It's interesting you mention NTT. My ISP uses NTT for transatlantic connectivity too (not VM). Also UK based.
I have two time servers in the ntp pool. One is in a datacenter in France. It syncs to several S1/S2 servers and to my rPi based S1 via GPS/PPS, which is the other server. The two servers are: France: http://www.pool.ntp.org/scores/149.202.2.105 (+/- 3ms). UK Stratum 1: http://www.pool.ntp.org/scores/82.70.138.66 (+10/-70ms) The UK one has NEVER had a good response from the monitor, in fact it's only recently it's become this good, usually having anywhere between +100/-1000ms on the graph). You might think maybe it's my home connection, or the local LAN or the raspberry pi or my GPS setup.. Well, I thought that too. So, I setup my server in France (which has a solid +/-3ms almost all the time on the monitoring station) to monitor my home ntp. The results are here: +---------------------+---------------------+-----------+-----------+-----------+-----------+-----------+-----------+ | minDate | maxDate | minOffset | maxOffset | avgOffset | minJitter | maxJitter | avjJitter | +---------------------+---------------------+-----------+-----------+-----------+-----------+-----------+-----------+ | 2017-01-20 10:40:30 | 2017-02-21 01:40:01 | -99.906 | 4.186 | 0.0892094 | 0.044 | 99.916 | 1.0873850 | +---------------------+---------------------+-----------+-----------+-----------+-----------+-----------+-----------+ This min offset/max jitter are probably a one off. What this shows is that the average ntp offset is 80microseconds. With an average jitter of 1ms. So, from that I would say that both the ntp servers are keeping good time. So, it's clearly something between this network and the monitor station. What I see on traceroutes is my home connection goes via NTT whereas the datacenter goes via a different route. At any rate, last week it was really terrible for me too. But since Saturday it's improved to the +10/-70ms I have now. On 20 February 2017 at 21:54, Ron Hahn <[email protected]> wrote: > Dan, > > I am seeing approx. 170ms times to ntplax7.ntppool.net (monitoring server) > on a traceroute. > > At hop 7 it enters ntt.net (NTT America) in NYC where almost 100ms is > added > to the transit time. London time is 24ms, NYC time is 120ms so it appears > there is high latency on the transatlantic link. > > My transit time to a Raleigh datacenter server is 128ms over the same > transatlantic circuit. > > So it seems Virgin Media upstream provider NTT America is the possible > cause of these problems. I will open a ticket in the morning about this > > Thank you, > > Ron > > > > On Mon, Feb 20, 2017 at 9:23 PM, Dan Geist <[email protected]> wrote: > > > The latency tracing to your IP from my ISP is pretty dramatic. I'm at 17 > > ms from Atlanta, GA to Ashburn near D.C. From that point, there's a jump > to > > around 143 ms. > > > > I'd suspect an upstream network issue that started around the same time > as > > your stats went down the tubes. The last 4 hops between that point and > the > > server are only a couple of ms. > > > > Dan > > > > ----- Original Message ----- > > > From: "Ron Hahn" <[email protected]> > > > To: "pool" <[email protected]> > > > Sent: Monday, February 20, 2017 2:03:00 PM > > > Subject: [Pool] Why is my server score suddenly so poor? > > > > > Colleagues, > > > > > > Looking for some help here as I have spent a lot of time looking at > this > > > without any improvements. :-( > > > > > > Since early Friday, 17th the pool monitoring server was reporting that > my > > > pool server: > > > > > > http://www.pool.ntp.org/scores/89.101.218.6 > > > > > > in increasingly negative scores - anywhere between -20 and -60 range. > > All > > > over up and down. :-( > > > > > > So thinking that something has gone horrible wrong on my side I check: > > > > > > - fibre interface (and reboot) > > > - switch (also reboot, no changes in some months) > > > - firewall config (logs and rules) > > > - LeoNTP appliance (reboot and also firmware upgrade as well) > > > - swap of stratum 1 source > > > - WAN utilisation (20-30%) > > > > > > I am finding nothing to explain why such low scores all of a sudden. > > > > > > I compared the LeoNTP box to my other stratum 1 sources and they are > > within > > > <1ms of each other - so I think time is good and not false ticking. > > > > > > I also wrote a script on my Raleigh (US) server to run ntpdate against > > this > > > every 5 minutes overnight. Only 4 timeouts in the entire night and > some > > > time this morning. > > > > > > Can anyone offer suggestions as to what to check next as this causing > me > > a > > > big head ache now. > > > > > > Thank you for the help, > > > > > > Ron > > > _______________________________________________ > > > pool mailing list > > > [email protected] > > > http://lists.ntp.org/listinfo/pool > > > > -- > > Dan Geist dan(@)polter.net > > > > > _______________________________________________ > pool mailing list > [email protected] > http://lists.ntp.org/listinfo/pool > _______________________________________________ pool mailing list [email protected] http://lists.ntp.org/listinfo/pool
