Re: [ntp:questions] Synchronize distributed PCs with GPS 1 PPS and NTPd for OWD measurements

Hi, Sandip-- On Sep 11, 2015, at 8:05 AM, sandip gangakhedkar wrote: > Hello, > > I am trying to sync the system clocks of two desktop/laptop computers > within sub millisecond accuracy. > > The goal is to have a setup for measuring One Way Delay of UDP packets > between

Re: [ntp:questions] Atheros AR9331 w/GPS + PPS

On Sep 10, 2015, at 3:46 AM, Gabs Ricalde wrote: > TL-WR703N, polling GPIO driver, ntpd maxpoll 2 > https://imgur.com/a/ILF9Y > > The offset depends on these things: the stability of the local clock, > PPS jitter, and loop time constant

Re: [ntp:questions] what's the matter with my ntp

On Aug 29, 2015, at 1:03 AM, Mike Cook michael.c...@sfr.fr wrote: For me this would not be considered acceptable. I would NEVER have ntp servers in virtual machines. +1 to this point. Your maxpoll default of 10(1024s) for the pool servers is too high. Try dropping it to 6 (64s) or 7(128s).

Re: [ntp:questions] iburst and NIST servers

On Aug 2, 2015, at 2:31 AM, Mike Cook michael.c...@sfr.fr wrote: Can anyone confirm that this is an issue? I habitually put an burst directive in my ntp.conf server statements. ex: server 129.6.15.30 noselect iburst minpoll 4 maxpoll 6 server 128.138.140.44 noselect iburst minpoll 4

Re: [ntp:questions] NTP Hardware Support

On Jun 22, 2015, at 3:54 AM, David Garijo dgman...@live.com wrote: Hello, I've been thinking of the possibility of adding hardware support for NTP so that it can timestamp the packets sent and received more accurately. OK. NTP talks to local hardware which provides timestamps via clock

Re: [ntp:questions] [Pool] Leap second configuration

Hi, Kiss-- Try questions@lists.ntp.org mailto:questions@lists.ntp.org; BCC:ing p...@lists.ntp.org. leap=00 means it's not primed to announce a leap second; if you wanted to test in more detail, set the date ahead to 2015-6-30 and see whether pending leap second announcement shows (leap=01).

Re: [ntp:questions] NTP setup in time sensitive environment

On Apr 22, 2015, at 3:24 PM, NVAP nva...@gmail.com wrote: *Questions:* 1) How can we assure that the sync will consistently result in +/- 5ms offset? If you weren't rebooting the Windows boxes potentially several times a day, Windows might do better. I've seen RRD graphs of stratum-2 Win 7

Re: [ntp:questions] chrony as a server

On Feb 24, 2015, at 11:40 AM, Paul tik-...@bodosom.net wrote: However, if you time things with a rhythm you can get to ~50 ms or better While these performance anecdotes are interesting they (starting with unruh@invalid) are all anecdotes. I didn't mention research and real numbers by

Re: [ntp:questions] chrony as a server

On Feb 23, 2015, at 11:57 PM, David Woolley david@ex.djwhome.demon.invalid wrote: On 23/02/15 21:23, William Unruh wrote: manual corrections are probably good to 1 sec. to get 1 sec at 2ppm is about 5 days per measurement or 10 days altogether. It's a long time since I did this, but 200ms

Re: [ntp:questions] NTP with 2 servers

On Feb 20, 2015, at 12:17 PM, Nuno Pereira nuno.pere...@g9telecom.pt wrote: In our infrastructure we had some ntp clients that don't have access to the world and so they are configured to use only 2 servers (by the way, the other have 2 more options). In reality both servers are the same, but

Re: [ntp:questions] Pool server gone wild

On Feb 20, 2015, at 10:55 AM, Jan Ceuleers jan.ceule...@computer.org wrote: Using dig on a sample of the pool it seems that DNS queries to the pool only ever return 4 entries. Per request, yes-- with something like a 150 or 300 second TTL. Hopefully, you get a different set of hosts returned

Re: [ntp:questions] NTP offset doesn't change.

