NAME

       ntpdc - special NTP query program

SYNOPSIS

       ntpdc [-ilnps] [-c command] [host] [...]

DESCRIPTION

       ntpdc  is used to query the ntpd daemon about its current state and to request changes in that state. The
       program may be run either in interactive mode or controlled using command line arguments. Extensive state
       and statistics information is available  through  the  ntpdc  interface.  In  addition,  nearly  all  the
       configuration  options  which  can  be  specified  at startup using ntpd's configuration file may also be
       specified at run time using ntpdc.

       If one or more request options are included on the command line when  ntpdc  is  executed,  each  of  the
       requests will be sent to the NTP servers running on each of the hosts given as command line arguments, or
       on  localhost  by  default. If no request options are given, ntpdc will attempt to read commands from the
       standard input and execute these on the NTP server running on the first host given on the  command  line,
       again  defaulting  to  localhost  when  no other host is specified. ntpdc will prompt for commands if the
       standard input is a terminal device.

       ntpdc uses NTP mode 7 packets to communicate with the NTP server, and hence can  be  used  to  query  any
       compatible  server  on  the  network  which  permits  it.  Note  that  since  NTP  is a UDP protocol this
       communication will be somewhat unreliable, especially over large distances in terms of network  topology.
       ntpdc makes no attempt to retransmit requests, and will time requests out if the remote host is not heard
       from within a suitable timeout time.

       The  operation  of  ntpdc  are  specific  to  the particular implementation of the ntpd daemon and can be
       expected to work only with this and maybe some previous versions of the daemon. Requests  from  a  remote
       ntpdc  program  which affect the state of the local server must be authenticated, which requires both the
       remote program and local server share a common key and key identifier.

       Note that in contexts where a host name is expected, a -4 qualifier preceding the host  name  forces  DNS
       resolution to the IPv4 namespace, while a -6 qualifier forces DNS resolution to the IPv6 namespace.

OPTIONS

       Specifying  a command line option other than -i or -n will cause the specified query (queries) to be sent
       to the indicated host(s) immediately. Otherwise, ntpdc will attempt to read interactive  format  commands
       from the standard input.

       -4     Force DNS resolution of following host names on the command line to the IPv4 namespace.

       -6     Force DNS resolution of following host names on the command line to the IPv6 namespace.

       -c command
              The following argument is interpreted as an interactive format command and is added to the list of
              commands to be executed on the specified host(s). Multiple -c options may be given.

       -i     Force  ntpdc  to  operate  in interactive mode. Prompts will be written to the standard output and
              commands read from the standard input.

       -l     Obtain a list of peers which are  known  to  the  server(s).  This  switch  is  equivalent  to  -c
              listpeers.

       -n     Output  all  host  addresses in dotted-quad numeric format rather than converting to the canonical
              host names.

       -p     Print a list of the peers known to the server as well  as  a  summary  of  their  state.  This  is
              equivalent to -c peers.

       -s     Print  a  list  of  the  peers  known  to the server as well as a summary of their state, but in a
              slightly different format than the -p switch. This is equivalent to -c dmpeers.

SEE ALSO

       /usr/share/doc/ntp-doc/html/ntpdc.html for the full documentation.

Network Time Protocol                            October 7, 2006                                        NTPDC(1)