Re: [ntp:questions] Some issues about NTP ( Server 2008R2)
hschu...@gmail.com wrote in message news:c7ea1a65-eb51-4708-98cb-5aa0d4b31...@googlegroups.com... Not working again. Actual polling rate: 256. The internal system clock (windows time UTC) was only one time altered between 16:00 and 21:00: You keep repeating that. If any of your associations has a '*' in front of it, NTP is working and the offset to that server should be low. That should tell you that your clock is running very close to 'real' time. NTP does _not_ work by setting your clock to a different time, over and over. It works by making your clock run faster or slower, as required. If this works, you see a lot of nothing happening. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] need option to ignore 'leap not in sync error'
Harlan Stenn st...@ntp.org wrote in message news:e1w5djb-000abl...@stenn.ntp.org... [...] I'm thinking we want to be pretty careful about when we'd recommend a local refclock, as it seems much better to recommend orphan mode as that seems to be a much better solution for a wider number of folks. What do others think? That orphan mode is inherently symmetrical, and a single master with a local clock backup is inherently asymmetrical. That the configuration of the larger group is simpler in the latter case. That I've been clinging to those as a barely honourable defence of the local clock for this thread's original scenario of a gateway server to a herd of sheep. The asymmetry may also be served by not including the gateway as an orphan but only as server to them all. I don't usually worry very much about the remaining single point of failure, or the possibility of that point being unsuitable as a holdover server. After running successfully for awhile, _all_ nodes should be stabilised fairly well. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] need option to ignore 'leap not in sync error'
Sanal, Arjun (NSN - IN/Bangalore) arjun.sa...@nsn.com wrote in message news:592c0209968e17479f27087d92c1f7e414e...@sgsimbx006.nsn-intra.net... [...] The setup is a blade server, which has one master blade server which runs the ntp server. All other blades sync the time from this master. The master itself gets it time from a higher ntp server. The problem is when the master says that it is not suitable for synchronization, the client blades shouldn't reject it. If they, do all the blades will end up with different time. Configure the local clock as a source at high stratum on the master. server 127.127.1.0 stratum 10 People will now fall all over you, and me, yelling that this is anathema, but you have explained to my satisfaction what you want, and this is how you do it. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] maxpoll
Michael mdw...@ads-securities.com wrote in message news:nnb039thbervf8v22htoa8clor81u5k...@4ax.com... [...] I am using minpoll 6 maxpoll 6 However after an amount of time ntpq shows the polling interval to be 1024. Any ideas why the maxpoll parameter is not being obeyed. Quite possibly because you're reading in the wrong place. You don't give us much to go on. It would be a good start if you could show us the actual configuration file and ntpq output. For the record - that by itself won't probably enable others to solve your problem. But it wouldn't be the first time that carefully laying out the evidence lets you spot the error, and it's a base for the next step. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTPD silently not tracking
unruh un...@invalid.ca wrote in message news:n5lUt.340835$qt4.176...@fx22.iad... On 2013-08-31, E-Mail Sent to this address will be added to the BlackLists Null@BlackList.Anitech-Systems.invalid wrote: [...] perhaps it has already been fixed in a more recent version. Sorry, but I have always found this to be a complete copout. You can keep the complainer busy till doomsday trying out different version and different configs. Do you know that others have had this person's problem? Do you know thatthe latest version fixes them? Otherwise you are simply sending him on a fishing expidition. As a developer (not NTP) myself, I don't react well to people complaining about bugs I've already solved, just not in the version they have. So the first reply is always going to be 'upgrade, and see if it goes away.' Especially with things like NTP, if it goes away, the problem is solved. Even if you're not sure, you try this first. Plain common sense, and common courtesy. No fishing expedition, just a one-time upgrade and if the problem stays we go to work. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTPD silently not tracking
Rob nom...@example.com wrote in message news:slrnl2684g.6em.nom...@xs8.xs4all.nl... [...] Like unruh, I hate developers and companies with this attitude. Well, thanks, I'll keep that in mind. For the record, I have no particular dislike for you. When there is no reason to believe that a particular problem is solved in a later release, it is just annoying when the suggestion from support departments is to first install the latest version and see if that fixes it. It is just a way to wave off the initial complaint and to keep others busy. I don't think that's it. It's just a sanity check. Development is always going to be in the most recent version. That's where the bug is going to be fixed. If the bug isn't in it anymore, you can solve your problem by upgrading. In that case, we all profit from work already done. Every place I've worked, we will also try to reproduce it on our own, in the latest version. But reproducing an NTP bug is often far more difficult than with most business software. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Standalone PPS
patrick200075...@gmail.com wrote in message news:aed3fdb6-3f27-4361-81e4-18b7b1833...@googlegroups.com... [...] I am trying run an electronic board I designed. A super stable OXCO generates pulse per second. I don't have any absolute reference time. The pulse has a constant but unpredictable phase due to the state of the electronics a power up. This can be specified as a parameter to a freerunning PPS source. Time1 or time2, perhaps; it has been discussed here years ago and memory is suitably fuzzy for my age. Combine it with one of the more conventional sources (the pool comes to mind) over some time to find out the phase error. How stable is 'super'? Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Using NTP to calibrate sound app
Maurice Janssen mauri...@xs4all.nl wrote in message news:5103d110$0$6943$e4fe5...@news.xs4all.nl... Maarten Wiltink maar...@kittensandcats.net wrote: Which is exactly why hardcoding pool.ntp.org _is_ allowable, in my opinion - and in fact indicated in such a case as this. In my opinion, it's not. Please read http://www.pool.ntp.org/en/vendors.html . I stand corrected. Indeed getting and using vendor.pool.ntp.org is superior. At that point, however, it strikes me that using time.vendor.tld serves the vendor even better, what with having actual control over the domain and all. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Using NTP to calibrate sound app
unruh un...@invalid.ca wrote in message news:tiLMs.55319$on7.49...@newsfe16.iad... On 2013-01-26, no-...@no-place.org no-...@no-place.org wrote: [...] I obviously don't want to hard-code for a specific time server because things could change after the user gets my app and it is unfair to send a whole block of users to the same server. The Server Pool looks promising. Does pool.ntp.org just behave like a Stratum 2 server so I could hard-code that URL into my implementation of NTP in my app? ... [...] And no you definitely should not hard code a site, unless it is one controlled by you. [...] Note pool.ntp.org does NOT have an IP-- each dns request gives a different IP, so you need the name, not an IP. Which is exactly why hardcoding pool.ntp.org _is_ allowable, in my opinion - and in fact indicated in such a case as this. Exactly because (as I suspect you meant) it is not a fixed site, but a symbolic name that translates to some reasonable site that is available now. Incidentally, to the OP, it's not a URL. It is a DNS name. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Enclosure for Sure Electronics GPS board
Terje Mathisen terje.mathisen at tmsw.no wrote in message news:r1ten9-2qc@ntp-sure.tmsw.no... [...] http://tmsw.no/sure_gps_in_freezer_box.jpg Perfectly workable, dirt cheap. :-) That's 'Scandinavian design, priceless.' Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Windows time question.
