Provided by: ntp_4.2.8p10+dfsg-5ubuntu7.3_amd64 bug

NAME

     ntpdc — vendor-specific NTPD control program

SYNOPSIS

     ntpdc [-flags] [-flag [value]] [--option-name[[=| ]value]] [ host ...]

DESCRIPTION

     ntpdc is deprecated.  Please use ntpq(1) instead - it can do everything ntpdc used to do,
     and it does so using a much more sane interface.

     ntpdc is a utility program used to query ntpd(8) about its current state and to request
     changes in that state.  It uses NTP mode 7 control message formats described in the source
     code.  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.

OPTIONS

     -4, --ipv4
             Force IPv4 DNS name resolution.  This option must not appear in combination with any
             of the following options: ipv6.

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

     -6, --ipv6
             Force IPv6 DNS name resolution.  This option must not appear in combination with any
             of the following options: ipv4.

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

     -c cmd, --command=cmd
             run a command and exit.  This option may appear an unlimited number of times.

             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).

     -d, --debug-level
             Increase debug verbosity level.  This option may appear an unlimited number of
             times.

     -D number, --set-debug-level=number
             Set the debug verbosity level.  This option may appear an unlimited number of times.
             This option takes an integer number as its argument.

     -i, --interactive
             Force ntpq to operate in interactive mode.  This option must not appear in
             combination with any of the following options: command, listpeers, peers, showpeers.

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

     -l, --listpeers
             Print a list of the peers.  This option must not appear in combination with any of
             the following options: command.

             Print a list of the peers known to the server as well as a summary of their state.
             This is equivalent to the 'listpeers' interactive command.

     -n, --numeric
             numeric host addresses.

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

     -p, --peers
             Print a list of the peers.  This option must not appear in combination with any of
             the following options: command.

             Print a list of the peers known to the server as well as a summary of their state.
             This is equivalent to the 'peers' interactive command.

     -s, --showpeers
             Show a list of the peers.  This option must not appear in combination with any of
             the following options: command.

             Print a list of the peers known to the server as well as a summary of their state.
             This is equivalent to the 'dmpeers' interactive command.

     -?, --help
             Display usage information and exit.

     -!, --more-help
             Pass the extended usage information through a pager.

     -> [cfgfile], --save-opts [=cfgfile]
             Save the option state to cfgfile.  The default is the last configuration file listed
             in the OPTION PRESETS section, below.  The command will exit after updating the
             config file.

     -< cfgfile, --load-opts=cfgfile, --no-load-opts
             Load options from cfgfile.  The no-load-opts form will disable the loading of
             earlier config/rc/ini files.  --no-load-opts is handled early, out of order.

     --version [{v|c|n}]
             Output version of program and exit.  The default mode is `v', a simple version.  The
             `c' mode will print copyright information and `n' will print the full copyright
             notice.

OPTION PRESETS

     Any option that is not marked as not presettable may be preset by loading values from
     configuration ("RC" or ".INI") file(s) and values from environment variables named:
       NTPDC_<option-name> or NTPDC
     The  environmental  presets  take  precedence  (are  processed later than) the configuration
     files.  The homerc files are "$HOME", and ".".  If any of these are  directories,  then  the
     file .ntprc is searched for within those directories.

USAGE

     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.  The ntpdc utility will prompt for commands if the standard input
     is a terminal device.

     The ntpdc utility 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.  The ntpdc utility 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(8) daemon
     and can be expected to work only with this and maybe some previous versions of the daemon.
     Requests from a remote ntpdc utility 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.

   Interactive Commands
     Interactive format commands consist of a keyword followed by zero to four arguments.  Only
     enough characters of the full keyword to uniquely identify the command need be typed.  The
     output of a command is normally sent to the standard output, but optionally the output of
     individual commands may be sent to a file by appending a ‘>’, followed by a file name, to
     the command line.

     A number of interactive format commands are executed entirely within the ntpdc utility
     itself and do not result in NTP mode 7 requests being sent to a server.  These are described
     following.

