Query the Network Time Protocol (NTP) daemon.
Start ntpq in interactive mode
Print a list of NTP peers
Print a list of NTP peers without resolving hostnames from IP addresses
Use ntpq in debugging mode
Print NTP system variables values
ntpq [-flags] [-flag [value]] [--option-name[[=| ]value]] [ host ...]
The ntpq utility program is used to query NTP servers to monitor NTP operations and performance, requesting information about current state and/or changes in that state. The program may be run either in interactive mode or controlled using command line arguments. Requests to read and write arbitrary variables can be assembled, with raw and pretty-printed output options being available. The ntpq utility can also obtain and print a list of peers in a common format by sending multiple queries to the server.
If one or more request options is included on the command line when ntpq 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, ntpq 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 ntpq utility will prompt for commands if the standard input is a terminal device.
ntpq uses NTP mode 6 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 ntpq utility makes one attempt to retransmit requests, and will time requests out if the remote host is not heard from within a suitable timeout time.
Note that in contexts where a host name is expected, a -4 qualifier preceding the host name forces resolution to the IPv4 namespace, while a -6 qualifier forces resolution to the IPv6 namespace. For examples and usage, see the NTP Debugging Techniques page.
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, ntpq will attempt to read interactive format commands from the standard input.
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.
A number of interactive format commands are executed entirely within the ntpq utility itself and do not result in NTP requests being sent to a server. These are described following.
A ‘?’ by itself will print a list of all the commands known to
ntpq. A ‘?’ followed by a command name will print
function and usage information about the command.
The arguments to this command consist of a list of items of the form name[=value], where the
is ignored, and can be omitted, in requests to the server to read
variables. The ntpq utility maintains an internal list
in which data to be included in messages can be assembled, and displayed
or set using the readlist and
writelist commands described below. The
addvars command allows variables and their optional
values to be added to the list. If more than one variable is to be
added, the list should be comma-separated and not contain white space.
The rmvars command can be used to remove individual
variables from the list, while the clearvars command
removes all variables from the list. The showvars
command displays the current list of optional variables.
Normally ntpq does not authenticate requests unless
they are write requests. The command authenticate
yes causes ntpq to send authentication
with all requests it makes. Authenticated requests causes some servers
to handle requests slightly differently. The command
authenticate causes ntpq to display
whether or not it is currently authenticating requests.
Causes output from query commands to be "cooked", so that variables
which are recognized by ntpq will have their values
reformatted for human consumption. Variables which ntpq
could not decode completely are marked with a trailing ‘?’.
With no argument, displays the current debug level. Otherwise, the
debugging level is changed as indicated.
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. Without any arguments, displays the current
Display refids as IPv4 or hash. Without any arguments, displays
whether refids are shown as IPv4 addresses or hashes.
Set the host to which future queries will be sent. The name
may be either a host name or a numeric address. Without any arguments,
displays the current host.
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.
Without any arguments, displays whether host names or numeric addresses
This command allows the specification of a key number to be used to
authenticate configuration requests. This must correspond to the
controlkey key number the server has been configured to
use for this purpose. Without any arguments, displays the current
Specify the digest algorithm to use for authenticating requests, with
default MD5. If ntpq was built with
OpenSSL support, and OpenSSL is installed, digest can be any
message digest algorithm supported by OpenSSL. If no argument is given,
the current keytype digest algorithm used is
Sets the NTP version number which ntpq claims in
packets. Defaults to 3, and note that mode 6 control messages (and
modes, for that matter) didn't exist in NTP version 1. There appear to
be no servers left which demand version 1. With no argument, displays
the current NTP version that will be used when communicating with
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.
Poll an NTP server in client mode n times. Poll not
Causes all output from query commands is printed as received from the
remote server. The only formating/interpretation done on the data is to
transform nonascii data into a printable (but barely understandable)
Specify a timeout period for responses to server queries. The default
is about 5000 milliseconds. Without any arguments, displays the current
timeout period. Note that since ntpq retries each query
once after a timeout, the total waiting time for a timeout will be twice
the timeout value set.
Display the version of the ntpq program.
