freebsd-nq/usr.sbin/xntpd/doc/ntpq.8

.\"
.\"	$Id: ntpq.8,v 1.5 1998/02/19 08:05:38 charnier Exp $
.\"
.Dd December 21, 1993
.Dt NTPQ 8
.Os
.Sh NAME
.Nm ntpq
.Nd standard Network Time Protocol query program
.Sh SYNOPSIS
.Nm
.Op Fl inp
.Op Fl c Ar command
.Op Ar host ...
.Sh DESCRIPTION
.Nm 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
controlled using command line arguments. Requests to read and write
arbitrary variables can be assembled, with raw and pretty\-printed
output options being available.
.Nm Ntpq
can also obtain and print a list of peers in a common format by sending
multiple 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
.Ar 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
.Ar localhost
when no other host is specified.
.Nm Ntpq
will prompt for commands if the standard input is a terminal device.
.Pp
.Nm Ntpq
uses NTP mode 6 packets to communicate with the NTP server, and hence
can be used to query any compatable 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.
.Nm 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.
.Pp
Command line options are described following. 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.
The following options are available:
.Bl -tag -width indent
.It Fl c Ar command
The following argument is interpreted as an interactive format
.Ar 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 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
.Em peers
interactive command.
.El
.Sh INTERNAL COMMANDS
.Pp
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
.Qq > ,
followed by a file name, to the command line.
.Pp
A number of interactive format commands are executed entirely within the
.Nm
program itself and do not result in NTP mode 6 requests being sent to a
server. These are described following.
.Pp
.Bl -tag -width indent
.It ? Op Ar command_keyword
A
.Qq ?
by itself will print a list of all the command keywords
known to this incarnation of
.Nm Ns .
A
.Qq ?
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 timeout Ar milliseconds
Specify a time out period for responses to server queries. The default
is about 5000 milliseconds. Note that since
.Nm
retries each query once after a time out the total waiting time for a
time out will be twice the time out value set.
.It 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 time
stamps in authenticated requests, so this command may be obsolete.
.It host Ar hostname
Set the host to which future queries will be sent.
.Ar Hostname
may be either a host name or a numeric
address.
.It Xo poll
.Op Ar #
.Op Ar verbose
.Xc
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.
.It keyid Ar #
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.
.It 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.
.It hostnames Ar yes | Ar no
If
.Ar yes
is specified, host names are printed in information
displays. If
.Ar no
is given, numeric addresses are printed
instead. The default is
.Ar yes
unless modified using the command line
.Fl n
switch.
.It raw
Cause all output from query commands is printed as received from the
remote server. The only formating/intepretation done on the data is to
transform nonascii data into a printable (but barely understandable)
form.
.It cooked
Cause output from query commands to be
.Qq cooked Ns .
Variables
which are recognized by the server will have their values reformatted
for human consumption. Variables which
.Nm
thinks should have a decodeable value but didn't are marked with a
trailing
.Qq ? Ns .
.It ntpversion Ar 1 | Ar 2 | Ar 3
Set the NTP version number which
.Nm
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.
.It authenticate Ar yes | Ar no
Normally
.Nm
does not authenticate requests unless they are write requests. The
command
.Em authenticate yes
causes
.Nm
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 peer display.
.It Xo addvars
.Aq variable_name Ns
.Op = Ns Aq value Ns
.Op ,...
.Xc
.It Xo rmvars
.Aq variable_name Ns
.Op ,...
.Xc
.It clearvars
The data carried by NTP mode 6 messages consists of a list of items of
the form
.Xo Aq variable_name Ns
.Pf = Aq value
.Xc
where the
.Qq = Ns Aq value
is ignored, and can be omitted, in requests
to the server to read variables.
.Nm Ntpq
maintains an internal list in which data to be included in control
messages can be assembled, and sent using the
.Em readlist
and
.Em writelist
commands described below. The
.Em 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
.Em rmvars
command can be used to remove individual variables from the list, while
the
.Em clearlist
command removes all variables from the list.
.It debug Ar more | Ar less | Ar off
Turn internal query program debugging on and off.
.It quit
Exit
.Nm Ns .
