Re: [ntp:questions] NTP on local networks
Thanks, I should have provided a number of additional details. The lab is an interior lab on the ground floor of a 3 story building with no windows. The work is not classified but security rules do make things difficult. GPS doesn't seem like an easy solution. The computers log data from an experiment(s). If the time stamps in the log files for one computer are off by 20-30ms from the time stamps in the log files of another computer then the results of the experiment could be impacted. However if all computers were off by the same offset from official time of a few seconds, it wouldn't matter. Off by more than a few seconds wouldn't make the data unusable but might cause some confusion when we go to find the right log files. The rubidium units I see on E-bay look like they were designed to go in a CD player. Would I need additional hardware to connect it to a computer and software to read it as a clock source? On 08/01/2012 01:24 AM, Chris Albertson wrote: On Tue, Jul 31, 2012 at 7:46 PM, Kennedy, Paulp.kenn...@fugro.com.auwrote: Exactly so. you can purchase a GPS receiver for well under $100 connect it to a serial port + pps on any of the pc's and have microsecond accuracy in a few hours. This 'master' can then serve time to all other PC's. The systems will then behave for years of unattended use. It is a far more cost effective solution. The OP said he can go into another room and connect to the Internet can sync a computer. It seems to me that there might be some rule that prevents wires going into the room he works in, else why not simply run an Ethernet cable. Many places do have such rules. He might work in a place where they process classified information. In that case they might not allow an antenna cable or any kind of wire to penetrate the room boundaries. If I have guessed correctly then what he needs is an atomic clock. Buy a few of those $40 Rubidium units that are on eBay regards pk -- Chris Albertson Redondo Beach, California ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on local networks
I tried setting ophan mode. on 192.168.0.5 I put tos orphan 6 at the end of the ntp.conf file on 192.168.0.4 I ran ntpdate to set the clock I got this [shackle@galactica-304 ~]$ sudo ntpdate -d 192.168.0.5 1 Aug 10:31:02 ntpdate[18776]: ntpdate 4.2.6p3-RC10@1.2239-o Thu Nov 25 16:18:33 UTC 2010 (1) Looking for host 192.168.0.5 and service ntp host found : 192.168.0.5 transmit(192.168.0.5) receive(192.168.0.5) transmit(192.168.0.5) receive(192.168.0.5) transmit(192.168.0.5) receive(192.168.0.5) transmit(192.168.0.5) receive(192.168.0.5) 192.168.0.5: Server dropped: Server has gone too long without sync server 192.168.0.5, port 123 stratum 6, precision -23, leap 00, trust 000 refid [192.168.0.5], delay 0.02597, dispersion 0.2 transmitted 4, in filter 4 reference time:. Thu, Feb 7 2036 1:28:16.000 originate timestamp: d3c3bca8.ef07b5bb Wed, Aug 1 2012 10:33:12.933 transmit timestamp: d3c3bc2c.7c88ab05 Wed, Aug 1 2012 10:31:08.486 filter delay: 0.02597 0.02600 0.02597 0.02605 0.0 0.0 0.0 0.0 filter offset: 124.4469 124.4469 124.4469 124.4469 0.00 0.00 0.00 0.00 delay 0.02597, dispersion 0.2 offset 124.446969 1 Aug 10:31:08 ntpdate[18776]: no server suitable for synchronization found [shackle@galactica-304 ~]$ It prints the right time and stratum but still stubbornly won't set the time. If I add server 192.168.0.5 to the ntp.conf on 192.168.0.4 and restart the ntp server on 192.168.0.4 there are no errors logged but I also see no improvement in the offset between the two systems after waiting a few minutes. -- Will On 07/31/2012 12:06 PM, unruh wrote: One option is to install a gps receiver onto one or more of your machines to deliver accurate time to them. The second option is to look into orphan mode, which was designed for your situation. Your problem is probably that you are using more than one of th emachines as the server and they have gotten out of sync with each otehr so that the other machines cannot figure out which is the more accurate time. You give no indication of what you have set up so it is pretty hard to figure out what is going wrong. On 2012-07-30, Will Shacklefordshac...