[opensuse] Where does my computer get the time?

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[opensuse] Q: Removing Connection...

Bob Williams

10 Jul 2016 10 Jul '16

10:15

If I don't use the ntp client, where does my computer get the current time? Does it synchronise with my router? Bob -- Bob Williams System: Linux 4.1.20-11-default Distro: openSUSE 42.1 (x86_64) Desktop: KDE Frameworks: 5.21.0, Qt: 5.5.1 and Plasma:

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James Knott

10 Jul 10 Jul

10:45

On 07/10/2016 06:15 AM, Bob Williams wrote:

...

If I don't use the ntp client, where does my computer get the current time? Does it synchronise with my router?

Bob

If you're not using NTP or some other time setting method, then it's just whatever you set your time to. It is possible for a DHCP server to point to an NTP server, but I don't know if openSUSE responds to that. It's also possible to use NTP multicast but, again, I don't know if openSUSE can use it. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Andrei Borzenkov

12:12

Отправлено с iPhone

...

It's also possible to use NTP multicast but, again, I don't know if openSUSE can use it.

Of course it can - it is using the same ntpd that can be configured to use multicast as well.-- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Per Jessen

13:35

James Knott wrote:

...

On 07/10/2016 06:15 AM, Bob Williams wrote:

...
If I don't use the ntp client, where does my computer get the current time? Does it synchronise with my router?

Bob

If you're not using NTP or some other time setting method, then it's just whatever you set your time to. It is possible for a DHCP server to point to an NTP server, but I don't know if openSUSE responds to that.

It does, the server is added dynamically.

...

It's also possible to use NTP multicast but, again, I don't know if openSUSE can use it.

NTP can use it, no probs. -- Per Jessen, Zürich (28.8°C) http://www.dns24.ch/ - free dynamic DNS, made in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

James Knott

14:28

On 07/10/2016 09:35 AM, Per Jessen wrote:

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If you're not using NTP or some other time setting method, then it's just whatever you set your time to. It is possible for a DHCP server to point to an NTP server, but I don't know if openSUSE responds to that. It does, the server is added dynamically.

I suspected as much, but never verified. I suppose if a server is specified the DHCP provided server is not used.

...

...
It's also possible to use NTP multicast but, again, I don't know if openSUSE can use it. NTP can use it, no probs.

Again, I suspected as such but have not seen any info about this. There are many things that may be available in openSUSE, but are apparently not documented. One thing Bob could do is fire up Wireshark and filter on NTP to see what's happening. I normally configure my computers to use either my firewall/router or a public server. There are plenty of those around. Incidentally, the University of Toronto has a pair of NTP servers tick.utoronto.ca and tock.utoronto.ca. ;-) -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

James Knott

16:05

On 07/10/2016 10:28 AM, James Knott wrote:

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I suspected as much, but never verified. I suppose if a server is specified the DHCP provided server is not used.

...
...

I just tried an experiment. I removed the NTP server config from my notebook computer. I then fired up Wireshark on the notebook and desktop computers to watch NTP. I also verified DHCP was providing a NTP server address to my notebook. I have seen a few NTP transactions on my desktop system, but none on my notebook. Both are running openSUSE 13.1, with static config on the desktop and network manager on the notebook. So, it appears openSUSE 13.1 is ignoring the NTP server addresses provided by DHCP. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Per Jessen

18:42

James Knott wrote:

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On 07/10/2016 10:28 AM, James Knott wrote:

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I suspected as much, but never verified. I suppose if a server is specified the DHCP provided server is not used.

...
...
I just tried an experiment. I removed the NTP server config from my notebook computer. I then fired up Wireshark on the notebook and desktop computers to watch NTP. I also verified DHCP was providing a NTP server address to my notebook. I have seen a few NTP transactions on my desktop system, but none on my notebook. Both are running openSUSE 13.1, with static config on the desktop and network manager on the notebook. So, it appears openSUSE 13.1 is ignoring the NTP server addresses provided by DHCP.

