NTPQ(8) NetBSD System Manager's Manual NTPQ(8)
NAME
ntpq - standard NTP query program
SYNOPSIS
ntpq [-dinp] [-c command ...] [host ...]
DESCRIPTION
ntpq is used to query NTP servers which implement the recommended NTP mode 6 control message format about current state and to request changes in that state. The program may be run either in interactive mode or con- trolled using command line arguments. Requests to read and write arbi- trary variables can be assembled, with raw and pretty-printed output options being available. 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 local- host 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 net- work topology. ntpq makes one attempt to retransmit requests, and will time requests out if the remote host is not heard from within a suitable timeout time. Command line options are described following. 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 format command and is added to the list of commands to be executed on the specified host(s). Multiple -c options may be given. -d Set debug mode. Most useful with -c. Multiple -d options increase the level of verbosity. At debug level four, the entire raw packet is dumped to the terminal. -i Force ntpq to operate in interactive mode. Prompts will be writ- ten 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 sum- mary 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 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 server. These are described following. ? [command_keyword] helpl [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 probably a better source of information about ntpq than this manual page. 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 messages can be assembled, and sent using the readlist and writelist commands described below. The addvars com- mand 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 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 command authenticate yes causes ntpq 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 authenti- cation on before doing a peer display. cooked Causes output from query commands to be cooked. Variables which are recognized by the server will have their values reformatted for human consumption. Variables which ntpq thinks should have a decodeable value but didn't are marked with a trailing ? debug more | less | off Turns internal query program debugging on and off. 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 [yes | no] If yes is specified, host names are printed in information dis- plays. If no is specified, numeric addresses are printed instead. The default is yes, unless modified using the command line -n 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 pur- pose. ntpversion 1 | 2 | 3 | 4 Sets the NTP version number which ntpq 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. quit Exit ntpq 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 formatting/interpretation done on the data is to transform non-ASCII data into a printable (but barely understandable) form. timeout milliseconds Specify a timeout period for responses to server queries. The default is about 5000 milliseconds. Note that since ntpq retries each query once after a timeout, the total waiting time for a timeout will be twice the timeout value set.
CONTROL MESSAGE COMMANDS
Each peer known to an NTP server has a 16 bit integer association identi- fier assigned to it. NTP control messages which 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 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 See the peers com- mand for a decode of the condition field. Note that the data returned by the associations command is cached internally in ntpq The index is then of use when dealing with stupid servers which use association identifiers which are hard for humans to type, in that for any subsequent commands which require an association identifier as an argument, the form and index may be used as an alternative. clockvar [assocID] [variable_name [= value [...]] [...] cv [assocID] [variable_name [= value [...]] [...] Requests that a list of the server's clock variables be sent. Servers which have a radio clock or other external synchroniza- tion will respond positively to this. If the association identi- fier 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. 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 associa- tions (i.e., fuzzballs). Such associations are normally omitted from the display when the associations command is used, but are included in the output of lassociations 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. lpeers Like R 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. mreadlist assocID assocID mrl 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 com- mand. mreadvar assocID assocID [variable_name [= value [...] mrv assocID assocID [variable_name [= [...] 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 com- mand. 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 inter- nally cached list of associations. This command performs identi- cally to the associations except that it displays the internally stored data rather than making a new query. peers Obtains a current list 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 this is unknown), the stratum of the remote peer, the type of the peer (local, uni- cast, 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 milliseconds. The character in the left margin indicates the fate of this peer in the clock selection process. Following is a list of these characters, the pidgeon used in the rv command, and a short explanation of the condition revealed. space reject The peer is discarded as unreachable, synchronized to this server (synch loop) or outrageous synchronization distance. x falsetick The peer is discarded by the intersection algorithm as a falseticker. . excess The peer is discarded as not among the first ten peers sorted by synchronization distance and so is probably a poor candidate for further consideration. - outlyer The peer is discarded by the clustering algorithm as an outlyer. + candidat The peer is a survivor and a candidate for the combining algorithm. # selected The peer is a survivor, but not among the first six peers sorted by synchronization distance. If the association is ephemeral, it may be demobilized to conserve resources. * sys.peer The peer has been declared the system peer and lends its variables to the system variables. o pps.peer The peer has been declared the system peer and lends its variables to the system variables. However, the actual system synchronization is derived from a pulse-per-second (PPS) signal, either indirectly via the PPS reference clock driver or directly via kernel interface. The flash variable is not defined in the NTP specification, but is included as a valuable debugging aid. It displays the results of the packet sanity checks defined in the NTP specification TEST1 through TEST9. The bits for each test read in increasing sequency from the least significant bit and are defined as fol- lows. The following TEST1 through TEST4 enumerate procedure errors. The packet timestamps may or may not be believed, but the remaining header data are ignored. TEST1 Duplicate packet. A copy from somewhere. TEST2 Bogus packet. It is not a reply to a message previously sent. This can happen when the NTP daemon is restarted and before a peer notices. TEST3 Unsynchronized. One or more timestamp fields are missing. This normally happens when the first packet from a peer is received. TEST4 Either peer delay or peer dispersion is greater than one second. Ya gotta be kidding. The following TEST5 through TEST10 enumerate errors in the packet header. The packet is discarded without inspecting its contents. TEST5 Cryptographic authentication fails. See the Authentication Options, refer to /usr/share/doc/html/ntp/authopt.htm page. TEST6 Peer is unsynchronized. Wind up its clock first. TEST7 Peer stratum is greater than 15. The peer is probably unsynchronized. TEST8 Either root delay or root dispersion is greater than one second. Too far from home. TEST9 Peer cryptographic authentication fails. Either the key identifier or key is wrong or somebody trashed our packet. TEST10 Access is denied. See the Access Control Options, refer to /usr/share/doc/html/ntp/accopt.htm page. pstatus assocID Sends a read status request to the server for the given associa- tion. 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. readlist [assocID] rl [assocID] Requests that the values of the variables in the internal vari- able 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. readvar assocID variable_name [= value] [...] rv 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 associ- ation ID 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. writevar assocID variable_name [= value [...] Like the readvar request, except the specified variables are written instead of read. writelist [assocID] Like the readlist request, except the internal list variables are written instead of read.
AUTHORS
David L. Mills (mills@udel.edu)
BUGS
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 timeouts since it assumes sort of a worst case. The program should improve the timeout estimate as it sends queries to a particular host, but doesn't. NetBSD 2.0.2 March 29, 2000 NetBSD 2.0.2
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