@nist.gov wrote: We have several computers with several different operating systems on a local network with no radios and no internet connection. The main goal is to keep them synchronized with each other. One frustration I have had is that clients tend to refuse to connect to servers on the network that are not good enough. I assume not good enough means too high a stratum although the stratum does not really matter (unless it is 15 or so) but disagreement amongst the servers does matter. error messages are not that clear. Perhaps if you told us what they were, they would be clearer to some of us than to you. My current solution is to take a laptop to another room with an internet connection, let it sit for an hour and then bring it back to connect the local network where finally the other computers will accept it and synchronize with it. Questions: How can I configure a client/peer to always accept a server as good enough or atleast always accept the server when no other server can be contacted? (please answer for any platform below you can) Fedora 6: Fedora 10: Fedora 14: Ubuntu 11.04: Windows XP: How can I configure a server to always consider itself good enough and report that (lie if necessary) so that any badly configured client will still connect?(please answer for any platform below you can) Fedora 6: Fedora 10: Fedora 14: Ubuntu 11.04: Windows XP: Just for my own curiosity, why is just refusing to do what the operator wants the default behavior for clients/peers? Why not always synchronize as well as you can with whichever peers/hosts you can contact? ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on local networks
Richard B. Gilbert rgilber...@comcast.net wrote: There is a fairly simple and not terribly expensive solution. It's a GPS timing receiver! They were available for about $100 the last time I looked. Can you put an antenna smaller than a hocky-puck where it will have a view of the sky? He already explained that it is not a requirement and not a possibility, and still you post this boilerplate reply... ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on local networks
On 7/30/2012 11:47 AM, Will Shackleford wrote: We have several computers with several different operating systems on a local network with no radios and no internet connection. The main goal is to keep them synchronized with each other. One frustration I have had is that clients tend to refuse to connect to servers on the network that are not good enough. I assume not good enough means too high a stratum although the error messages are not that clear. How is a system designated not good enough? How about giving us the full and exact text of whatever message you are getting. Cut and paste would be best but a carefully made copy should serve. My current solution is to take a laptop to another room with an internet connection, let it sit for an hour and then bring it back to connect the local network where finally the other computers will accept it and synchronize with it. Questions: How can I configure a client/peer to always accept a server as good enough or at least always accept the server when no other server can be contacted? (please answer for any platform below you can) You can't without doing violence! There is a fairly simple and not terribly expensive solution. It's a GPS timing receiver! They were available for about $100 the last time I looked. Can you put an antenna smaller than a hocky-puck where it will have a view of the sky? If you can,whip out your check book! There are other time broadcasts that should be within a few milliseconds. WWV broadcasts time on several freqencies 5MHz, 10MHz and several others. Canada and most other countries also have a time broadcast . ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on local networks
Will Shackleford wrote: Thanks, I should have provided a number of additional details. The lab is an interior lab on the ground floor of a 3 story building with no windows. The work is not classified but security rules do make things difficult. GPS doesn't seem like an easy solution. The computers log data from an experiment(s). If the time stamps in the log files for one computer are off by 20-30ms from the time stamps in the log files of another computer then the results of the experiment could be impacted. However if all computers were off by the same offset from official time of a few seconds, it wouldn't matter. Off by more than a few seconds wouldn't make the data unusable but might cause some confusion when we go to find the right log files. The rubidium units I see on E-bay look like they were designed to go in a CD player. Would I need additional hardware to connect it to a computer and software to read it as a clock source? I have an LPRO-101 that I've not yet powered up. It's about size of a CDROM drive but I will be fitting mine with a large heatsink to avoid temperature gradients. Peak power usage is above 24V@2A but that drops to maybe 0.5A when unit has reached operating temperature. With a lower current supply the unit will take longer to warm up or may not even reach operating temperature. Next problem is that the 10 MHz output needs dividing to give 1 PPS and that needs synchronising against an accurate 1 PPS signal, eg from GPS. For level of accuracy you need, you could synchronise vs ntp but I've no idea how to get a 1 PPS from ntp. A radioclock would probably be ok, eg in UK I receive MSF which can be within around +/- 1ms. DCF from Germany can also be received but is subject to propogation effects and fading. The DCF signal is phase modulated at the second so if near to the transmitter you have usec accuracy. David ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on local networks
