Content-type: text/html Man page of ntpq


Section: Maintenance Commands (8)
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ntpq - Network Time Protocol (NTP) monitor program for xntpd  


/usr/bin/ntpq [-inp] [-c command] [host1 host2 ...]  


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. Outputs all host addresses in dotted-decimal notation rather than converting to the canonical host names. 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. 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.  


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.  



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.


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.


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. Default is 3. Mode 6 control messages (and modes, for that matter) did not exist in NTP version 1.


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.


Exits ntpq.


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.


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.


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.


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.


Obtains and prints a list of all peers and clients having the destination address.


Prints data for all associations, including out-of-spec client associations, from the internally cached list of associations.


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.


An old form of the peers command with the reference ID replaced by the local interface address.


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.


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 ( 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: Indicates the peer was discarded due to high stratum or failed sanity checks, or both. 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. 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.


Prints the variables on the variable list.


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.  


The hostname is not in the local /etc/host file. Check that xntpd is running on the remote host being queried.  


Specifies the command path  


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.  


Commands: ntpdate(8), ntpsetup(8), xntpd(8), xntpdc(8)

Files: ntp.conf(4) delim off



Interactive Commands
Control Message Commands

This document was created by man2html, using the manual pages.
Time: 02:40:29 GMT, October 02, 2010