unruh un...@wormhole.physics.ubc.ca wrote in message news:slrnis0nra.4on.un...@wormhole.physics.ubc.ca... [...] Unfortunately , AFAIK, usb is terrible for delivering a PPS-- ie no interrupt lines-- IIRC, USB is polled at 1000 Hz. That means that, if done well, it should be able to gather PPS with an error of 0.5 ms at most. Probably still a sight better than NTP over WAN. I understand that the PPS from GPS units tends to come from a well- chosen flank on a 10 MHz signal. Quite a difference in degree admittedly (4 zeroes!), but not in kind. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntpq 4.2.7p153 only shows 5 peers
Maarten Wiltink maar...@kittensandcats.net wrote in message news:4dab473d$0$81485$e4fe5...@news.xs4all.nl... Hal Murray hal-use...@ip-64-139-1-69.sjc.megapath.net wrote in message news:b_6dnrsnemkzszbqnz2dnuvz_vydn...@megapath.net... [...] I forget the term, but servers that get added via DNS don't show up to ntpq until they get enough responses. In that case 'ntp.your.org' (sic) is unlikely to ever appear. Correction. I should have known better. In order of rising surprise: - The domain is registered (no great surprise really) - ntp.your.org resolves to 204.9.54.119 - It runs an NTP daemon and responds to ntpq - It has a reference clock configured What is the world coming to? I can't even spot obvious placeholders correctly anymore. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntpq 4.2.7p153 only shows 5 peers
Hal Murray hal-use...@ip-64-139-1-69.sjc.megapath.net wrote in message news:b_6dnrsnemkzszbqnz2dnuvz_vydn...@megapath.net... In article iof9dn$alt$1...@speranza.aioe.org, Edward T. Mischanko etm1...@hotmail.com writes: ntpq 4.2.7p153 only shows 5 peers when many more are configured? server 127.127.20.0 minpoll 3 maxpoll 3 prefer fudge 127.127.20.0 time2 0.800 refid PPS flag1 1 flag3 1 server tick.cerias.purdue.edu burst server tock.cerias.purdue.edu burst It's a bug/feature that was introduced a while ago when the DNS stuff was cleaned up. I forget the term, but servers that get added via DNS don't show up to ntpq until they get enough responses. In that case 'ntp.your.org' (sic) is unlikely to ever appear. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Secure NTP
j...@specsol.spam.sux.com wrote in message news:5lpu58-278@mail.specsol.com... Uwe Klein uwe_klein_habertw...@t-online.de wrote: [...] The $something trading solutions that require exact timematch ( remember the recent rush of ntp users requiring u-second global time match ) over a set of widely distributed hosts allow fraud in various ways if you can manipulate the time for some select host. One more time, if time is critical to your operation you do NOT have one and only one NTP server. You have serveral servers with local GPS and CDMA NTP boxes. Let's see you spoof the Internet, GPS, and CDMA all at the same time. I'll solve (the subproblems of) the big problems just like the little problems. One at a time. That there are other lines of defence is no reason to neglect any one of them. Every single one is there in case the other ones fail. Any and all of the other ones. You do not improve security by stacking the lemon meringue walls higher, or thicker. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Allan deviation survey
David L. Mills mi...@udel.edu wrote in message news:4c8b9ab7.2050...@udel.edu... David Woolley wrote: David L. Mills wrote: Running a precision time server on a busy public machine with a widely varying load is not a good idea and I have no interest in that. As indicated by the sort of questions the group is getting recently, it is becoming the norm to run time servers on virtual machines, because that is how businesses now run all their servers. The whole point of virtual machines is that the host is busy and running a varied load! With due respect, your comment has nothing to do with the issue. Allan deviation is between a quartz crystal oscillator, timer interrupt, interpolation mechanism and a kerel syscall to read. the clock. It has nothing whatsoever to do with virtual machines. Timer interrupts are very much affected by virtual machines. Timer interrupts are among the things virtualised and it turns out they show much larger jitter in a virtual than in a physical machine. The oscillator is influenced by the ambient temperature in the casing and this varies, indirectly and with a certain delay, with CPU load. Running s...@home may actually be a good idea after all. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] running NTP as server only
Rob nom...@example.com wrote in message news:slrni6q3i8.ie0.nom...@xs8.xs4all.nl... unruh un...@wormhole.physics.ubc.ca wrote: On 2010-08-19, Rob nom...@example.com wrote: unruh un...@wormhole.physics.ubc.ca wrote: On 2010-08-17, folkert folk...@vanheusden.com wrote: Is it possible to run the NTP daemon only as a server and not as a local-clock maintainer? Reason: I have a virtual machine which gets its time via the vmware tooling from the hardware server it is running on. Now this virtual machine needs to distribute the time to clients. Aarrgdaagh. Why would you have a virtual machine, with its remarkably unreliabl e clock serve its time to others? Some companies are virtualizing all their hardware. E.g. this is happening where I work as well. All the servers have been replaced by a number of Vmware ESX machines. So there is no physical hardware machine left to run as the ntp server. uh, to quote Landauer, all information is physical. All virtual machines MUST also run on physical machines. But that does not mean you can run NTP on them. E.g. on VMware ESX, you cannot do this. (there is an NTP running on the console session, but that is just a virtual machine running a Linux variant, it is not running on the physical machine either) And not so long ago, somebody quoted a more recent whitepaper here that said running NTP in the virtual machines was now working much better and in fact recommended. In situations where the host has enough cores that they can be allocated more persistently to running VMs, I can even see this work. The problem used to be, mostly, that interrupts didn't (always) arrive on time. Yet another problem solved by throwing hardware, to wit interrupt lines, at it. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] running NTP as server only
folkert folk...@vanheusden.com wrote in message news:20100817145830.gh5...@belle.intranet.vanheusden.com... Is it possible to run the NTP daemon only as a server and not as a local-clock maintainer? Reason: I have a virtual machine which gets its time via the vmware tooling from the hardware server it is running on. Now this virtual machine needs to distribute the time to clients. server 127.127.1.0 comes to mind. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] service w32tm for client put into MS domain
RICCARDO ric.castell...@alice.it wrote in message news:cc308ec7-ac80-4bcd-ae55-b0d8c527b...@u11g2000vbd.googlegroups.com... If I put my Win XP client into Microsoft domain, it will synchronize to my domai controller ? Where I can verify this configuration to be sure it will take time from DC and not external source ? w32tm /? told me in ten seconds about the options /query /source. It may not be exactly what you want. I suggest you read the rest of the help text. You might have started with that, you know. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] SNTP with 1ms of precision?
unruh un...@wormhole.physics.ubc.ca wrote in message news:slrni1mjri.fnp.un...@wormhole.physics.ubc.ca... On 2010-06-17, Marcelo Pimenta marcelopiment...@gmail.com wrote: [...] What's your SO? Define SO. Operating System in Italian. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Routers and NTP Timing loops
Jacobs, Kevin J. kjac...@mitre.org wrote in message news:70189427bd8ce046b781f28d29c21aee0c9bd78...@imcmbx4.mitre.org... I had an interesting experience with a Cisco router as ntp master 9 using itself as an NTP source and it's neighboring switch as the only other NTP source. The switch had the exact same configuration right back at the router!. So what happens? Is NTP smart enough to know that this is a bad idea? If not, what goofy things happen if you establish an NTP timing loop? I know that if this were frequency references and stratum 3 clocks, they would ultimately peg at the end of their frequency range (not good) but I don't know what happens from a time perspective. I had some interesting date-time issues and this is a potential root cause. Just looking to see if anyone has had similar experience and have done some in-depth research in this area. The reference implementation gets a refid with every association to prevent exactly this. If the refid of a server is recognised as that of the client itself, the server is not considered a viable time source. I don't think it breaks cycles of three or more machines. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] SNTP with 1ms of precision?
Marcelo Pimenta marcelopiment...@gmail.com wrote in message news:aanlktilq6m8apeoasibr-o8mhwifqkfv9xyf6mudr...@mail.gmail.com... [...] The NTP algorithm is much more complicated than the SNTP algorithm. The short, short version: there is no SNTP algorithm. SNTP is NTP _without_ the algorithms. Using NTP means continuously adjusting the speed of your clock so it tracks real time as best you can make it, while SNTP is simply asking what time [they think] it is. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] SNTP with 1ms of precision?
Marcelo Pimenta marcelopiment...@gmail.com wrote in message news:aanlktilaoduniqjgpigohpzvjcv_zmsw_tr7naj6b...@mail.gmail.com... [...] accuracy of 1ms. On a local network 100usec?? Even if we use only switches(no routers), how is that possible if I have 4 types of Latency increasing about 80us? The latency is corrected for. A query-response cycle is a back-and-forth exchange. The assumption is that the latency for the response (going forth) is equal to the latency for the response (going back), and both are half of the total latency, which you do know. So you estimate that the response was sent half the total latency time before the moment you received it. This often works well, and sometimes not so well. Domestic ADSL with a saturated upstream and downstream capacity left is one common case where it works not so well. [...] I need accurancy at least of 1ms in 100% of time. That's a *very* tall order. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] what happens when sys.peer turns stratum 16?
unruh un...@wormhole.physics.ubc.ca wrote in message news:slrni06c8h.l1a.un...@wormhole.physics.ubc.ca... resiliating against one falseticker That only requires 3 servers. And 4 has a problem that two can wander off togetehr ( eg both depend on the same bad timesource). and then the two groups cannot outvote each other either. You are, of course, right. And that's why the requirement is really four _independent_ servers. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] VM host not snyching time
David Woolley da...@ex.djwhome.demon.invalid wrote in message news:hobhio$u1...@news.eternal-september.org... Ramesh wrote: I am trying to synchronize the time of my VM server with ntpd. I have the following configuration. Not a good idea. VMs play tricks with time. They shouldn't be used for applications that require high precision time and any time synchronisation should be done on the host. He _is_ synchronising the host. Or trying to. Do VMs still have problems responding to timer ticks when there are enough cores to go around? Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] ntpd and database servers
Evandro Menezes evan...@mailinator.com wrote in message news:f80da063-b512-4bee-abb6-2760290d8...@c29g2000yqd.googlegroups.com... Doesn't NTP know UTC via the root dispersion? If so, then instead of giving out its time, it could give out UTC. I'm sure that there may be more to it, but just a thought. At a guess, it's named dispersion because it defines an interval from x-d to x+d. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Simple but good NTP server
Jan Ceuleers janspam.ceule...@skynet.be wrote in message news:4b5dda15$0$2866$ba620...@news.skynet.be... [...] - It does not explicitly say so at the page above, but the Soekris model that Poul-Henning used was the 4501. I've only got 4801s and they're not as good for timing. Why did you get 4801s? I recall reading here that the 4501 was no longer for sale, but Soekris' own website offers them. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] Problem with system clock refresh
JuanFran juanfranciscoj...@gmail.com wrote in message news:d693971e-be41-4a9b-9926-ed4a04f5b...@j9g2000vbp.googlegroups.com... Good mornig. I have a trouble with NTP. I want a refresh my sistem clock (client) with a LAN Server each 5 minutes. I dont know any parameter of NTP protocol for this configuration. Its possible? The refresh it done usually, but takes a long time. NTP does not work that way anyway, making it a meaningless way of measuring the closeness of two clocks. So, what is your real problem? Why do you want a five minute limit? Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] NTP absolute accuracy?