On 7/31/2012 12:06 PM, unruh wrote: One option is to install a gps receiver onto one or more of your machines to deliver accurate time to them. The second option is to look into orphan mode, which was designed for your situation. Your problem is probably that you are using more than one of th emachines as the server and they have gotten out of sync with each otehr so that the other machines cannot figure out which is the more accurate time. You give no indication of what you have set up so it is pretty hard to figure out what is going wrong. On 2012-07-30, Will Shackleford shac...@nist.gov wrote: We have several computers with several different operating systems on a local network with no radios and no internet connection. The main goal is to keep them synchronized with each other. One frustration I have had is that clients tend to refuse to connect to servers on the network that are not good enough. I assume not good enough means too high a stratum although the stratum does not really matter (unless it is 15 or so) but disagreement amongst the servers does matter. error messages are not that clear. Perhaps if you told us what they were, they would be clearer to some of us than to you. My current solution is to take a laptop to another room with an internet connection, let it sit for an hour and then bring it back to connect the local network where finally the other computers will accept it and synchronize with it. Questions: How can I configure a client/peer to always accept a server as good enough or atleast always accept the server when no other server can be contacted? (please answer for any platform below you can) Fedora 6: Fedora 10: Fedora 14: Ubuntu 11.04: Windows XP: How can I configure a server to always consider itself good enough and report that (lie if necessary) so that any badly configured client will still connect?(please answer for any platform below you can) Fedora 6: Fedora 10: Fedora 14: Ubuntu 11.04: Windows XP: Just for my own curiosity, why is just refusing to do what the operator wants the default behavior for clients/peers? Why not always synchronize as well as you can with whichever peers/hosts you can contact? NTP needs a stable and accurate source of time. Such sources are provided by most national governments. In the U.S. the the National Bureau of Standards keeps the official clock for the U.S. The official time is supplied in Canada by an agency called Communications Branch, National Research Council. Just about every country has it's own standard clock and they go to great lengths to ensure that all these clocks are accurate and stable. How do you calibrate your atomic clock? That's easy. You load your clock into a truck with a battery pack and take your truck or your airplane and go to the National Bureau of Standards. The staff bring a coaxial cable to your vehicle, connect it to your clock(s) input and zap If you are really fanatical, you correct for the length of the cable, . . . . Most of us don't go quite that far. I, for instance, have a GPS timing receiver which keeps my computers marching to the same beat. It's overkill but I enjoyed doing it. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on local networks
Given all the mention of NBS, someone should point out the the OP appears to actually be working at the National Bureau of Standards, which has been called NIST for... decades now. So the below-mentioned clock-containing truck might not have to drive far. :) --Jeff On 8/2/2012 8:13 AM, Richard B. Gilbert wrote: On 7/31/2012 12:06 PM, unruh wrote: One option is to install a gps receiver onto one or more of your machines to deliver accurate time to them. The second option is to look into orphan mode, which was designed for your situation. Your problem is probably that you are using more than one of th emachines as the server and they have gotten out of sync with each otehr so that the other machines cannot figure out which is the more accurate time. You give no indication of what you have set up so it is pretty hard to figure out what is going wrong. On 2012-07-30, Will Shackleford shac...