On Feb 12, 2015, at 11:21 PM, Terje Mathisen terje.mathi...@tmsw.no wrote: I've considered packing some insulation around the crystal, this would tend to stabilize (while also increasing) the temperature, but this would also be likely to reduce its lifetime, and the motherboard would probably

Re: [ntp:questions] NTP offset doesn't change.

On Feb 12, 2015, at 12:49 AM, William Unruh un...@invalid.ca wrote: On 2015-02-11, Charles Swiger cswi...@mac.com mailto:cswi...@mac.com wrote: On Feb 11, 2015, at 7:23 AM, Rob nom...@example.com mailto:nom...@example.com wrote: But I see it has also been explained elsewhere in the thread

Re: [ntp:questions] NTP offset doesn't change.

On Feb 12, 2015, at 1:56 AM, Rob nom...@example.com wrote: Charles Swiger cswi...@mac.com wrote: On Feb 11, 2015, at 7:23 AM, Rob nom...@example.com wrote: But I see it has also been explained elsewhere in the thread: ntpd has a maximum on the momentary drift of 500ppm, no matter

Re: [ntp:questions] Updating ntpd OSX10.4

Hi, Geoff-- Yes, testing whether your build of ntpd starts and runs normally can be done before rebooting the system. It's not likely that you would encounter any problems after rebooting if the initial test run is fine. Even if ntpd suddenly fails, that's not going to prevent you from starting

Re: [ntp:questions] NTP offset doesn't change.

On Feb 12, 2015, at 4:02 PM, William Unruh un...@invalid.ca wrote: You're describing a TCXO; using a temperature sensor to compensate for thermal drift would gain perhaps a factor of 5 accuracy. No, that is a hardware solution. There are software solutions-- a termistor to meaure the

Re: [ntp:questions] NTP offset doesn't change.

On Feb 11, 2015, at 7:23 AM, Rob nom...@example.com wrote: But I see it has also been explained elsewhere in the thread: ntpd has a maximum on the momentary drift of 500ppm, no matter if it is static or dynamic or the sum of two. I think that is not warranted. Do you believe that a clock

Re: [ntp:questions] Red Hat vote for chrony

On Dec 9, 2014, at 2:41 AM, Terje Mathisen terje.mathi...@tmsw.no wrote: [ ... ] Yes; you're describing calibrating a temperature-compensated XO, or TCXO. There are also versions of ntp which have a temp compensation/measurement system compiled in to apply to the clocks. It does tend to give

Re: [ntp:questions] Red Hat vote for chrony

On Dec 9, 2014, at 11:38 AM, William Unruh un...@invalid.ca wrote: Well, yes. You can get a PCI(e) card with a TCXO or OCXO and an optional GPS module like the Beagle ClockCard or a SpectraCom TSync for a few hundred bucks. That's quite a bit more than a $40 GPS puck, but these will also

Re: [ntp:questions] Red Hat vote for chrony

On Dec 7, 2014, at 7:19 PM, William Unruh un...@invalid.ca wrote: I suspect most people are a bit more likely to use air conditioning to control ambient temperature changes then they are to desolder and swap out their crystals in the hopes of obtaining more precise timekeeping

Re: [ntp:questions] Red Hat vote for chrony

On Dec 7, 2014, at 7:27 PM, William Unruh un...@invalid.ca wrote: On 2014-12-07, Charles Swiger cswi...@mac.com wrote: On Dec 6, 2014, at 8:33 AM, William Unruh un...@invalid.ca wrote: On 2014-12-06, Charles Swiger cswi...@mac.com wrote: [ ... ] Dude, give it a rest. You've just acknowledged

Re: [ntp:questions] Red Hat vote for chrony

On Dec 8, 2014, at 9:19 AM, William Unruh un...@invalid.ca wrote: Data point: for a normal desktop machine I have at home, which has a 95W TDP i5 CPU and a 145W 970 GPU, I can see a ~12C temperature change on the motherboard temp sensor between idle and full load on both as the total system