Unruh unruh-s...@physics.ubc.ca wrote in message news:iebhm.50125$db2.41...@edtnps83... [...] The problem is that I have no idea what the accuracy of any of those items is. YOur ISP's timesever may be a stratum 7 getting time from a bunch of bozos. Or itmay be stratum 1 getting its time from a well implimented GPS clock. ntpq -p will tell you that. And ntptrace does exactly that, climbing the chain up from you to stratum 1. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] NTP 4.2.5p238-RC Released
Steve Kostecke koste...@ntp.org wrote in message news:slrnhefcpf.krv.koste...@stasis.kostecke.net... [...] A fully featured news-reader can kill-file articles on their subject!!! Since the release announcements are automated the subject line format is stable and you may safely kill articles with a Subject: containing RC Released! Careful, Steve. You're starting to look like Richard. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Strange NTP problem on AMD Geode LX cards.
Unruh unruh-s...@physics.ubc.ca wrote in message news:lv9ym.47716$ph1.37...@edtnps82... E-Mail Sent to this address will be added to the BlackLists n...@blacklist.griffin-technologies.invalid writes: Unruh wrote: It is an unshielded efficient radiator, the motherboard. Unshielded because the manufacturer does not want to spend the money to shield it. Do you buy / use equipment that you have decided are the source of objectionable levels of EMI? I do not have the equipment to measure the radiation given off. The manufacturers do. If you tell me how I can get the information as to how much it emits, I will certainly include that in my decision process. The motherboard that costs an unexplained ten dollars more than the competition _may_ have spent it on shielding. Guess how many people will buy it? Remember, by your own admission, _you_ _cannot tell_. (Lying on the box? Who'd do such a horrible thing?) Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Strange NTP problem on AMD Geode LX cards.
Unruh unruh-s...@physics.ubc.ca wrote in message news:_mmym.46645$db2.5...@edtnps83... Maarten Wiltink maar...@kittensandcats.net writes: Unruh unruh-s...@physics.ubc.ca wrote in message news:lv9ym.47716$ph1.37...@edtnps82... E-Mail Sent to this address will be added to the BlackLists n...@blacklist.griffin-technologies.invalid writes: Unruh wrote: It is an unshielded efficient radiator, the motherboard. Unshielded because the manufacturer does not want to spend the money to shield it. Do you buy / use equipment that you have decided are the source of objectionable levels of EMI? I do not have the equipment to measure the radiation given off. The manufacturers do. If you tell me how I can get the information as to how much it emits, I will certainly include that in my decision process. The motherboard that costs an unexplained ten dollars more than the competition _may_ have spent it on shielding. Guess how many people will buy it? Remember, by your own admission, _you_ _cannot tell_. (Lying on the box? Who'd do such a horrible thing?) That is why one has regulations. Indeed. Just imagine the radio interference that e.g. motherboards might cause if there were no rules limiting it. (As another, very practical, example of well-intentioned regulations, there is the 'CE' mark featured on products that should be safe to use. There is a test to determine if your product may carry it. OR - you can simply slap it on and wait to be challenged. Then, if the challenger proves you don't deserve the mark, you have to take it off. A procedure officially sanctioned as 'self-declaration'.) Tebrgwrf, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Strange NTP problem on AMD Geode LX cards.
Unruh unruh-s...@physics.ubc.ca wrote in message news:6rmxm.46378$db2.43...@edtnps83... Maarten Wiltink maar...@kittensandcats.net writes: Unruh unruh-s...@physics.ubc.ca wrote in message news:k8yxm.46291$db2.44...@edtnps83... No idea what spread spectrum means for a clock. That there is a certain jitter explicitly introduced in its effective frequency. Probably in the form of a random offset, that averages to zero, to every tick, so you're certain that the long-term frequency doesn't change. I am afraid I am left as confused as before. HOw introducing random offsets would stop the frequency from changing I have no idea. Say you have a clock running at 1 Hz. One tick per second. Naively, you might spread its spectrum by changing the frequency. Let it run at 0.5 Hz some seconds, 1.5 Hz some others. That's two ticks some seconds, two thirds of one others. The average frequency works out to 0.75 Hz. Not what you want. Alternatively, instead of ticking at the top of every second, add a random offset to the time when every tick happens. After an hour, there will have been 3,600 ticks. Still 1 Hz. It sounds like a terrible idea, but that may be ignorance. If you want the best clock possible, it is. But that's not the only consideration. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Strange NTP problem on AMD Geode LX cards.
Unruh unruh-s...@physics.ubc.ca wrote in message news:k8yxm.46291$db2.44...@edtnps83... [...] No idea what spread spectrum means for a clock. That there is a certain jitter explicitly introduced in its effective frequency. Probably in the form of a random offset, that averages to zero, to every tick, so you're certain that the long-term frequency doesn't change. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] SIGINFO for Portable OpenNTP on Linux
RedGrittyBrick redgrittybr...@spamweary.invalid wrote in message news:4aa0e178$0$2541$da0fe...@news.zen.co.uk... I'm using OpenNTP 3.9p1 (http://www.openntpd.org/) on an RedHat 8 Linux server. Oh great. Now you'll get a hundred people telling you that OpenNTP is Not Real NTP. The docs at http://www.openbsd.org/cgi-bin/man.cgi?query=ntpd say When ntpd receives a SIGINFO signal, it writes its peer and sensor status to syslog(3). Is this the man page for (reference) NTP or does it apply to OpenNTP? However SIGINFO isn't defined on Linux. Has this feature been removed from the Portable version of OpenNTP or is there some other signal I can send, or some other way to get peer status (hopefully similar to ntpq -p on xntpd) to monitor convergence etc. According to Wikipedia, SIGINFO is 'a synonym for' SIGPWR on Linux. You might try that instead. Presumably this would be somewhat easy to find in the source. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] NTP stops when client address changes?
David J Taylor david-tay...@blueyonder.not-this-part.nor-this.co.uk.invalid wrote in message news:qlxem.64507$oo7.50...@text.news.virginmedia.com... [...] However, why would the communication fail when the client address changed? I thought that the sending address was part of any UDP packet, so that if the client address changed, things should carry on working. Would NTP normally stop working like this, or is there something in the user's network configuration which isn't quite right? This isn't an IT guru, just a regular Windows user connecting to his regular ISP via an ADSL modem. It may be the local socket that stops working when the network interface changes underneath it. Is this a one-machine actual modem, as opposed to the more usual router? I'd expect the latter to involve NAT and thus shield its clients from the specific bit that changes. But a dedicated modem connection might have this exact effect. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Solaris 8 xntpd vs ntpd?
Unruh unruh-s...@physics.ubc.ca wrote in message news:k4hbm.38535$ph1.26...@edtnps82... David Woolley da...@ex.djwhome.demon.co.uk.invalid writes: Unruh wrote: xntp is ntpd 3 as far as I know. The current ntp is ntp 4 which has a lot of improvements and changes. ntp4 is the only version which is supported. I assume that Sun support the NTP V3 implementation that they supply, and wouldn't support the current one, installed lcoally. And exactly what Sun support do you expect to get? Sun is not an expert on ntp. NTP? Oh, you should look here, then. Substitute predictable website, mailing list, or newsgroup. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Local (own site) NTP servers.
Richard B. Gilbert rgilber...@comcast.net wrote in message news:vdadnwa89vi0xpxxnz2dnuvz_redn...@giganews.com... [...] The Meinberg NTP software is standard NTPD with a Windows installer! If you are really good with Windows you might be able to install an X86 version of NTPD on a Windows system without Meinberg. ... Really good is vastly overstated. Put the binaries somewhere and install ntpd.exe as a service. There's even a (custom) instsrv.exe that comes with it, although I think I used the generic one from the Resource Kit. Then figure out where ntp.conf goes by default[0] and it works. I wouldn't trust my parents to get it working, but my sister-in-law should be able to do it. Groetjes, Maarten Wiltink [0] Or pass a parameter to the executable. ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] NTP 4.2.5p180 adds IPv6 support on Windows
David J Taylor david-tay...@blueyonder.not-this-part.nor-this.co.uk.invalid wrote in message news:9blul.36424$oo7.26...@text.news.virginmedia.com... [...] So, one question which now arises is: how should the current Windows NTP handle the libeay32.dll version issue? Having it packaged with Meinberg's distribution, and putting it into the application directory seems to be an approach which works. And it does. That other Windows installation had no problems. Should those installing by copying ntpd.exe etc. from Zip archives be expected to look after libeay32.dll themselves? Should the bindings be dynamic rather than static so that ntpd can fall back if the required entry point or even the DLL isn't available? Should the correct version of libeay32.dll always be included with the Zip archive? Speaking as a user, it seems kind of silly not to include parts without which things don't work. My logic was that if this DLL wasn't included, it was something external, and would be stable enough that a copy from an older version should work - perhaps five and a half years _is_ stretching it, but I felt sure enough that when it didn't work, I assumed there was another problem. The point being, this is a not very dumb user working with what he has, and it doesn't work. Include the DLL, already. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] NTP 4.2.5p180 adds IPv6 support on Windows
David J Taylor david-tay...@blueyonder.not-this-part.nor-this.co.uk.invalid wrote in message news:qzaul.35766$oo7.25...@text.news.virginmedia.com... Maarten Wiltink wrote: A Windows 2000 without IPv6 says 'Ordinal not found : The ordinal 3852 could not be located in the dynamic link library LIBEAY32.dll.' Copying the DLL into the directory didn't help, either. What libeay32.dll do you have? Mine is dated 13-Jan-2009, and is 1,105,392 bytes. file version 0.9.8.10, product version, 0.9.8j (I think). It's in the ntp\bin\ directory. ntpd.exe is working fine - Windows 2000 server, no IPv6. It came with NTP-4.2.0 Windows binaries dated 2003-10-17. The DLL is dated 2003-06-04, 827 392 bytes, no version information. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] NTP 4.2.5p180 adds IPv6 support on Windows
Dave Hart daveh...@gmail.com wrote in message news:0fd7b5c0-3f34-4dc7-8d2c-fce10cf4a...@h28g2000yqd.googlegroups.com... You can find binaries at: http://davehart.net/ntp/win/x86/ntp-4.2.5p180-win-x86-bin.zip http://davehart.net/ntp/win/x86/ntp-4.2.5p180-win-x86-debug-bin.zip Testing on the earliest supported versions of Windows has been light. My binaries unfortunately are unable to load on Windows NT 4, at all due to the compiler dropping support, but I'm particularly interested in results on Windows 2000, with or without the IPv6 stack installed. A Windows 2000 without IPv6 says 'Ordinal not found : The ordinal 3852 could not be located in the dynamic link library LIBEAY32.dll.' Copying the DLL into the directory didn't help, either. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] PPS from an external OCXO source. Correcting drift is it possible?
