Re: [ntp:questions] Client doesn't drop failed source

Rob wrote: It would be very unwise to use TCP for something like NTP. Information sent by an application via a TCP socket will be re-sent by Agreed, but the thread had gone off topic. ___ questions mailing list questions@lists.ntp.org http://lists.

Re: [ntp:questions] Client doesn't drop failed source

E-Mail Sent to this address will be added to the BlackLists wrote: I can perhaps see idling the connection to keep it open when the poll rate is at ~ 1 minute, however what about when the poll rate decreases to ~ 17 minutes? (or less often if so configured) There are no network cost in keep

Re: [ntp:questions] NTP servers redundancy

Brian Utterback wrote: You are incorrect. It is relevant. In practice, no two servers EVER have exactly the same time. And each time NTP decides to switch to the other server, it is also going to adjust the clock frequency to The clock frequency is based on the combined offset, so, unless you

Re: [ntp:questions] Client doesn't drop failed source

David Mills wrote: Not true. The dispersion does increase, but the server is valid until the dispersion exceeds the select threshold, usually in four or five more missed messages. That's why I said the quality measures are invalidated, rather than the server is invalidated. I probably shou

Re: [ntp:questions] Client doesn't drop failed source

Danny Mayer wrote: More importantly, TCP requires a 3-way handshake before it can deliver the packet, so there is setup time, delivery and tear-down time involved as well just to deliver one small packet. One wouldn't set up a TCP connection for each message!

Re: [ntp:questions] NTP servers redundancy

Steve Kostecke wrote: If both servers are within 128ms of each other, the clients will slew toward the time seen from the new time server. If the server are more than 128ms "apart", the clients will step to the time seen from the new time server. If they are more than roughly their root distan

Re: [ntp:questions] Client doesn't drop failed source

David Woolley wrote: Looking at the, slightly out of date, 4.2.4p4, a reachability of 1/8 is still acceptable. Rejection during startup will be based on a high On a further look, it looks like the source's quality measures are invalidated after three consecutive missed re

Re: [ntp:questions] NTP servers redundancy

j...@free.fr wrote: Does the NTP algorithm enable that when a server go down (or is no more synchronized), its clients switch easily to the second one, without any visible synchronization interruption ?? ntpd doesn't normally use a worker-standby model (it may if you use prefer more than onc

Re: [ntp:questions] ntpd and database servers

nodata wrote: *confused* What does a 2.6 tickless kernel do? It sets the hardware timer only to interrupt when the next event has been scheduled to occur, rather than at a constant rate. I believe it also uses heuristics to consolidate timer events, so that multiple events can be handled

Re: [ntp:questions] ntpd and database servers

unruh wrote: man adjtimes -t val, --tick val Set the number of microseconds that should be added to the system time for each kernel tick interrupt. For a kernel with From previous replies, it looks like recent Linux versions and that for the OP's unnamed OS, vi

Re: [ntp:questions] ntpd and database servers

unruh wrote: Note, chrony, another implimentation of ntp, can adjust the clock much Although I tend to agree that for most users chrony may behave better than ntpd, it is a user of the NTP wire formats, but not an implementation of NTP. Obeying the slew rate limit is necessary before you ca

Re: [ntp:questions] ntpd and database servers

nodata wrote: Would you mind explaining the link between CONFIG_HZ and the tick value? The example in the man page is not clear (it uses the same tick value as I have on a CONFIG_HZ=1000 box). Is the statement "Increasing val by 1 speeds up the system clock by about 100 ppm, or 8.64 sec/day."

Re: [ntp:questions] ntpd and database servers

nodata wrote: Which brings me to my problem: once this problem came to our attention, we wanted to fix it, slowing the system clock until time caught up. It wouldn't matter if this took a few weeks. Make sure that you are running Unix or Linux, then disable ntpd on both machines and use t

Re: [ntp:questions] Date Jumped

Maynard wrote: On 1/7/10, the date on our domain controller jumped to 12/7/10, and NTP doesn use day/month/year dates, and nor does Unix. A one digit change in a human readable date implies a human error or a misread of a reference clock that uses human format times. was there for about 1

Re: [ntp:questions] Client doesn't drop failed source

E-Mail Sent to this address will be added to the BlackLists wrote: On 1/11/2010 2:24 PM, David Woolley wrote: BlackLists wrote: I see nothing "wrong" with having several, {I've done it} as long as it is understood that are always included in the combining algorithm and don&

Re: [ntp:questions] Client doesn't drop failed source

Michael Moroney wrote: Can anyone point me to anything similar to "How to explain NTP to Project Managers" esp. explaining how a preferred clock server is included even Unfortunately its primary author fancies himself as a mathematician, so the main documentation is a mathematical treatise. H

Re: [ntp:questions] Client doesn't drop failed source

I see nothing "wrong" with having several, {I've done it} as long as it is understood that are always included in the combining algorithm and don't get discarded. AFAICT At least in 4.2.4p4, they are never included in the combining algorithm. If one ignores some complications due to loc

Re: [ntp:questions] Client doesn't drop failed source

E-Mail Sent to this address will be added to the BlackLists wrote: I see nothing "wrong" with having several, {I've done it} as long as it is understood that are always included in the combining algorithm and don't get discarded. AFAICT Nothing is guaranteed when you go outside the specif

Re: [ntp:questions] NTP server can not synchronize with external NTP server

nast linux wrote: I got the problem, my NTP server can not synchronize with external NTP server. Firewall. In particular these days, OS' firewall. As you are using a pool server, the other possibility, of trying to use a V3 server with a V4 client, without setting the client downversion, s

Re: [ntp:questions] Client doesn't drop failed source

Michael Moroney wrote: that synchronizes with the four clocks, and ntpq> peers shows one of the primaries with a "*" in the first column meaning it was synchronized to as time source, the other 3 show "+" as expected, meaning they are usable sources. We disconnect the antenna of the selected cl

Re: [ntp:questions] Client doesn't drop failed source

Michael Moroney wrote: David Woolley writes: If it remains the best choice it could take up to 8192 seconds before all the samples are flushed from the FIFO and it becomes completely ineligible. There is logic to discourage early switching, as clock hopping is, itself, considered a bad

Re: [ntp:questions] Client doesn't drop failed source

David Woolley wrote: OK. This is why this configuration is NOT simple! My original comments, and my reply to Michael, are based on not using prefer. You Sorry, reply to Richard. ___ questions mailing list questions@lists.ntp.org http

Re: [ntp:questions] Client doesn't drop failed source

E-Mail Sent to this address will be added to the BlackLists wrote: However, if a prefer peer is among the survivors, the combining algorithm is not used. Instead, the offset of the prefer peer is used exclusively as the final synchronization source." OK. This is why this configu

Re: [ntp:questions] Client doesn't drop failed source

Richard B. Gilbert wrote: Michael Moroney wrote: David Woolley writes: Michael Moroney wrote: that synchronizes with the four clocks, and ntpq> peers shows one of the primaries with a "*" in the first column meaning it was synchronized to as time source, the other 3 show &q

Re: [ntp:questions] Client doesn't drop failed source

Michael Moroney wrote: Very simple. driftfile SYS$SPECIFIC:[TCPIP$NTP]TCPIP$NTP.DRIFT server 10.136.3.70 prefer server 10.136.3.71 prefer That's not simple. You are only supposed ot have, at most, one prefer source. server 10.98.63.50 server 10.98.63.150 __

Re: [ntp:questions] Is dispersion > jitter in all situations

B wrote: I want to know the accuracy on a certain NTP-server at stratum 3. It is easy to calulate the absolute error bounds that wont be exceeded with this equation OFFSET +/- [DELTA/2 + DISPERSION]. This will in my case be OFFSET +/- 4 seconds, but I need to know more precise, ie an indicator o

Re: [ntp:questions] ntp-4.2.6 doesn't compile for Windows

Steve Kostecke wrote: You need to load our CA's root certificate in your browser. Please visit http://www.cacert.org/index.php?id=3 to do so. Or rather the person or organisation that owns the PC should do this. They may delegate it back to you, but it involves a security policy decision wh

Re: [ntp:questions] How to debug GPS PPS?