@nist.gov wrote: We have several computers with several different operating systems on a local network with no radios and no internet connection. The main goal is to keep them synchronized with each other. One frustration I have had is that clients tend to refuse to connect to servers on the network that are not good enough. I assume not good enough means too high a stratum although the stratum does not really matter (unless it is 15 or so) but disagreement amongst the servers does matter. error messages are not that clear. Perhaps if you told us what they were, they would be clearer to some of us than to you. My current solution is to take a laptop to another room with an internet connection, let it sit for an hour and then bring it back to connect the local network where finally the other computers will accept it and synchronize with it. Questions: How can I configure a client/peer to always accept a server as good enough or atleast always accept the server when no other server can be contacted? (please answer for any platform below you can) Fedora 6: Fedora 10: Fedora 14: Ubuntu 11.04: Windows XP: How can I configure a server to always consider itself good enough and report that (lie if necessary) so that any badly configured client will still connect?(please answer for any platform below you can) Fedora 6: Fedora 10: Fedora 14: Ubuntu 11.04: Windows XP: Just for my own curiosity, why is just refusing to do what the operator wants the default behavior for clients/peers? Why not always synchronize as well as you can with whichever peers/hosts you can contact? NTP needs a stable and accurate source of time. Such sources are provided by most national governments. In the U.S. the the National Bureau of Standards keeps the official clock for the U.S. The official time is supplied in Canada by an agency called Communications Branch, National Research Council. Just about every country has it's own standard clock and they go to great lengths to ensure that all these clocks are accurate and stable. How do you calibrate your atomic clock? That's easy. You load your clock into a truck with a battery pack and take your truck or your airplane and go to the National Bureau of Standards. The staff bring a coaxial cable to your vehicle, connect it to your clock(s) input and zap If you are really fanatical, you correct for the length of the cable, . . . . Most of us don't go quite that far. I, for instance, have a GPS timing receiver which keeps my computers marching to the same beat. It's overkill but I enjoyed doing it. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on local networks
On Wed, Aug 1, 2012 at 6:40 AM, Will Shackleford shac...@nist.gov wrote: The rubidium units I see on E-bay look like they were designed to go in a CD player. Would I need additional hardware to connect it to a computer and software to read it as a clock source? There are other Rb units on eBay. This one would be ideal. It has a 1 pulse per second output Item number: 300599635767 I have one of these. It also has a pps out but that feature is undocumented. This is the one many people paid $40 for. Seems demand as had an effect on the price Item number: 280905645392 There are many more like this. You only need the PPS to keep the system clock running at the correct rate. These Rb units have an typeical error at the 1E-11 level. Good enough for your use. On 08/01/2012 01:24 AM, Chris Albertson wrote: On Tue, Jul 31, 2012 at 7:46 PM, Kennedy, Paulp.kenn...@fugro.com.au** wrote: Exactly so. you can purchase a GPS receiver for well under $100 connect it to a serial port + pps on any of the pc's and have microsecond accuracy in a few hours. This 'master' can then serve time to all other PC's. The systems will then behave for years of unattended use. It is a far more cost effective solution. The OP said he can go into another room and connect to the Internet can sync a computer. It seems to me that there might be some rule that prevents wires going into the room he works in, else why not simply run an Ethernet cable. Many places do have such rules. He might work in a place where they process classified information. In that case they might not allow an antenna cable or any kind of wire to penetrate the room boundaries. If I have guessed correctly then what he needs is an atomic clock. Buy a few of those $40 Rubidium units that are on eBay regards pk -- Chris Albertson Redondo Beach, California __**_ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/**questionshttp://lists.ntp.org/listinfo/questions __**_ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/**questionshttp://lists.ntp.org/listinfo/questions -- Chris Albertson Redondo Beach, California ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on local networks