Kat schwar3...@gmail.com wrote in message news:c5391c04-b342-4922-b520-ff862fa38...@v1g2000prd.googlegroups.com... homebuilt OCXO PPS I have two problems with it. 1. It starts off with a random offset. You can fudge that in the configuration file. It's a common problem with an easy solution. 2. The offset drifts at about 20 milliseconds a day. You can't fudge that as far as I know. Perhaps the expectation is that PPS signals are generally much better - this is 2.3e-10 which sounds rather good until you realise it's 20 ms each day. How far are you willing to go? You might be able to build a clock based on the PPS that is amenable to disciplining through NTP, but if it's only for holdover during Internet outages, perhaps you'd be more helped with a way to keep the offset down (or at least known) between Internet outages. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] (no subject)
Varrun Ashok varrunas...@yahoo.com wrote in message news:77927.74008...@web55108.mail.re4.yahoo.com... Hello everybody, Why does ntp (ntp-4.2.4p4 in specific) require an operating system? ... Well, for one thing because it expects to be disciplining a software clock. For another thing, because it wants to talk UDP to other hosts. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Ntp looses sync
Towli to...@oldboyz.dk wrote in message news:49d3328d$0$90265$14726...@news.sunsite.dk... We're testing a DCF77 appliance box (EMC professional from www.gude.info), which every now and the looses its connection to the DCF77 signal and switches over to quartz mode. Upon doing this, our test switch looses its sync to it, and considers it a stratum 11 server instead of a stratum 1. The switch also has configured an ordinary stratum 5 windows-server, and it seems to me that it uses this one, when the appliance box is seen as being stratum 11 (and syslog says the switch lost ntp-sync to the stratum 11 appliance box, but syncs back when the DCF77 signal is restored). Will a switch allways use the lower stratum server? Simple version: yes. Can i stop the switch from synching with other servers (when the dcf box looses its signal and runs in the otherwise reliable quarts-mode), while still having a backup ntp server configured in case the appliance bos goes down? You might be able to mark the DCF box as a 'preferred' server. For the exact syntax, see the manual. Is a constant sync important or is it ok for the switch to synch with different servers 'along the way'? Constant sync is nice but redundancy is better. Note that for redundancy to be useful, some flexibility is required. As an aside, the DCF box takes pains to play nice and warn about reduced accuracy but it may well be better than a Windows host even then. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] http://www.ntp.org/ = a blank page?
David J Taylor david-tay...@blueyonder.neither-this-bit.nor-this.co.uk wrote in message news:jzqtl.5203$lc7.2...@text.news.virginmedia.com... Martin Burnicki wrote: [...] We did't ever have any problems using the DNS servers of our ISPs. At the time, mine was using servers in the USA (from the UK) and via non-reciprocal paths. Even now, it seems to be using servers from abroad, and has no local reference clock I don't think that anyone cared for it. I think you're talking about your ISP's _NTP_ server(s) here. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Mixed maxpoll values for mixed LAN/Internet servers - sensible?
David J Taylor david-tay...@blueyonder.neither-this-bit.nor-this.co.uk wrote in message news:qctpl.13$lc...@text.news.virginmedia.com... It's been suggested that if I have a mixture of a known-good (i.e. GPS/PPS-based) LAN server, and some Internet-based backup servers, I could use an ntp configuration file with different maxpolls, with the idea that syncing more often to a good source will produce even lower offsets. Polling more often will produce lower offsets, yes, but mostly because it doesn't allow time for larger errors to grow. Once phase error is no longer dominant, the poll interval is lengthened to better correct frequency error. Not an idle pursuit. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] NTP over redundant peer links, undetected loops
Dave Hart daveh...@gmail.com wrote in message news:03463add-146a-457d-9869-9caddf6f8...@i18g2000prf.googlegroups.com... On Feb 17, 9:01 am, Maarten Wiltink maar...@kittensandcats.net wrote: My home network is on 192.168.27/24. I took the number from my street address. My brother (independently!) picked 53 for his network, by the same mechanism[0]. We have an OpenVPN tunnel between those networks. We have no routing problems. [0] And when they renumbered his house, he renumbered his network. Okay, I wouldn't have done that. I've taken the same approach a couple of times at different addresses with 192.168.address.0/24. I also have a VPN going with my brother. Sadly, his employer requires security software that requires he use 192.168.1.0/24 for his home network to be able to VPN in to work. As a workaround, I've sometimes subnetted a hotel 192.168.1.0/24 hotel address, claiming 192.168.1.2 and using netmask 192.168.1.252, so that when I VPN all but the first few addresses of my brother's network are visible. Scary. You _are_ me. (-: (Actually, it was my employer, not his, that had a spurious 192.168.0/24 requirement somewhere, so I guess that introduces a cross in the connection somewhere.) Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] NTP over redundant peer links, undetected loops
Richard B. Gilbert rgilber...@comcast.net wrote in message news:zbsdneivucyrrafunz2dnuvz_oodn...@giganews.com... [...] This won't solve the OP's problem as I understand it. But this time, that's not the OP's or his problem's fault. RFC-1918 prescribes three address families for private networks: 192.168.1.X 172.16.X.Y 10.X.Y.Z It does not. Please stop treating Dave Hart as an idiot and spend some productive time rereading RFC1918. While you're at it, find out about CIDR and see if you can figure out that the three ranges are really 192.168.W.X (not just .1.X), 172.16-31.X.Y (not just 172.16), and 10.X.Y.Z. At least you got that last one right. Randomising which subrange you use _does_ solve these routing problems most of the time, just like generating a random host id does solve the undetected loop problem _most of the time_. My home network is on 192.168.27/24. I took the number from my street address. My brother (independently!) picked 53 for his network, by the same mechanism[0]. We have an OpenVPN tunnel between those networks. We have no routing problems. Groetjes, Maarten Wiltink [0] And when they renumbered his house, he renumbered his network. Okay, I wouldn't have done that. ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] NTP over redundant peer links, undetected loops
Dave Hart daveh...@gmail.com wrote in message news:3a359156-5610-4c6c-8d4f-6f7fbab96...@x11g2000pro.googlegroups.com... RFC1918 addresses are of course not globally unique, so are particularly ill-suited to a reference ID used for loop detection. [...] Why play roulette if you have a globally unique IPv4 address to use as a refid? ... You do? Lucky you. RFC1918 addresses are all I have[0], except for the one address on the outside of my modem, which of them all is the _least_ suitable because it's the one place in my network where I don't have, nor currently want, NTP service[1]. RFC1918 addresses may not be globally unique, but they are also not routeable, so within any given network they _will_ be unique. While multi-homed hosts may seem to be a counter-example, living as they do on several networks at the same time, I think they still need unambiguous network addresses around them. Groetjes, Maarten Wiltink [0] Well, except for 127.0.0.1, but I'm not suggesting we use that. [1] I do think that the Pool is a great idea, though. ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] refid 'STC ' ? What does STC signify?
