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 two moving nodes, over

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 (controlled by the poll interval

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

On Aug 29, 2015, at 1:03 AM, Mike Cook 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). -1 to this.

Re: [ntp:questions] iburst and NIST servers

On Aug 2, 2015, at 2:31 AM, Mike Cook 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 maxpoll 6 >

Re: [ntp:questions] NTP Hardware Support

On Jun 22, 2015, at 3:54 AM, David Garijo 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 drivers. Unles

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

Hi, Kiss-- Try mailto:questions@lists.ntp.org>>; BCC:ing . 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). Regards, -- -Chuck On May 28, 2015, at 7:

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

On Apr 22, 2015, at 3:24 PM, NVAP 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 boxes that meet yo

Re: [ntp:questions] chrony as a server

On Feb 24, 2015, at 11:40 AM, Paul 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 accident. Data is

Re: [ntp:questions] chrony as a server

On Feb 23, 2015, at 11:57 PM, David Woolley 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 is more like it (might ha

Re: [ntp:questions] NTP with 2 servers

On Feb 20, 2015, at 12:17 PM, Nuno Pereira 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 with different > IPs. I

Re: [ntp:questions] Pool server gone wild

On Feb 20, 2015, at 10:55 AM, Jan Ceuleers 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 from: dig 0.uk.pool.ntp.o

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

On Feb 12, 2015, at 11:21 PM, Terje Mathisen 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 conduct > heat too

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

On Feb 12, 2015, at 4:02 PM, William Unruh 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 temperature o

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 1:56 AM, Rob wrote: > Charles Swiger wrote: >> On Feb 11, 2015, at 7:23 AM, Rob 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 >>&

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

On Feb 12, 2015, at 12:49 AM, William Unruh wrote: > On 2015-02-11, Charles Swiger mailto:cswi...@mac.com>> > wrote: >> On Feb 11, 2015, at 7:23 AM, Rob > <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 11, 2015, at 7:23 AM, Rob 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 which loses or gains

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

On Dec 9, 2014, at 11:38 AM, William Unruh 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 >> freewh

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

On Dec 9, 2014, at 2:41 AM, Terje Mathisen 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 much better

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

On Dec 8, 2014, at 12:04 PM, Phil W Lee 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 class machines

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

On Dec 8, 2014, at 9:19 AM, William Unruh 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 draw goes

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

On Dec 7, 2014, at 7:27 PM, William Unruh wrote: > On 2014-12-07, Charles Swiger wrote: >> On Dec 6, 2014, at 8:33 AM, William Unruh wrote: >>> On 2014-12-06, Charles Swiger wrote: [ ... ] >> Dude, give it a rest. You've just acknowledged that the chrony docs

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

On Dec 7, 2014, at 7:19 PM, William Unruh 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 > > Actually ai

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

On Dec 7, 2014, at 12:47 PM, Paul wrote: > On Sun, Dec 7, 2014 at 2:42 PM, Charles Swiger 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 ta

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

On Dec 6, 2014, at 8:33 AM, William Unruh wrote: > On 2014-12-06, Charles Swiger wrote: >> >>> On Dec 5, 2014, at 8:39 PM, William Unruh wrote: [ ... ] >>>> Just like your claim whether the chrony docs recommend using maxpoll=4 >>>> across the ne

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

> On Dec 6, 2014, at 11:46 AM, Paul wrote: >> On Sat, Dec 6, 2014 at 7:27 AM, Charles Swiger 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 5, 2014, at 8:39 PM, William Unruh 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

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

On Dec 5, 2014, at 5:01 PM, Paul wrote: > On Fri, Dec 5, 2014 at 7:06 PM, Charles Swiger wrote: >> No, he used a $1500 rubidium clock to accurately measure the timekeeping >> quality of a $220 Soekris computer, and concluded: >> >> "The data on this page was

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

On Dec 5, 2014, at 5:55 PM, Paul 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 and commodit

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

On Dec 5, 2014, at 5:55 PM, Paul 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 and commodit

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

On Dec 5, 2014, at 5:55 PM, Paul 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 and commodit

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

On Dec 5, 2014, at 11:53 AM, William Unruh 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 from the

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

On Dec 5, 2014, at 11:47 AM, Paul wrote: > On Fri, Dec 5, 2014 at 9:37 AM, Charles Swiger 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 startin

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

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

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

On Dec 4, 2014, at 7:00 PM, William Unruh 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 is with Redh

Re: [ntp:questions] Possible new attack?