Richard B. Gilbert wrote: Your biggest problem may be that Windows is not exactly the world's greatest time keeper! The clock "ticks" every 17 milliseconds! Did you mean to write 1ms? I'm not sure if the latest actually go down to 500 microseconds. Still poor compared with the sub-microsec

Re: [ntp:questions] Meinberg NTP monitor, silly question

David J Taylor wrote: > > I do wish there were some way of speeding this up - a variable loop > bandwidth or something like that. > It already does have one, and has had one since at least version 3. ___ questions mailing list questions@lists.ntp.or

Re: [ntp:questions] Meinberg NTP monitor, silly question

G8KBV wrote: > A silly question if I may, and yes I've been poking arround the Meinberg > website and forum for hours, and can't find the answer. Likewise the > (non existant) help within the program, though I'm *sure* I've seen text > on this somewhere, but can't find it at the moment. These

Re: [ntp:questions] Help with reference identifier for stratum 2 version 4.

Poster Matt wrote: You also need to take note of the errata , although this question is not covered there. ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/

Re: [ntp:questions] Help with reference identifier for stratum 2 version 4.

Poster Matt wrote: >> >> It's an opaque hash of the identity of the server's upstream server. >> New code is not supposed to put any further meaning on it. > > Thanks David. But... > > Then why does RFC 2030 say the reference identifier "contains the low > order 32 bits of the last transmit ti

Re: [ntp:questions] Help with reference identifier for stratum 2 version 4.

Poster Matt wrote: > Hi, > > I've written a C# class to handle communications with a SNTP server, > mainly as a learning exercise. It is working perfectly except for one > aspect which has confused me. That is the reference identifier as it is > used by secondary servers and using version 4. I

Re: [ntp:questions] Single best NTP status indicator of clock accuracy?

E-Mail Sent to this address will be added to the BlackLists wrote: > > I contend root dispersion is, the diff to UTC. Root dispersion approximates the difference from UTC if ntpd's solution for the clock frequency is out by exactly 15ppm. Generally the frequency solution is much better than t

Re: [ntp:questions] Single best NTP status indicator of clock accuracy?

unruh wrote: > The root dispersion is an estimate of the error in the remote clock's time. > It is not an > estimate of the difference in time between your clock and the true time. Although it contains some terms that relate to errors in remote clocks, its main component is an estimate of the w

Re: [ntp:questions] Single best NTP status indicator of clock accuracy?

unruh wrote: > > Offset. That is ntp's best guess as to the difference between the time > on your clock and the true UTC time. ntp keeps no record of the rate No. It is the difference between the time on your clock and the last measurement from other clocks. It includes the instantaneous mea

Re: [ntp:questions] Single best NTP status indicator of clock accuracy?

kjans wrote: > > I have several remote/embedded Linux devices that I am monitoring > via SNMP and want to monitor a single variable to know how accurate > the device thinks its time is. The device doesn't think much about how accurate it is, only about how repeatable. > > There seems t

Re: [ntp:questions] Win2k3 Server as NTP server?

David J Taylor wrote: > "Why Tea" wrote in message > >> 2) If I were to do a trial run of ntpd on Windows 2003, how do >>I measure its ntpd performance in order to make a >>judgment? > > I use MRTG, Meinberg's monitor, and my own NTP Plotter package. > I think he was really asking ab

Re: [ntp:questions] help with setting up NTP on windows with a USB GPS

David J Taylor wrote: > Stated requirement: > > - around 1 millisecond (on Window 2000 or XP IIRC). > > Observed performance examples: These don't tell you the jitter due to the scheduling of the application program and interrupt latencies from the real world events to the point where the co

Re: [ntp:questions] help with setting up NTP on windows with a USB GPS

John Hasler wrote: > If I tell a client that he should install a used machine and it fails he > will blame me. If I tell him to buy a new one and it fails he will > blame the vendor (or more likely, if I recommend a used machine he will > buy a new one anyway and then never hire me again since he

Re: [ntp:questions] Win2k3 Server as NTP server?