phr...@gmail.com wrote in message news:bef5f066-1c61-4ff4-8cc0-c0cfad9ec...@n33g2000pri.googlegroups.com... [...] So other than using ntptrace to see if the refclock is reported as an upstream server (an unlikely stratum 0) or something else, there's really no way to know what the heck it is in reality. I can't say that idea gives me a warm, fuzzy feeling. And you are totally right. Trust is hard on the Internet. It is often best established out-of-band. Ntptrace can help, though. Correct me if I'm wrong, but my non-caffeinated brain is telling me someone driven by a budget could set up a server using nothing but it's LCL clock as a source but fudge the ID to be something else. On an isolated network, there'd be no way to detect this (assuming for this academic argument you don't wear a reasonably accurate watch). I can imagine a group of such servers peering with each other endlessly hunting around themselves. Again, you're completely right. (You were already told you look decidedly non-stupid, right?) However, if you're caught in such an isolated network, you're probably close enough that (a) you _can_ detect your situation, and (b) you know who to walk up to and throw The Book[0] at. If ntpd came with a fixStupidNtpConf.ss script, I'd feel better about this. That's actually very easy. Configure three Pool servers. It's really hard to do worse with that than with any recogniseably stupid configuration. On the other hand, if you have the intelligence to recognise your configuration as stupid, you can probably also do better than the Pool. Groetjes, Maarten Wiltink [0] The NTP Book, that is. There is one. His Timeliness Dave Mills wrote it. ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Tracking the drift of a GPS clock relative to a HW clock
ryad@gmail.com wrote in message news:896fd879-86c6-4c12-9528-139e59d24...@w1g2000prk.googlegroups.com... [...] I'm trying to track the drift of my GPS clock RELATIVE to the clock that I would have obtained without GPS (and vice versa). If I understand you correctly, you want to generate a log with two timestamps on each entry: one free-running, one GPS-synced. You could _not_ run NTP on your test machine, and whenever a message is logged, fetch a timestamp from another machine that does run NTP. Microsecond accuracy on that machine is not very hard with a GPS clock, but getting it into the test machine with the same accuracy may be a bit of a problem. It's mostly a matter of having the transfer take about the same time each time; if a good timestamp always arrives in exactly thirty milliseconds, that's good, you can correct for that. Another avenue is to run NTP on the test machine but not let it touch the clock (or not let it believe the other NTP server or for that matter any other server; you want a free-running clock). You still need the GPS-synchronised other NTP server, but running NTP on the test machine gives you easy, continuous, and fast access to an estimate of the current error in the local, free-running clock, and thus an idea of what the 'real' time is. My final goal is to convert a series of gps timestamps to the equivalent unsychronized timestamps. Whereas I propose doing it the other way around. It produces the same information and it's easier to do. I think. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Why can't clocks do inital synchronization?
j...@specsol.spam.sux.com wrote in message news:9bca36-5p@mail.specsol.com... Unruh unruh-s...@physics.ubc.ca wrote: uh, ntpdate is severely depricated, and ntpd -g is what is supposed to be used. If ntpd -g fails it is a bug. Uhh, lots of mainline 'nix's don't have a -g option to ntpd and still have ntpdate, e.g. Solaris 10. Yup. Legacy stuff doesn't go away by wishing it to. It's still a bug, though. Ntpdate is most unlikely to get fixed; ntpd -g at least has a chance. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Should ntpd log failure to syslog?
Hal Murray hal-use...@ip-64-139-1-69.sjc.megapath.net wrote in message news:fpadnsquvyltjt_unz2dnuvz_uadn...@megapath.net... I think you are assuming here, that the servers will fail one by one with no one noticing or correcting the problems. This scenario seems rather unlikely to me. Any publicly available server has hundreds or even thousands of clients keeping an eye on it. If it goes belly up the failure will surely be noticed. What if the failure is the company going out of business or a policy change or ... ...Or a change of IP address. Or what I think might be the worst one: your own NTP server accidentally running into a transient 1001-second offset and exiting. A year ago. (Sure it's unlikely. But how do you *know*? Answer: through monitoring.) Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Sub-millisecond NTP synchronization for local network
Unruh [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] What should I be doing to get 20 us? Buy all new computers with gigabit Ethernet? I suspect buying better switches. And it looks to me like you should definitely NOT go to gigabit Ethernet if you want good timing. Seeing as how gigabit Ethernet uses jumbo frames to reach decent throughput, I suspect it's subject to higher jitter at the network level. NTP frames are short, but if it's contending with a large download, there will be a relatively large unpredictable delay on the line. Better switches would probably help in my case. Calling my attic 'low budget' would be putting it nicely. In response to Hal's observation that faster computers seem to have lower delays, my fastest (by far) host has the second-lowest delay (~0.77 ms), but the one to beat it is .56 ms through a RealTek 8139 on a machine half as fast. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Sub-millisecond NTP synchronization for local network
Unruh [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] Getting 20microseconds over a local net is easy. On a local net, the delay should only be about 100microseconds, certainly not milliseconds. ... I must be doing something horribly, horribly wrong then. Delay is on the order of 1 millisecond (0.6-1.3) and offsets are currently *very* good, all between -1 and 1 millisecond. What should I be doing to get 20 us? Buy all new computers with gigabit Ethernet? Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Rejecting Good Peers
Cal Webster [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] I haven't restarted the servers yet in case I need to query some more info. Do you think this could be a contributing factor in this problem? If you haven't restarted the machines, that's okay. You never have to, restarting NTP is enough. If you haven't restarted the NTP daemons, they will not have the new configuration. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Rejecting Good Peers
Calvin Webster [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] On Wed, 2008-12-03 at 09:08 +0100, Maarten Wiltink wrote: Cal Webster [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] I haven't restarted the servers yet in case I need to query some more info. Do you think this could be a contributing factor in this problem? If you haven't restarted the machines, that's okay. You never have to, restarting NTP is enough. If you haven't restarted the NTP daemons, they will not have the new configuration. Thank you for being specific Maarten. If I were a Linux novice that information would be very helpful. It's hard to judge skill level from a few posts. When I say servers I mean the ntpd daemons on each host. I only restart hosts for kernel updates or shutdown in case of destructive whether. :-) And thank you for taking the note in the spirit in which it was meant. 'Server' is unfortunately an ambiguous term and I thought I'd head off some possible confusion. Not necessarily yours. There is still some confusion on my part left unsettled, though. If you haven't restarted the NTP processes, they will not have the new configuration. Yes, that _would_ be a contributing factor - any problems that are due to the old configuration would have no reason to go away. How should I read that question? Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] ntp survey
Antonio M. Moreiras [EMAIL PROTECTED] wrote in message
news:[EMAIL PROTECTED]
Maarten Wiltink escreveu:
Antonio M. Moreiras [EMAIL PROTECTED] wrote in message
news:[EMAIL PROTECTED]
Aiming to collect and analyze data from NTP network, a survey will
be held at all hosts available for public access on the NTP network,
using a program developed for this purpose. The survey will start
today and will last some days.
My gateway runs NTP ('of course') but it's not available for public
access. Would you, in general, want to include such hosts?
how the survey works
Said that, we can eventually reach your gateway, sorry...
I'm afraid you have misunderstood me. There is no need to apologise,
if you'll have my server, I'd _like_ to be included in the survey. I'm
just trying to clear up if you want to restrict yourself to hosts that
are of use to the public at large, or survey all NTP hosts that you can.
We would like
to be able to get some information from it, but we know that
(generalizing) it will be impossible. ...
Well, as per above, I'll be happy to punch a hole in the firewall for
you. Will future scans be run from the same IP addresses? Will they be
announced again? (Could you do so a few days _before_ it starts?)
Groetjes,
Maarten Wiltink
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Re: [ntp:questions] ntp survey
Antonio M. Moreiras [EMAIL PROTECTED] wrote in message
news:[EMAIL PROTECTED]
Aiming to collect and analyze data from NTP network, a survey will be
held at all hosts available for public access on the NTP network,
using a program developed for this purpose. The survey will start
today and will last some days.
My gateway runs NTP ('of course') but it's not available for public
access. Would you, in general, want to include such hosts?