.El
.Sh CONTROL MESSAGE COMMANDS
Each peer known to an NTP server has a 16 bit integer
.Em association identifier
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.
.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
.Em peers
command, which will send a preprogrammed series of messages to obtain
the data it needs, and the
.Em mreadlist
and
.Em mreadvar
commands, which will iterate over a range of associations.
.Bl -tag -width indent
.It associations
Obtain and print 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 \*(L"associations\*(R"
command is cached internally in
.Nm Ns .
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
.Em &index
may be used as an alternative.
.It lassocations
Obtain and print a list of association identifiers and peer statuses
for all associations for which the server is maintaining state. This
command differs from the
.Em 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
.Em associations
command is used, but are included in the
output of
.Em lassociations Ns .
.It passociations
Print association data concerning in\-spec peers from the internally
cached list of associations. This command performs identically to the
.Em associations
except that it displays the internally stored
data rather than making a new query.
.It lpassociations
Print data for all associations, including out\-of\-spec client
associations, from the internally cached list of associations. This
command differs from
.Em passociations
only when dealing with fuzzballs.
.It pstatus Ar assocID
Send 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 pidgin English.
.It Xo readvar
.Op Ar assocID Ns
.Pf [ Aq variable_name Ns
.Op = Ns Aq value Ns
.Op ,...]
.Xc
Request 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.
.It Xo rv
.Op Ar assocID Ns
.Pf [ Aq variable_name Ns
.Op = Ns Aq value Ns
.Op ,...]
.Xc 
An easy\-to\-type short form for the
.Em readvar
command.
.It Xo writevar
.Ar assocID
.Aq variable_name Ns
.Pf = Ns Aq value Ns
.Op ,...
.Xc
Like the
.Em readvar
request, except the specified variables are written instead of read.
.It readlist Op Ar assocID
Request 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 rl Op Ar assocID
An easy\-to\-type short form of the
.Em readlist
command.
.It writelist Op Ar assocID
Like the
.Em readlist
request, except the internal list variables are written instead of read.
.It Xo mreadvar
.Ar assocID assocID [
.Aq variable_name Ns
.Op = Ns Aq value Ns
.Op ,...]
.Xc
Like the
.Em 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
.Em associations
command.
.It Xo mrv
.Ar assocID assocID [
.Aq variable_name Ns
.Op = Ns Aq value Ns
.Op ,...]
.Xc
An easy\-to\-type short form of the
.Em mreadvar
command.
.It mreadlist Ar assocID assocID
Like the
.Em 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
.Em associations
command.
.It mrl Ar assocID assocID
An easy\-to\-type short form of the
.Em mreadlist
command.
.It Xo clockvar
.Op Ar assocID Ns
.Pf [ Aq variable_name Ns
.Op = Ns Aq value Ns
.Op ,...]
.Xc
Request 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
.Qq 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 Xo cv
.Op Ar assocID Ns
.Pf [ Aq variable_name Ns
.Op = Ns Aq value Ns
.Op ,...]
.Xc
An easy\-to\-type short form of the
.Em clockvar
command.
.It peers
Obtain 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 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
seconds.
.Pp
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;
.Qq x
designated falsticker
by the intersection algorithm;
.Qq \&.
culled from the end of the
candidate list;
.Qq -
discarded by the clustering algorithm;
.Qq +
included in the final selection set;
.Qq #
selected
for synchronization but distance exceeds maximum;
.Qq *
selected
for synchronization; and
.Qq o
selected for synchronization, pps
signal in use.
.Pp
Note that since the
.Em 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.
.Pp
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 or
.Qq REFCLK(<implementation number>, <parameter>) .
On
.Qq hostnames no
only IP\-addresses will be displayed.
.It lpeers
Like
.Em 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 opeers
An old form of the
.Em peers
command with the reference ID
replaced by the local interface address.
.El
.Sh HISTORY
Written by
.An Dennis Ferguson
at the University of Toronto.
.Sh BUGS
The
.Em peers
command is non\-atomic and may occasionally result in spurious error
messages about invalid associations occurring and terminating the
command.
.Pp
The timeout time is a fixed constant, which means you wait a long time
for time outs since it assumes sort of a worst case. The program should
improve the time out estimate as it sends queries to a particular host,
but doesn't.