Control Message Commands
Association ids are used to identify system, peer and clock variables. System variables are assigned an association id of zero and system name space, while each association is assigned a nonzero association id and peer namespace. Most control commands send a single message to the server and expect a single response message. The exceptions are the peers command, which sends a series of messages, and the mreadlist and mreadvar commands, which iterate over a range of associations.
Display a list of peers in the form:
where the output is just like the peers command
except that the refid is displayed in hex format and
the association number is also displayed.
Display a list of mobilized associations in the form:
Display the authentication statistics counters: time since reset,
stored keys, free keys, key lookups, keys not found, uncached keys,
expired keys, encryptions, decryptions.
Display all clock variables in the variable list for those
associations supporting a reference clock.
Display a list of clock variables for those associations supporting a
Send the remainder of the command line, including whitespace, to the
server as a run-time configuration command in the same format as a line
in the configuration file. This command is experimental until further
notice and clarification. Authentication is of course required.
Send each line of filename to the server as run-time
configuration commands in the same format as lines in the configuration
file. This command is experimental until further notice and
clarification. Authentication is required.
Display status and statistics counters for each local network
interface address: interface number, interface name and address or
broadcast, drop, flag, ttl, mc, received, sent, send failed, peers,
uptime. Authentication is required.
Display network and reference clock I/O statistics: time since reset,
receive buffers, free receive buffers, used receive buffers, low water
refills, dropped packets, ignored packets, received packets, packets
sent, packet send failures, input wakeups, useful input wakeups.
Display kernel loop and PPS statistics: associd, status, pll offset,
pll frequency, maximum error, estimated error, kernel status, pll time
constant, precision, frequency tolerance, pps frequency, pps stability,
pps jitter, calibration interval, calibration cycles, jitter exceeded,
stability exceeded, calibration errors. As with other ntpq output, times
are in milliseconds; very small values may be shown as exponentials. The
precision value displayed is in milliseconds as well, unlike the
precision system variable.
Perform the same function as the associations command, except display
mobilized and unmobilized associations, including all clients.
Display a list of all peers and clients showing
dstadr (associated with the given IP version).
Display the last obtained list of associations, including all
Display a list of all peers and clients (associated with the given IP
Display monitor facility status, statistics, and limits: enabled,
addresses, peak addresses, maximum addresses, reclaim above count,
reclaim older than, kilobytes, maximum kilobytes.
Perform the same function as the readlist command
for a range of association ids.
This range may be determined from the list displayed by any command
Perform the same function as the readvar command for
a range of association ids. This range may be determined from the list
displayed by any command showing associations.
Display traffic counts of the most recently seen source addresses
collected and maintained by the monitor facility. With the exception of
sort=[-]sortorder, the options filter the list
ntpd(8). The limited and
kod options return only entries representing client
addresses from which the last packet received triggered either
discarding or a KoD response. The
mincount=count option filters entries
representing less than count packets. The
laddr=localaddr option filters entries for
packets received on any local address other than localaddr.
resall=hexmask filter entries containing none
or less than all, respectively, of the bits in hexmask, which
must begin with 0x. The sortorder defaults to
lstint and may be addr,
lstint, or any of those preceded by ‘-’ to reverse the
sort order. The output columns are:
Interval in seconds between the receipt of the most recent packet from this address and the completion of the retrieval of the MRU list by ntpq.
Average interval in s between packets from this address.
Restriction flags associated with this address. Most are copied unchanged from the matching restrict command, however 0x400 (kod) and 0x20 (limited) flags are cleared unless the last packet from this address triggered a rate control response.
Rate control indicator, either a period, L or K for no rate control response, rate limiting by discarding, or rate limiting with a KoD response, respectively.
Packet version number.
Packets received from this address.
Source port of last packet from this address.
host or DNS name, numeric address, or address followed by claimed DNS name which could not be verified in parentheses.
Obtain and print the old-style list of all peers and clients showing
dstadr (associated with the given IP version), rather
than the refid.