David Taylor wrote: I have information on my Web site on the easy-to-use Sure GPS, as well as the low-cost Garmin GPS 18x LVC. http://www.satsignal.eu/ntp/Sure-GPS.htm http://www.satsignal.eu/ntp/FreeBSD-GPS-PPS.htm Mine are using simple puck antennas, indoors, on the top floor of a two-storey building. Be aware that USB-connected devices will give far less accuracy than serial-port connected ones, but may be adequate if half-a second is all you need. This summer I received two more SURE boards, it took about an hour total to solder on the two required patch wires on each of them. (I used David's pictures to remind me where to put the patch wires!) Together with a pair of old laptops (with proper serial ports) this gives me another set of Stratum1 servers, for a total outlay of less than $100. I've seen reports here that one of the timing nuts have measured the SURE board as giving a PPS signal that's in the 25-50 ns range? According to the loopstats files my laptop is mostly in the 3-500 ns range, with excursions up to a us or two, obviously due to interrupt response time jitter and temperature variations. Terje -- - Terje.Mathisen at tmsw.no almost all programming can be viewed as an exercise in caching ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on local networks
On 01/08/2012 10:15, Terje Mathisen wrote: [] This summer I received two more SURE boards, it took about an hour total to solder on the two required patch wires on each of them. (I used David's pictures to remind me where to put the patch wires!) Together with a pair of old laptops (with proper serial ports) this gives me another set of Stratum1 servers, for a total outlay of less than $100. I've seen reports here that one of the timing nuts have measured the SURE board as giving a PPS signal that's in the 25-50 ns range? According to the loopstats files my laptop is mostly in the 3-500 ns range, with excursions up to a us or two, obviously due to interrupt response time jitter and temperature variations. Terje Tom Van Baak's page reports RMS error of 22 nanoseconds. http://www.leapsecond.com/pages/MG1613S/ and is well worth reading in any case! -- Cheers, David Web: http://www.satsignal.eu ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on local networks
On 2012-08-01, Chris Albertson albertson.ch...@gmail.com wrote: On Tue, Jul 31, 2012 at 7:46 PM, Kennedy, Paul p.kenn...@fugro.com.auwrote: Exactly so. you can purchase a GPS receiver for well under $100 connect it to a serial port + pps on any of the pc's and have microsecond accuracy in a few hours. This 'master' can then serve time to all other PC's. The systems will then behave for years of unattended use. It is a far more cost effective solution. The OP said he can go into another room and connect to the Internet can sync a computer. It seems to me that there might be some rule that prevents wires going into the room he works in, else why not simply run an Ethernet cable. Many places do have such rules. He might work in a place where they process classified information. In that case they might not allow an antenna cable or any kind of wire to penetrate the room boundaries. If I have guessed correctly then what he needs is an atomic clock. Buy a few of those $40 Rubidium units that are on eBay Atomic clocks need to be synchronized to UTC, and they do eventually drift as well. regards pk -- Chris Albertson Redondo Beach, California ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on local networks
On 2012-08-01, Terje Mathisen terje.mathisen at tmsw.no wrote: David Taylor wrote: I have information on my Web site on the easy-to-use Sure GPS, as well as the low-cost Garmin GPS 18x LVC. http://www.satsignal.eu/ntp/Sure-GPS.htm http://www.satsignal.eu/ntp/FreeBSD-GPS-PPS.htm Mine are using simple puck antennas, indoors, on the top floor of a two-storey building. Be aware that USB-connected devices will give far less accuracy than serial-port connected ones, but may be adequate if half-a second is all you need. This summer I received two more SURE boards, it took about an hour total to solder on the two required patch wires on each of them. I have found that simply soldering a wire from the PPS output jumper hole on the board to the DCD pin on the serial port works, at least with my serial ports on my computer. While it give more accurate timing pulses, it is really irrelevant, since the interrupt service time is in the usec to many usec range. This means that the soldering is much easier. In David's you have to sloder to the tiny legs of surface mount chips, which has its dangers if you are not very good or steady with the soldering iron. (I used David's pictures to remind me where to put the patch wires!) Together with a pair of old laptops (with proper serial ports) this gives me another set of Stratum1 servers, for a total outlay of less than $100. I've seen reports here that one of the timing nuts have measured the SURE board as giving a PPS signal that's in the 25-50 ns range? The problem I have had with the sure boards is the antenna they send. Of two Sure boards I got, one of the antennas was defective ( very intermittent, and got worse over time). While I notified Sure and they said they would seend me a new antenna, they never did. According to the loopstats files my laptop is mostly in the 3-500 ns range, with excursions up to a us or two, obviously due to interrupt response time jitter and temperature variations. Look at the refclock file instead at the input time variations. I get in the 1-10usec range because if interrupt timing problems. Terje ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on local networks
