Symmetricom Time Server Manual Do Utilizador

Appendix A: NTP Version 3, NTPQ, and NTPDC

Note: A number of  NTP-related programs, such as NTPDC and  NTPQ, are not 
supported, in the conventional sense, by Dr. Mills’ NTP, and therefore cannot be 
supported by Symmetricom, Inc. (TrueTime, Inc. is now Symmetricom, Inc.)  The user of 
these programs does so at his or her own risk.

NTPQ and NTPDC are query programs used to obtain TimeVault’s offset, relative to any 
server for which the unit is configured (page 3-36 or page 4-69 show where this list is 
located in the "ntp.conf" file), as well as information about any of the unit’s 
synchronization sources, such as ACTS.  A separate SNMP alarm (trapMsg7, see ) 
notifies you when the TimeVault offset is greater than 1 second relative to the first NTP 
server in the ntp.conf file list, and the server is not otherwise in an alarm condition.

NTPQ is a query program that uses the standard protocol defined in RFC-1305 to 
diagnose and repair problems that affect the operation of NTP.  NTPQ uses NTP mode 6 
(control mode) packets to query NTP servers (and any compatible servers on the network 
that permit it) about current state, as well as to request changes in that state.  NTPQ can 
also obtain and print a list of peers in a common format by sending multiple queries to the 
server.

NTPDC is a special query program that uses NTP mode 7 (private mode) packets  to 
provide extensive state and statistics information and can be used to set configuration 
options at run time. 

The NTP daemon sends information about the current calculated offset between its time 
and the time of each of its NTP peers.  The NTPDC command formats the information on 
the standard output.

NTPQ and NTPDC are fully documented at the following Internet sites: 

• NTPQ: http://www.eecis.udel.edu/~ntp/ntp_spool/html/ntpq.htm

and

• http://www.doc.ic.ac.uk/~mac/manuals/hpux-manual-pages/hpux/usr/local/man/man8/ntpq.8.html