Certainly possible :-) - the sysVinit NTP start-up script had some functions for adding and removed time-servers. I don't rely on DHCP supplying the NTP server address either, that's a per-box config job. -- Per Jessen, Zürich (31.5°C) http://www.hostsuisse.com/ - virtual servers, made in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

ellanios82

19:13

On 07/10/2016 09:42 PM, Per Jessen wrote:

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James Knott wrote:

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On 07/10/2016 10:28 AM, James Knott wrote:

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I suspected as much, but never verified. I suppose if a server is specified the DHCP provided server is not used. I just tried an experiment. I removed the NTP server config from my notebook computer. I then fired up Wireshark on the notebook and desktop computers to watch NTP. I also verified DHCP was providing a NTP server address to my notebook. I have seen a few NTP transactions on my desktop system, but none on my notebook. Both are running openSUSE 13.1, with static config on the desktop and network manager on the notebook. So, it appears openSUSE 13.1 is ignoring the NTP server addresses provided by DHCP. Certainly possible :-) - the sysVinit NTP start-up script had some functions for adding and removed time-servers. I don't rely on DHCP supplying the NTP server address either, that's a per-box config job.

- just put mine into /etc/ntp.conf : *server nero.grnet.gr iburst server chronos.asda.gr iburst server chronos.duth.gr iburst* *............* * regards* ** -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Bob Williams

18:37

On 10/07/16 15:28, James Knott wrote:

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On 07/10/2016 09:35 AM, Per Jessen wrote:

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If you're not using NTP or some other time setting method, then it's just whatever you set your time to. It is possible for a DHCP server to point to an NTP server, but I don't know if openSUSE responds to that. It does, the server is added dynamically.

I suspected as much, but never verified. I suppose if a server is specified the DHCP provided server is not used.

...
...
It's also possible to use NTP multicast but, again, I don't know if openSUSE can use it. NTP can use it, no probs.

Again, I suspected as such but have not seen any info about this.

There are many things that may be available in openSUSE, but are apparently not documented.

One thing Bob could do is fire up Wireshark and filter on NTP to see what's happening. I normally configure my computers to use either my firewall/router or a public server. There are plenty of those around. Incidentally, the University of Toronto has a pair of NTP servers tick.utoronto.ca and tock.utoronto.ca. ;-)

Sorry to take so long to reply; I've been trying the various suggestions in this thread (and watching Andy Murray win at Wimbledon). It took me a while to Wireshark working usefully, it's not something I'm familiar with. Anyway, I was able to ascertain the following. 1. YaST accepts my router address as an ntp server and says that it is reachable and responds correctly. 2. After any configuration change, YaST wants to install SuSEfirewall, which means removing shorewall, which I don't want to do. 3. Wireshark shows no ntp activity after closing (with 'Cancel') YaST. 4. sudo systemctl restart ntpd.service works, and immediately generates traffic in Wireshark, but it only shows traffic from my machine to the router, no responses in the other direction. Bob -- Bob Williams System: Linux 4.1.20-11-default Distro: openSUSE 42.1 (x86_64) Desktop: KDE Frameworks: 5.21.0, Qt: 5.5.1 and Plasma:

Carlos E. R.

18:51

On 2016-07-10 20:37, Bob Williams wrote:

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On 10/07/16 15:28, James Knott wrote:

...
On 07/10/2016 09:35 AM, Per Jessen wrote:

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If you're not using NTP or some other time setting method, then it's just whatever you set your time to. It is possible for a DHCP server to point to an NTP server, but I don't know if openSUSE responds to that. It does, the server is added dynamically.

I suspected as much, but never verified. I suppose if a server is specified the DHCP provided server is not used.

...
...
It's also possible to use NTP multicast but, again, I don't know if openSUSE can use it. NTP can use it, no probs.

Again, I suspected as such but have not seen any info about this.