Hi Will, good questions. Before I offer an answer: 1. can you please provide samples of the ntp.conf files you have in place. It would really assist. 2. can you please provide the version of ntpd you are using? regards pk Questions: How can I configure a client/peer to always accept a server as good enough or atleast always accept the server when no other server can be contacted? (please answer for any platform below you can) Fedora 6: Fedora 10: Fedora 14: Ubuntu 11.04: Windows XP: How can I configure a server to always consider itself good enough and report that (lie if necessary) so that any badly configured client will still connect?(please answer for any platform below you can) Fedora 6: Fedora 10: Fedora 14: Ubuntu 11.04: Windows XP: Just for my own curiosity, why is just refusing to do what the operator wants the default behavior for clients/peers? Why not always synchronize as well as you can with whichever peers/hosts you can contact? ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on local networks
One option is to install a gps receiver onto one or more of your machines to deliver accurate time to them. The second option is to look into orphan mode, which was designed for your situation. Your problem is probably that you are using more than one of th emachines as the server and they have gotten out of sync with each otehr so that the other machines cannot figure out which is the more accurate time. You give no indication of what you have set up so it is pretty hard to figure out what is going wrong. On 2012-07-30, Will Shackleford shac...@nist.gov wrote: We have several computers with several different operating systems on a local network with no radios and no internet connection. The main goal is to keep them synchronized with each other. One frustration I have had is that clients tend to refuse to connect to servers on the network that are not good enough. I assume not good enough means too high a stratum although the stratum does not really matter (unless it is 15 or so) but disagreement amongst the servers does matter. error messages are not that clear. Perhaps if you told us what they were, they would be clearer to some of us than to you. My current solution is to take a laptop to another room with an internet connection, let it sit for an hour and then bring it back to connect the local network where finally the other computers will accept it and synchronize with it. Questions: How can I configure a client/peer to always accept a server as good enough or atleast always accept the server when no other server can be contacted? (please answer for any platform below you can) Fedora 6: Fedora 10: Fedora 14: Ubuntu 11.04: Windows XP: How can I configure a server to always consider itself good enough and report that (lie if necessary) so that any badly configured client will still connect?(please answer for any platform below you can) Fedora 6: Fedora 10: Fedora 14: Ubuntu 11.04: Windows XP: Just for my own curiosity, why is just refusing to do what the operator wants the default behavior for clients/peers? Why not always synchronize as well as you can with whichever peers/hosts you can contact? ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on local networks
Will Shackleford wrote: We have several computers with several different operating systems on a local network with no radios and no internet connection. The main goal is to keep them synchronized with each other. You should be able to do a time island with ntp orpahn mode: e.g. I use something similar to this on all PCs / Devices # ALL (Clients and/or Servers) tos cohort 1 orphan 11 restrict default limited kod nomodify notrap restrict 127.0.0.1 restrict source nomodify keys /etc/ntp.keys # e.g. contains: 123 M YOUR_MD5_KEY trustedkey 123 manycastserver 224.0.1.1 manycastclient 224.0.1.1 key 123 preempt multicastclient 224.0.1.1 key 123 preempt broadcastclient One frustration I have had is that clients tend to refuse to connect to servers on the network that are not good enough. I assume not good enough means too high a stratum although the error messages are not that clear. You should be able to tell with: ntpq -n -c lpe -c las -c rv 0 -c rv 1 -c rv 2 -c rv 3 -c rv 4 and the decodes in your html files that come with ntp, http://www.eecis.udel.edu/~mills/ntp/html/decode.html My current solution is to take a laptop to another room with an internet connection, let it sit for