ntpq(8)
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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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