Current Path : /usr/src/usr.sbin/ntp/doc/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
Current File : //usr/src/usr.sbin/ntp/doc/ntpq.8 |
.\" .\" $FreeBSD: release/9.1.0/usr.sbin/ntp/doc/ntpq.8 210933 2010-08-06 14:33:42Z joel $ .\" .Dd May 17, 2006 .Dt NTPQ 8 .Os .Sh NAME .Nm ntpq .Nd standard NTP query program .Sh SYNOPSIS .Nm .Op Fl inp .Op Fl c Ar command .Op Ar host .Op Ar ... .Sh DESCRIPTION The .Nm utility is used to monitor NTP daemon .Xr ntpd 8 operations and determine performance. It uses the standard NTP mode 6 control message formats defined in Appendix B of the NTPv3 specification RFC1305. 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. .Pp The program can 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 .Nm can also obtain and print a list of peers in a common format by sendingmultiple queries to the server. .Pp If one or more request options is included on the command line when .Nm 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, .Nm 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 .Nm utility will prompt for commands if the standard input is a terminal device. .Pp The .Nm 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 .Nm 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. .Pp For examples and usage, see the .Qq NTP Debugging Techniques page (available as part of the HTML documentation provided in .Pa /usr/share/doc/ntp ) . .Pp The following options are available: .Bl -tag -width indent .It Fl 4 Force DNS resolution of following host names on the command line to the IPv4 namespace. .It Fl 6 Force DNS resolution of following host names on the command line to the IPv6 namespace. .It Fl 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 .Fl c options may be given. .It Fl d Turn on debugging mode. .It Fl i Force .Nm to operate in interactive mode. Prompts will be written to the standard output and commands read from the standard input. .It Fl n Output all host addresses in dotted-quad numeric format rather than converting to the canonical host names. .It Fl p Print a list of the peers known to the server as well as a summary of their state. This is equivalent to the .Ic peers interactive command. .El .Pp Note that in contexts where a host name is expected, a .Fl 4 qualifier preceding the host name forces DNS resolution to the IPv4 namespace, while a .Fl 6 qualifier forces DNS resolution to the IPv6 namespace. Specifying a command line option other than .Fl i or .Fl n will cause the specified query (queries) to be sent to the indicated host(s) immediately. Otherwise, .Nm will attempt to read interactive format commands from the standard input. .Ss "Internal Commands" 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. 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 .Ql \&> , followed by a file name, to the command line. A number of interactive format commands are executed entirely within the .Nm utility itself and do not result in NTP mode 6 requests being sent to a server. These are described following. .Bl -tag -width indent .It Ic \&? Op Ar command_keyword .It Ic help Op Ar command_keyword A .Sq Ic \&? by itself will print a list of all the command keywords known to this incarnation of .Nm . A .Sq Ic \&? followed by a command keyword will print function and usage information about the command. This command is probably a better source of information about .Nm than this manual page. .It Xo Ic addvars .Ar variable_name Ns Op = Ns Ar value ... .Xc .It Ic rmvars Ar variable_name ... .It Ic clearvars The data carried by NTP mode 6 messages consists of a list of items of the form .Ql variable_name=value , where the .Ql =value is ignored, and can be omitted, in requests to the server to read variables. The .Nm utility maintains an internal list in which data to be included in control messages can be assembled, and sent using the .Ic readlist and .Ic writelist commands described below. The .Ic 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 .Ic rmvars command can be used to remove individual variables from the list, while the .Ic clearlist command removes all variables from the list. .It Ic cooked Causes output from query commands to be "cooked", so that variables which are recognized by .Nm will have their values reformatted for human consumption. Variables which .Nm thinks should have a decodable value but did not are marked with a trailing .Ql \&? . .It Xo Ic debug .Cm more | .Cm less | .Cm off .Xc Turns internal query program debugging on and off. .It Ic delay Ar 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. .It Ic host Ar hostname Set the