Groetjes,
Maarten Wiltink
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Re: [ntp:questions] Isolated Network Drift Problem
Cal Webster [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] On Tue, 2008-11-25 at 14:10 -0500, Richard B. Gilbert wrote: [...] Your NTP server need not live in a computer room; it can be anywhere that you have a LAN connection! A PC that has been retired from desktop service can be recycled as an NTP server. A 486/33 has more enough computing power to be an NTP server. You'll probably have to settle for a Pentium because I think the museums have cornered the market in 486s! ;-) 'Museum' would be a very benevolent term to apply to my junk pile. [...] Yeah, I do a lot of recycling here, what with our tiny budget. It would have to be something reliable, though, if it's going to be our primary time server. I'd probably reserve a couple of our old Dell Dimension XPS PIII machines installed with Fedora 9/10. Like DNS setup, NTP setups benefit greatly from layering. You could very well have your master time server under the roof, five feet from the GPS antenna. That places it at the far end of a length of Ethernet cabling, which copes with distance very well. The next layer is formed by three stratum-2 servers, preferably peered and with backup sources and whatnot, so that when the master server goes off-line, at best they'll shift to backup sources and at worst they will at least drift as a group. The clients talk to the stratum-2's, never to the stratum-1. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Isolated Network Drift Problem
Cal Webster [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] What's the best way to determine which of our NTP servers provides the best local clock? First order: reset drift (delete all their drift files), synchronise their watches, let them run for a few days, and see which one has drifted least. Correct for drift. This depends on how well you can put them all in the same starting state by hand, and on the time source you use to measure drift at the end. You can correct for the former by waiting longer. You _cannot_ outwit your dependency on the latter. Second order: after the previous procedure, they should all drift very little, and no one significantly more than any other. The one that stays closest to that time source you're comparing against has 'the best local clock'. This depends mostly on temperature stability. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] xntp both serve and client
fenwayfool [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Is it possible to turn off xntp server functionality? Effectively, yes. Strictly, no. That is, xntpd seems to always have port 123 open. This shows up on a port scan even though the system I have really only requires client functionality. Seems like I could restrict server access via the ntp.conf file but port 123 would still be open... I don't want random port scans to show the port as open. It's _UDP_ port 123. UDP being stateless, if you want to hear replies to your queries, you need to listen some of the time. The easiest way to do that, is to listen all of the time. NTP takes that way. If you have a very smart firewall, you could configure it to only let the port show as open for a few seconds after a request came out of it. Don't come asking me how to do that, though, it's way over my head. As a benefit, NTP will provide diagnostic information when asked on that same port. You may not care for it, but it allows for easy checking that an NTP client is actually running well and where it's getting its time from and so on. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Slow convergence of NTP with GPS/PPS
Ryan Malayter [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] Or does the PPS signal not depend on the serial baud rate? It's generally rigged to trigger an interrupt in the receiving machine. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Slow convergence of NTP with GPS/PPS
Unruh [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] The longer poll intervals are mainly about keeping packets off the servers. In principle it is always better to poll more. ... Yes, but. One of the given reasons for polling less often is to let the host clock accrue more error so that it becomes better measureable amid other error sources, for example jitter from random network delays. But you can poll every second and still correct very small frequency errors, if only you don't _forget_ polls from very long ago. Keeping a simple FIFO queue of poll results is too simple. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Let ntp server not synchronize time from other servers
WANG Cong [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] if there's no server lines, I _always_ got: # /usr/sbin/ntpdate -u -b 192.168.90.41 28 Aug 11:21:35 ntpdate[10515]: no server suitable for synchronization found (192.168.90.41 is my own NTP server.) It seems that without servers, you have no synchronisation sources left. (Which is probably correct.) So you fake one. server 127.127.1.0 fudge 127.127.1.0 stratum 14 These two lines will cause your server to believe its own, free-running, clock and consider itself synchronised and serve time, while indicating that the time served is of quite atrocious quality. Is there any particular reason why you won't take the time from anyone? Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Let ntp server not synchronize time from other servers
WANG Cong [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] On Aug 28, 12:49 pm, Maarten Wiltink [EMAIL PROTECTED] wrote: server 127.127.1.0 fudge 127.127.1.0 stratum 14 Cool! It works! 8-) But there's a little problem, when I changed my ntp.conf, I have to wait for several minutes until it works well, if not, I got: 192.168.90.41: Server dropped: strata too high NTP really solves a different problem than yours. It's slower than it might be as a result. Nothing you can fix. Live with it. I googled a bit, and someone said this is due to the time of the server is far from correct, but it is not. See below: # /usr/sbin/ntpdate -u pool.ntp.org 28 Aug 14:23:38 ntpdate[18923]: adjust time server 194.117.9.136 offset -0.174164 sec # LC_ALL=en_US-UTF8 date Thu Aug 28 14:23:42 WEST 2008 At the same time, I ran this on the server: date Thu Aug 28 14:23:47 BST 2008 That's not the same time. There's a five second difference! Please realise that you are dealing with a product, and a crowd, to whom 128ms time difference is enough to go to emergency measures, and 500PPM speed difference is enough to stop trying permanently. [...] Is there any particular reason why you won't take the time from anyone? Yes, because we want: 1. Configure the time of the server manually, no matter how wrong it is. :) I've been in that boat. It can be a right pain to test expiration dates with a clock that won't stay in 2099 or more than a few seconds. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] NTP Drifts +ve and -ve
Unruh [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] (actually since it is a second order critically damped system, this is not really accurate. The correction action goes to zero faster than that, overshots by something like 20% and then comes back to zero). ... Never thought I'd be picking nits about this, but isn't that a strongly damped system? ISTR critical damping being defined as not overshooting. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Can i control the NTP Sync?
David Woolley [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] Using UTC internally is, I think, only true of NT, ... Which, conveniently, is also the only Windows family that will run NTP. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Windows built-in SNTP/NTP clients
David J Taylor [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] I guess the correct approach there would be if all the clients responded to SNMP requests, rather than using a proprietary protocol. ... It's stuck in my head that NTP has Assigned Numbers (MIBs? I'm not up to speed on SNMP) already, and SNMP capability could be added without too much trouble. I'm tying to see the catch - would this be for monitoring purposes only? There are many people who want to reconfigure on the fly; on the other hand there are probably even more people who only want to watch. And it might make sense for some high-end appliance manufacturer to develop, even. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] ntp server help
Mikel Jimenez [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] How can I configure the server to cameras get server time every very very short time? My objective is to get the server and 4 cameras syncronizhed, not more 0.01s desyncronizhed, taking reference the server. One way would be to configure the server for broadcast mode, and the clients for listening to the broadcasts. Then the server would send out timestamps every 64 seconds (I think), which for NTP purposes qualifies as quite often. But that's not the normal way to have a small number of clients work. It is more common to run NTP on the clients and let it adjust the clock until it runs very nearly exactly right. That works much better than leaving the clock to run slow or fast and jolt it back or forward as required 'every very very short time'. Two things may be wrong with a clock: it may simply be off (reading for example ten past midnight at midnight), and it may be running fast or slow (say, advancing sixty-one minutes every hour). Most clocks suffer from both. Most people know no better than to set back that clock twenty-four minutes every day. Doing that more often will require smaller adjustments each time, and also have the clock being closer to real time on average. But NTP can slow down or speed up the clock as well. It can really make the clock run at sixty minutes per hour[0]. And then you only need to make the rough adjustment once, if at all. After that, the clock is adjusted by making it run faster or slower (only a _veeery_ little bit) when it needs it. Very soon, you get to the point where the time difference between client and server must be allowed to accumulate for quite a long time before you can even reliably see it, so you are correcting real error and not just measurement noise. NTP will start by polling every 64 seconds. When it is running well, it will poll less and less, until it stops at polling every 1024 seconds (just over 17 minutes). And the offset will be not just under 0.01 seconds, it can be under 0.01 _milli_seconds. If it's running well. Groetjes, Maarten Wiltink [0] These numbers are faked. A more realistic error is a tenth of a second per hour. ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] seeking community in new york city
Richard B. Gilbert [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [EMAIL PROTECTED] wrote: I need vis-a-vis help in New York City. If you are competent with NTP, GPS, and computers then please contact me: [EMAIL PROTECTED] What problem are you trying to solve? A standard incompetence problem of the I'm more of a people person type. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Generating keys for ntpdc control
Bob [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] I never see ntpdc touch the ntp.keys file - not sure if it's supposed to. ... No, it isn't. It's supposed to send questions to ntpd, which is supposed to send answers. Ntpd may touch local files, ntpdc should be network-transparent. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Utility to measure time drift
jkvbe [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] I'm looking for a utility like clockdiff(8) to measure the time delta between different machines. The utility itself should run on Windows, but the machines under investigation are running Linux. The usual approach is to set up a machine that has all the machines under scrutiny as servers in its NTP configuration, possibly all marked noselect - I'm not sure about that bit. Ntpq -p will then tell you the offset to them all, relative to a single base (the monitoring server's own notion of time). Note that this is subject to all the vagaries of normal NTP life. If the DSL connection to one server is heavily overloaded, the offset will reflect that. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Where is the log file?
