xntpd(8) System Manager's Manual xntpd(8)
NAME
xntpd - 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 display. 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). Pre-
vents 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 authentication keys. See ntp.keys(4) for infor-
mation on the authentication key file format. Specifies a log file instead of logging to syslog. Specifies the name of the file to record
the daemon's process id. Specifies 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 variable. 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 proto-
col 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 running 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 resolution. See
ntp_intro(7) and Network Administration 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
HISTORY
Written by Dennis Ferguson at the University of Toronto. Text amended by David Mills at the University of Delaware.
xntpd(8)