[ntp:questions] Re: NTP Stats within norm?
Scott L. Glidden
scottg at industrial-logic.com
Tue May 30 13:15:58 UTC 2006
> Err. . . . What sort of a "fudge factor" are you talking about?
To offset the delay from using Bluetooth vs. RS232
>
> If you have a GPS receiver, you will probably get better time from it than
> you can get over the internet. If you have a receiver designed for
> timing service, there should be no question about it. But even a receiver
> designed for navigation might still deliver better time than the internet.
I will post my current stats at the bottom of this page..
> Your GPS receiver will make your server Stratum 1. Other stratum 1
> servers may wish to peer with you; this is something you should discuss
> with the owners thereof. Your chances of finding someone to peer with are
> better if: you have a reliable environment; e.g. you don't reboot
> randomly, you don't succumb to power failures unless they are of extended
> duration, your network connection is 24x7 and maybe you have redundant
> network connections. A static IP address is pretty much a requirement.
> I'd say that a GPS receiver designed for timing service is probably also a
> requirement.
The whole server farm is on a APC Smart UPS 2200 va and 1400 va (Server
2003, Solaris 10, FreeBSD, Linux 2.6) Static IP
>
> People who operate stratum 1 servers may be hobbyists such as I, but it's
> more likely that they have compelling business requirements for accurate
> and reliable time.
Yes, to keep my server logs sane. To help tie events together to determine
cause/effect, etc...
Here is a screen cap of my current stats. NTPD has not settled as I just did
a restart to tweak my fudge factor, so I imagine jitter should improve over
time..
[root at ns2 scripts]# ./ntpstat
remote refid st t when poll reach delay offset
jitter
==============================================================================
*GPS_NMEA(0) .GPS. 0 l 35 64 377 0.000 3.501
2.729
+time-a.nist.gov .ACTS. 1 u 225 256 377 48.358 0.560
7.257
+time-b.nist.gov .ACTS. 1 u 221 256 377 50.417 -0.309
7.289
+ntp1.twc.weathe .CDMA. 1 u 222 256 377 33.810 2.548
1.752
+ntp2.twc.weathe .CDMA. 1 u 227 256 377 34.419 4.382
3.312
+ns1.usg.edu 130.207.244.240 2 u 220 256 377 25.399 1.904
3.178
+ns2.usg.edu .GPS. 1 u 220 256 377 31.233 1.589
2.328
+ns3.usg.edu 65.212.71.102 2 u 226 256 377 26.641 1.430
3.278
-ns4.usg.edu 130.207.244.240 2 u 222 256 377 32.992 3.330
3.656
-caesar.cs.wisc. 129.7.1.66 2 u 223 256 377 47.108 -3.876
2.212
+ntp2.usno.navy. .USNO. 1 u 219 256 377 55.524 1.911
3.212
+ntp1.usno.navy. .USNO. 1 u 227 256 377 55.743 1.295
2.919
assID=0 status=0474 leap_none, sync_uhf_clock, 7 events,
event_peer/strat_chg,
version="ntpd 4.2.1p252-RC at 1.1514 Tue May 16 11:30:27 UTC 2006 (1)",
processor="i686", system="Linux/2.6.11-6mdksmp", leap=00, stratum=1,
precision=-19, rootdelay=0.000, rootdispersion=9.081, peer=3640,
refid=GPS, reftime=c826c3aa.fe11bedb Tue, May 30 2006 9:14:18.992,
poll=9, clock=c826c3ce.07aca035 Tue, May 30 2006 9:14:54.029, state=4,
offset=2.441, frequency=-39.483, jitter=3.202, noise=2.517,
stability=0.436
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