Hello Brandon, Which version of ntp is deployed on your system? Any relevant/suspect output in syslog when restarting ntpd? What does ntpq report?
First guess: please remember http://bugs.ntp.org/show_bug.cgi?id=3367 - this was staged (only) for ntp-4.2.8p11. Make sure that either your ntp has the patch already or patch your sources manually. br Joachim On 10/09/2018 01:26 AM, Brandon Applegate wrote: > Hello, > > For years I’ve have ntpd+NMEA+PPS working great. My OS was Ubuntu server > 12.04 - and then (currently) 14.04. GPS is a Garmin LVC 18x. > > I use setserial to set low_latency, I’ve reduced the NMEA sentence to bare > minimum, etc. All the usual tweaks. All of this going into a real UART > serial PCI slot board (no USB) on a full size PC. > > My relevant ntp.conf for this: > > server 127.127.20.0 mode 1 minpoll 4 maxpoll 4 > fudge 127.127.20.0 flag1 1 flag2 0 flag3 1 time2 0.600 > > I decided to try to upgrade, and hit nothing but roadblocks. So far I’ve > tried both Debian 9 and Ubuntu 18.04. What I observe is that my GPS offset > steadily climbs and climbs. It never seems to decrease. I’ve also tried the > above config with flag3 set to 0 (“soft” PPS). In all of these cases I’ve > verified with ppswatch that I have pps coming in on the port. It really > seems like something has changed in the kernel in the past few years that’s > causing this. It’s about the only thing I can think of as a variable. I’ve > tried distro ntpd packages as well as compiling a few versions of the latest > source. All with the same behavior. > > Anyone have any ideas what could cause this behavior ? > > -- > Brandon Applegate - CCIE 10273 > PGP Key fingerprint: > 0641 D285 A36F 533A 73E5 2541 4920 533C C616 703A > "For thousands of years men dreamed of pacts with demons. > Only now are such things possible." > > _______________________________________________ > questions mailing list > questions@lists.ntp.org > http://lists.ntp.org/listinfo/questions > _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions