Use the ntpq -p command on the aster system to check on the status of NTP on the various data systems. It is also a good general check of the health of the network:
ntpq -p
remote refid st t when poll reach delay offset jitter
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+profile.isff.uc GPS_NMEA(0) 3 u 271 512 377 2.572 -0.413 2.746
+downwind1.isff. GPS_NMEA(0) 3 u 209 512 377 2.544 -0.496 0.983
-downwind2.isff. GPS_NMEA(0) 3 u 283 512 377 2.571 -0.373 0.033
*upwind.isff.uca GPS_NMEA(0) 3 u 175 512 377 2.548 -0.446 0.726
+pressure1.isff. GPS_NMEA(0) 3 u 445 512 377 2.529 -0.503 0.126
+pressure2.isff. GPS_NMEA(0) 3 u 219 512 377 2.603 -0.413 0.659
-gatexfer-4.ucar 143.25.232.51 3 u 247 512 377 748.012 -4.281 108.822
LOCAL(0) .LOCL. 10 l 15 64 377 0.000 0.000 0.001
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The offset column shows the millisecond difference between the aster system clock and the clocks on the various data systems. The above shows good agreement between all systems.
A value of 377 in the reach column indicates that the last 8 attempts to reach the system were successful (octal 377 is 11111111 binary). If this is other than 377, then either the network or the remote system is sick.
gatexfer-4.ucar is a NTP system at UCAR. Since it is reached via the satellite link, it will have a large and varying delay, and is just a crude reference.