Re: [ntp:questions] Red Hat vote for chrony

On Dec 8, 2014, at 12:04 PM, Phil W Lee p...@lee-family.me.uk wrote: With air-conditioning on, the temperature change shrinks to about 5C, which reduces the thermal wandering of the XO by a factor of 2. That seems to be a worthwhile improvement, not largely irrelevant. Of course, server

Re: [ntp:questions] Red Hat vote for chrony

On Dec 6, 2014, at 11:46 AM, Paul tik-...@bodosom.net wrote: On Sat, Dec 6, 2014 at 7:27 AM, Charles Swiger cswi...@mac.com wrote: Um, certainly? Are you concerned about the quality of the XO which shipped with a Soekris board? That'd be important if you were running a stratum-2

Re: [ntp:questions] Red Hat vote for chrony

On Dec 6, 2014, at 8:33 AM, William Unruh un...@invalid.ca wrote: On 2014-12-06, Charles Swiger cswi...@mac.com wrote: On Dec 5, 2014, at 8:39 PM, William Unruh un...@invalid.ca wrote: [ ... ] Just like your claim whether the chrony docs recommend using maxpoll=4 across the network to a LAN

Re: [ntp:questions] Red Hat vote for chrony

On Dec 7, 2014, at 12:47 PM, Paul tik-...@bodosom.net wrote: On Sun, Dec 7, 2014 at 2:42 PM, Charles Swiger cswi...@mac.com wrote: ... Heck, even today's modern smartphone has an AGPS chip and more horsepower than a ~2002-era Soekris with an embedded CPU. I have no idea what you're talking

Re: [ntp:questions] Red Hat vote for chrony

On Dec 5, 2014, at 8:39 PM, William Unruh un...@invalid.ca wrote: This is obviously false. What do you think /etc/ntp.drift is? It is the offset from the standard rate of the clock. That memory is never used except on bootup. ntpd has to know how much to alter the drift. Ah, so you

Re: [ntp:questions] Red Hat vote for chrony

On Dec 5, 2014, at 3:42 AM, William Unruh un...@invalid.ca wrote: On 2014-12-05, Charles Swiger cswi...@mac.com wrote: On Dec 4, 2014, at 7:00 PM, William Unruh un...@invalid.ca wrote: [ ... ] Actually Miroslav Lichvar IS an expert. He is the chrony maintainer, has done a lot of testing

Re: [ntp:questions] Red Hat vote for chrony

On Dec 5, 2014, at 11:47 AM, Paul tik-...@bodosom.net wrote: On Fri, Dec 5, 2014 at 9:37 AM, Charles Swiger cswi...@mac.com wrote: I also make sure that my timeservers are running in temperature-controlled environments so that such daily drifts you mention are minimized. I'm starting

Re: [ntp:questions] Red Hat vote for chrony

On Dec 5, 2014, at 11:53 AM, William Unruh un...@invalid.ca wrote: [ ... ] It simply alters the rate at any time so as to decrease the offset, and it does this measurement by measurement. It has no memory. This is obviously false. What do you think /etc/ntp.drift is? It is the offset

Re: [ntp:questions] Red Hat vote for chrony

On Dec 5, 2014, at 5:55 PM, Paul tik-...@bodosom.net wrote: [ ... ] Even back in 2002 with very inexpensive commodity hardware, FreeBSD was able to achieve accuracy measured to ~260 nanoseconds: H. So phk uses a $1,500 rubidium standard as a system oscillator and you call it inexpensive

Re: [ntp:questions] Red Hat vote for chrony

On Dec 5, 2014, at 5:55 PM, Paul tik-...@bodosom.net wrote: [ ... ] Even back in 2002 with very inexpensive commodity hardware, FreeBSD was able to achieve accuracy measured to ~260 nanoseconds: H. So phk uses a $1,500 rubidium standard as a system oscillator and you call it inexpensive