On Oct 6, 2014, at 11:36 AM, Evandro Menezes 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 > suspicious clien

Re: [ntp:questions] Best practices

Hi, Mike-- On May 21, 2014, at 1:38 PM, Mike Edwards 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 mixture > of peer an

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

Hi-- On Jul 22, 2014, at 8:53 AM, Nick 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 well on Win 7 x6

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 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. (AFAICT for a remote system, anyway.)

Re: [ntp:questions] NTP.log interpretation

Hi, Greg-- On Apr 21, 2014, at 9:13 AM, GregL 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, because > that only dns

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

Hi-- On Apr 7, 2014, at 4:39 PM, Harlan Stenn 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

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

Hi-- On Apr 7, 2014, at 12:12 PM, Harlan Stenn 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 event, freq_s

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

Hi-- On Apr 7, 2014, at 12:12 PM, Harlan Stenn wrote: > Charles Swiger writes: >> For a given S2 server, say NTP1, I'd recommend: >> >> server S1-1 iburst prefer >> server S1-2 >> server S1-3 >> server S1-4 >> server _some_outside_box_ >&g

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

Hi-- On Apr 6, 2014, at 8:13 AM, Jason Rabel 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,

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

On Apr 5, 2014, at 11:45 AM, Jason Rabel 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 get their time solely > from

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 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: > > drift

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

Hi-- On Mar 7, 2014, at 7:30 AM, David Taylor 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 compiled for. (The size of ntpd is n

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

Hi-- On Feb 18, 2014, at 1:25 AM, David Taylor 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 this easier for notes just ad

Re: [ntp:questions] Checking pool membership?

Hi-- On Feb 12, 2014, at 2:25 PM, Rick Jones 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 Unreachable, port

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

Hi-- On Feb 3, 2014, at 2:58 AM, joeri delvoy 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 do what you've asked

Re: [ntp:questions] NTP request retry?

Hi-- On Jan 27, 2014, at 10:10 AM, Rob 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 activity. > > Wh

Re: [ntp:questions] using IFF, GQ, MV keys for authentication at the same time

Hi-- On Jan 22, 2014, at 1:12 PM, ardi wrote: > Is it possible to generate and use all types of authentication keys > (IFF,GQ,MV) at the same time on ntp server and client ? It's possible to generate different types of keys and use different ones for different connections. I don't think you

Re: [ntp:questions] NTP not syncing

Hi, all-- On Dec 6, 2013, at 4:13 AM, Martin Burnicki 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. Unless your computer's qua

Re: [ntp:questions] Strange refid

On Nov 12, 2013, at 3:00 PM, David Woolley 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 or printable characters from

Re: [ntp:questions] NTP not syncing

On Nov 4, 2013, at 11:36 AM, Harlan Stenn 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 system clock i

Re: [ntp:questions] NTP not syncing

Hi-- On Nov 4, 2013, at 9:40 AM, Antonio Marcheselli 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 of the loc

Re: [ntp:questions] ISP bloked port 123

Hi-- On Sep 16, 2013, at 2:28 PM, Bert Gøtterup Petersen 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 > how understand l

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

Hi, Ron-- On Aug 27, 2013, at 3:02 PM, Ron Hahn (EI2JP) 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]# /usr/local/sbin/ntpq -c p

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

Hi-- On Aug 13, 2013, at 2:41 PM, Harlan Stenn 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 with ntpd w

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

On Jul 31, 2013, at 10:36 AM, Rick Jones wrote: > Charles Swiger 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

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

On Jul 31, 2013, at 6:01 AM, Charles Elliott 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 thousands or tens of thou

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

Hi-- On Jul 30, 2013, at 7:24 AM, Biswajit Panigrahi 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 large bitmap which tra

Re: [ntp:questions] stepout value

Hi-- On Jul 25, 2013, at 12:14 PM, Orna Sumszyk 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, which was released

Re: [ntp:questions] help for Ntp architecture

Hi-- On Jul 9, 2013, at 4:01 PM, David Woolley 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 >> ref

Re: [ntp:questions] help for Ntp architecture

Hi-- On Jul 9, 2013, at 10:49 AM, Vuilmet Nicolas 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 of ntp clients. >>

Re: [ntp:questions] Tighter regulation?

On May 23, 2013, at 10:02 PM, "Mischanko, Edward T" 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 you have a better source of tim

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

Hi, Martin-- On Jan 25, 2013, at 5:23 AM, Martin Burnicki 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 open include

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

Hi-- On Jan 8, 2013, at 2:16 AM, David Taylor 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 floating point > support in the Ras