John Allen wrote: > This thread has intrigued me because I think I may have a similar > problem. > My Windows XP system ran Terje's NTP 4.2.0a happily from May 2004 > until sometime in the last month - I can't be as precise as David > Taylor. My PC was synchronizing to my server running Linux also with NTP > 4.2.0. Using NTPMonitor occasionally, I was seeing offsets typically > 20-50 > ms from reliable low-stratum servers - more than satisfactory for me > and I paid very little attention to it. The SP2 upgrade went smoothly > some months ago. > Sometime in the last few weeks NTP on the PC has completely lost the > ability to synchronize with the server. I'm seeing offsets increasing > by several seconds an hour - they are consistent across my server and > distant stratum 1-3 servers. The offsets are alway negative which > means (I think) that the PC's time is running faster than the server. > > I've tried all the obvious things - installing later and earlier > versions of ntpd, removing applications running in the > background...none of these seems to affect the behaviour of NTP in > the slightest. I've made some fairly major changes to the PC in the > last 2 months, some of which I'm not keen to reverse - like > installing Visual Studio C++ Express Edition, .NET 2.0 runtime, > Windows SDK, BIOS upgrade, so there are plenty of things which could > have clobbered NTP. > Here is the output from > ntpq -c "rv 0" deeley > assID=0 status=c074 sync_alarm, sync_unspec, 7 events, > event_peer/strat_chg, version="ntpd 2004 May 07 8:37:39 (1)"?, > processor="unknown", system="WINDOWS/NT", leap=11, stratum=16, > precision=-20, rootdelay=0.000, rootdispersion=32.160, peer=0, > refid=STEP, > reftime=00000000.00000000 Thu, Feb 7 2036 7:28:16.000, poll=4, > clock=0xc7449871.72e5796b, state=3, offset=0.000, frequency=0.000, > noise=2299.254, jitter=870.642, stability=0.000 > > (only 45 minutes after restarting the NTP service) > > Some of this looks a bit strange so maybe I'm out of my depth here, > but I'm curious to know if this could be a similar issue to David > Taylor's. > John
John, I'm not an expert in reading those "rv" outputs, but if you are on stratum 16 it means you aren't synchronised. Try the command: ntpq -p deeley. The "reach" column should show 377 for each server - octal for a bit field of 8 ones meaning 8 good connections. My guess is that you may have a TCP/IP problem, like a firewall blocking access from your NTP client to its servers. BTW: I've now written a program to force the MM timer to have a resolution of 1ms permanently, and this seems to have fixed the problem I had. David _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