There are many things that may be available in openSUSE, but are apparently not documented.

One thing Bob could do is fire up Wireshark and filter on NTP to see what's happening. I normally configure my computers to use either my firewall/router or a public server. There are plenty of those around. Incidentally, the University of Toronto has a pair of NTP servers tick.utoronto.ca and tock.utoronto.ca. ;-)

Sorry to take so long to reply; I've been trying the various suggestions in this thread (and watching Andy Murray win at Wimbledon).

It took me a while to Wireshark working usefully, it's not something I'm familiar with. Anyway, I was able to ascertain the following.

1. YaST accepts my router address as an ntp server and says that it is reachable and responds correctly.

Ah. It is then a question of people testing their routers to see which work and which don't. Mine it seems not: ============================================================================== Telcontar:~ # rcntp status remote refid st t when poll reach delay offset jitter ============================================================================== LOCAL(0) .LOCL. 10 l 30 64 1 0.000 0.000 0.000 *AmonLanc.valino 5.196.160.139 3 u 19 64 1 0.121 0.108 0.095 hora.ngn.rima-t 172.20.47.7 5 u 28 64 1 13.553 -0.073 0.000 router.valinor .INIT. 16 u - 64 0 0.000 0.000 0.000 <==== oldrouter.valin .INIT. 16 u - 64 0 0.000 0.000 0.000 <==== ntp.redimadrid. 193.147.107.33 2 u 25 64 1 21.226 -0.419 0.000 masip.celingest .INIT. 16 u - 64 0 0.000 0.000 0.000 dnscache-madrid 140.203.204.77 2 u 23 64 1 14.441 -9.085 0.000 bwntpz.bluewin. 195.186.133.100 2 u 22 64 1 56.994 -8.239 0.000 dalek.roflcopte 195.83.222.27 2 u 21 64 1 32.272 0.469 0.000 ns0.luns.net.uk 158.43.192.66 2 u 20 64 1 51.795 3.369 0.000 static-21.herco 158.227.98.15 2 u 19 64 1 49.730 -8.368 0.000 monitordns.tbw. 195.186.11.242 2 u 18 64 1 47.289 -3.079 0.000 oods.roflcopter 195.83.222.27 2 u 17 64 1 32.220 0.328 0.000 time.videxio.ne 131.188.3.223 2 u 16 64 1 52.460 -3.166 0.000

...

2. After any configuration change, YaST wants to install SuSEfirewall, which means removing shorewall, which I don't want to do.

Block SuSEfirewall, set to never install, whatever the wording is. Yes, YaST accepting other firewalls is something that should be done in the near future.

...

3. Wireshark shows no ntp activity after closing (with 'Cancel') YaST.

Cancel aborts.

...

4. sudo systemctl restart ntpd.service works, and immediately generates traffic in Wireshark, but it only shows traffic from my machine to the router, no responses in the other direction.

Try as I do above. -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)

Per Jessen

11 Jul 11 Jul

06:09

Carlos E. R. wrote:

...

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2. After any configuration change, YaST wants to install SuSEfirewall, which means removing shorewall, which I don't want to do.

Block SuSEfirewall, set to never install, whatever the wording is.

Tabooing I think it used to be called, but I doubt if that will work - YaST will probably still suggest installing SuSEfirewall. https://bugzilla.opensuse.org/show_bug.cgi?id=898865

...

Yes, YaST accepting other firewalls is something that should be done in the near future.

...
3. Wireshark shows no ntp activity after closing (with 'Cancel') YaST.

Cancel aborts.

Yes, that throws away all your changes, Bob. -- Per Jessen, Zürich (23.2°C) http://www.hostsuisse.com/ - virtual servers, made in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

James Knott

10 Jul 10 Jul

19:24

On 07/10/2016 02:37 PM, Bob Williams wrote:

...

2. After any configuration change, YaST wants to install SuSEfirewall, which means removing shorewall, which I don't want to do.

