The ntpq utility is the tool to monitor the NTP daemon status. After configure NTP server you can use this tool to see the synchronization server status, and determine performance:
~ $ ntpq -pn remote refid st t when poll reach delay offset jitter ============================================================================== *220.127.116.11 18.104.22.168 2 u 127 128 377 8.786 -0.448 0.094 -22.214.171.124 126.96.36.199 2 u 70 128 377 36.129 -1.790 0.079 -188.8.131.52 184.108.40.206 2 u 52 128 377 40.330 3.975 0.055 +220.127.116.11 18.104.22.168 2 u 57 128 377 21.482 -0.364 0.093 127.127.1.0 .LOCL. 10 l 37m 64 0 0.000 0.000 0.000
* : custom time server source
# : source selected, distance exceeds maximum value
o : the PPS (Pulse Per Second) source if you have a PPS capable system and refclock
+ : candidate, it is considered a good source
– : discarded, quality is not good
x : false ticker, this one is considered to distribute bad time
blank : source discarded, failed sanity or high stratum
The identification of the time source to which the remote machine is synced. May be a radio clock or another ntp server.
Stratum of the remote machine, 16 is “unsynchronized”, 0 is the best value. A stratum 0 could be a radio clock or the ntp servers private caesium clock.
l = local (such as a GPS, WWVB)
u = unicast (most common)
m = multicast
b = broadcast
– = netaddr
Seconds since the last poll of the remote machine.
The polling interval in seconds.
Connections to reach source, 377 means all connections got success.
The time delay (in milliseconds) to communicate with the remote source.
The offset (in milliseconds) between our time and that of the remote source.
The observed difference (in milliseconds) of time with the remote source.