David J Taylor [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Alan wrote: The Windows Event log shows an error, Unable to initialize .rnd file: [...] I'm not sure about this, but I think the SSL package used in NTP tries to write a random number file to the root directory of the hard disk, and most likely Windows Vista in not allowing access. ... I think that's exactly it. The location defaults to c:\ on Windows, which is a staggeringly bad default in my opinion, but at least it is configurable through an environment variable. On this machine, I have this: randfile=%systemroot%\system32\drivers\etc\.rnd which makes it use the same filename but in the Windows equivalent of Unix's /etc directory, mostly because ntp.conf lives there, too. A temp directory might be a better place and note that they might have deduced that from an environment variable as well. Something under an equivalent of the /var directory might be better still but I'm not sure what that would be. All Users/Application Data perhaps? Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] NTP shows all servers in condition reject
Danny Mayer [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] Windows servers are know to be extremely bad to be used as an NTP server and cannot be relied upon. Even if they are running NTP? Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] question about DST
[EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] On May 31, 9:54 pm, Unruh [EMAIL PROTECTED] wrote: Rule Pakistan 2002 only - Apr Sun=2 0:01 1:00 S Rule Pakistan 2002 only - Oct Sun=2 0:01 0 - Rule Pakistan 2008 only - Jun 1 0:00 1:00 S Rule Pakistan 2008 only - Sep 1 0:00 0 - [...] Thanks for the step by step instructions, its works on Linux (centos) I'll update after doing it on other OS (Solaris). I wonders what will be procedure when after three months when the clocks go back? Don't wonder. Read the rule file and you'll _know_. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] clock keeps getting behind, driftfile is 0.000
[EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Hi this, is the ntpq -p output: [EMAIL PROTECTED] ~]# ntpq -p remote refid st t when poll reach delay offset === sectionzero.org 35.65.96.0 3 u 171 1024 3762.065 347330. steghoefer.eu 87.239.10.1903 u 200 1024 3772.182 351371. nieuwland-240.c 213.136.12.533 u 132 1024 3770.728 347218. fw-enschede-6.i 193.190.230.65 2 u 201 1024 3775.566 346919. *LOCAL(0).LOCL. 10 l 33 64 3770.0000.000 (Jitter column removed to fit on an 80-character line.) The access restrictions in our conf file are only for prohibiting other servers to sync with this one, so it looks ok to me? No, that's definitely not okay. All those servers have a reach of 377 (or almost), which is good. Time is getting from them to you. But it's about 350 seconds off. Actually, *you*'re probably 350 seconds off. And because you've told your NTP that the local clock knows best, it's believing (and serving) that. Either remove the local clock, or set your clock closer to good time before allowing NTP to start, or tell NTP to accept a large step once at startup. The first option may result in NTP consistenly dying shortly after startup. IIRC, the maximum step it will take is 1000 seconds. You are below that, so NTP may actually survive. Or not. Check. The second option can be facilitated with a manual sntp/ntpdate command, or with a list of NTP servers to poll for an automatic sntp/ntpdate command as part of the NTP subsystem startup. Read your startup scripts; /etc/step-tickers is where old Red Hat distributions look (don't take my word for it, take grep's). The third option is spelled '-g' on the command line that starts the ntpd process. Read the documentation. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Can we write NTP server using c#
Rajesh kankran [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Actually i have code for ntp client...and i m using localhost as server as NTP is installed on my pc only. So you would be trying to synchronise a host to itself? I foresee problems. in order to get response i have not written code for server but still server responding to me and generating message because of NTP installed. then can u pls tell me Why should i write code for server...? Means what server should do if write code for that?because it is already responding to client with time stamp. The NTP system is designed to distribute known good time across a mesh or graph of connected machines. The starting points are (expected to be) 'reference clocks', usually in UTC, and nodes further in the network are explicitly allowed to take time from several sources. Sources can be reference clocks if you have them (relatively few hosts do), or other nodes closer to reference clocks. The point is that distributing _known good_ time effectively requires every server to be a client as well, because that is the part where the clock in a given host is made to run 'better'. An additional point is that for monitoring purposes (_checking_ before you accept it as known good), almost every client[0] is allowed to also run as a server. Groetjes, Maarten Wiltink [0] 'Client' in the sense of 'not _intended_ as a server'. As may have become obvious, the distinction between clients and servers in NTP is blurry. ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] frequency adjusting only
Unruh [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [... Delay] assumed to be symmetric and is already cancelled. The ONLY way to really measure if there assymetry is to put a real clock on each of the machines (Ie, a clock synchronized to usec accuracy to UTC-- eg a GPS PPS ) and measure the offset of each of the machines from GPS time. I wonder. Would it be possible to rig a PPS signal that isn't really synchronised to anything, and distribute it to all the machines? It wouldn't even need to use a very precise second. (ISTR (possibly wrongly) that this was a single-lab setup. For a WAN situation, it would be useless.) Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Problem with time synchronisaton
Hal Murray [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] The problem here is that the distribution does not contain a decent assortment of example configuration files for common configurations. So the OS distributors/aggregators/vendors each cobble together their own one size fits all configuration file. I suspect they would do that anyway. Because they usually want one size to fit all. But does a local refclock make sense in a typical setup? Given the above, yes. It doesn't actually hurt a client (if a server is available), and an isolated server needs it. Differentiating between leaf node, dependent server, and isolated server is too hard for some. Especially since the difference is only in the configuration, and a dependent server, while it could use the Pool, would often need manual configuration. And I'm not even talking about broadcast/multicast. The logical end result is a distribution with three or four Pool servers and a local clock. It falls down with multiple installations in an isolated network, but works everywhere else. It may not be optimal, but it's the best you can do under a wide set of circumstances. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] 3 Questions about setting up NTP
unix2266 [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] I'm setting up a new NTP server to sync time for our network. I have one Linux server that needs to point to that NTP server My 3 questions are: 1. I added the IP address for the NTP server to the /etc/hosts file on the Linux server. Is that all i need to do to make the Linux server point to the NTP server? No. /etc/hosts maps hostnames to IP addresses. It has nothing to do with NTP per se. Add either the hostname or the IP address to the configuration file for NTP, usually /etc/ntp.conf (but check). 2. After pointing the Linux server to the NTP server, do i need to reboot the Linux server or restart any daemon on the Linux server? in other words, what do i need to do to make sure the changes i made in the /etc/hosts took affect? No need to reboot. Just start or restart the NTP daemon/service. How to do that varies. 3. Is there a way to test the NTP server to make sure it interact with the Linux server will work fine if i have a timing issue on the Linux server? I want to test it so if something happens for real i don't look like a dummy Run 'ntpq -p' against it. Specify the hostname of the NTP server as an additional parameter after the '-p'. An NTP server should really respond to ntpq. If it doesn't, it _may_ be working fine but you have no easy way to check. If it does, there will be lines listing its references; if one has an asterisk in front of it, it's generally fine. Assuming, that is, that the reference so marked is itself fine. You haven't told us where your new NTP server is getting its time from. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Linux 11-minute mode (RTC update)
Noob [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] What do you think about the following script? while true do sleep 660 # or some other value? hwclock --utc --systohc done That, apart from the sleep, it would make a nice cron job. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] high precision tracking: trying to understand sudden jumps
Unruh [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] Would I really believe that the CDMA cell phone network would care if their time signal were accurate to usec? I would. Because IIUC, this is the basis on which they divide timeslots between stations. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] high precision tracking: trying to understand sudden jumps
Unruh [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Richard B. Gilbert [EMAIL PROTECTED] writes: Forcing the poll interval to 16 seconds is not always a good idea! Ntpd will select a poll interval, generally starting at 64 seconds, and ramping up to as long as 1024 seconds as the clock is beaten into submission! It is his network, he is not going to overload it. So, if he wants a 16 sec poll interval that is up to him. I agree it is not a good idea for remote servers, but on his own system it is fine. [...] ??? The longer polls are in order not to swamp the remote server whith 1 people all polling every 16 sec ( or 1 sec) There is nothing in ntp itself that mandates a longer poll interval. In fact a shorter poll interval makes ntp much more responsive to changes ( clock drifts, etc) The very short poll intervals correct large errors quickly and the very long intervals correct small errors very accurately! No for a properly designed system both should be corrected. You seem to be missing the point. Once the large errors have been corrected, NTP goes on to the small errors. For that, it _needs_ a longer poll interval. That this gives the server more air is a happy coincidence, but not why it does it. Given the measurement error, you need to let the small error accumulate over a longer period. Otherwise it would simply be lost in the noise. Do the math: assume the (constant!) measurement error to be +/- 1 ms, the frequency error in my local host to be 1000 PPM (1/1000). With a 1 s polling interval, the real value is 1 ms and the measurement will be between 0 and 2 ms. Not very good. With a 1000 s polling interval, the real value is 1 s and the measurement will be between 0.999 and 1.001 s. Now that's useful to correct your clock with. Now use more realistic numbers, like 50 PPM to start with, a polling interval of 64 s and I'm not exactly sure what for the measuring jitter. But the gist should be clear: that 50 PPM will go down, the SNR will worsen, and the polling interval should go up to improve it again. Starting with a short interval is good to correct large errors quickly. Backing off once you've done so is good to avoid pestering the server, but it's also good to correct small errors accurately, and _that_ is why it's done. And of course, once a larger than expected offset is measured, the polling interval is shortened again. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] SNTP server + ntpd 4.2.4 client
Unruh [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] Look, an SNTP client is not supposed to act as a server. Period. Unless... its clock is disciplined by means external to NTP. For example, by a reference clock. Not all reference clocks must necessarily be NTP servers; there are other ways to use them to make sure that some clock in the next computer over runs Very Close to UTC. It has been said right here that many if not most of the black box stratum-1 servers operate by the exact mechanism you condemn: an SNTP client polling a local refclock at some suitably short interval, presumably with a simple feedback loop but without the full NTP and its higher math other assorted magic. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] SNTP server + ntpd 4.2.4 client
Steve Kostecke [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] On 2008-03-25, Ryan Malayter [EMAIL PROTECTED] wrote: [...] Would we have the pool scheme in the development versions of ntpd now if OpenNTPD hadn't implemented it first? Really? They did? The NTP Pool was implemented at first as a bunch of public NTP servers, with clever use of DNS to make it work. The point I'm trying to make is that it worked before and without any NTP implementation knowing about it. It does work better when the NTP client is aware of the need to re-resolve hostnames under certain circumstances, but those same circumstances occur outside the pool, just not as often or as pressing. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] 1 Machine, 2 NICs, 2 Instances of ntpd; Possible?
Unruh [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Maarten Wiltink [EMAIL PROTECTED] writes: [...] The client part might operate without a server, or perhaps a downgraded server that does not serve time but only offers status monitoring. Sure, but the server cannot operate without the client. YOu can certainly write an SNTP client, which is never a server. But servers need the full client functionality. Some implementation of it, anyway. And a full NTP client can exist without a full server around it. At which point the code sculptor in me starts envisioning separate modules and clearly defined interfaces and pretty interlocking and interchangeable parts. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] 1 Machine, 2 NICs, 2 Instances of ntpd; Possible?
David Woolley [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Maarten Wiltink wrote: David Woolley [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] stratum root distance root dispersion system peer local reference time leap bits etc. Yes. Those are all client-part statistics that could easily be made available to a server-part for dishing out to anyone interested in evaluating the status and quality indicators of your server. ... These things are needed for the core protocol. You cannot act as a valid server to even the most primitive of valid clients without them. They are not diagnostic information for ntpq, they are needed to construct a valid server packet. Not all statistics are diagnostics. Some are, as you say, core. Without them you don't even have a compliant SNTP server; you basically have an RDATE like server with sub-second resolution. An SNTP or local clock server might have to make some of them up. System peer? Root dispersion? Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] 1 Machine, 2 NICs, 2 Instances of ntpd; Possible?
