NetBSD/usr.sbin/ntp/ntpq/ntpq.8

.\"	$NetBSD: ntpq.8,v 1.15 2003/10/25 12:32:55 fredb Exp $
.\" Converted from HTML to mandoc by ntp-html2mdoc.pl
.\"
.Dd March 29, 2000
.Dt NTPQ 8
.Os
.Sh NAME
.Nm ntpq
.Nd standard NTP query program
.Sh SYNOPSIS
.Nm
.Op Fl dinp
.Op Fl c Ar command ...
.Op Ar host ...
.Sh DESCRIPTION
.Pa 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.
.Pa 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
.Pa 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,
.Pa ntpq
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.
.Pa ntpq
will prompt for commands if the standard input is a terminal device.
.Pp
.Pa 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.
.Pa 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.
.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
.Ar host(s)
immediately.
Otherwise,
.Pa ntpq
will attempt to read interactive format commands from the standard input.
.Bl -tag -width indent
.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
Set debug mode.
Most useful with
.Fl c .
Multiple
.Fl d
options increase the level of verbosity.
At debug level four,
the entire raw packet is dumped to the terminal.
.It Fl i
Force
.Pa ntpq
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
.Pa peers
interactive command.
.El
.Sh 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 "\*[Lt]", followed by a file name, to the
command line. A number of interactive format commands are executed entirely
within the
.Pa ntpq
program itself and do not result in NTP mode 6
requests being sent to a server. These are described following.
.Bl -tag -width indent
.It Ar \&? [ command_keyword ]
.It Ar helpl [ command_keyword ]
A
.Pa \&?
by itself will print a list of all the command keywords
known to this incarnation of
.Pa ntpq .
A
.Pa \&?
followed by
a command keyword will print function and usage information about the
command. This command is probably a better source of information about
.Pa ntpq
than this manual page.
.It Ar addvars variable_name [ = value] [...]
.It Ar rmvars variable_name [...]
.It Ar clearvars
The data carried by NTP mode 6 messages consists of a list of items of
the form
.Ar variable_name
=
.Ar value ,
where the " =
.Ar value
" is ignored, and can be omitted, in requests to the
server to read variables.
.Pa 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 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 command can be used to remove individual
variables from the list, while the clearlist command removes all variables
from the list.
.It Ar authenticate yes | no
Normally
.Pa ntpq
does not authenticate requests unless they are write
requests. The command authenticate yes causes
.Pa 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 authentication on before doing a peer display.
.It Ar cooked
Causes output from query commands to be
.Pa "cooked" .
Variables which
are recognized by the server will have their values reformatted for human
consumption. Variables which
.Pa ntpq
thinks should have a decodeable
value but didn't are marked with a trailing
.Pa \&?
.
.It Ar debug more | less | off
Turns internal query program debugging on and off.
.It Ar 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.
.It Ar host hostname
Set the host to which future queries will be sent. Hostname may be either
a host name or a numeric address.
.It Ar hostnames [yes | no]
If
.Pa "yes"
is specified, host names are printed in information displays.
If
.Pa "no"
is specified, numeric addresses are printed instead. The
default is
.Em yes ,
unless modified using the command line
.Fl n
switch.
.It Ar 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.
.It Ar ntpversion 1 | 2 | 3 | 4
Sets the NTP version number which
.Pa 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.
.It Ar quit
Exit
.Pa ntpq
.
.It Ar 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 Ar 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.
.It Ar timeout milliseconds
Specify a timeout period for responses to server queries. The default is
about 5000 milliseconds. Note that since
.Pa ntpq
retries each query
once after a timeout, the total waiting time for a timeout will be twice
the timeout value set.
.El
.Sh 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 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 Ar 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
.Pa condition
field. Note that the data returned
by the
.Pa "associations"
command is cached internally in
.Pa 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.
.It Ar clockvar [assocID] [variable_name [ = value [...] ] [...]
.It Ar 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 synchronization will respond positively
to this. If the association identifier is omitted or zero the request is
for the variables of the
.Pa "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 Ar 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
.Pa "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
.Pa "associations"
command is used, but are included in the output of
.Pa "lassociations"
.
.It Ar lpassociations
Print data for all associations, including out-of-spec client associations,
from the internally cached list of associations. This command differs from
.Pa "passociations"
only when dealing with fuzzballs.
.It Ar 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 Ar mreadlist assocID assocID
.It Ar mrl assocID assocID
Like the
.Pa 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
.Pa associations
command.
.It Ar mreadvar assocID assocID [ variable_name [ = value [ ... ]
.It Ar mrv assocID assocID [ variable_name [ = [ ... ]
Like the
.Pa 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
.Pa associations
command.
.It Ar opeers
An old form of the
.Pa peers
command with the reference ID replaced
by the local interface address.
.It Ar passociations
Prints association data concerning in-spec peers from the internally cached
list of associations. This command performs identically to the
.Pa "associations"
except that it displays the internally stored data rather than making a
new query.
.It Ar 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 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
.Pa rv
command, and a short explanation of the condition
revealed.
.Bl -tag -width indent
.It space reject
The peer is discarded as unreachable, synchronized to this server (synch
loop) or outrageous synchronization distance.
.It x     falsetick
The peer is discarded by the intersection algorithm as a falseticker.
.It .     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 -     outlyer
The peer is discarded by the clustering algorithm as an outlyer.
.It +     candidat
The peer is a survivor and a candidate for the combining algorithm.
.It #     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 *     sys.peer
The peer has been declared the system peer and lends its variables to the
system variables.
.It 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.
.El
.Pp
The
.Pa 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
.Pa TEST1
through
.Pa TEST9 .
The bits for each test read in increasing sequency from
the least significant bit and are defined as follows.
The following
.Pa TEST1
through
.Pa TEST4
enumerate procedure
errors. The packet timestamps may or may not be believed, but the remaining
header data are ignored.
.Bl -tag -width indent
.It TEST1
Duplicate packet. A copy from somewhere.
.It 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.
.It TEST3
Unsynchronized. One or more timestamp fields are missing. This normally
happens when the first packet from a peer is received.
.It TEST4
Either peer delay or peer dispersion is greater than one second. Ya gotta
be kidding.
.El
.Pp
The following
.Pa TEST5
through
.Pa TEST10
enumerate errors
in the packet header. The packet is discarded without inspecting its contents.
.Bl -tag -width indent
.It TEST5
Cryptographic authentication fails. See the
.%T "Authentication Options" ,
refer to
.Pa /usr/share/doc/html/ntp/authopt.htm
page.
.It TEST6
Peer is unsynchronized. Wind up its clock first.
.It TEST7
Peer stratum is greater than 15. The peer is probably unsynchronized.
.It TEST8
Either root delay or root dispersion is greater than one second. Too far
from home.
.It TEST9
Peer cryptographic authentication fails. Either the key identifier or key
is wrong or somebody trashed our packet.
.It TEST10
Access is denied. See the
.%T "Access Control Options" ,
refer to
.Pa /usr/share/doc/html/ntp/accopt.htm
page.
.El
.Pp
.It Ar pstatus 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 Ar readlist [ assocID ]
.It rl [ 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 Ar readvar assocID variable_name [ = value ] [ ... ]
.It Ar 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 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 Ar writevar assocID variable_name [ = value [ ... ]
Like the readvar request, except the specified variables are written instead
of read.
.It Ar writelist [ assocID ]
Like the readlist request, except the internal list variables are written
instead of read.
.El
.Sh AUTHORS
David L. Mills (mills@udel.edu)
.Sh 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.