Why Tea wrote: > Can Windows 2003 server be used as an NTP server I presume you mean w32time? Out of the box, it is very non-compliant, however, I think it might be possible to configure it to be a compliant, if rather poor, server. The sensible approach to running on Windows is to the referen

Re: [ntp:questions] Polling time backoff

Rob wrote: > And of course it is always "better" to have a short poll interval, for > any kind of error that you want to correct. You may need to add some > filtering to the samples before feeding the result in the loop, but 16 > samples in 1024 seconds will always be providing better information

Re: [ntp:questions] Win2k3 Server as NTP server?

Richard B. Gilbert wrote: > > Running NTPD on Windows *as* *a* *server* would be most people's LAST > choice unless there is no other! Windows "Vista" may have changed this > but, the last time I looked, Windows' clock "ticks" every 17 > milliseconds. Using this as a server is like "measure

Re: [ntp:questions] Remaining synced on an unsynchronised peer?

Richard B. Gilbert wrote: > unruh wrote: >> do not know, that part of the problem is the level. The >> machines will always have a level one higher than the system they are systems, not system. ntpd gets its time from a mix of that of the times on all the systems listed with a * or + in ntpq

Re: [ntp:questions] Remaining synced on an unsynchronised peer?

unruh wrote: > On 2009-11-30, Michael Butow wrote: >>> Use the cohort option? >> Seems to me I would need to move to manycasting to do that, and I am not >> even sure I want to... I want the peers (in-system) to both/all "give up" >> as soon as they no longer see the world outside the system. >>

Re: [ntp:questions] help with setting up NTP on windows with a USB GPS

jack wrote: > > I tried the serial port on my B&B serial board and the 1PPS signal is > not detected. I don't how how serialpps.sys sees the signal and am > thinking the DCD signal is not sent over the PCI bus. It won't be sent, on any serial interface, but it will be readable. All backplane si

Re: [ntp:questions] test 123

test wrote: > test Test failed, it came out on a discussion group, not a test group. (Tests on discussion groups should contain details of why a test group is not appropriate.) ___ questions mailing list questions@lists.ntp.org https://lists.ntp.org/m

Re: [ntp:questions] help with setting up NTP on windows with a USB GPS

jack wrote: > Using user-mode PPS timestamp > > Does it mean NTP reads the GPS strings and sees the 1PPS signal? It probably means you have configured PPS on Windows, as Windows doesn't have kernel mode support for ntpd. I doubt that it implies that anything is working. > > ___

Re: [ntp:questions] help with setting up NTP on windows with a USB GPS

jack wrote: > > I am trying to setup NTP on Windows XP with a USB GPS at "COM1". I can You are making life difficult. Without PPS, GPS has poor accuracy, and potentially high jitter. USB adds a lot of extra jitter. Windows is not the best platform for time keeping. > > I installed the Mein

Re: [ntp:questions] 500ppm - is it too small?

Unruh wrote: > adjtime does not change the rate at all except to eliminate the input offset. > Ie, > you cannot use it to slow down or speed up the clock in a predictable manner. > You Nonetheless, this is how ntpd worked before the introduction of the kernel time discipline, on operating syst

Re: [ntp:questions] 500ppm - is it too small?

Unruh wrote: > David Woolley writes: > >> Unruh wrote: > >>> The problem is that Mills hardcoded this into the kernel routines for > >> It, and lower values, e.g. 100ppm where hardcoded into kernels before >> nptd was a factor. The interface that ntp

Re: [ntp:questions] 500ppm - is it too small?