host to which future queries will be sent. Hostname may be either a host name or a numeric address. .It Ic hostnames Cm yes | Cm no If .Cm yes is specified, host names are printed in information displays. If .Cm no is specified, numeric addresses are printed instead. The default is .Cm yes , unless modified using the command line .Fl n switch. .It Ic keyid Ar keyid This command specifies the 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. .It Xo Ic ntpversion .Cm 1 | .Cm 2 | .Cm 3 | .Cm 4 .Xc Sets the NTP version number which .Nm claims in packets. Defaults to 3, Note that mode 6 control messages (and modes, for that matter) did not exist in NTP version 1. There appear to be no servers left which demand version 1. .It Ic passwd This command prompts for a password (which will not be echoed) which will be used to authenticate configuration requests. The password must correspond to the key configured for NTP server for this purpose. .It Ic quit Exit .Nm . .It Ic 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 nonascii data into a printable (but barely understandable) form. .It Ic timeout Ar milliseconds Specify a timeout period for responses to server queries. The default is about 5000 milliseconds. Note that since .Nm retries each query once after a timeout, the total waiting time for a timeout will be twice the timeout value set. .El .Ss Control Message Commands Each association known to an NTP server has a 16 bit integer association identifier. 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. .Pp 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. .Bl -tag -width indent .It Ic 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 command for a decode of the .Sq condition field. Note that the data returned by the .Ic associations command is cached internally in .Nm . 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. .It Xo Ic clockvar Op Ar assocID .Oo .Ar variable_name Ns Op = Ns Ar value ... .Oc .Ar ... .Xc .It Xo Ic cv Op Ar assocID .Oo .Ar variable_name Ns Op = Ns Ar value ... .Oc .Ar ... .Xc Requests that a list of the server's clock variables be sent. Servers which 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 variables of the .Sq 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. .It Ic 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 .Ic associations command only for servers which retain state for out-of-spec client associations (i.e., fuzzballs). Such associations are normally omitted from the display when the .Ic associations command is used, but are included in the output of .Ic lassociations . .It Ic lpassociations Print data for all associations, including out-of-spec client associations, from the internally cached list of associations. This command differs from .Ic passociations only when dealing with fuzzballs. .It Ic 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. .It Ic mreadlist Ar assocID Ar assocID .It Ic mrl Ar assocID Ar assocID Like the .Ic 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 .Ic associations command. .It Xo Ic mreadvar Ar assocID Ar assocID .Oo .Ar variable_name Ns Op = Ns Ar value ... .Oc .Xc .It Xo Ic mrv Ar assocID Ar assocID .Oo .Ar variable_name Ns Op = Ns Ar value ... .Oc .Xc Like the .Ic 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 .Ic associations command. .It Ic opeers An old form of the .Ic peers command with the reference ID replaced by the local interface address. .It Ic passociations Displays association data concerning in-spec peers from the internally cached list of associations. This command performs identically to the .Ic associations except that it displays the internally stored data rather than making a new query. .It Ic 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, 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 milliseconds. The character at the left margin of each line shows the synchronization status of the association and is a valuable diagnostic tool. The encoding and meaning of this character, called the tally code, is given later in this page. .It Ic pstatus Ar 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 pidgeon English. .It Ic readlist Ar assocID .It Ic rl Ar 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. .It Xo Ic readvar Ar assocID .Ar variable_name Ns Op = Ns Ar value .Ar ... .Xc .It Xo Ic rv Ar assocID .Ar variable_name Ns Op = Ns Ar value .Ar ... .Xc 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 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. The encoding and meaning of the variables derived from NTPv3 is given in RFC-1305; the encoding