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ntpq(8)
NAME
ntpq - Network Time Protocol (NTP) monitor program for xntpd
SYNOPSIS
/usr/bin/ntpq [-inp] [-c command] [host1 host2...]
OPTIONS
-i Forces ntpq to operate in interactive mode. Prompts are written to the
standard output and commands read from the standard input. This is the
default.
-n Outputs all host addresses in dotted-decimal notation rather than
converting to the canonical host names.
-p Prints 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.
-c command
Interprets command as an interactive format command and adds it to the
list of commands to be executed on the specified host(s). Multiple -c
options may be given.
Specifying the -c or -p options sends the specified query (queries) to the
indicated host(s) immediately; localhost is the default. Otherwise, ntpq
attempts to read interactive format commands from the standard input.
DESCRIPTION
The ntpq program is used to monitor NTP hosts running xntpd. The program
may be run either in interactive mode or controlled using command line
arguments. Requests to read arbitrary variables can be assembled, with raw
and formatted output options available. The ntpq program 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 xntpd daemons running on
each of the hosts given as command line arguments, or on localhost by
default. If no request options are given, ntpq attempts to read commands
from the standard input and execute these on the first host given on the
command line, defaulting to localhost when no other host is specified. The
ntpq program will prompt for commands if the standard input is a terminal
device.
The ntpq program uses NTP mode 6 packets to communicate with the xntpd
daemons, and therefore can be used to query any compatible daemon on the
network that permits it. Note: Since NTP uses the UDP protocol, this
communication will be somewhat unreliable, especially over large network
topologies. The ntpq program makes one attempt to retransmit requests, and
will time out if the remote host is not heard from within a suitable time.
COMMANDS
Interactive Commands
Interactive format commands consist of a keyword followed by zero or more
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 > (redirect metacharacter), followed by a
file name, to the command line.
A number of interactive format commands are executed entirely within the
ntpq program itself and do not result in NTP mode 6 requests being sent to
a daemon. These commands are as follows:
? [command_keyword]
A ? by itself prints a list of all the command keywords known to this
version of ntpq. A ? followed by a command keyword prints function and
usage information about the command.
addvars variable_name[=value] [,...]
rmvars variable_name [,...]
clearvars
The data carried by NTP mode 6 messages consists of a list of items of
the form:
variable_name=value
where the value is ignored, and can be omitted, in requests to the
server to read variables. The ntpq program maintains an internal list
in which data to be included in control messages can be assembled, and
sent using the readlist and writelist commands. 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 separated by
commas and not contain white space. The rmvars command can be used to
remove individual variables from the list, while the clearlist command
removes all variables from the list.
authenticate yes|no
Normally ntpq does not authenticate requests unless they are write
requests. The authenticate yes command causes ntpq to send
authentication with all requests it makes. Authenticated requests
cause some servers to handle requests slightly differently. To prevent
any mishap, do a peer display before turning on authentication.
cooked
Reformats variables that are recognized by the server. Variables that
ntpq does not recognize are marked with a trailing ?.
debug more|less|off
Adjusts level of ntpq debugging. The default is off.
delay milliseconds
Specifies a time interval to be added to timestamps included in
requests that 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 time stamps in authenticated requests, so this
command may be obsolete.
help
Same as ?.
host [hostname]
Sets the host to which future queries will be sent; hostname may be
either a host name or a Internet address. If hostname is not specified,
the current host is used.
hostnames yes|no
If yes is specified, prints host names in information displays. If no
is specified, prints Internet addresses instead. The default is yes
unless modified using the command line -n option.
keyid #
Specifies 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.
keytype md5|des
Setsthe authentication key to either md5 or des. Only md5 is supported
in this implementation.
ntpversion 1|2|3
Sets the NTP version number that ntpq claims in packets. To display
the NTP version that ntpq currently claims, execute ntpversion with no
arguments. Although most servers run version 3 or better, ntpq claims
version 2 by default for backwards compatibility. (Note that Mode 6
control messages, and modes, for that matter, did not exist in NTP
version 1.)
passwd
Prompts you to type in a password (which will not be echoed) that is
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 [#] [verbose]
Polls the current server in client mode. The first argument is the
number of times to poll (default is 1) while the second argument may be
given to obtain a more detailed output of the results.
quit
Exits ntpq.
raw Prints all output from query commands as received from the remote
server. The only data formatting performed is to translate nonascii
data into a printable form.
timeout milliseconds
Specifies a timeout period for responses to server queries. The
default is about 5000 milliseconds. Since ntpq retries each query once
after a timeout, the total waiting time for a timeout will be twice the
timeout value.
Control Message Commands
Each peer known to an NTP server has a 16-bit integer association
identifier assigned to it. NTP control messages that carry peer variables
must identify the peer the values correspond to by including its
association ID. An association ID of 0 is special, and indicates the
variables are system variables whose names are drawn from a separate name
space.
Control message commands result in one or more NTP mode 6 messages being
sent to the server, and cause the data returned to be printed in some
format. Most commands currently implemented send a single message and
expect a single response. The current exceptions are the peers command,
which will send a preprogrammed series of messages to obtain the data it
needs, and the mreadlist and mreadvar commands, which will iterate over a
range of associations.
associations
Obtains and prints a list of association identifiers and peer status
for in-spec peers of the server being queried. The list is printed in
columns. The first of these is an index numbering the associations from
1 for internal use, the second is the actual association identifier
returned by the server and the third the status word for the peer.