I have absolutely no idea why that would happen, unless you're trying to make some settings that affect the firewall. On the NTP configuration, all you have to do is select the server. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Carlos E. R.

23:37

On 2016-07-10 21:24, James Knott wrote:

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On 07/10/2016 02:37 PM, Bob Williams wrote:

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2. After any configuration change, YaST wants to install SuSEfirewall, which means removing shorewall, which I don't want to do.

I have absolutely no idea why that would happen, unless you're trying to make some settings that affect the firewall. On the NTP configuration, all you have to do is select the server.

Because YaST tries to be helpful opening the nntp port in the firewall :-) -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)

Per Jessen

18:47

James Knott wrote:

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On 07/10/2016 09:35 AM, Per Jessen wrote:

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If you're not using NTP or some other time setting method, then it's just whatever you set your time to. It is possible for a DHCP server to point to an NTP server, but I don't know if openSUSE responds to that. It does, the server is added dynamically.

I suspected as much, but never verified. I suppose if a server is specified the DHCP provided server is not used.

I think it's just added, ntp will work out for itself if it's any good. (not alwasys what you'd want, but not a bad default).

...

...
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It's also possible to use NTP multicast but, again, I don't know if openSUSE can use it. NTP can use it, no probs.

Again, I suspected as such but have not seen any info about this.

No info needed, but it requires manual configuration. It's standard ntp functionality.

...

There are many things that may be available in openSUSE, but are apparently not documented.

Of course - the functionality is available in openSUSE just as in other distro, just not explicitly supported by openSUSE.

...

One thing Bob could do is fire up Wireshark and filter on NTP to see what's happening.

Yup.

...

I normally configure my computers to use either my firewall/router or a public server. There are plenty of those around. Incidentally, the University of Toronto has a pair of NTP servers tick.utoronto.ca and tock.utoronto.ca. ;-)

Nice naming! Chuckle! For a public service, I thought it was generally agreed to use the ntp pool servers: http://www.pool.ntp.org -- Per Jessen, Zürich (31.1°C) http://www.dns24.ch/ - your free DNS host, made in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Carlos E. R.

18:53

On 2016-07-10 20:47, Per Jessen wrote:

...

For a public service, I thought it was generally agreed to use the ntp pool servers:

http://www.pool.ntp.org

Yes. I found out that my router queries a server from my ISP, so I manually added that, then a few pool entries: server 0.pool.ntp.org server 1.pool.ntp.org server 2.pool.ntp.org server 3.pool.ntp.org server 0.ch.pool.ntp.org server 0.fr.pool.ntp.org server 0.uk.pool.ntp.org server 0.es.pool.ntp.org -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)

James Knott

19:39

On 07/10/2016 02:53 PM, Carlos E. R. wrote:

...

Yes. I found out that my router queries a server from my ISP, so I manually added that, then a few pool entries:

server 0.pool.ntp.org server 1.pool.ntp.org server 2.pool.ntp.org server 3.pool.ntp.org

server 0.ch.pool.ntp.org server 0.fr.pool.ntp.org server 0.uk.pool.ntp.org server 0.es.pool.ntp.org

If you wish, you can add my server at 172.16.1.1. ;-) -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Carlos E. R.

23:39

On 2016-07-10 21:39, James Knott wrote:

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On 07/10/2016 02:53 PM, Carlos E. R. wrote:

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Yes. I found out that my router queries a server from my ISP, so I manually added that, then a few pool entries:

server 0.pool.ntp.org server 1.pool.ntp.org server 2.pool.ntp.org server 3.pool.ntp.org

server 0.ch.pool.ntp.org server 0.fr.pool.ntp.org server 0.uk.pool.ntp.org server 0.es.pool.ntp.org

If you wish, you can add my server at 172.16.1.1. ;-)

Thanks, but it probably is the other side of the world ;-) -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)