Perform the same function as the associations
command, except that it uses previously stored data rather than making a
Display a list of peers in the form:
single-character code indicating current value of the select field of the
host name (or IP number) of peer. The value displayed will be truncated to 15 characters unless the ntpq -w option is given, in which case the full value will be displayed on the first line, and if too long, the remaining data will be displayed on the next line.
source IP address or
stratum: 0 for local reference clocks, 1 for servers with local reference clocks, ..., 16 for unsynchronized server clocks
u: unicast or manycast client, b: broadcast or multicast client, p: pool source, l: local (reference clock), s: symmetric (peer), A: manycast server, B: broadcast server, M: multicast server
time in seconds, minutes, hours, or days since the last packet was received, or ‘-’ if a packet has never been received
poll interval (s)
reach shift register (octal)
offset of server relative to this host
offset RMS error estimate.
Display the statistics for the peer with the given associd:
associd, status, remote host, local address, time last received, time
until next send, reachability change, packets sent, packets received,
bad authentication, bogus origin, duplicate, bad dispersion, bad
reference time, candidate order.
Display all system or peer variables. If the associd is
omitted, it is assumed to be zero.
Display the specified system or peer variables. If associd
is zero, the variables are from the System Variables
name space, otherwise they are from the Peer Variables
name space. The associd is required, as the same name can occur
in both spaces. If no name is included, all operative variables
in the name space are displayed. In this case only, if the
associd is omitted, it is assumed to be zero. Multiple names
are specified with comma separators and without whitespace. Note that
time values are represented in milliseconds and frequency values in
parts-per-million (PPM). Some NTP timestamps are represented in the
format YYYYMM DD TTTT, where YYYY is
the year, MM the month of year, DD the day of month
and TTTT the time of day.
Display the access control (restrict) list for ntpq.
Authentication is required.
Save the current configuration, including any runtime modifications made by :config or config-from-file, to the NTP server host file filename. This command will be rejected by the server unless
appears in the
ntpd(8) configuration file.
filename can use
date(1) format specifiers to
substitute the current date and time, for example,
The filename used is stored in system variable
savedconfig. Authentication is required.
Display system operational summary: associd, status, system peer,
system peer mode, leap indicator, stratum, log2 precision, root delay,
root dispersion, reference id, reference time, system jitter, clock
jitter, clock wander, broadcast delay, symm. auth. delay.
Display system uptime and packet counts maintained in the protocol
module: uptime, sysstats reset, packets received, current version, older
version, bad length or format, authentication failed, declined,
restricted, rate limited, KoD responses, processed for time.
Display interval timer counters: time since reset, timer overruns,
calls to transmit.
Set all system or peer variables included in the variable list.
Set the specified variables in the variable list. If the associd is zero, the variables are from the System Variables name space, otherwise they are from the Peer Variables name space. The associd is required, as the same name can occur in both spaces. Authentication is required.
Status Words and Kiss Codes
The current state of the operating program is shown in a set of status words maintained by the system. Status information is also available on a per-association basis. These words are displayed by the readlist and associations commands both in hexadecimal and in decoded short tip strings. The codes, tips and short explanations are documented on the
page. The page also includes a list of system and peer messages, the code for the latest of which is included in the status word.
Information resulting from protocol machine state transitions is displayed using an informal set of ASCII strings called
The original purpose was for kiss-o'-death (KoD) packets sent by the server to advise the client of an unusual condition. They are now displayed, when appropriate, in the reference identifier field in various billboards.
The following system variables appear in the readlist billboard. Not all variables are displayed in some configurations.
NTP software version and build time
hardware platform and version
operating system and version
leap warning indicator (0-3)
precision (log2 s)
total roundtrip delay to the primary reference clock
total dispersion to the primary reference clock
reference id or
date and time of day
system peer association id
time constant and poll exponent (log2 s) (3-17)
minimum time constant (log2 s) (3-10)
combined offset of server relative to this host
frequency drift (PPM) relative to hardware clock
combined system jitter
clock frequency wander (PPM)
TAI-UTC offset (s)
NTP seconds when the next leap second is/was inserted
NTP seconds when the NIST leapseconds file expires
The jitter and wander statistics are exponentially-weighted RMS averages. The system jitter is defined in the NTPv4 specification; the clock jitter statistic is computed by the clock discipline module.