This is followed by a number of columns containing data decoded from
the status word. Note: The data returned by the associations command
is cached internally in ntpq. The index is then used when dealing with
servers that use association identifiers. For any subsequent commands
which require an association identifier as an argument, the form &index
may be used as an alternative.
cl An easy-to-type short form of the clocklist command.
clocklist [assocID]
Reads the clock variables included in the variable list.
clockvar [assocID] [variable_name[=value] [,...]]
Requests that the server send a list of the clock variables. Servers
that have a radio clock or other external synchronization will respond
positively to this. If the association identifier is omitted or zero,
the request is for the system clock variables and will generally get a
positive response from all servers with a clock. If the server treats
clocks as pseudo-peers, and can possibly have more than one clock
connected at once, referencing the appropriate peer association ID will
show the variables of a particular clock. If you omit the variable
list, the server returns a default variable display.
cv [assocID] [variable_name[=value] [,...]]
An easy-to-type short form of the clockvar command.
lassociations
Obtains and prints a list of association identifiers and peer status
for all associations for which the server is maintaining state. This
command differs from the associations command only for servers which
retain state for out-of-spec client associations. Such associations
are normally omitted from the display when the associations command is
used, but are included in the output of lassociations.
lopeers
Obtains and prints a list of all peers and clients having the
destination address.
lpassociations
Prints data for all associations, including out-of-spec client
associations, from the internally cached list of associations.
lpeers
Like peers, except a summary of all associations for which the server
is maintaining state is printed. This can produce a much longer list
of peers.
mreadlist assocID assocID
Like the readlist command except the query is done for each of a range
of (nonzero) association IDs. This range is determined from the
association list cached by the most recent associations command.
mreadvar assocID assocID [variable_name[=value] [,...] ]
Like the readvar command except the query is done for each of a range
of (nonzero) association IDs. This range is determined from the
association list cached by the most recent associations command.
mrl assocID assocID
An easy-to-type short form of the mreadlist command.
mrv assocID assocID [variable_name[=value] [,...]]
An easy-to-type short form of the mreadvar command.
opeers
An old form of the peers command with the reference ID replaced by the
local interface address.
passociations
Prints association data concerning in-spec peers from the internally
cached list of associations. This command performs identically to the
associations except that it displays the internally stored data rather
than making a new query.
peers
Obtains a list of in-spec peers of the server, along with a summary of
each peer's state. Summary information includes the address of the
remote peer, the reference ID (0.0.0.0 if the refID is unknown), the
stratum of the remote peer, the polling interval, in seconds, the
reachability register, in octal, and the current estimated delay,
offset and dispersion of the peer, all in milliseconds.
The character in the left margin indicates the fate of this peer in the
clock selection process. The codes are as follows:
<sp>
Indicates the peer was discarded due to high stratum or failed
sanity checks, or both.
x Indicates the peer was designated falseticker by the intersection
algorithm.
. Indicates that this peer was culled from the end of the candidate
list.
- Indicates that the peer was discarded by the clustering algorithm.
+ Indicates that the peer was included in the final selection set.
# Indicates the peer was selected for synchronization, but distance
exceeds the maximum.
* Indicates the peer was selected for synchronization.
o Indicates the peer was selected for synchronization; pps signal in
use.
Since the peers command depends on the ability to parse the values in
the responses it gets, it might fail to work with servers that poorly
control the data formats.
The contents of the host field may be one of four forms: 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.
pstatus assocID
Sends a read status request to the server for the given association.
The names and values of the peer variables returned will be printed.
Note: The status word from the header is displayed preceding the
variables, both in hexadecimal and in English.
readlist [assocID]
Requests that the server return the values of the variables in the
internal variable list. If the association ID is omitted or is 0, the
variables are assumed to be system variables. Otherwise, they are
treated as peer variables. If the internal variable list is empty, a
request is sent without data; the remote server should return a default
display.
readvar [assocID] [variable_name[=value] [,...]]
Requests that the values of the specified variables be returned by the
server by sending a read variables request. If the association ID is
omitted or is given as zero, the variables are system variables;
otherwise, they are peer variables, and the values returned are those
of the corresponding peer. If the variable list is empty, a request is
sent without data; the remote server should return a default display.
rl [assocID]
An easy-to-type short form of the readlist command.
rv [assocID] [variable_name[=value] [,...]]
An easy-to-type short form for the readvar command.
showvars
Prints the variables on the variable list.
version
Prints the ntpq version number.
writelist [assocID]
Like the readlist request, except the internal list variables are
written instead of read.
writevar assocID variable_name=value [,...]
Like the readvar request, except the specified variables are written
instead of read.
ERRORS
· ***Can't find host hostname
Explanation:
The hostname is not in the local /etc/host file.
· hostname: timed out, nothing received ***Request timed out
Explanation:
Check that xntpd is running on the remote host being queried.
NOTES
The peers command is non-atomic and may occasionally result in spurious
error messages about invalid associations occurring and terminating the
command.
The timeout time is a fixed constant, which means you wait a long time for
time outs since it assumes sort of a worst case.
FILES
/usr/bin/ntpq
Specifies the command path
SEE ALSO
Commands: ntpdate(8), xntpd(8), xntpdc(8)
Files: ntp.conf(4)
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