xntpd(8)xntpd(8)NAMExntpd - Network Time Protocol (NTP) daemon
SYNOPSIS
/usr/sbin/xntpd [-abdgmx] [-c conffile] [-e auth_delay] [-f driftfile]
[-k keyfile] [-l logfile] [-p pidfile] [-r broaddelay] [-s statdir] [-t
trustedkey] [-v sysvar] [-V def_sysvar]
OPTIONS
Runs in authenticate mode. Listens for broadcast NTP and synchronizes
to this if available. Specify debugging mode. This option may occur
multiple times, with each occurence indicating greater detail of dis‐
play. Allows xntpd to correct any time difference, including differ‐
ences greater than 1000 seconds. Listens for multicast messages and
synchronizes to them if available (requires multicast kernel). Causes
the xntpd daemon to exit after the first time the clock is set. With
this option a volley of messages are exchanged to groom the data and
the clock is set in about a minute. If nothing is heard after a couple
of minutes, the daemon times out and exits. This behavior is the same
as the ntpdate program, which is to be retired. The -g and -x options
can be used with this option. Prevents xntpd from setting the system
time backward. In NTP version 3, the default allows xntpd to set the
system time backward. Specifies an alternate configuration file.
Specifies the time (in seconds) it takes to compute the NTP encryption
field on this computer. Specifies the location of the drift file.
Specifies the location of the file which contains the NTP authentica‐
tion keys. See ntp.keys(4) for information on the authentication key
file format. Specifies a log file instead of logging to syslog. Spec‐
ifies the name of the file to record the daemon's process ID. Speci‐
fies the default round trip delay (in seconds) to be used if the daemon
cannot automatically compensate for network delay when synchronizing to
broadcasts. Specifies the directory in which to create statistics
files. Adds a key number to the trusted key list. Adds a system vari‐
able. Adds a system variable listed by default.
DESCRIPTION
The xntpd daemon maintains a system's time-of-day in agreement with
Internet standard time servers. The xntpd daemon is a complete imple‐
mentation of the Network Time Protocol (NTP) version 3 standard as
defined by RFC 1305, but also retains compatibility with version 1 and
version 2 servers as defined by RFC 1059 and RFC 1119, respectively.
The xntpd daemon does all computations in fixed point arithmetic and
requires no floating point code. The computations done in the protocol
and clock adjustment code are carried out with high precision and with
attention to the details that might introduce systematic bias into the
computations, to try to maintain an accuracy suitable for synchronizing
with even the most precise external time source.
The xntpd daemon reads its configuration from a file at startup time.
The default configuration file is /etc/ntp.conf. The xntpd daemon can
be monitored and configuration options altered while the daemon is run‐
ning by using either the ntpq(8) or the xntpdc(8) program.
The xntpd daemon includes support for several commercially available
external reference clocks. See ntp.conf(4) for information on the use
and configuration of reference clocks.
The Tru64 UNIX operating system also provides the NTP_TIME and
MICRO_TIME kernel options to allow greater accuracy and time resolu‐
tion. See ntp_intro(7) and Network Administration: Services for more
information.
FILES
Default name of the configuration file Conventional name of the drift
file Conventional name of the key file
SEE ALSO
Commands: ntp(1), ntpdate(8), ntpq(8), xntpdc(8)
Files: ntp.conf(4), ntp.keys(4)
Network Administration: Services
HISTORY
Written by Dennis Ferguson at the University of Toronto. Text amended
by David Mills at the University of Delaware.
xntpd(8)