an hour and then bring it back to connect the local network where finally the other computers will accept it and synchronize with it. That is likely the ever increasing dispersion. How can I configure a client/peer to always accept a server as good enough or atleast always accept the server when no other server can be contacted? Add prefer for your primary server? server primary.time-island.nist.gov iburst prefer You might also want to increase mindist, however too much will likely end up in several groups walking away from each other; e.g. tos mindist 0.020 Just for my own curiosity, why is just refusing to do what the operator wants the default behavior for clients/peers? Why not always synchronize as well as you can with whichever peers/hosts you can contact? operator wants and ntp commanded to are not equal? -- E-Mail Sent to this address blackl...@anitech-systems.com will be added to the BlackLists. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on local networks
BlackLists wrote: Will Shackleford wrote: We have several computers with several different operating systems on a local network with no radios and no internet connection. The main goal is to keep them synchronized with each other. You should be able to do a time island with ntp orpahn mode: Sorry, I should have included references, it is covered in the html files that come with ntp: http://www.eecis.udel.edu/~mills/ntp/html/orphan.html http://www.eecis.udel.edu/~mills/ntp/html/miscopt.html#tos http://support.ntp.org/bin/view/Support/OrphanMode -- E-Mail Sent to this address blackl...@anitech-systems.com will be added to the BlackLists. ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on local networks
Unruh had the correct advice: Buy a (cheap) GPS device for a master clock and propagate the correct time. If something is worth doing, it is worth doing right. Become a force, develop a reputation, for progress, one of the foundations of Western Civilization. The new BU-353, not the old one you can find for about $30, but the one that costs about $42, at USGlobalSat.com will do the job within a half second or better, and it is trivial to set up. All you need is a free USB port and a window, or preferably a thin roof, that faces the satellites. The Sure (search for Sure Electronics) GPS demo board is supposed to give much more accurate time, but it is a pain to set up. There are beaucoup people on this list that know a lot more about GPS clocks than I and most are willing to help, if you just ask. Meinberg at www.meinberg.de sells lots of very accurate clocks, and there are several other places like it. Search for GPS clocks or NTP clocks. Charles Elliott -Original Message- From: questions-bounces+elliott.ch=verizon@lists.ntp.org [mailto:questions-bounces+elliott.ch=verizon@lists.ntp.org] On Behalf Of Will Shackleford Sent: Monday, July 30, 2012 11:47 AM To: questions@lists.ntp.org Subject: [ntp:questions] NTP on local networks We have several computers with several different operating systems on a local network with no radios and no internet connection. The main goal is to keep them synchronized with each other. One frustration I have had is that clients tend to refuse to connect to servers on the network that are not good enough. I assume not good enough means too high a stratum although the error messages are not that clear. My current solution is to take a laptop to another room with an internet connection, let it sit for an hour and then bring it back to connect the local network where finally the other computers will accept it and synchronize with it. Questions: How can I configure a client/peer to always accept a server as good enough or atleast always accept the server when no other server can be contacted? (please answer for any platform below you can) Fedora 6: Fedora 10: Fedora 14: Ubuntu 11.04: Windows XP: How can I configure a server to always consider itself good enough and report that (lie if necessary) so that any badly configured client will still connect?(please answer for any platform below you can) Fedora 6: Fedora 10: Fedora 14: Ubuntu 11.04: Windows XP: Just for my own curiosity, why is just refusing to do what the operator wants the default behavior for clients/peers? Why not always synchronize as well as you can with whichever peers/hosts you can contact? ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on local networks
