (I know that's highly subjective) time keeping? This would be
>> a hobbyist thing and I'm not running an important business, if you were
>> going to ask.
>>
>> Next question...Do most folks here use the NTPD client, or it is a
>> mixture of Chrony and openNTPD? Maybe some folks just go with what ships
>> with their OS?
>> The comparison chart is pretty nice and lays each option out nicely:
>> https://chrony.tuxfamily.org/comparison.html
>>
>> I think that's all for now. Feel free to provide any URLs to any
>> resources I should check out about time sycing, NTP, etc.
>
> Sean,
>
> I have been running NTP on multiple systems since 2002, including Linux 
> and Windows (2000 and later), both with hardware sync (GPS18, GPS18x and 
> multiple GPS devices for the Raspberry Pi), and with LAN and Wi-Fi 
> network sources.  I find NTP easy to manage and monitor over multiple 
> systems, and the fact that it runs on Windows, and can accept GPS 
> devices on Windows very valuable.  You can easily get within 10 
> microseconds in Linux (but be careful of the temperature and GPS antenna 
> location), and within 200 microseconds on Windows when using an attached 
> GPS/PPS device.
>

Hi Dave,

Thank you for the reply. I found your website about 3 weeks ago and got
the urge to checkout GPS devices, like the GPS18, Raspberry pi options,
etc. Thank you for it and all of the graphs. You certainly have many Pis
keep track of the time! I don't recall, are you apart of the NTP Pool?

I found your website to have a wealth of great information that's quite
well compiled and thoughout. I hope your health is much better this
year and that you're on the road to recovery.

Primarily I run FreeBSD and was surprised to learn that it can have
better precision than Linux, although the articles I read were FreeBSD
8.0 era. Do you find FreeBSD generic kernel comparable with Linux? From
what it sounds like, a Raspberry Pi with the device below will give me
"pretty accurate" (my words) time, which I can use to sync my devices in
my home.


>http://www.satsignal.eu/mrtg/performance_ntp.php
>
> For the Raspberry Pi:
>
>  
> https://store.uputronics.com/index.php?route=product/product_id=81
>

That's pretty well priced, cheaper than the Garmin

> In terms of installations, I think that NTP will have by far the 
> greatest number, and of the three you listed, only NTP runs on Windows.

Well I don't really have any Windows installations, but I will keep NTP
in mind when I want to run time syncing on Windows. As an aside, what
does Windows natively use to keep time and sync?

Thanks,
Sean

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Re: [ntp:questions] Help with RESTRICT

[David Taylor]

On 30/01/2017 20:14, Antonio Marcheselli wrote:

Hello all

[First, I am using google groups, in the past I was told it was causing hassle 
in terms of formatting but BT have discontinued their news server and I am 
unable to find an alternative - apologies if these messages are not properly 
formatted.]

I am looking for some advice on the RESTRICT parameter.

My configuration file has the following line in it:

restrict 172.20.0.0 mask 255.255.0.0 notrust noquery nomodify nokod

With the above, a server on 172.20.21.11 was unable to poll the time.
I checked on a working configuration and found the below

restrict 172.20.0.0/16 mask 255.255.0.0 notrust noquery nomodify nokod

but I am concerned that the /16 bit is simply making the whole line void which 
would explain why it's then working.

Basically, I need the 'nokod'. For umpteen reasons, I want the NTP server to 
never ban any client on the LAN. But I thought that a little restriction would 
be good practice too.

Could you please tell me if the /16 is indeed required or whether I have just 
made the whole line void?

Thanks for your help!


Antonio,

For a free text-only news server, try Eternal September:

  https://www.eternal-september.org/

although it seems its security certificate might not be correct.

I'm confused by NTP's restrict lines, but I was advised that these allow 
LAN-only access:


# Suggestions for NTP restrictions (accepting ntpq commands from the LAN):
restrict source notrap nomodify nopeer
restrict 127.0.0.1
restrict ::1
restrict 192.168.0.0 mask 255.255.255.0

Perhaps that helps?

--
Cheers,
David
Web: http://www.satsignal.eu

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