Uwe Klein wrote: > A: > An off by 1000ppm xtal is not an easy reason > for exchanging motherboards with your vendor. > B: It pretty much has to be broken, as it is so far outside the production spread that is unlikely to be working reliably. > An off by 1000ppm xtal is differently broken > from

Re: [ntp:questions] Stratum 1 configuration hints

shane-dated-2...@csy.ca wrote: > > I am running a stratum 1 server (Garmin 18 LVC) on Linux and think I have it > humming pretty smoothly at this point. Offset around 8 US and jitter 1-2US. If typical offset is significantly larger than jitter, you have a wander problem or you are making measure

Re: [ntp:questions] 500ppm - is it too small?

Unruh wrote: > > The problem is that Mills hardcoded this into the kernel routines for It, and lower values, e.g. 100ppm where hardcoded into kernels before nptd was a factor. The interface that ntpd uses in user space mode typically had this sort of limit. __

Re: [ntp:questions] 500ppm - is it too small?

Joseph Gwinn wrote: > No, 8 bits isn't arbitrary. > > Computer hardware is simplified if the various word lengths are all > powers of two. Not significantly. Early machines commonly did not use 8 bit multiples, and they would have been much more sensitive to efficient use of hardware. Abo

Re: [ntp:questions] Keeping NTP Honest Redux

Unruh wrote: > David Woolley writes: > >> Unruh wrote: >>> David Woolley writes: >>> > >>>> Looking at the graphs, one needs the first derivative of the rate, as well. >>> Why? If you want the details of how chrony works, I could supply i

Re: [ntp:questions] Keeping NTP Honest Redux

Unruh wrote: > David Woolley writes: > >> Looking at the graphs, one needs the first derivative of the rate, as well. > > Why? If you want the details of how chrony works, I could supply it, but it > uses Because most of the time the first derivative is almost constant,

Re: [ntp:questions] Keeping NTP Honest Redux

Unruh wrote: > Well, you do have that choice, only in different names. chrony uses an > entirely > different algorithm (directly estimating the rate and the offset from a > sequence Looking at the graphs, one needs the first derivative of the rate, as well. > of measurments). Of course you do

Re: [ntp:questions] Keeping NTP Honest Redux

David J Taylor wrote: > http://www.satsignal.eu/mrtg/performance_narvik.php How much of that offset do you attribute to actual clock error? If most of it, that graph makes a strong case for a low maxpoll, or a different algorithm. ___ questions mail

Re: [ntp:questions] NTP absolute accuracy?

David Malone wrote: > The Rugby unit was built by Ian Dowse, and is described here: > > http://www.maths.tcd.ie/~dwmalone/time/rugby.html > This is a simple AM detector for the slow code (I don't know if the fast code is still transmitted). It doesn't phase lock onto the carrier. _

Re: [ntp:questions] Frequently asked question about error bounds?

berra.84 wrote: > And for last, how can root delay be lower than delay for server > xx.xx.xx.x2 ? Because root delay is the input root delay. You have to add the last hop delay to get the output root delay. ___ questions mailing list questions@lists

Re: [ntp:questions] NTP absolute accuracy?

John Hasler wrote: > Should be as good as WWVB, which is good to within 100usec. The Most receivers only use the slow code (including the simple hardware solutions for ntpd). For high accuracy you would have to sync to the carrier, and possibly use the fast time codes. > propagation delay is

Re: [ntp:questions] Frequently asked question about error bounds?

berra.84 wrote: > 1) In the documentation for RFC1305 p. 102 it can be read that the > true offset between > client and server must lie somewhere in the correctness interval, > defined by > I=[theta - delta/2 - epsilon, theta + delta/2 + epsilon] This is (more) correct. I'm not sure if it fully

Re: [ntp:questions] NTP absolute accuracy?

