Slashdot Mirror

← Back to Stories (view on slashdot.org)

NTP Pool Project Reaches 500 Servers

Posted by CowboyNeal on from the about-time dept.

flok writes "Finally after 3 years the NTP Pool project has reached 500 servers! The NTP pool project tries to be an accurate and free time-source to every internet-connected device. Everybody who's system has running an NTP daemon which can give an accurate time-indication can join the project. Not only is it handy to have accurate time on your workstation to be able to see when you need to leave the house to catch the train in time, it is also usefull to be able to accurately correlate events between your system and others in case one gets hacked."

6 of 165 comments (clear)

  1. PCs keep lousy time. by Anonymous Coward · · Score: 2, Interesting

    What is it with PCs? I've owned several over the last 15 years, and without exception
    the clocks simply could not keep accurate time. I've bought 5 buck watches at wal-mart that
    kept better time than my PCs. In some cases, they lose (or gain) several (somtimes tens of)
    seconds per day.

    Is it those Dallas chips that can't keep time? or is it the clock frequency division that
    most PCs use?

    1. Re:PCs keep lousy time. by Almost-Retired · · Score: 4, Interesting

      Thats only as good as the operators on duty when looked at on a shorter term than a daily basis. So I have to tell a story here that illustrates the problem, in this case one that having an NTP setup (which didn't exist except in older protocols in 1978) wouldn't have fixed unless it was applied directly to the generator controls on the power grid.

      Anyway, about 2pm my board operator at the tv station I was the CE at came running into my office and said the tape machine was going crazy, he though it was running fast and the on air picture wasn't viewable even after being time base corrected.
      He'd put that tape in 3 of them without making it work.

      As I walked through the control room I was just barely aware that the air conditioning and all the fans in the transmitter seemed to be working real well. I looked at the tape machine, whose main drive motor was a synchronous type whose speed is locked to the powerline frequency, and it did indeed appear to be running fast by a rather large margin. Looking at a motorized wall clock, I noted it was about 18 minutes faster than my trusty timex. So I timed the wall clock second hand against the timex and came up with a powerline frequency of around 71 hz. Voltage was also up a bit, to about 130 at the wall socket, so my transmitter was running very well indeed.

      Calling the local electrickery people, I got a number for the WAPA control center up in Utah someplace and called them up. Argueing with the sexytary for a couple of minutes I finally got through to an operator on duty, introduced myself as the CE at a tv station down in New Mexico and then asked him if his clocks were fast. He first didn't get it, then checked his watch against the wall clock and muttered OMG. He said I'll get that fixed asap and I hung up since there wasn't a watts line account there & Ma Bell was very proud of her daytime business rates...

      About 2 minutes later you could hear the fans and stuff gradually slowing down, and it finally settled at about 59hz until time had caught up with the wall clocks again.

      I think some folks either got some overtime or got to go home a few minutes early that day, so there were what one could have called collateral damages, if even only to the economy west of the mississippi. The whole west side of the country is all synched up, presumably so is whats east of the river. Anyway, it was such an odd occurance that I still have to grin when I recall it nearly 30 years later. One of those things that couldn't ever happen, but did. :-)

      --
      Cheers, gene

  2. Why we removed our servers from the pool... by jafo · · Score: 5, Interesting

    We've run public NTP servers for the better part of a decade now, mostly for the convenience of geographically local folks like the various LUGs. When I found out about the pool, I had our servers added there. Everything was fine for a few months, then over a month we started getting phone calls from firewall admins about how our time servers were attacking their networks. Every time a machine in their network would ask our servers for the time, our servers responded with 10 packets spaced at 1 second intervals, so these improperly configured firewalls were logging a lot of packets from us.

    I finally shut it down after one particular call, the third that week, where the caller was rude and abusive when I suggested that he should be doing more investigation about the traffic before calling someone else to complain about it. Being a public service, it's just not something that scales well to have to field these calls. I hated to do it, but it was just too much of a distraction.

    I'm not saying that you shouldn't add your servers to the pool... I just thought it was an amusing story.

    Sean

    1. Re:Why we removed our servers from the pool... by wayne · · Score: 2, Interesting
      Every time a machine in their network would ask our servers for the time, our servers responded with 10 packets spaced at 1 second intervals

      Uh, your servers are supposed to only reply with *ONE* packet.

      That said, I have also had a few people complain to me about my machine attacking them because they have configured their machine to use the NTP pool. Over the last 2 years, it has totalled around 3, so you must have had really bad luck.

      Overall, I have been very happy with my involvement with the NTP pool. It has been working very well and I like being to help others out. I have also created a bunch of NTP monitoring scripts to help NTP pool members make sure things are running smoothly. These scripts confirm that being in the pool really doesn't generate that much traffic, so even people with cable modems/DSL (with static IP addresses) can easily participate.

      --
      SPF support for most open source mail servers can be found at libspf2.
  3. Auto-configure ntp via dhcp by jrp2 · · Score: 2, Interesting

    "It would also be nice if ISPs would set up their own pools (and advertise them) so clients wouldn't have to go off network"

    Agreed. Most do, but as you mention, don't advertise them. I am not sure how many people would actually know what to do with them if they were advertised though.

    It would be quite slick if they advertised them via DHCP, and clients used that info to auto-configure their ntp client. All quite possible and very easy to do by the ISP. NTP servers can be advertised via dhcp.

    http://gentoo-wiki.com/HOWTO_NTP

    http://www.greyware.com/software/domaintime/techni cal/architecture/dhcp.asp

    --
    The only athletic sport I ever mastered was backgammon - Douglas William Jerrold
  4. Re:Confused by Almost-Retired · · Score: 2, Interesting

    Well now, if you stop and think of it, that would be the worst case scenario one could imagine, cause some dip would leave his web browser sitting on the page watching the clock update itself every second. Do that 10 times and you've used a quite measurable portion of the servers bandwidth.

    You would be amazed at the number of folks who figure its allright to do that, I mean its there, why not use it attitude? So no, no admin in his right mind would set that up. Or if he did, he should be dismissed as not being worthy of the job title of a sysadmin.

    I swear, the average intelligence of a slashdot post is dropping below the average intelligence at large these days.

    So prove me wrong and lets see if there is such a thing in this thread.

    However, I'd like to see the instructions for making a server out of one box and keeping the rest of the local system synched to it made more widely available. You have to dig to find them, and I think they are a bit dated but I could reduce the 'client' count by 2 here at home by doing it.

    --
    Cheers, Gene