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
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.