     ? command_keyword

     help command_keyword
             A ‘?’ will print a list of all the command keywords known to this incarnation of
             ntpdc.  A ‘?’ followed by a command keyword will print function and usage
             information about the command.  This command is probably a better source of
             information about ntpq(1) than this manual page.

     delay milliseconds
             Specify a time interval to be added to timestamps included in requests which require
             authentication.  This is used to enable (unreliable) server reconfiguration over
             long delay network paths or between machines whose clocks are unsynchronized.
             Actually the server does not now require timestamps in authenticated requests, so
             this command may be obsolete.

     host hostname
             Set the host to which future queries will be sent.  Hostname may be either a host
             name or a numeric address.

     hostnames [yes | no]
             If yes is specified, host names are printed in information displays.  If no is
             specified, numeric addresses are printed instead.  The default is yes, unless
             modified using the command line -n switch.

     keyid keyid
             This command allows the specification of a key number to be used to authenticate
             configuration requests.  This must correspond to a key number the server has been
             configured to use for this purpose.

     quit    Exit ntpdc.

     passwd  This command prompts you to type in a password (which will not be echoed) which will
             be used to authenticate configuration requests.  The password must correspond to the
             key configured for use by the NTP server for this purpose if such requests are to be
             successful.

     timeout milliseconds
             Specify a timeout period for responses to server queries.  The default is about 8000
             milliseconds.  Note that since ntpdc retries each query once after a timeout, the
             total waiting time for a timeout will be twice the timeout value set.

   Control Message Commands
     Query commands result in NTP mode 7 packets containing requests for information being sent
     to the server.  These are read-only commands in that they make no modification of the server
     configuration state.

     listpeers
             Obtains and prints a brief list of the peers for which the server is maintaining
             state.  These should include all configured peer associations as well as those peers
             whose stratum is such that they are considered by the server to be possible future
             synchronization candidates.

     peers   Obtains a list of peers for which the server is maintaining state, along with a
             summary of that state.  Summary information includes the address of the remote peer,
             the local interface address (0.0.0.0 if a local address has yet to be determined),
             the stratum of the remote peer (a stratum of 16 indicates the remote peer is
             unsynchronized), the polling interval, in seconds, the reachability register, in
             octal, and the current estimated delay, offset and dispersion of the peer, all in
             seconds.

             The character in the left margin indicates the mode this peer entry is operating in.
             A ‘+’ denotes symmetric active, a ‘-’ indicates symmetric passive, a ‘=’ means the
             remote server is being polled in client mode, a ‘^’ indicates that the server is
             broadcasting to this address, a ‘~’ denotes that the remote peer is sending
             broadcasts and a ‘~’ denotes that the remote peer is sending broadcasts and a ‘*’
             marks the peer the server is currently synchronizing to.

             The contents of the host field may be one of four forms.  It may be a host name, an
             IP address, a reference clock implementation name with its parameter or
             REFCLK(implementation_number, parameter).  On hostnames no only IP-addresses will be
             displayed.

     dmpeers
             A slightly different peer summary list.  Identical to the output of the peers
             command, except for the character in the leftmost column.  Characters only appear
             beside peers which were included in the final stage of the clock selection
             algorithm.  A ‘.’ indicates that this peer was cast off in the falseticker
             detection, while a ‘+’ indicates that the peer made it through.  A ‘*’ denotes the
             peer the server is currently synchronizing with.

     showpeer peer_address [...]
             Shows a detailed display of the current peer variables for one or more peers.  Most
             of these values are described in the NTP Version 2 specification.

     pstats peer_address [...]
             Show per-peer statistic counters associated with the specified peer(s).

     clockstat clock_peer_address [...]
             Obtain and print information concerning a peer clock.  The values obtained provide
             information on the setting of fudge factors and other clock performance information.

     kerninfo
             Obtain and print kernel phase-lock loop operating parameters.  This information is
             available only if the kernel has been specially modified for a precision timekeeping
             function.

     loopinfo [oneline | multiline]
             Print the values of selected loop filter variables.  The loop filter is the part of
             NTP which deals with adjusting the local system clock.  The ‘offset’ is the last
             offset given to the loop filter by the packet processing code.  The ‘frequency’ is
             the frequency error of the local clock in parts-per-million (ppm).  The ‘time_const’
             controls the stiffness of the phase-lock loop and thus the speed at which it can
             adapt to oscillator drift.  The ‘watchdog timer’ value is the number of seconds
             which have elapsed since the last sample offset was given to the loop filter.  The
             oneline and multiline options specify the format in which this information is to be
             printed, with multiline as the default.

     sysinfo
             Print a variety of system state variables, i.e., state related to the local server.
             All except the last four lines are described in the NTP Version 3 specification,
             RFC-1305.