Jan Ceuleers wrote: > This is however only the best case, because it assumes that the > uplink is not saturated. If it is, and if you are able to prioritise your I suspect most severe asymmetry cases actually happen because the downlink is saturated. That's is exacerbated by the fact that it is

Re: [ntp:questions] NTP 4.2.5p239-RC Released

Could I suggest limiting release candidates to one a week. Very few people will have time to deal with them in less than about a week. I'd deduce from the large number of recent "release candidates" that the code is actually some way from being ready to release. ___

Re: [ntp:questions] testing slew only mode (-x), not slewing correctly (linux sles10, ntpd v 4.1.1)

RedGrittyBrick wrote: > Can you provide a URL that refers to the issue you describe with an > undesirable RTC interaction with NTPD on SCO OpenServer? > Only that it actually happens on 3.2v4.2 (I'll have to double check the version, when I get back to the office.) ___

Re: [ntp:questions] Strange NTP problem on AMD Geode LX cards.

David Hawkins wrote: > > (The drift file will always start at zero on these systems as they operate > from read only flash, the /var directory is constructed in /dev/shm at boot) The correct cold start condition for the drift file is to be not present at all. This will cause ntpd to do a frequ

Re: [ntp:questions] testing slew only mode (-x), not slewing correctly (linux sles10, ntpd v 4.1.1)

Brian Utterback wrote: > > The interaction between the OS kernel and the RTC is platform and OS > dependent. You should not assume that the RTC plays no role while the > system is running. Possibly, but the only OSes on which I've seen this interaction are SunOS 4, and SCO Openserver, on both

Re: [ntp:questions] testing slew only mode (-x), not slewing correctly (linux sles10, ntpd v 4.1.1)

E-Mail Sent to this address will be added to the BlackLists wrote: > > If over three weeks, a cheap generic RTC gets out by 10 minutes, > it is broken. Thats an average of 1.6 seconds drift, in the > same direction, every hour? NTP uses the software clock, which is typically less accurate tha

Re: [ntp:questions] testing slew only mode (-x), not slewing correctly (linux sles10, ntpd v 4.1.1)

Richard B. Gilbert wrote: > If it means thirty minutes ago, I would expect the clock to be > within a few milliseconds of the correct time. If not I would > regard the clock as broken! I'm assuming reasonably constant temperature! During the first hour or so after starting, the magnitude of the

Re: [ntp:questions] testing slew only mode (-x), not slewing correctly (linux sles10, ntpd v 4.1.1)

E-Mail Sent to this address will be added to the BlackLists wrote: is fundamentally flawed. > > I guess I could see 10 minutes (or more) if the time had > never been set to anything reasonable; However 10 minutes The default is 128ms and there is a second number, something like 500ms, for th

Re: [ntp:questions] testing slew only mode (-x), not slewing correctly (linux sles10, ntpd v 4.1.1)

Steve Kostecke wrote: > On 2009-10-22, David Woolley wrote: > >> I believe that the official policy line is that database systems that >> require monotonic time for their distributed transaction logic are >> fundamentally flawed. > > It is the database peo

Re: [ntp:questions] testing slew only mode (-x), not slewing correctly (linux sles10, ntpd v 4.1.1)

Rick Jones wrote: > > What does "mostly" mean here? I see discussion all over the place > (perhaps it is now entrenched into folklore?) about how one "never" > wants to have the clock of say a database server "stepped." The only limitations of which I'm aware are: - it will still step if the o

Re: [ntp:questions] testing slew only mode (-x), not slewing correctly (linux sles10, ntpd v 4.1.1)

JohnLund wrote: > I am trying to test the slew only mode of ntpd on an embedded system > that has ntpd v. 4.1.1. We cause a time jump of 1 minute on the This is generally considered a garbage in condition. > configured NTP server for this embedded system and track the ntp log > messages (var/log

Re: [ntp:questions] If the EMI shoe was on the other foot...