Steve Kostecke [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] John Johnson wrote: [...] Now, is what I am trying to do feasible? No. One ntpd is all you need. I think you must be using a different definition of the word 'feasible' from everybody else. As a software guy, I've wondered before about the monolithic nature of the NTP package. Splitting it into a client and server part might make some people (think OpenBSD) very happy. The objection when raised earlier was that the server may be asked for statistics about things that happen in the client; ISTM this could be solved. Also, the much-sought feature of re-resolving dried up associations could be done from a cron job with ntpq/ntpdc. Determining for certain what configuration to use might be a problem. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Default config on Ubuntu doesn't work as client
Michael B Allen [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] Could the fact that Ubuntu is running in VMWare Server be a problem? Yes. Very much so. Install the VMWare tools and let the virtual machine host control the passage of time on the clients. Only run NTP on the host machine. There's a whitepaper somewhere. It boils down to 'Virtual machines are not suited to real-time software. Let the host control time, it will do a better job.' Time synchronisation in the clients is off by default, and they _will_ drift. I have two old Linux machines now virtualised, both without VMWare tools installed. With adjtimex I managed to get one below 1PPM and it now steps half a second each week; for the other one (kernel 2.0) I didn't find or compile an adjtimex yet and it steps 2.5 seconds each day. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] 1 Machine, 2 NICs, 2 Instances of ntpd; Possible?
Steve Kostecke [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] On 2008-03-11, Maarten Wiltink [EMAIL PROTECTED] wrote: As a software guy, I've wondered before about the monolithic nature of the NTP package. Splitting it into a client and server part might make some people (think OpenBSD) very happy. There is considerable overlap between an NTP Client and an NTP Server. NTP Clients and NTP Servers both: 1. Poll time sources (e.g. NTP Servers, ref-clocks) 2. Discipline the system clock This _is_ what I'd call the 'client part'. The server part would assume or require that the clock is being disciplined by a client implementation. 3. Utilize NTP Authentication You may have a point there. But I have a feeling that they use it differently, one as a client and one as a server. (No surprise there.) [...] The objection when raised earlier was that the server may be asked for statistics about things that happen in the client; ISTM this could be solved. By adding another layer of complexity ... Yes. Decoupling always adds complexity at the interface. But as a software guy I appreciate the focus it adds to the decoupled modules. Also, the much-sought feature of re-resolving dried up associations could be done from a cron job with ntpq/ntpdc. Determining for certain what configuration to use might be a problem. A 're-resolve' command in ntpq would be useful. I don't have the details handy, but aren't there already commands to remove and create associations? Probably only in ntpdc, though. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Default config on Ubuntu doesn't work as client
Richard B. Gilbert [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] My experience with VMWare is limited to VMWare ESX. With ESX all you need to do is to log in as root, edit ntp.conf to include your favorite servers, start ntpd and enjoy. Is that the free one? (The free one is what I have at home. It's free.) With the free version, you have to install the VMware tools in every client, and enable 'Time synchronization between the virtual machine and the host operating system' on the options tab. (This is on a Windows client.) Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] 1 Machine, 2 NICs, 2 Instances of ntpd; Possible?
Steve Kostecke [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] Currently NTP uses port 123/UDP for both the source and destination port. What you are proposing would require the use of a different source port to work on a single-homed host. This would result in a DOS when polling a server that enforces the NTP port. I'm no IP wizard, but isn't there a SO_REUSEPORT flag or something like that? Anyway, I frankly doubt that requiring a specific source port is still a good thing. Dit it ever accomplish anything above testing that the sender has root on the remote machine? By now, it mostly serves to chase off innocent NATted clients. Another thing to consider is the fact that you would now have two processes which both require high priority access to the system clock. I can see how that would be a party killer. But the current, monolithic NTP can't discipline the clock and answer polls at the exact same time, either. The obvious choice would be to give the client part priority over the server part. Things might actually get *better*. [...] Decoupling always adds complexity at the interface. But as a software guy I appreciate the focus it adds to the decoupled modules. [...] I'd point out that the source is available for anyone to modify, but that statement seems to interpreted as an attempt to stifle discussion. Well, I appreciate the source being available and all, but unfortunately I already have a hobby to take up six nights a week. Plus, while patches might be accepted, I doubt that a major rewrite of the entire codebase would. Sorry. Sometimes I wish I were still twenty-two and had the patience to do it, and the perseverence to get it changed. At thirty- seven, all I have left is the questionable sideline-based wisdom to see room for improvement. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] 1 Machine, 2 NICs, 2 Instances of ntpd; Possible?
David Woolley [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Maarten Wiltink wrote: separating NTP client and server parts [...] The server part would assume or require that the clock is being disciplined by a client implementation. It needs to share rather more than the clock. Things like: stratum root distance root dispersion system peer local reference time leap bits etc. Yes. Those are all client-part statistics that could easily be made available to a server-part for dishing out to anyone interested in evaluating the status and quality indicators of your server. As part of _requiring_ that the clock be disciplined by an NTP client part. You're not going to trust that; you're going to check it. Of course there is overhead in having the server part query for the client part's statistics, and transferring them. That's not the point. Nor do I have any illusions about any of this ever happening. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] drift value very large and very unstable
David Woolley [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Danny Mayer wrote: We supply neither an ntp.conf file nor a startup file so this comment makes no sense. This kind of thing belongs in the Support wiki which is constantly updated. You need to supply both. Otherwise the packagers will do it for you and they will get it wrong. ISTM there are two things that would go into a default ntp.conf to be supplied by the current NTP developer effort: servers, and a drift file. For the drift file, I suspect the Filesystem Standard (whatever it's called these days) defines some place where it might usefully be put. For the servers, we have the Pool. We still _want_ that to be used, right? Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Time reset
Venu Gopal [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] So its true that when CPU load is high, kernel might be loosing ticks. When I repeated the same in other clients the drift was in the order of few milliseconds. I suppose it has something to do with the amount of CPU load and disk I/O when crond performs its tasks. More often disk I/O then CPU load. And then often because DMA is disabled. Could you check that? Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Issues with w32tm on AD network
Martin Burnicki [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] I guess a Windows domain would work without a local DNS since the names of the Windows machines could also be resolved by the WINS service ... DNS _is_ used as a database for some domain information. You can, with some work, use a non-local DNS but that's probably as far as it goes. NTP information would not go into DNS, though, and that's as close as this subject will ever come to saying anything NTP-related. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] ntpdate.c unsafe buffer write
David L. Mills [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Is there also a random backoff after an increase of the polling interval? No. However, there is a small dither of a few percent at all poll intervals to resist self-synchronization. The natural behavior of a bunch of oscillators near the same frequency is to become one giant phase-locked oscillator. Adding a bit of random fuzz at each poll turns each oscillator into a mini random-walk which breaks up that tendency. The fuzz is not a lot, like 10 percent. Do you mean the dither alluded to above is cumulative? I was never much good with statistics and remember only that the expectation of the offset after N steps in a random walk is sqrt(N) times the average step size. Not a clue what the distribution might be. Intuitively, I would be aiming for uniform, and randomly adding half a polling interval delay when doubling it seemed to me like it would do that. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] ntpdate.c unsafe buffer write
David L. Mills [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] No, there is no random delay at startup. Each association starts one second after the previous one. The random backoff occurs only after a step. Is there also a random backoff after an increase of the polling interval? No. However, there is a small dither of a few percent at all poll intervals to resist self-synchronization. Wouldn't that be a nice feature to add? If it's currently polling a server on, say second 100 (reckoned externally) of 256, to go to either 100 _or 356_ of 512. I understand that there are already some random waits in the client code and Internet servers are well protected by random noise. But for large numbers of clients in a uniform environment that were all started at about the same time, is there any way they tend to naturally disperse across the final 1024s polling interval? Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] ntpd not responding on localhost
Richard B. Gilbert [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] Nick Bright wrote: ntpq pe remote refid st t when poll reach delay offset = 217.160.254.116 0.0.0.0 16 u- 12800.0000.000 75.144.70.350.0.0.0 16 u- 12800.0000.000 72.232.254.202 0.0.0.0 16 u- 12800.0000.000 208.75.88.4 0.0.0.0 16 u- 12800.0000.000 [...] Assuming that you waited at least 30 minutes before printing that ntpq banner, the servers you have configured are unreachable. Poll interval is at 128. It's been trying for some time, and already backing off. [...] AFAIK there is no good reason to block port 123. Your paranoia is slipping. The default state is closed, then if somebody comes asking you open a port... maybe. My firewall has a port 123 hole for the secondary server _only_ (which doesn't even use it, incidentally). The other hosts can get time from the firewall and its slave. I'm certainly not letting through NTP traffic for them. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
Re: [ntp:questions] Configuration files missing after make all
[EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] [...] my prefix is /home/joah/ntp, so the conf-files should be at /home/joah/ntp/etc. Definitely not. NTP is a system-wide service. Even wider, in fact; it should not be run inside virtual machines. Groetjes, Maarten Wiltink ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
