If the host has the NTP service enable but don’t send any data to the query, the server is configured correctly.

ntpq -pncrv 192.168.123.12

timed out, nothing received
***Request timed out 

But … if you send a query and get information back… the server is vulnerable to attacks.

Obtain kernel information and other NTP server parameters.

ntpq -pncrv IP

 

Example:

 ntpq -pncrv 192.168.123.89

     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
*200.156.12.14      .GPS.            1 u  219 1024  377    5.934    0.028   0.006
+178.20.4.68      .GPS.            1 u  215 1024  377   13.166    0.042   0.030
associd=0 status=06f4 leap_none, sync_ntp, 15 events, freq_mode,
version="ntpd [email protected] Wed May  8 21:55:29 UTC 2013 (1)",
processor="x86_64", system="Linux/3.0.101-0.47.71-default", leap=00,
stratum=2, precision=-20, rootdelay=5.934, rootdispersion=18.169,
peer=49695, refid=200.156.12.14,
reftime=e02063ef.71ec06c0  Tue, Feb 26 2019 19:18:39.445, poll=10,
clock=e02064ca.e2fc87a1  Tue, Feb 26 2019 19:22:18.886, state=4,
offset=0.042, frequency=6.834, jitter=0.011, noise=0.029,

 

2 Which servers are synchronizing

 ntpq -n -c peer 192.168.123.89

     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
*200.156.12.14      .GPS.            1 u  241 1024  377    5.934    0.028   0.006
+178.20.4.68        .GPS.            1 u  237 1024  377   13.166    0.042   0.030