John Hasler wrote: > David Woolley writes: >> EMI is at submultiples of the raw FSB side because instruction rates >> and loop rates also introduce strong periodic elements. > > Which spread-spectrum (especially real spread spectrum, less so mere FM) > mitigates. The

Re: [ntp:questions] If the EMI shoe was on the other foot...

Michael Deutschmann wrote: > On Sat, 10 Oct 2009, David Woolley wrote: >> The general view in the amateur radio community is that spread spectrum >> computer clocks are a bad thing, because they spread the misery. > > So we can turn off spread spectrum with no guilt, then.

Re: [ntp:questions] Interface restrictions confusing me

Brian Utterback wrote: > You misunderstand. David's answer has nothing to do with firewalls. The > ntpd daemon binds the addresses so that it can choose the port and > addresses to send on. I gave him the benefit of the doubt and assumed he meant that, if you are really paranoid about the port

Re: [ntp:questions] Strange NTP problem on AMD Geode LX cards.

Unruh wrote: >> Rick Jones wrote: >> For anyone that cared enough about emissions, (and not about price) >> they could always get a EMSEC / TEMPEST, Level A / 1, PC. > > In one case to make it so that it does not destroy other people's enjoyment of > their system, and the other to make sure a de

Re: [ntp:questions] Synching to unkonw Ntp server?

Towli wrote: > By chance i just saw 2 undefined ntp-servers showing up on my 3750 doing > a "show ntp ass". I have defined 3 internal DCF77 servers and 1 > Gps-Ntp_server. > The 2 "scavenger" ntp-servers are not mentioned in the running config - > how on earth can my switches be synching with

Re: [ntp:questions] If the EMI shoe was on the other foot...

Michael Deutschmann wrote: > > Would the experts here then want the government to mandate spread > spectrum be ON, and if so, what sort of modulation to use? The general view in the amateur radio community is that spread spectrum computer clocks are a bad thing, because they spread the misery.

Re: [ntp:questions] Interface restrictions confusing me

Juergen Beisert wrote: > Why is port 123 open on eth0? To allow the replies to come back in from the time servers. ntpd sends UDP packets with both source and destination set to 123, not just when talking to peers. ___ questions mailing list questio

Re: [ntp:questions] 500ppm - is it too small?

nemo_outis wrote: > ... >> Instead I see what looks like a religion, where questions are treated as > apostasy or treason. Sycophancy is common on internet forums. In this particular case, my view is that any clock that is out by more than 500ppm has something fundamentally wrong with it that

Re: [ntp:questions] 500ppm - is it too small?

John Hasler wrote: > David Woolley writes: >> Traditionally, at least, the time of year clock basically used digital >> watch hardware, just lacking the trimmer capacitor, for find >> adjustment. > > Watch hardware uses series-resonant tuning-fork crystals that

Re: [ntp:questions] 500ppm - is it too small?

Richard B. Gilbert wrote: > David J Taylor wrote: >> "Richard B. Gilbert" <> wrote in message >> news:-zkdnagr0u362bnxnz2dnuvz_ogdn...@giganews.com... >> [] >>> Do you disagree with the 500 PPM limit? 500 PPM works out to 43 >>> seconds per day. A clock that gains or loses that much time every

Re: [ntp:questions] NTP stops when client address changes?

David J Taylor wrote: > > Anyway, it seems that your understanding is the same as mine, that even > if a router's wide-area IP address changes, NTP on a PC should keep > working. The address shouldn't, of course, change! There are known problems if the address of the actual PC interface chang

Re: [ntp:questions] Solaris 8 xntpd vs ntpd?

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

Re: [ntp:questions] NTPD Run

nasa138 wrote: > Do I have to have ntp.conf file to tell ntp where the server is? You need an ntp configuration file (some distributors change the name) to either tell ntpd the servers to use, or to tell it the encryption keys so that you can use ntpq to set the servers have it has started. __

Re: [ntp:questions] Solaris 8 xntpd vs ntpd?