Exactly so. you can purchase a GPS receiver for well under $100 connect it to a serial port + pps on any of the pc's and have microsecond accuracy in a few hours. This 'master' can then serve time to all other PC's. The systems will then behave for years of unattended use. It is a far more cost effective solution. regards pk -Original Message- From: questions-bounces+p.kennedy=fugro.com...@lists.ntp.org [mailto:questions-bounces+p.kennedy=fugro.com...@lists.ntp.org] On Behalf Of Charles Elliott Sent: Wednesday, 1 August 2012 8:26 AM To: 'Will Shackleford'; questions@lists.ntp.org Subject: Re: [ntp:questions] NTP on local networks Unruh had the correct advice: Buy a (cheap) GPS device for a master clock and propagate the correct time. If something is worth doing, it is worth doing right. Become a force, develop a reputation, for progress, one of the foundations of Western Civilization. The new BU-353, not the old one you can find for about $30, but the one that costs about $42, at USGlobalSat.com will do the job within a half second or better, and it is trivial to set up. All you need is a free USB port and a window, or preferably a thin roof, that faces the satellites. The Sure (search for Sure Electronics) GPS demo board is supposed to give much more accurate time, but it is a pain to set up. There are beaucoup people on this list that know a lot more about GPS clocks than I and most are willing to help, if you just ask. Meinberg at www.meinberg.de sells lots of very accurate clocks, and there are several other places like it. Search for GPS clocks or NTP clocks. Charles Elliott -Original Message- From: questions-bounces+elliott.ch=verizon@lists.ntp.org [mailto:questions-bounces+elliott.ch=verizon@lists.ntp.org] On Behalf Of Will Shackleford Sent: Monday, July 30, 2012 11:47 AM To: questions@lists.ntp.org Subject: [ntp:questions] NTP on local networks We have several computers with several different operating systems on a local network with no radios and no internet connection. The main goal is to keep them synchronized with each other. One frustration I have had is that clients tend to refuse to connect to servers on the network that are not good enough. I assume not good enough means too high a stratum although the error messages are not that clear. My current solution is to take a laptop to another room with an internet connection, let it sit for an hour and then bring it back to connect the local network where finally the other computers will accept it and synchronize with it. Questions: How can I configure a client/peer to always accept a server as good enough or atleast always accept the server when no other server can be contacted? (please answer for any platform below you can) Fedora 6: Fedora 10: Fedora 14: Ubuntu 11.04: Windows XP: How can I configure a server to always consider itself good enough and report that (lie if necessary) so that any badly configured client will still connect?(please answer for any platform below you can) Fedora 6: Fedora 10: Fedora 14: Ubuntu 11.04: Windows XP: Just for my own curiosity, why is just refusing to do what the operator wants the default behavior for clients/peers? Why not always synchronize as well as you can with whichever peers/hosts you can contact? ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
Re: [ntp:questions] NTP on local networks
-Original Message- From: questions-bounces+p.kennedy=fugro.com...@lists.ntp.org [mailto:questions-bounces+p.kennedy=fugro.com...@lists.ntp.org] On Behalf Of Charles Elliott Sent: Wednesday, 1 August 2012 8:26 AM To: 'Will Shackleford'; questions@lists.ntp.org Subject: Re: NTP on local networks Unruh had the correct advice: Buy a (cheap) GPS device for a master clock and propagate the correct time. If something is worth doing, it is worth doing right. Become a force, develop a reputation, for progress, one of the foundations of Western Civilization. The new BU-353, not the old one you can find for about $30, but the one that costs about $42, at USGlobalSat.com will do the job within a half second or better, and it is trivial to set up. All you need is a free USB port and a window, or preferably a thin roof, that faces the satellites. The Sure (search for Sure Electronics) GPS demo board is supposed to give much more accurate time, but it is a pain to set up. There are beaucoup people on this list that know a lot more about GPS clocks than I and most are willing to help, if you just ask. Meinberg at www.meinberg.de sells lots of very accurate clocks, and there are several other places like it. Search for GPS clocks or NTP clocks. Charles Elliott This post never made it to the newsgroup, so perhaps the gateway is stuck or very slow? I have information on my Web site on the easy-to-use Sure GPS, as well as the low-cost Garmin GPS 18x LVC. http://www.satsignal.eu/ntp/Sure-GPS.htm http://www.satsignal.eu/ntp/FreeBSD-GPS-PPS.htm Mine are using simple puck antennas, indoors, on the top floor of a two-storey building. Be aware that USB-connected devices will give far less accuracy than serial-port connected ones, but may be adequate if half-a second is all you need. -- Cheers, David Web: http://www.satsignal.eu ___ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