Per Jessen

11 Jul 11 Jul

06:02

Carlos E. R. wrote:

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On 2016-07-10 21:39, James Knott wrote:

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On 07/10/2016 02:53 PM, Carlos E. R. wrote:

...
Yes. I found out that my router queries a server from my ISP, so I manually added that, then a few pool entries:

server 0.pool.ntp.org server 1.pool.ntp.org server 2.pool.ntp.org server 3.pool.ntp.org

server 0.ch.pool.ntp.org server 0.fr.pool.ntp.org server 0.uk.pool.ntp.org server 0.es.pool.ntp.org

If you wish, you can add my server at 172.16.1.1. ;-)

Thanks, but it probably is the other side of the world ;-)

He's pulling you leg, it's private space, not routable. -- Per Jessen, Zürich (23.1°C) http://www.hostsuisse.com/ - virtual servers, made in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Carlos E. R.

12:17

On 2016-07-11 08:02, Per Jessen wrote:

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Carlos E. R. wrote:

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On 2016-07-10 21:39, James Knott wrote:

...
On 07/10/2016 02:53 PM, Carlos E. R. wrote:

...
Yes. I found out that my router queries a server from my ISP, so I manually added that, then a few pool entries:

server 0.pool.ntp.org server 1.pool.ntp.org server 2.pool.ntp.org server 3.pool.ntp.org

server 0.ch.pool.ntp.org server 0.fr.pool.ntp.org server 0.uk.pool.ntp.org server 0.es.pool.ntp.org

If you wish, you can add my server at 172.16.1.1. ;-)

Thanks, but it probably is the other side of the world ;-)

He's pulling you leg, it's private space, not routable.

Oops. I never remember that range. -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)

James Knott

12:39

On 07/11/2016 02:02 AM, Per Jessen wrote:

...

He's pulling you leg, it's private space, not routable.

Actually, it is routable, just not over the Internet. The only non-routable IPv4 addresses are those 169.254.0.0/16 link local addresses and the 127.0.0.0/8 loopback block. Not sure about the "Class E" addresses though. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

James Knott

10 Jul 10 Jul

19:34

On 07/10/2016 02:47 PM, Per Jessen wrote:

...

...
I normally configure my computers to use either my firewall/router or

...
a public server. There are plenty of those around. Incidentally, the University of Toronto has a pair of NTP servers tick.utoronto.ca and tock.utoronto.ca. ;-) Nice naming! Chuckle!

For a public service, I thought it was generally agreed to use the ntp pool servers:

http://www.pool.ntp.org

I don't use those UoT servers, as I seem to recall reading you need permission to use them. I often use ca.pool.ntp.org when setting up systems, but my own computers and firewall are configured to use ntp.nrc.ca, with my firewall also configured for ntp.chu.nrc.ca and ca.pool.ntp.org as backups. Both the nrc servers are operated by Canada's National Research Council and so I pay for them through my taxes. ;-) Incidentally, ntp.chu.nrc.ca is the official time standard station for Canada, which broadcasts on a few shortwave bands, similar to the way the U.S. NIST has WWV etc. Either way, I have no problem using a public government owned server, whereas I wouldn't use privately owned ones, other than through pool.ntp.org. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

James Knott

11 Jul 11 Jul

01:25

On 07/10/2016 02:47 PM, Per Jessen wrote:

...

For a public service, I thought it was generally agreed to use the ntp pool servers:

http://www.pool.ntp.org

I just checked my firewall and found the following: remote refid st t when poll reach delay offset jitter ============================================================================== *132.246.11.238 132.246.11.231 2 u 336 512 377 33.705 -1.620 9.594 +209.87.233.53 209.87.233.50 2 u 159 512 377 30.656 -5.951 5.123 +206.108.0.132 .CDMA. 1 u 276 512 377 10.865 -14.290 2.309 I see the last one is a stratum 1! It's the one I connect to via ca.pool.ntp.org When I look up the host name, it's ntp2.torix.ca. Torix is the Toronto Internet Exchange. http://torix.ca/ It's address, on Front St. W., is the building where I worked for over 17 years, first as a computer tech, maintaining mini-computers and also in planning, where I planned the installation of telecommunications equipment, mostly in the central office. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

James Knott

10 Jul 10 Jul

16:22

On 07/10/2016 09:35 AM, Per Jessen wrote:

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...
It's also possible to use NTP multicast but, again, I don't know

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if openSUSE can use it. NTP can use it, no probs.

