Monitoring NTP status
When NTP is installed, you can monitor the synchronization status by running
ntptime.
A healthy system may report:
ntp_gettime() returns code 0 (OK)
time de24c0cf.8d5da274 Tue, Feb 6 2018 16:03:27.552, (.552210980),
maximum error 224455 us, estimated error 383 us, TAI offset 0
ntp_adjtime() returns code 0 (OK)
modes 0x0 (),
offset 1279.543 us, frequency 2.500 ppm, interval 1 s,
maximum error 224455 us, estimated error 383 us,
status 0x2001 (PLL,NANO),
time constant 10, precision 0.001 us, tolerance 500 ppm,In particular, note the following most important parts of output:
-
maximum error 22455 us: This value is well under the 10-second maximum error required by Kudu. -
status 0x2001 (PLL,NANO): This indicates a healthy synchronization status.
In contrast, a system without NTP properly configured and running will output something like the following:
ntp_gettime() returns code 5 (ERROR)
time de24c240.0c006000 Tue, Feb 6 2018 16:09:36.046, (.046881),
maximum error 16000000 us, estimated error 16000000 us, TAI offset 0
ntp_adjtime() returns code 5 (ERROR)
modes 0x0 (),
offset 0.000 us, frequency 2.500 ppm, interval 1 s,
maximum error 16000000 us, estimated error 16000000 us,
status 0x40 (UNSYNC),
time constant 10, precision 1.000 us, tolerance 500 ppm,
Note the UNSYNC status and the 16-second maximum error.
If more detailed information is needed, the ntpq or
ntpdc tools can be used to dump further information about which
network time servers are currently acting as sources:
$ ntpq -nc lpeers
remote refid st t when poll reach delay offset jitter
------------------------------------------------------------------------------
-108.59.2.24 130.133.1.10 2 u 13 64 1 71.743 0.373 0.016
+192.96.202.120 129.6.15.28 2 u 12 64 1 72.583 -0.426 0.028
-69.10.161.7 204.26.59.157 3 u 11 64 1 15.741 2.641 0.021
-173.255.206.154 45.56.123.24 3 u 10 64 1 43.502 0.199 0.029
-69.195.159.158 128.138.140.44 2 u 9 64 1 53.885 -0.016 0.013
*216.218.254.202 .CDMA. 1 u 6 64 1 1.475 -0.400 0.012
+129.250.35.250 249.224.99.213 2 u 7 64 1 1.342 -0.640 0.018
45.76.244.193 216.239.35.4 2 u 6 64 1 17.380 -0.754 0.051
69.89.207.199 212.215.1.157 2 u 5 64 1 57.796 -3.411 0.059
171.66.97.126 .GPSs. 1 u 4 64 1 1.024 -0.374 0.018
66.228.42.59 211.172.242.174 3 u 3 64 1 72.409 0.895 0.964
91.189.89.198 17.253.34.125 2 u 2 64 1 135.195 -0.329 0.171
162.210.111.4 216.218.254.202 2 u 1 64 1 28.570 0.693 0.306
199.102.46.80 .GPS. 1 u 2 64 1 55.652 -0.039 0.019
91.189.89.199 17.253.34.125 2 u 1 64 1 135.265 -0.413 0.037
$ ntpq -nc opeers
remote local st t when poll reach delay offset disp
------------------------------------------------------------------------------
-108.59.2.24 10.17.100.238 2 u 17 64 1 71.743 0.373 187.573
+192.96.202.120 10.17.100.238 2 u 16 64 1 72.583 -0.426 187.594
-69.10.161.7 10.17.100.238 3 u 15 64 1 15.741 2.641 187.569
-173.255.206.154 10.17.100.238 3 u 14 64 1 43.502 0.199 187.580
-69.195.159.158 10.17.100.238 2 u 13 64 1 53.885 -0.016 187.561
*216.218.254.202 10.17.100.238 1 u 10 64 1 1.475 -0.400 187.543
+129.250.35.250 10.17.100.238 2 u 11 64 1 1.342 -0.640 187.588
45.76.244.193 10.17.100.238 2 u 10 64 1 17.380 -0.754 187.596
69.89.207.199 10.17.100.238 2 u 9 64 1 57.796 -3.411 187.541
171.66.97.126 10.17.100.238 1 u 8 64 1 1.024 -0.374 187.578
66.228.42.59 10.17.100.238 3 u 7 64 1 72.409 0.895 187.589
91.189.89.198 10.17.100.238 2 u 6 64 1 135.195 -0.329 187.584
162.210.111.4 10.17.100.238 2 u 5 64 1 28.570 0.693 187.606
199.102.46.80 10.17.100.238 1 u 4 64 1 55.652 -0.039 187.587
91.189.89.199 10.17.100.238 2 u 3 64 1 135.265 -0.413 187.621
