ntpq(1Mtcp)

Synopsis

Description

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. ntpq 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. ntpq makes one attempt to retransmit requests, and will time requests out if the remote host is not heard from within a suitable time out time.

Command line options are described below. 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.

-c

The command argument is interpreted as an interactive format command and is added to the list of commands to be executed on the specified host(s). Multiple -c options may be given.

-i

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

-n

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

-p

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

Internal commands

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 server. They are described here.

? [command_keyword]

A ``?'' by itself will print a list of all the command keywords known to this incarnation of ntpq. A ``?'' followed by a command keyword will print function and usage information about the command. This command is an excellent supplement to this manual page.

timeout milliseconds

Specify a time out period for responses to server queries. The default is about 5000 milliseconds. Note that since ntpq retries each query once after a time out, the total waiting time for a time out will be twice the time out value set.

delay milliseconds

Specify a time interval to be added to timestamps included in requests requiring 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.

poll [#] [verbose]

Poll 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.

NOTE: The poll command is not currently implemented. It did appear in previous versions of NTP, and thus, is documented here.

keyid #

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

passwd

This command prompts you to type in a password (which will not be echoed) that 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.

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NOTE: keyid and passwd are constructed in the NTP keys file.

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hostnames yes|no

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

raw

Causes all output from query commands to be printed as received from the remote server. The only formatting done on the data is to transform non ASCII data into a printable (but barely understandable) form.

cooked

Causes output from query commands to be ``cooked''. Variables that are recognized by the server will have their values reformatted for clarity. Variables that ntpq thinks should have a decodeable value but didn't are marked with a trailing ``?''.

ntpversion 1|2|3

Sets the NTP version number that ntpq claims in packets. Defaults to 3 since mode 6 control messages (and modes, for that matter) didn't exist in NTP version 1.

authenticate yes|no

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 cause some servers to handle requests slightly differently, and can occasionally cause problems with fuzzball servers if you turn authentication on before doing a peer display.

addvars variable_name[=value][,... ] rmvars variable_name[,... ] clearvars

The addvars command allows variables and their optional values to be added to the list of NTP mode 6 messages. 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. ntpq maintains an internal list in which data to be included in control messages can be assembled, and sent using the readlist and writelist commands described below. 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 clearlist command removes all variables from the list.

debug more|less|no

Turns internal query program debugging on and off.

quit

Exit ntpq.

Control message commands

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 a format appropriate to the command used. 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.

This process has special use for three terms. They are:

in-spec peers

Peers that are synchronized.

out-of-spec peers

Peers that are, for some reason, not yet in sync. There are many reasons for being out-of-sync. For example, peers may be not yet in sync or somehow broken.

fuzzball

Fuzzballs are clocks that survey and average ticks from many different clocks. They are described in detail in a paper by David Miller on the University of Delaware web page. For more information, access the web page at http://www.eecis.udel.edu/~ntp.

associations

Obtains and prints a list of association identifiers and peer statuses 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 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 that the data returned by the associations command is cached internally in ntpq. The index is then used when dealing with servers which use association identifiers. For any subsequent commands which require an association identifier as an argument, the form &index may be used as an alternative.

lassociations

Obtains and prints a list of association identifiers and peer statuses 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 (that is, fuzzballs). Such associations are normally omitted from the display when the associations command is used, but are included in the output of lassociations.

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.

lpassociations

Print data for all associations, including out-of-spec client associations, from the internally cached list of associations. This command differs from passociations only when dealing with fuzzballs.

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 that the status word from the header is displayed preceding the variables, both in hexadecimal and in abbreviated English.

readvar [ assocID ] [ variable_name[=value][, ... ] ]

Requests that the values of the specified variables be returned by the server. If the associationID is omitted or is given as zero the variables are system variables, otherwise they are peer variables and the values returned will be those of the corresponding peer. Omitting the variable list will send a request with no data, which should induce the server to return a default display.

rv [ assocID ] [ variable_name[=value][, ... ] ]

A short form for the readvar command.

writevar assocID variable_name=value[, ... ]

Requests that the values of the specified variables be written to the server. If the associationID is omitted or is given as zero the variables are system variables, otherwise they are peer variables and the values returned will be those of the corresponding peer. Omitting the variable list will send a request with no data, which should induce the server to return a default display.

readlist [ assocID ]

Requests that the values of the variables in the internal variable list be returned by the server. 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, which should induce the remote server to return a default display.

rl [ assocID ]

An easy-to-type short form of the readlist command.

writelist [ assocID ]

Requests that the values of the variables in the internal variable list be written to the server. 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, which should induce the remote server to return a default display.

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.

mrv assocID assocID [ variable_name[=value][, ... ] ]

A short form of the mreadvar command.

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.

mrl assocID assocID

A short form of the mreadlist command.

clockvar [ assocID ] [ variable_name[=value][, ... ] ]

Requests that a list of the server's clock variables be sent. Servers having 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 variables of the ``system clock'' and will generally get a positive response from all servers with a clock. If the server treats clocks as pseudo-peers, and hence can possibly have more than one clock connected at once, referencing the appropriate peer association ID will show the variables of a particular clock. Omitting the variable list will cause the server to return a default variable display.

cv [ assocID ] [ variable_name[=value][, ... ] ]

A short form of the clockvar command.

peers

Obtains a list of in-spec peers of the server, along with a summary of each peer's state. Summary information includes the remote peer's designation, the reference ID (0.0.0.0 if the refID is unknown), the stratum of the remote peer, the type of peer (local, unicast, multicast or broadcast), when the last packet was received, 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 fate of this peer in the clock selection process. The codes mean: <sp> discarded due to high stratum and/or failed sanity checks; "x" designated falsticker by the intersection algorithm; "." culled from the end of the candidate list; "-" discarded by the clustering algorithm; "+" included in the final selection set; "#" selected for synchronization, but the distance exceeds maximum; " "o" selected for synchronization, pps signal in use.

Note that since the peers command depends on the ability to parse the values in the responses it gets, it may fail to work from time to time with servers which poorly control the data formats.

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 of REFCLK(<implementation number>, <parameter>). On hostnames no only IP addresses will be displayed.

lpeers

Like peers, except it prints a summary of all associations for which the server is maintaining state. This can produce a much longer list of peers from fuzzball servers.

opeers

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

Exit codes

References

RFC 1059, RFC 1119, RFC 1305