table of contents
NTPDC(1) | General Commands Manual (user) | NTPDC(1) |
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_keywordhelp
command_keyword- A ‘
?
’ will print a list of all the command keywords known to this incarnation ofntpdc
. 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. Ifno
is specified, numeric addresses are printed instead. The default isyes
, 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). Onhostnames
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
andmultiline
options specify the format in which this information is to be printed, withmultiline
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
anddisable
configuration commands, respectively. These are theauth
,bclient
,monitor
,pll
,pps
andstats
flags. See the ntpd(8) documentation for the meaning of these flags. There are two additional flags which are read only, thekernel_pll
andkernel_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
anddisable
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
anduntrustedkey
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¶
David L. Mills, Network Time Protocol (Version 3), RFC1305.
AUTHORS¶
The formatting directives in this document came from FreeBSD.
COPYRIGHT¶
Copyright (C) 1992-2020 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.
June 23 2020 | Debian |