<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div><br class=""><blockquote type="cite" class=""><div class=""><div class=""><br class="">Easy with the 28 refclock. Not sure on the 20. DO you even see the <br class="">coarse time with ntpq -p?<br class=""></div></div></blockquote><div><br class=""></div><div>I don’t know enough to answer regarding “coarse time”. Here’s my output (FreeBSD-10.3-RELEASE):</div><div><br class=""></div><div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo; color: rgb(203, 203, 203);" class=""><span style="font-variant-ligatures: no-common-ligatures; color: #afad24" class=""><b class="">[</b></span><span style="font-variant-ligatures: no-common-ligatures" class=""><b class="">2.3-RELEASE</b></span><span style="font-variant-ligatures: no-common-ligatures; color: #afad24" class=""><b class="">][</b></span><span style="font-variant-ligatures: no-common-ligatures" class=""><b class="">admin</b></span><span style="font-variant-ligatures: no-common-ligatures; color: #c33720" class=""><b class="">@</b></span><span style="font-variant-ligatures: no-common-ligatures" class=""><b class=""><a href="http://burns.springfield.com" class="">burns.springfield.com</a></b></span><span style="font-variant-ligatures: no-common-ligatures; color: #afad24" class=""><b class="">]</b></span><span style="font-variant-ligatures: no-common-ligatures; color: #000000" class="">/root</span><span style="font-variant-ligatures: no-common-ligatures; color: #c33720" class=""><b class="">:</b></span><span style="font-variant-ligatures: no-common-ligatures; color: #000000" class=""> ntpq -p</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> remote refid st t when poll reach delay offset jitter</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">==============================================================================</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">oGPS_NMEA(0) .GPS. 0 l 6 16 377 0.000 -0.002 0.003</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">*<a href="http://tock.usshc.com" class="">tock.usshc.com</a> .GPS. 1 u 26 64 377 32.138 4.606 0.901</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">+<a href="http://clock.isc.org" class="">clock.isc.org</a> .GPS. 1 u 21 64 377 70.356 -0.027 0.995</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">-<a href="http://tick.apple.com" class="">tick.apple.com</a> .GPS. 1 u 47 64 227 147.752 40.539 163.016</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">-ntp.wdc1.us.lea 199.102.46.72 2 u 47 64 377 49.799 20.090 3.552</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">-leeloo.scurvyne 173.162.192.156 2 u 47 64 377 142.869 16.063 34.157</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">-2001:19f0:8000: 132.163.4.101 2 u 2 64 377 65.329 -7.336 0.499</span></div><div style="margin: 0px; font-size: 11px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">+67.212.117.78 128.138.141.172 2 u 46 64 377 38.889 -4.778 0.341</span></div><div class=""><br class=""></div></div><blockquote type="cite" class=""><div class=""><div class=""><blockquote type="cite" class="">Regarding 28 ref clock, that is SHM? Why that rather than NMEA (20)?<br class=""></blockquote><br class="">gpsd handles a lot more GPS types than #20. So let gpsd handle the GPS.<br class="">gpsd passes the time it determines to ntpd using the SHM (shmctl) <br class="">interface.<br class=""></div></div></blockquote><div><br class=""></div><div>So the type 28 (SHM) is coming from gpsd on the same box? I still like KISS (no need for other GPS type info)...</div><br class=""><blockquote type="cite" class=""><div class=""><div class="">The long term goal is to kill off #20 as no need to maintain 2 NMEA<br class="">parsers.<br class=""></div></div></blockquote><br class=""><div>Understood. I still like KISS...</div><br class=""><blockquote type="cite" class=""><div class=""><div class="">time1 adjusts the PPS derived time, time2 adjusts the NMEA derived time.<br class=""></div></div></blockquote><div><br class=""></div>So for type 20 (NMEA local) & PPS, time2 would be the correct place to put the fudge factor (assuming time1 (PPS) is dead nuts).<br class=""><br class=""><blockquote type="cite" class=""><div class=""><div class=""><blockquote type="cite" class="">What’s a good way to “tune” my NTP config?<br class=""></blockquote><br class="">Compare it to another ntpd server and see which has the least jitter/wander.<br class=""></div></div></blockquote><br class=""><div>Got it.</div><br class=""><blockquote type="cite" class=""><div class=""><div class=""><blockquote type="cite" class="">What’s a good way to monitor my NTP performance?<br class=""></blockquote><br class="">I stare at the results of:<br class=""><br class="">root@pi2:~# watch ntpq -p<br class=""><br class="">Watch how you local refclock(s) compare to some others.<br class=""></div></div></blockquote><div><br class=""></div><div>Got it.</div></div><br class=""></body></html>