             The ‘system flags’ show various system flags, some of which can be set and cleared
             by the enable and disable configuration commands, respectively.  These are the auth,
             bclient, monitor, pll, pps and stats flags.  See the ntpd(8) documentation for the
             meaning of these flags.  There are two additional flags which are read only, the
             kernel_pll and kernel_pps.  These flags indicate the synchronization status when the
             precision time kernel modifications are in use.  The ‘kernel_pll’ indicates that the
             local clock is being disciplined by the kernel, while the ‘kernel_pps’ indicates the
             kernel discipline is provided by the PPS signal.

             The ‘stability’ is the residual frequency error remaining after the system frequency
             correction is applied and is intended for maintenance and debugging.  In most
             architectures, this value will initially decrease from as high as 500 ppm to a
             nominal value in the range .01 to 0.1 ppm.  If it remains high for some time after
             starting the daemon, something may be wrong with the local clock, or the value of
             the kernel variable kern.clockrate.tick may be incorrect.

             The ‘broadcastdelay’ shows the default broadcast delay, as set by the broadcastdelay
             configuration command.

             The ‘authdelay’ shows the default authentication delay, as set by the authdelay
             configuration command.

     sysstats
             Print statistics counters maintained in the protocol module.

     memstats
             Print statistics counters related to memory allocation code.

     iostats
             Print statistics counters maintained in the input-output module.

     timerstats
             Print statistics counters maintained in the timer/event queue support code.

     reslist
             Obtain and print the server's restriction list.  This list is (usually) printed in
             sorted order and may help to understand how the restrictions are applied.

     monlist [version]
             Obtain and print traffic counts collected and maintained by the monitor facility.
             The version number should not normally need to be specified.

     clkbug clock_peer_address [...]
             Obtain debugging information for a reference clock driver.  This information is
             provided only by some clock drivers and is mostly undecodable without a copy of the
             driver source in hand.

   Runtime Configuration Requests
     All requests which cause state changes in the server are authenticated by the server using a
     configured NTP key (the facility can also be disabled by the server by not configuring a
     key).  The key number and the corresponding key must also be made known to ntpdc.  This can
     be done using the keyid and passwd commands, the latter of which will prompt at the terminal
     for a password to use as the encryption key.  You will also be prompted automatically for
     both the key number and password the first time a command which would result in an
     authenticated request to the server is given.  Authentication not only provides verification
     that the requester has permission to make such changes, but also gives an extra degree of
     protection again transmission errors.

     Authenticated requests always include a timestamp in the packet data, which is included in
     the computation of the authentication code.  This timestamp is compared by the server to its
     receive time stamp.  If they differ by more than a small amount the request is rejected.
     This is done for two reasons.  First, it makes simple replay attacks on the server, by
     someone who might be able to overhear traffic on your LAN, much more difficult.  Second, it
     makes it more difficult to request configuration changes to your server from topologically
     remote hosts.  While the reconfiguration facility will work well with a server on the local
     host, and may work adequately between time-synchronized hosts on the same LAN, it will work
     very poorly for more distant hosts.  As such, if reasonable passwords are chosen, care is
     taken in the distribution and protection of keys and appropriate source address restrictions
     are applied, the run time reconfiguration facility should provide an adequate level of
     security.

     The following commands all make authenticated requests.

     addpeer peer_address [keyid] [version] [prefer]
             Add a configured peer association at the given address and operating in symmetric
             active mode.  Note that an existing association with the same peer may be deleted
             when this command is executed, or may simply be converted to conform to the new
             configuration, as appropriate.  If the optional keyid is a nonzero integer, all
             outgoing packets to the remote server will have an authentication field attached
             encrypted with this key.  If the value is 0 (or not given) no authentication will be
             done.  The version can be 1, 2 or 3 and defaults to 3.  The prefer keyword indicates
             a preferred peer (and thus will be used primarily for clock synchronisation if
             possible).  The preferred peer also determines the validity of the PPS signal - if
             the preferred peer is suitable for synchronisation so is the PPS signal.

     addserver peer_address [keyid] [version] [prefer]
             Identical to the addpeer command, except that the operating mode is client.

     broadcast peer_address [keyid] [version] [prefer]
             Identical to the addpeer command, except that the operating mode is broadcast.  In
             this case a valid key identifier and key are required.  The peer_address parameter
             can be the broadcast address of the local network or a multicast group address
             assigned to NTP.  If a multicast address, a multicast-capable kernel is required.

