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 check of the general 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. I'm hoping that the offset values will stay within a millisecond of each other.
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.
The poll column lists the number of seconds between NTP polls. NTP will adjust this value depending on the stability of the various clocks. "when" is the current counter. When it reaches the value for "poll", a system will be polled, and new values for the clock parameters will be displayed.
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.
LOCAL is the local system clock, which is being synchronized to the remote systems. A host with a "*" in the first column is the current synchronization host. Systems with a "+" are considered good candidates for synchronization. Systems with a "-" are considered less trustworthy.