Re: [ntp:questions] Red Hat vote for chrony

On Dec 5, 2014, at 5:55 PM, Paul tik-...@bodosom.net wrote: [ ... ] Even back in 2002 with very inexpensive commodity hardware, FreeBSD was able to achieve accuracy measured to ~260 nanoseconds: H. So phk uses a $1,500 rubidium standard as a system oscillator and you call it inexpensive

Re: [ntp:questions] Red Hat vote for chrony

On Dec 4, 2014, at 7:00 PM, William Unruh un...@invalid.ca wrote: [ ... ] Actually Miroslav Lichvar IS an expert. He is the chrony maintainer, has done a lot of testing comparing chrony to ntpd ( which showed that chrony controlled the clock a factor of 2 to 20 times better than ntpd did), and

Re: [ntp:questions] Possible new attack?

On Oct 6, 2014, at 11:36 AM, Evandro Menezes aevan...@gmail.com wrote: I've noticed a couple of NTP clients with the unusual avgint of 16s with hundreds of accesses to my NTP server in the pool. I added a restriction, in addition to the recommended ones already in place, to cope with the

Re: [ntp:questions] Best practices

Hi, Mike-- On May 21, 2014, at 1:38 PM, Mike Edwards mced...@gmail.com wrote: I'm looking for information on best practices to configure ntp for a medium sized network. I'm looking for something similar to the whitepapers published by Cisco. Cisco outlines several configurations with a

Re: [ntp:questions] ntp-4.2.6p5 on Win 7 x64

Hi-- On Jul 22, 2014, at 8:53 AM, Nick m...@privacy.net wrote: The box is very lightly loaded. ntp runs well on Mint 17 and the drift is reported to be -17ppm. That seems to indicate that your hardware is sane and reasonable timekeeping works fine under some platforms. ntp does not run

Re: [ntp:questions] Thoughts on KOD

Hi-- On Jul 7, 2014, at 2:03 PM, E-Mail Sent to this address will be added to the BlackLists Null@BlackList.Anitech-Systems.invalid wrote: Which product / abused NTP Server / Network / ... immediately re-tried if they got a KOD? I've seen that sort of misbehavior from a Lucent / Avaya PBX.

Re: [ntp:questions] NTP.log interpretation

Hi, Greg-- On Apr 21, 2014, at 9:13 AM, GregL greg.leibfr...@gmail.com wrote: What you are saying is that if we are currently using a DNS load balancer appliance to point 'ntp.host' to ntp1.host or ntp2.host (ntp1 unless it fails, then to ntp2)that is really isn't doing us any good,

Re: [ntp:questions] server and peer lines correct?

Hi-- On Apr 6, 2014, at 8:13 AM, Jason Rabel ja...@extremeoverclocking.com wrote: Charles Swiger wrote: Your comment means a discussion of best practices of configuring these stratum-1s is also beyond the scope of answers to your post. Odd, but have this as you would Charles, my S1

Re: [ntp:questions] server and peer lines correct?

Hi-- On Apr 7, 2014, at 12:12 PM, Harlan Stenn st...@ntp.org wrote: Why would you not want to iburst all of the servers? iburst helps to populate the reachability field quickly. That reduces the interval it takes for an NTP server to move from: associd=0 status=c012 leap_alarm, sync_unspec, 1

Re: [ntp:questions] server and peer lines correct?

Hi-- On Apr 7, 2014, at 4:39 PM, Harlan Stenn st...@ntp.org wrote: Charles Swiger writes: [ ... ] However, the transition doesn't happen any faster if you only use one server with iburst, or with all of the server lines. The data I've seen doesn't show any significant differences

Re: [ntp:questions] server and peer lines correct?