I have just set up my desktop system to multicast NTP on both IPv4 and IPv6. I can see them coming into the notebook computer, but have no way to determine if they're being used. When setting up NTP in Yast, there is an incoming broadcast setting, but haven't tried it. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Per Jessen

18:50

James Knott wrote:

...

On 07/10/2016 09:35 AM, Per Jessen wrote:

...
...
It's also possible to use NTP multicast but, again, I don't know

...
if openSUSE can use it. NTP can use it, no probs.

I have just set up my desktop system to multicast NTP on both IPv4 and IPv6. I can see them coming into the notebook computer, but have no way to determine if they're being used. When setting up NTP in Yast, there is an incoming broadcast setting, but haven't tried it.

"ntpq -pn" will tell you if they're being used. For instance: temp78:~ # ntpq -pn remote refid st t when poll reach delay offset jitter ============================================================================== +192.168.2.254 .DCFa. 1 u 741 1024 377 0.426 -0.668 1.486 *fe80::202:a5ff: 192.168.2.137 2 m 9 16 377 0.000 9.749 6.914 the fe80: server is the multicast. The 192.168 server works over broadcast. -- Per Jessen, Zürich (30.6°C) http://www.hostsuisse.com/ - dedicated server rental in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Bob Williams

18:54

On 10/07/16 19:50, Per Jessen wrote:

...

James Knott wrote:

...
On 07/10/2016 09:35 AM, Per Jessen wrote:

...
...
It's also possible to use NTP multicast but, again, I don't know

...
if openSUSE can use it. NTP can use it, no probs.

I have just set up my desktop system to multicast NTP on both IPv4 and IPv6. I can see them coming into the notebook computer, but have no way to determine if they're being used. When setting up NTP in Yast, there is an incoming broadcast setting, but haven't tried it.

"ntpq -pn" will tell you if they're being used. For instance:

temp78:~ # ntpq -pn remote refid st t when poll reach delay offset jitter ============================================================================== +192.168.2.254 .DCFa. 1 u 741 1024 377 0.426 -0.668 1.486 *fe80::202:a5ff: 192.168.2.137 2 m 9 16 377 0.000 9.749 6.914

the fe80: server is the multicast. The 192.168 server works over broadcast.

Hmm... # ntpq -pn No association ID's returned -- Bob Williams System: Linux 4.1.20-11-default Distro: openSUSE 42.1 (x86_64) Desktop: KDE Frameworks: 5.21.0, Qt: 5.5.1 and Plasma:

James Knott

19:37

On 07/10/2016 02:50 PM, Per Jessen wrote:

...

"ntpq -pn" will tell you if they're being used. For instance:

temp78:~ # ntpq -pn remote refid st t when poll reach delay offset jitter ============================================================================== +192.168.2.254 .DCFa. 1 u 741 1024 377 0.426 -0.668 1.486 *fe80::202:a5ff: 192.168.2.137 2 m 9 16 377 0.000 9.749 6.914

the fe80: server is the multicast. The 192.168 server works over broadcast.

I'll have to remember that. On my desktop system, it shows: # ntpq -pn remote refid st t when poll reach delay offset jitter ============================================================================== *132.246.11.238 132.246.11.231 2 u 237 512 377 31.093 -0.300 7.501 224.0.1.1 .MCST. 16 u - 64 0 0.000 0.000 0.000 ff02::101 .MCST. 16 u - 64 0 0.000 0.000 0.000 -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Per Jessen

11 Jul 11 Jul

05:46

James Knott wrote:

...

