ntpdc - special NTP query program


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


   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.


   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.


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


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