ntpq(ADMN) 19 June 1992 ntpq(ADMN) Name ntpq - standard Network Time Protocol query program Syntax ntpq [ -inp ] [ -c command ] [ host ] [ ... ] Description ntpq queries NTP servers that implement the recommended mode 6 control message format about current state, and requests 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 avail- able. ntpq 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 com- mands 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 here. 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 following argument is interpreted as an interactive for- mat command and is added to the list of commands to be exe- cuted 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 the peers interactive command. Internal commands Interactive format commands consist of a keyword followed by zero to four arguments. Only enough characters of the full keyword to uniquely iden- tify 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 ``>'', followed by a filename, 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 server. They are described here. ? [command_keyword] A ``?'' by itself will print a list of all the command key- words known to this incarnation of ntpq. 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 ntpq than 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 time stamps 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. This command is currently just wishful thinking. keyid # This command allows the specification of a key number to be used to authenticate configuration requests. This must cor- respond 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 configura- tion requests. The password must correspond to the key con- figured for use by the NTP server for this purpose if such requests are to be successful. 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 com- mand line -n switch. raw Causes all output from query commands to be printed as received from the remote server. The only formatting/interpretation 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''. Vari- ables that are recognized by the server will have their values reformatted for human consumption. Variables that ntpq thinks should have a decodeable value but didn't are marked with a trailing ``?''. ntpversion 1|2 Sets the NTP version number that ntpq claims in packets. Defaults to 2 since mode 6 control messages (and modes, for that matter) didn't exist in NTP version 1. There appear to be no servers left that demand 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. Authenti- cated requests cause some servers to handle requests slightly differently, and can occasionally cause problems with fuzz- ball servers if you turn authentication on before doing a peer display. 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. ntpq maintains an internal list in which data to be included in control mes- sages can be assembled, and sent using the readlist and wri- telist 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 com- mand can be used to remove individual variables from the list, while the clearlist command removes all variables from the list. debug more|less|off Turns internal query program debugging on and off. quit Exit ntpq. Control message commands Each peer known to an NTP server has a 16 bit integer association identifier assigned to it. NTP control messages which carry peer vari- ables 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 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 associa- tions command is cached internally in ntpq. The index is then of use when dealing with servers which use association identifiers which are hard for humans to type, in that for any subsequent commands which require an association identif- ier as an argument, the form &index may be used as an alter- native. lassocations Obtains and prints a list of association identifiers and peer statuses for all associations for which the server is main- taining 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 lassocia- tions. passociations Prints association data concerning in-spec peers from the internally cached list of associations. This command per- forms 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 associa- tions. This command differs from passociations only when dealing with fuzzballs. pstatus assocID Sends a read status request to the server for the given asso- ciation. 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 pidgeon English. 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 associationID is omitted or is given as zero the vari- ables 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 dis- play. rv [assocID] [<variable_name>[=<value>][,...] ] An easy-to-type short form for the readvar command. writevar assocID <variable_name>=<value>[,...] Like the readvar request, except the specified variables are written instead of read. 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] Like the readlist request, except the internal list variables are written instead of read. 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>][,...] ] An easy-to-type 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 An easy-to-type 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 synchroniza- tion will respond positively to this. If the association identifier is omitted or zero the request is for the vari- ables of the ``system clock'' and will generally get a posi- tive 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>][,...] ] An easy-to-type 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 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 seconds. In addition, the character in the left margin indicates the fate of this peer in the clock selection algorithm. Characters only appear beside peers which were included in the final stage of the clock selection algorithm. A ``.'' indicates that this peer was cast off in the falseticker detection, while a ``+'' indicates that the peer made it through. A ``*'' denotes the peer the server is currently synchronizing with. Note that since the peers com- mand 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. 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 from fuzzball servers. opeers An old form of the peers command with the reference ID replaced by the local interface address.