Lockon wrote: > Thank you for the detailed explanation! > > To get my feet wet, I may like to start with the built-in version; > however, will the version 3 protocol client communicate with the > current servers out there (presumably they all run protocol version > 4)? > Version 4 servers will r

Re: [ntp:questions] NTP Performance on WINNT

Unruh wrote: > > In other words, there is a random noise component to the "software clock > time" and to the measurement of UTC via the net, or whatever, and that In the estimate of the time on the servers and peers. There will also be an error term from reading the local clock, but it ought t

Re: [ntp:questions] Solaris 8 xntpd vs ntpd?

Lockon wrote: > Hi, I would appreciate if someone could tell me the reason to use the > freeware ntpd rather than xntpd that is built into Solaris 8. I have > searched but I can find no compelling argument. xntpd in Solaris is an older version of the freeware ntpd. I'm not sure about this case,

Re: [ntp:questions] NTP Performance on WINNT

Steve Kostecke wrote: >> I'm just not so sure if I can absolutely count on ntpq to determine >> time offset of NTP synced machines... > > ntpq does not calculate anything. It merely displays information > returned from the ntpd it is querying. > I believe that he means the combination of ntpq an

Re: [ntp:questions] Local (own site) NTP servers.

Richard B. Gilbert wrote: > > ISTR reading that the Intel 80x86 line was CISC on top and RISC > underneath. I couldn't swear to it though. All I ever saw or worked > with was the CISC part of it. I think that pretty much defines CISC. CISC machines are normally micro-program driven machine

Re: [ntp:questions] NTP Performance on WINNT

Unruh wrote: > > You can absolutely count on ntpq to tell you what ntp thinks the offset > is based on its querying of the servers or refclocks. What makes you > "not so sure". I don't think he wants the NTP "offset" metric; I think he wants the difference between software clock time and true U

Re: [ntp:questions] NTP Performance on WINNT

paul wrote: > > Hi David, I am wondering is there any other means to profile NTP > performance, like some kind of hardware setup to measure time offset > of two machine? You need access to the source code of the clock interrupt service routine and the ability to directly right to something like

Re: [ntp:questions] Local (own site) NTP servers.

Uwe Klein wrote: > > David, where do you see RISC mentioned? http://www.sima.com.tw/download/R8610_D06_20051003.pdf linked from http://sites.google.com/site/bifferboard/Home/hardware-specification linked from http://sites.google.com/site/bifferboard/ linked from http://bifferos.bizhat.com/

Re: [ntp:questions] Local (own site) NTP servers.

G8KBV wrote: > > To get Faros (HF Beacon monitoring program, runs on Windows, It looks to me as though that application requires timing to better than about 10ms, and probably won't benefit much more below about 2.5ms. I'm assuming that they are trying to treat the morse code station ident as

Re: [ntp:questions] Local (own site) NTP servers.

Hal Murray wrote: > > Please see: > http://en.wikipedia.org/wiki/NTP_server_misuse_and_abuse Although probably true about this case, a quick skim makes me think that this article breaks the Original Research rules for Wikipedia. I think any one incident would be borderline on the rule, but

Re: [ntp:questions] Local (own site) NTP servers.

G8KBV wrote: > Wonder if this will get posed, or returned to me.. As far as I know, Google groups rejects synchronously. A direct NNTP client certainly would. > > So... I'm about to try a couple of Windows "solutions" > (opportunities) One the "Tardis" program, that would appear Unless you a

Re: [ntp:questions] Testing Sync Across Several Systems

Jan Ceuleers wrote: ce the box1thru50.domain.tld with the DNS names of your 50 boxes. If they're not in DNS, and you know their static IP addresses you can specify those instead. > > The .INIT. means that your monitoring host has not received any NTP packets > from these machines at all yet. Tw

Re: [ntp:questions] Keeping NTP Honest

Richard B. Gilbert wrote: > David Woolley wrote: >> >> Such improvements are unlikely as it turns out that the subject of >> this thread is an area where Dave Mills refuses to acknowledge a problem. > > There is no problem unless you insist on shutting down you

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