On Apr 5, 2014, at 11:45 AM, Jason Rabel ja...@extremeoverclocking.com wrote: [ ... ] I have four stratum-1 servers connected to GPS receivers. The stratum-1 servers are configured to be completely independent, they don't talk to each other (for reasons beyond the scope of this post). They

Re: [ntp:questions] Not being able to sync the embedded target (client) with the host (server)

Hi-- On Mar 14, 2014, at 9:05 AM, Laszlo Papp lp...@kde.org wrote: I was told that this would not be a bug, although I could not figure out yet why it is not working. Told by whom? As far as I know, this should work simply by putting the following two lines into the client configuration:

Re: [ntp:questions] Help with cross-compiling NTP for the Raspberry Pi requested

Hi-- On Mar 7, 2014, at 7:30 AM, David Taylor david-tay...@blueyonder.co.uk.invalid wrote: [ ... ] No, still getting an ntpd which is 2.87 MB in size, whereas on the Raspberry Pi native build it's 2.0 MB. The Intel Debian version is 2.74 MB. Run 'file ntpd' to see which architecture it's

Re: [ntp:questions] Cross-compiling NTP for the Raspberry Pi

Hi-- On Feb 18, 2014, at 1:25 AM, David Taylor david-tay...@blueyonder.co.uk.invalid wrote: On 17/02/2014 21:03, Harlan Stenn wrote: [] Sincerely appreciated. And please consider just making notes and incremental changes on our wiki. If you'd like to see a %COMMENT{}% box in there to make

Re: [ntp:questions] Checking pool membership?

Hi-- On Feb 12, 2014, at 2:25 PM, Rick Jones rick.jon...@hp.com wrote: Is there a direct/straightforward way to check if a given IP is a member of one of the NTP pools? In particular I am curious to know if 69.65.40.29 is in a pool. While doing some other work, I saw an ICMP Destination

Re: [ntp:questions] status information after ntpd -q

Hi-- On Feb 3, 2014, at 2:58 AM, joeri delvoy boterhoeks...@gmail.com wrote: i would like to use the command ntpd -q to synchronize with a server once, but i need some feedback from the command about the status. ntpd was designed and is intended to run all of the time as a daemon, but you can

Re: [ntp:questions] NTP request retry?

Hi-- On Jan 27, 2014, at 10:10 AM, Rob nom...@example.com wrote: Despite lots of tracing I still cannot really pinpoint the problem. The only thing I see is that ping has absolutely zero loss and all usual protocols work fine, but ntp indicates a high loss when there is no other network

Re: [ntp:questions] NTP not syncing

Hi, all-- On Dec 6, 2013, at 4:13 AM, Martin Burnicki martin.burni...@meinberg.de wrote: Agreed. If ntpd would do initial corrections faster we wouldn't even need a drift file, and it didn't matter if an OS kernel computed slightly different clock frequencies each time the system reboots.

Re: [ntp:questions] Strange refid

On Nov 12, 2013, at 3:00 PM, David Woolley david@ex.djwhome.demon.invalid wrote: There are, by definition, no ASCII characters with code points higher than 127. The original (1960s) ASCII character set was 7-bit only. 8-bit variants of ASCII which preserved the 0-127 range and added graphics

Re: [ntp:questions] NTP not syncing

Hi-- On Nov 4, 2013, at 9:40 AM, Antonio Marcheselli pu...@me.la wrote: Would it be wiser to delete the drift file at boot - by script - and let ntpd resync and recreate a new drift file? Normally, no. The drift file lets ntpd perform a first-order correction of the average intrinsic drift

Re: [ntp:questions] NTP not syncing

On Nov 4, 2013, at 11:36 AM, Harlan Stenn st...@ntp.org wrote: Running ntpdate every hour instead of running ntpd won't work if there are database servers or dovecot or other apps that require monotonic time. Did you somehow know whether the existing 500+ ppm drift is stable? But if the

Re: [ntp:questions] ISP bloked port 123

Hi-- On Sep 16, 2013, at 2:28 PM, Bert Gøtterup Petersen b...@bang-olufsen.dk wrote: Well we see different issues in different countries. The problem that I am in the development department, but the individual customer issue happens in the field somewhere fare away and handled by people

