<html><head></head><body><div class="yahoo-style-wrap" style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:16px;"><div dir="ltr" data-setdir="false">I have a precision time and frequency device that provides, among other things, a serial port outputting NMEA data and pps with a specified accuracy of +/- 1 ns.</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">This has been working just fine for many years.</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">After an upgrade to Ubuntu 24.04.1 I found legacy ntp had been replaced by ntpsec-1.2.2 and the reference clock no longer works. The output of ntpq -pn is:</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false"><div>xNMEA(0) .PPS. 0 l - 16 377 0.0000 -96.9056 0.5170<br>+192.168.0.100 .PPS. 1 u 24 1024 377 0.1328 -0.8315 0.7548<br>*192.168.0.101 .PPS. 1 u 332 1024 377 0.1171 -0.8703 0.8439<br>+192.168.0.21 .PPS. 1 u 137 1024 377 0.1565 1.5477 0.7258<br><br></div>The relevant lines from ntp.conf are:</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false"><div>server 127.127.20.0 mode 16 minpoll 4 iburst<br>fudge 127.127.20.0 time1 -0.0007 flag1 1 flag2 0 flag3 1 refid PPS<br><br></div>In going through the documentation I found that it says the 127.127.x.y is replaced by a new symbol notation but is still recognized, so that should not be an issue. I did not find anything else that needs to be changed other than the location of the statistics files which I process to provide graphic status, but I may have missed something.</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">So, can anyone tell me what I need to do here to get it working again with ntpsec?</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">Also, is it a true statement that all I have to do to change to the new naming scheme is to change <span>127.127.20.0 to nmea?</span></div><div dir="ltr" data-setdir="false"><span><br></span></div><div dir="ltr" data-setdir="false"><span><br></span></div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false"><br></div></div></body></html>