On 07/10/2016 02:50 PM, Per Jessen wrote:

...
"ntpq -pn" will tell you if they're being used. For instance:

temp78:~ # ntpq -pn remote refid st t when poll reach delay offset jitter ============================================================================== +192.168.2.254 .DCFa. 1 u 741 1024 377 0.426 -0.668 1.486 *fe80::202:a5ff: 192.168.2.137 2 m 9 16 377 0.000 9.749 6.914

the fe80: server is the multicast. The 192.168 server works over broadcast.

I'll have to remember that. On my desktop system, it shows:

# ntpq -pn remote refid st t when poll reach delay offset jitter ============================================================================== *132.246.11.238 132.246.11.231 2 u 237 512 377 31.093 -0.300 7.501 224.0.1.1 .MCST. 16 u - 64 0 0.000 0.000 0.000 ff02::101 .MCST. 16 u - 64 0 0.000 0.000 0.000

I guess that is where you are serving time from? This is my server: # ntpq -pn remote refid st t when poll reach delay offset jitter ============================================================================== *127.127.8.0 .DCFa. 0 l 23 64 377 0.000 -0.009 0.383 127.127.1.0 .LOCL. 10 l 34 64 377 0.000 0.000 0.001 x162.23.41.10 .PPS. 1 u 437 1024 377 4.963 -11.134 0.426 192.168.7.255 .BCST. 16 u - 16 0 0.000 0.000 0.001 ff05::101 .MCST. 16 u - 16 0 0.000 0.000 0.001 -- Per Jessen, Zürich (22.8°C) http://www.dns24.ch/ - your free DNS host, made in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Patrick Shanahan

10 Jul 10 Jul

11:18

* Bob Williams [07-10-16 06:18]:

...

If I don't use the ntp client, where does my computer get the current time?

the inaccurate an uncorrected clock chip on your motherboard.

...

Does it synchronise with my router?

only if *you* configure it to do so. -- (paka)Patrick Shanahan Plainfield, Indiana, USA @ptilopteri http://en.opensuse.org openSUSE Community Member facebook/ptilopteri http://wahoo.no-ip.org Photo Album: http://wahoo.no-ip.org/gallery2 Registered Linux User #207535 @ http://linuxcounter.net -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Bob Williams

11:48

On 10/07/16 12:18, Patrick Shanahan wrote:

...

* Bob Williams [07-10-16 06:18]:

...
If I don't use the ntp client, where does my computer get the current time?

the inaccurate an uncorrected clock chip on your motherboard.

Ah!

...

...
Does it synchronise with my router?

only if *you* configure it to do so.

No surprises there, then. My router (Draytek Vigor 2830Vn) can get it's time from an internet ntp server, but I can't see anything to suggest that it will act as a server to LAN clients. YaST can configure ntp, but it requires SuSEFirewall, which I don't have as I am using Shorewall. Seems to be a Catch 22 situation. Bob -- Bob Williams System: Linux 4.1.20-11-default Distro: openSUSE 42.1 (x86_64) Desktop: KDE Frameworks: 5.21.0, Qt: 5.5.1 and Plasma:

James Knott

12:32

On 07/10/2016 07:48 AM, Bob Williams wrote:

...

YaST can configure ntp, but it requires SuSEFirewall, which I don't have as I am using Shorewall.

That is incorrect. You just configure it to use a NTP server. You might be able to use your router, but I can't say for certain. The firewall settings are for when you use that computer as a NTP server, which openSUSE does automagically. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Per Jessen

13:33

Bob Williams wrote:

...

On 10/07/16 12:18, Patrick Shanahan wrote:

...
* Bob Williams [07-10-16 06:18]:

...
If I don't use the ntp client, where does my computer get the current time?

the inaccurate an uncorrected clock chip on your motherboard.

Ah!

...
...
Does it synchronise with my router?

only if *you* configure it to do so.

No surprises there, then. My router (Draytek Vigor 2830Vn) can get it's time from an internet ntp server, but I can't see anything to suggest that it will act as a server to LAN clients.

Try it, it's likely using NTP which by default also acts as a server. -- Per Jessen, Zürich (28.4°C) http://www.hostsuisse.com/ - dedicated server rental in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Carlos E. R.

13:41

On 2016-07-10 13:48, Bob Williams wrote:

...

On 10/07/16 12:18, Patrick Shanahan wrote:

...

No surprises there, then. My router (Draytek Vigor 2830Vn) can get it's time from an internet ntp server, but I can't see anything to suggest that it will act as a server to LAN clients.

YaST can configure ntp, but it requires SuSEFirewall, which I don't have as I am using Shorewall.

No, it does not require SuSEfirewall. It will configure SuSEfirewall automatically, though, which is different. -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)

James Knott

14:13

On 07/10/2016 07:48 AM, Bob Williams wrote:

...

Seems to be a Catch 22 situation.

Perhaps you can use one of these: ;-) http://www.nist.gov/pml/div688/clock-082213.cfm -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Per Jessen

18:38

Bob Williams wrote:

...

YaST can configure ntp, but it requires SuSEFirewall, which I don't have as I am using Shorewall.

Yeah, somebody in the YaST team cocked it up, thinking there can only be one firewall. Just ignore that pop-up window and carry on. -- Per Jessen, Zürich (31.6°C) http://www.hostsuisse.com/ - virtual servers, made in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

Bob Williams

18:44

On 10/07/16 19:38, Per Jessen wrote:

...

Bob Williams wrote:

...
YaST can configure ntp, but it requires SuSEFirewall, which I don't have as I am using Shorewall.

Yeah, somebody in the YaST team cocked it up, thinking there can only be one firewall. Just ignore that pop-up window and carry on.

Thank you for that clarification. I think I'll configure my machine to synchronise with the internet ntp servers, and my router can synchronise with the desktop machine. Many thanks for all the helpful advice. Bob -- Bob Williams System: Linux 4.1.20-11-default Distro: openSUSE 42.1 (x86_64) Desktop: KDE Frameworks: 5.21.0, Qt: 5.5.1 and Plasma:

Carlos E. R.

18:57

On 2016-07-10 20:44, Bob Williams wrote:

...

On 10/07/16 19:38, Per Jessen wrote:

...

Thank you for that clarification. I think I'll configure my machine to synchronise with the internet ntp servers, and my router can synchronise with the desktop machine.

Better that the router configures with an outside server, because it is impossible that the internal server gets the time before the router boots ;-) -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)

Bob Williams

20:43

On 10/07/16 19:57, Carlos E. R. wrote:

...

On 2016-07-10 20:44, Bob Williams wrote:

...
On 10/07/16 19:38, Per Jessen wrote:

...
Thank you for that clarification. I think I'll configure my machine to synchronise with the internet ntp servers, and my router can synchronise with the desktop machine.

Better that the router configures with an outside server, because it is impossible that the internal server gets the time before the router boots ;-)

Point taken. Done. -- Bob Williams System: Linux 4.1.20-11-default Distro: openSUSE 42.1 (x86_64) Desktop: KDE Frameworks: 5.21.0, Qt: 5.5.1 and Plasma:

Carlos E. R.

12:58

On 2016-07-10 12:15, Bob Williams wrote:

...

If I don't use the ntp client, where does my computer get the current time? Does it synchronise with my router?

Is the clock absolutely correct to the second? Maybe /usr/lib/systemd/system/time-sync.target. -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)

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Andrei Borzenkov
Bob Williams
Carlos E. R.
ellanios82
James Knott
Patrick Shanahan
Per Jessen