DESCRIPTION
This manual page briefly documents the
ntpq command. The [= prog-name =] utility program is used to query NTP servers which implement the standard NTP mode 6 control message formats defined in Appendix B of the NTPv3 specification RFC1305, requesting information about current state and/or changes in that state. The same formats are used in NTPv4, although some of the variables have changed and new ones added. The description on this page is for the NTPv4 variables. 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 [= prog-name =] 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 [= prog-name =] 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, [= prog-name =] 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 [= prog-name =] utility will prompt for commands if the standard input is a terminal device.
The [= prog-name =] utility 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 [= prog-name =] 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.
Specifying a command line option other than or will cause the specified query (queries) to be sent to the indicated host(s) immediately. Otherwise, [= prog-name =] 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 [= prog-name =] utility itself and do not result in NTP mode 6 requests being sent to a server. These are described following.
? [command_keyword]
A by itself will print a list of all the command keywords known to this incarnation of [= prog-name =] . 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 [= prog-name =] than this manual page.
addvars
rmvars variable_name ...
clearvars The data carried by NTP mode 6 messages consists of a list of items of the form where the is ignored, and can be omitted, in requests to the server to read variables. The [= prog-name =] utility maintains an internal list in which data to be included in control messages can be assembled, and sent using the and commands described below. The 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 command can be used to remove individual variables from the list, while the command removes all variables from the list.
authenticate [ yes | no ] Normally [= prog-name =] does not authenticate requests unless they are write requests. The command causes [= prog-name =] to send authentication with all requests it makes. Authenticated requests causes some servers to handle requests slightly differently, and can occasionally melt the CPU in fuzzballs if you turn authentication on before doing a display. The command causes [= prog-name =] to display whether or not [= prog-name =] is currently autheinticating requests.
cooked Causes output from query commands to be "cooked", so that variables which are recognized by [= prog-name =] will have their values reformatted for human consumption. Variables which [= prog-name =] thinks should have a decodable value but didn't are marked with a trailing ] With no argument, displays the current debug level. Otherwise, the debug level is changed to the indicated level.
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 Cm yes | Cm no If is specified, host names are printed in information displays. If is specified, numeric addresses are printed instead. The default is unless modified using the command line 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.
ntpversion [ ] Sets the NTP version number which [= prog-name =] claims in packets. Defaults to 3, 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 servers.
quit Exit [= prog-name =] .
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.
raw 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) form.
timeout Ar milliseconds Specify a timeout period for responses to server queries. The default is about 5000 milliseconds. Note that since [= prog-name =] retries each query once after a timeout, the total waiting time for a timeout will be twice the timeout value set.