When the NTPv4 daemon is compiled with the OpenSSL software library, additional system variables are displayed, including some or all of the following, depending on the particular Autokey dance:
Autokey host name for this host
Autokey group name for this host
host flags (see Autokey specification)
OpenSSL message digest algorithm
OpenSSL digest/signature scheme
NTP seconds at last signature update
certificate subject, issuer and certificate flags
NTP seconds when the certificate expires
The following peer variables appear in the readlist billboard for each association. Not all variables are displayed in some configurations.
source (remote) IP address
source (remote) port
destination (local) IP address
destination (local) port
leap indicator (0-3)
precision (log2 s)
total roundtrip delay to the primary reference clock
total root dispersion to the primary reference clock
reference id or
last packet received time
reach register (octal)
host mode (1-6)
peer mode (1-5)
host poll exponent (log2 s) (3-17)
peer poll exponent (log2 s) (3-17)
symmetric key id
interleave delay (see
The bias variable is calculated when the first broadcast packet is received after the calibration volley. It represents the offset of the broadcast subgraph relative to the unicast subgraph. The xleave variable appears only for the interleaved symmetric and interleaved modes. It represents the internal queuing, buffering and transmission delays for the preceding packet.
When the NTPv4 daemon is compiled with the OpenSSL software library, additional peer variables are displayed, including the following:
peer flags (see Autokey specification)
Autokey server name
peer flags (see Autokey specification)
OpenSSL digest/signature scheme
initial key id
initial key index
Autokey signature timestamp
Autokey group name for this association
The following clock variables appear in the clocklist billboard for each association with a reference clock. Not all variables are displayed in some configurations.
ASCII time code string (specific to device)
poll messages sent
bad date or time
fudge time 1
fudge time 2
driver reference id
Force IPv4 name resolution. This option must not appear in combination with any of the following options: ipv6.
Force resolution of following host names on the command line to the IPv4 namespace.
Force IPv6 name resolution. This option must not appear in combination with any of the following options: ipv4.
Force resolution of following host names on the command line to the IPv6 namespace.
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).
Increase debug verbosity level. This option may appear an unlimited number of times.
Set the debug verbosity level. This option may appear an unlimited number of times. This option takes an integer number as its argument.
Force ntpq to operate in interactive mode. This option must not appear in combination with any of the following options: command, peers.
Force ntpq to operate in interactive mode. Prompts will be written to the standard output and commands read from the standard input.
numeric host addresses.
Output all host addresses in dotted-quad numeric format rather than converting to the canonical host names.
Always output status line with readvar.
By default, ntpq now suppresses the associd=... line that precedes the output of readvar (alias rv) when a single variable is requested, such as ntpq -c "rv 0 offset". This option causes ntpq to include both lines of output for a single-variable readvar. Using an environment variable to preset this option in a script will enable both older and newer ntpq to behave identically in this regard.
Print a list of the peers. This option must not appear in combination with any of the following options: interactive.
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.
Set default display type for S2+ refids. This option takes a keyword as its argument. The argument sets an enumeration value that can be tested by comparing them against the option value macro. The available keywords are:
or their numeric equivalent.
The default keyword for this option is:
Set the default display format for S2+ refids.
Display the full 'remote' value.
Display the full value of the 'remote' value. If this requires more than 15 characters, display the full value, emit a newline, and continue the data display properly indented on the next line.
Display usage information and exit.
Pass the extended usage information through a pager.
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.
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.
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.
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:
NTPQ_<option-name> or NTPQ
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.
See OPTION PRESETS for configuration environment variables.
See OPTION PRESETS for configuration files.
One of the following exit values will be returned:
Successful program execution.
The operation failed or the command syntax was not valid.
A specified configuration file could not be loaded.
libopts had an internal operational error. Please report it to firstname.lastname@example.org. Thank you.
The University of Delaware and Network Time Foundation
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>.
Please send bug reports to: http://bugs.ntp.org, email@example.com
This manual page was AutoGen-erated from the ntpq option definitions.