     unconfig peer_address [...]
             This command causes the configured bit to be removed from the specified peer(s).  In
             many cases this will cause the peer association to be deleted.  When appropriate,
             however, the association may persist in an unconfigured mode if the remote peer is
             willing to continue on in this fashion.

     fudge peer_address [time1] [time2] [stratum] [refid]
             This command provides a way to set certain data for a reference clock.  See the
             source listing for further information.

     enable [auth | bclient | calibrate | kernel | monitor | ntp | pps | stats]

     disable [auth | bclient | calibrate | kernel | monitor | ntp | pps | stats]
             These commands operate in the same way as the enable and disable configuration file
             commands of ntpd(8).

             auth    Enables the server to synchronize with unconfigured peers only if the peer
                     has been correctly authenticated using either public key or private key
                     cryptography.  The default for this flag is enable.

             bclient
                     Enables the server to listen for a message from a broadcast or multicast
                     server, as in the multicastclient command with default address.  The default
                     for this flag is disable.

             calibrate
                     Enables the calibrate feature for reference clocks.  The default for this
                     flag is disable.

             kernel  Enables the kernel time discipline, if available.  The default for this flag
                     is enable if support is available, otherwise disable.

             monitor
                     Enables the monitoring facility.  See the documentation here about the
                     monlist command or further information.  The default for this flag is
                     enable.

             ntp     Enables time and frequency discipline.  In effect, this switch opens and
                     closes the feedback loop, which is useful for testing.  The default for this
                     flag is enable.

             pps     Enables the pulse-per-second (PPS) signal when frequency and time is
                     disciplined by the precision time kernel modifications.  See the "A Kernel
                     Model for Precision Timekeeping" (available as part of the HTML
                     documentation provided in /usr/share/doc/ntp) page for further information.
                     The default for this flag is disable.

             stats   Enables the statistics facility.  See the Monitoring Options section of
                     ntp.conf(5) for further information.  The default for this flag is disable.

     restrict address mask flag [...]
             This command operates in the same way as the restrict configuration file commands of
             ntpd(8).

     unrestrict address mask flag [...]
             Unrestrict the matching entry from the restrict list.

     delrestrict address mask [ntpport]
             Delete the matching entry from the restrict list.

     readkeys
             Causes the current set of authentication keys to be purged and a new set to be
             obtained by rereading the keys file (which must have been specified in the ntpd(8)
             configuration file).  This allows encryption keys to be changed without restarting
             the server.

     trustedkey keyid [...]

     untrustedkey keyid [...]
             These commands operate in the same way as the trustedkey and untrustedkey
             configuration file commands of ntpd(8).

     authinfo
             Returns information concerning the authentication module, including known keys and
             counts of encryptions and decryptions which have been done.

     traps   Display the traps set in the server.  See the source listing for further
             information.

     addtrap address [port] [interface]
             Set a trap for asynchronous messages.  See the source listing for further
             information.

     clrtrap address [port] [interface]
             Clear a trap for asynchronous messages.  See the source listing for further
             information.

     reset   Clear the statistics counters in various modules of the server.  See the source
             listing for further information.

ENVIRONMENT

     See OPTION PRESETS for configuration environment variables.

FILES

     See OPTION PRESETS for configuration files.

EXIT STATUS

     One of the following exit values will be returned:

     0  (EXIT_SUCCESS)
             Successful program execution.

     1  (EXIT_FAILURE)
             The operation failed or the command syntax was not valid.

     66  (EX_NOINPUT)
             A specified configuration file could not be loaded.

     70  (EX_SOFTWARE)
             libopts had an internal operational error.  Please report it to
             autogen-users@lists.sourceforge.net.  Thank you.

SEE ALSO

     ntp.conf(5), ntpd(8)

     David L. Mills, Network Time Protocol (Version 3), RFC1305.

AUTHORS

     The formatting directives in this document came from FreeBSD.

COPYRIGHT

     Copyright (C) 1992-2017 The University of Delaware and Network Time Foundation all rights
     reserved.  This program is released under the terms of the NTP license,
     <http://ntp.org/license>.

BUGS

     The ntpdc utility is a crude hack.  Much of the information it shows is deadly boring and
     could only be loved by its implementer.  The program was designed so that new (and
     temporary) features were easy to hack in, at great expense to the program's ease of use.
     Despite this, the program is occasionally useful.

     Please report bugs to http://bugs.ntp.org .

     Please send bug reports to: http://bugs.ntp.org, bugs@ntp.org

NOTES

     This manual page was AutoGen-erated from the ntpdc option definitions.