Further examples of NTP

This example demonstrates the use of ntpq and ntpdc to list the servers that chicago.mynet.com is currently polling. The server marked with an asterisk (*) is the one that chicago is currently synchronizing with. chicago is also listening for broadcast packets on the subnet with IP address 10.0.246, but no packets are currently being broadcast there. Note the difference in the units used by ntpq and ntpdc to display delay, offset, and dispersion. The former uses milliseconds, whereas the latter uses seconds.

chicago# ntpq
ntpq> peer

     remote           refid        st  when poll reach delay offset   disp
==========================================================================
 10.0.246.255     0.0.0.0       16 never   64    0    0.0   0.00  64000
*acapulco.mynet.com  clepsydra.dec  2    53   64  376   81.1  -1.00   12.4
+moscow.mynet.com    norad.arc.nas  2    11   64   37   41.2  30.00 7504.3

chicago# ntpd
ntpd> peer

     remote           local           st poll reach  delay   offset   disp
===========================================================================
*acapulco.mynet.com  10.0.246.16    2   64  376  0.0811 -0.001003 0.0124
-moscow.mynet.com    10.0.246.7     2   64   37  0.0412  0.030001 7.5043
^10.0.246.255     0.0.0.0          16   64    0  0.0000  0.000000 64.000

This information tells us, among other things, that:

• chicago is currently synchronizing with acapulco.

• acapulco is at stratum 2, implying that chicago is at stratum 3.

• chicago is polling acapulco once every 64 seconds.

• The reachability register for acapulco is octal 376.

• The clock on chicago is 1 millisecond, or more precisely, 1003 microseconds, behind the clock on acapulco.

• The roundtrip delay to acapulco is 81 milliseconds.

• The dispersion is 12.4 milliseconds.