and meaning of the additional NTPv4 variables are given later in this page. .It Xo Ic writevar Ar assocID .Ar variable_name Ns Op = Ns Ar value .Ar ... .Xc Like the readvar request, except the specified variables are written instead of read. .It Ic writelist Op Ar assocID Like the readlist request, except the internal list variables are written instead of read. .El .Ss Tally Codes The character in the left margin in the .Sq peers billboard, called the tally code, shows the fate of each association in the clock selection process. Following is a list of these characters, the pigeon used in the .Ic rv command, and a short explanation of the condition revealed. .Bl -tag -width indent .It space .Pq reject The peer is discarded as unreachable, synchronized to this server (synch loop) or outrageous synchronization distance. .It x .Pq falsetick The peer is discarded by the intersection algorithm as a falseticker. .It \&. .Pq 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. .It \&- .Pq outlyer The peer is discarded by the clustering algorithm as an outlyer. .It \&+ .Pq candidat The peer is a survivor and a candidate for the combining algorithm. .It \&# .Pq 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. .It \&* .Pq sys.peer The peer has been declared the system peer and lends its variables to the system variables. .It o .Pq 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. .El .Ss System Variables The .Cm status , .Cm leap , .Cm stratum , .Cm precision , .Cm rootdelay , .Cm rootdispersion , .Cm refid , .Cm reftime , .Cm poll , .Cm offset , and .Cm frequency variables are described in RFC-1305 specification. Additional NTPv4 system variables include the following. .Bl -tag -width indent .It version Everything you might need to know about the software version and generation time. .It processor The processor and kernel identification string. .It system The operating system version and release identifier. .It state The state of the clock discipline state machine. The values are described in the architecture briefing on the NTP Project page linked from www.ntp.org. .It peer The internal integer used to identify the association currently designated the system peer. .It jitter The estimated time error of the system clock measured as an exponential average of RMS time differences. .It stability The estimated frequency stability of the system clock measured as an exponential average of RMS frequency differences. .El .Pp When the NTPv4 daemon is compiled with the OpenSSL software library, additional system variables are displayed, including some or all of the following, depending on the particular dance: .Bl -tag -width indent .It flags The current flags word bits and message digest algorithm identifier (NID) in hex format. The high order 16 bits of the four-byte word contain the NID from the OpenSSL ligrary, while the low-order bits are interpreted as follows: .Bl -tag -width indent .It 0x01 autokey enabled .It 0x02 NIST leapseconds file loaded .It 0x10 PC identity scheme .It 0x20 IFF identity scheme .It 0x40 GQ identity scheme .El .It hostname The name of the host as returned by the Unix .Fn gethostname library function. .It hostkey The NTP filestamp of the host key file. .It cert A list of certificates held by the host. Each entry includes the subject, issuer, flags and NTP filestamp in order. The bits are interpreted as follows: .Bl -tag -width indent .It 0x01 certificate has been signed by the server .It 0x02 certificate is trusted .It 0x04 certificate is private .It 0x08 certificate contains errors and should not be trusted .El .It leapseconds The NTP filestamp of the NIST leapseconds file. .It refresh The NTP timestamp when the host public cryptographic values were refreshed and signed. .It signature The host digest/signature scheme name from the OpenSSL library. .It tai The TAI-UTC offset in seconds obtained from the NIST leapseconds table. .El .Ss Peer Variables The .Cm status , .Cm srcadr , .Cm srcport , .Cm dstadr , .Cm dstport , .Cm leap , .Cm stratum , .Cm precision , .Cm rootdelay , .Cm rootdispersion , .Cm readh , .Cm hmode , .Cm pmode , .Cm hpoll , .Cm ppoll , .Cm offset , .Cm delay , .Cm dspersion , .Cm reftime variables are described in the RFC-1305 specification, as are the timestamps .Cm org , .Cm rec and .Cm xmt . Additional NTPv4 system variables include the following. .Bl -tag -width indent .It flash The flash code for the most recent packet received. The encoding and meaning of these codes is given later in this page. .It jitter The estimated time error of the peer clock measured as an exponential