Re: [ntp:questions] Help with Oncore PPS - Update

Hi, Ron-- On Aug 27, 2013, at 3:02 PM, Ron Hahn (EI2JP) ntp-questi...@dhco.org wrote: So the everything is appearing to be wired correctly and ntpd is communicating with the OnCore board. So far, so good. Now the output from ntpq -c pe is not looking so good: [root@jupiter /etc]#

Re: [ntp:questions] Failure modes on Windows Server 2008 R2 64-bit

Hi-- On Aug 13, 2013, at 2:41 PM, Harlan Stenn st...@ntp.org wrote: Originally, ITAR concerns. It also increases our workload for limited benefit. If you are building NTP on windows you should have the knowledge to get and install OpenSSL. I wonder how many of the Windows users do anything

Re: [ntp:questions] ntpq -p command query

On Jul 31, 2013, at 6:01 AM, Charles Elliott elliott...@verizon.net wrote: If he is using broadcast mode, what earthly difference does it make how often he broadcasts? If you have a small # of machines per collision domain, then broadcasting frequently probably won't matter. If you've got

Re: [ntp:questions] ntpq -p command query

On Jul 31, 2013, at 10:36 AM, Rick Jones rick.jon...@hp.com wrote: Charles Swiger cswi...@mac.com wrote: If you have a small # of machines per collision domain, then broadcasting frequently probably won't matter. If you've got thousands or tens of thousands of machines to deal with, and need

Re: [ntp:questions] ntpq -p command query

Hi-- On Jul 30, 2013, at 7:24 AM, Biswajit Panigrahi bp00106...@techmahindra.com wrote: Both are communicating properly. I would like to test when the connectivity between those two goes down, after how much time the reach option in ntpq -p command becomes zero. The reach field is a 1-byte

Re: [ntp:questions] stepout value

Hi-- On Jul 25, 2013, at 12:14 PM, Orna Sumszyk orna.sums...@gmail.com wrote: I saw this on many internet sites. For example see http://doc.ntp.org/4.1.1/debug.htm: ...if the counter is greater than the stepout interval, which defaults to 900 s... That's the documentation for ntpd-4.1.1,

Re: [ntp:questions] help for Ntp architecture

Hi-- On Jul 9, 2013, at 10:49 AM, Vuilmet Nicolas nicolas.vuil...@laposte.net wrote: Sorry display schemas is bad. Retry Indeed yes, your diagrams came through better this time. Le 08/07/2013 10:39, nicolas.vuil...@laposte.net a écrit : Hi, I have a NTP architecture synchronize hundreds

Re: [ntp:questions] help for Ntp architecture

Hi-- On Jul 9, 2013, at 4:01 PM, David Woolley david@ex.djwhome.demon.invalid wrote: On 09/07/13 19:09, Charles Swiger wrote: You might (and probably should) configure your stratum-1 servers to be peers of each other. That way, they will continue to keep good time even if their reference

Re: [ntp:questions] Tighter regulation?

On May 23, 2013, at 10:02 PM, Mischanko, Edward T edward.mischa...@arcelormittal.com wrote: It takes too long to figure out it needs a more aggressive correction. If I leave maxpoll at the default of 1024 seconds, my clock drifts outside of 5 milliseconds consistently. Measured by what? If

Re: [ntp:questions] p351 fails to build on MSVC++2008EE

Hi, Martin-- On Jan 25, 2013, at 5:23 AM, Martin Burnicki martin.burni...@meinberg.de wrote: Chuck Swiger wrote: On 24/01/2013 12:52, Mischanko, Edward T wrote: I thought we were going to fix this? c:\3\ntp-dev-4.2.7p351\sntp\libopts\option-xat-attribute.h(38) : fatal error C1083: Cannot

Re: [ntp:questions] Loopstats jitter field mostly zero?

Hi-- On Jan 8, 2013, at 2:16 AM, David Taylor david-tay...@blueyonder.co.uk.invalid wrote: Thanks, Harlan. I see that a function SQRT() is used, and that this function is defined as sqrt() in ntp.h: #define SQRT(x) (sqrt(x)) I recall seeing /something/ about hardware and software