average of RMS time differences. .It unreach The value of the counter which records the number of poll intervals since the last valid packet was received. .El .Pp When the NTPv4 daemon is compiled with the OpenSSL software library, additional peer variables are displayed, including the following: .Bl -tag -width indent .It flags The current flag bits. This word is the server host status word with additional bits used by the Autokey state machine. See the source code for the bit encoding. .It hostname The server host name. .It initkey Ar key The initial key used by the key list generator in the Autokey protocol. .It initsequence Ar index The initial index used by the key list generator in the Autokey protocol. .It signature The server message digest/signature scheme name from the OpenSSL software library. .It timestamp Ar time The NTP timestamp when the last Autokey key list was generated and signed. .El .Ss Flash Codes The .Cm flash code is a valuable debugging aid displayed in the peer variables list. It shows the results of the original sanity checks defined in the NTP specification RFC-1305 and additional ones added in NTPv4. There are 12 tests designated .Sy TEST1 through .Sy TEST12 . The tests are performed in a certain order designed to gain maximum diagnostic information while protecting against accidental or malicious errors. The .Sy flash variable is initialized to zero as each packet is received. If after each set of tests one or more bits are set, the packet is discarded. .Pp Tests .Sy TEST1 through .Sy TEST3 check the packet timestamps from which the offset and delay are calculated. If any bits are set, the packet is discarded; otherwise, the packet header variables are saved. .Sy TEST4 and .Sy TEST5 are associated with access control and cryptographic authentication. If any bits are set, the packet is discarded immediately with nothing changed. .Pp Tests .Sy TEST6 through .Sy TEST8 check the health of the server. If any bits are set, the packet is discarded; otherwise, the offset and delay relative to the server are calculated and saved. TEST9 checks the health of the association itself. If any bits are set, the packet is discarded; otherwise, the saved variables are passed to the clock filter and mitigation algorithms. .Pp Tests .Sy TEST10 through .Sy TEST12 check the authentication state using Autokey public-key cryptography, as described in the .Sx Authentication Options section of .Xr ntp.conf 5 . If any bits are set and the association has previously been marked reachable, the packet is discarded; otherwise, the originate and receive timestamps are saved, as required by the NTP protocol, and processing continues. .Pp The .Cm flash bits for each test are defined as follows. .Bl -tag -width indent .It 0x001 .Pq TEST1 Duplicate packet. The packet is at best a casual retransmission and at worst a malicious replay. .It 0x002 .Pq TEST2 Bogus packet. The packet is not a reply to a message previously sent. This can happen when the NTP daemon is restarted and before somebody else notices. .It 0x004 .Pq TEST3 Unsynchronized. One or more timestamp fields are invalid. This normally happens when the first packet from a peer is received. .It 0x008 .Pq TEST4 Access is denied. See the .Sx Access Control Support section of .Xr ntp.conf 5 . .It 0x010 .Pq TEST5 Cryptographic authentication fails. See the .Sx Authentication Options section of .Xr ntp.conf 5 . .It 0x020 .Pq TEST6 The server is unsynchronized. Wind up its clock first. .It 0x040 .Pq TEST7 The server stratum is at the maximum than 15. It is probably unsynchronized and its clock needs to be wound up. .It 0x080 .Pq TEST8 Either the root delay or dispersion is greater than one second, which is highly unlikely unless the peer is unsynchronized to Mars. .It 0x100 .Pq TEST9 Either the peer delay or dispersion is greater than one second, which is higly unlikely unless the peer is on Mars. .It 0x200 .Pq TEST10 The autokey protocol has detected an authentication failure. See the .Sx Authentication Options section of .Xr ntp.conf 5 . .It 0x400 .Pq TEST11 The autokey protocol has not verified the server or peer is proventic and has valid public key credentials. See the .Sx Authentication Options section of .Xr ntp.conf 5 . .It 0x800 .Pq TEST12 A protocol or configuration error has occurred in the public key algorithms or a possible intrusion event has been detected. See the .Sx Authentication Options section of .Xr ntp.conf 5 . .El .Sh SEE ALSO .Xr ntp.conf 5 , .Xr ntpd 8 , .Xr ntpdc 8 .Sh BUGS The .Ic 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 does not.