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diff --git a/usr.sbin/ntp/doc/ntpd.8 b/usr.sbin/ntp/doc/ntpd.8 new file mode 100644 index 0000000..91e35a1 --- /dev/null +++ b/usr.sbin/ntp/doc/ntpd.8 @@ -0,0 +1,278 @@ +.\" +.\" $FreeBSD$ +.\" +.Dd January 10, 2000 +.Dt NTPD 8 +.Os +.Sh NAME +.Nm ntpd +.Nd Network Time Protocol (NTP) daemon +.Sh SYNOPSIS +.Nm ntpd +.Op Fl aAbdm +.Op Fl c Ar conffile +.Op Fl f Ar driftfile +.Op Fl k Ar keyfile +.Op Fl l Ar logfile +.Op Fl p Ar pidfile +.Op Fl r Ar broadcastdelay +.Op Fl s Ar statsdir +.Op Fl t Ar trustedkey +.Op Fl v Ar variable +.Op Fl V Ar variable +.Sh DESCRIPTION +.Nm +is an operating system daemon +which sets and maintains the system time-of-day +in synchronism with Internet standard time servers. +.Nm +is a complete implementation of the Network Time Protocol (NTP) +version 4, +but also retains compatibility with version 3, +as defined by RFC 1305, +and version 1 and 2, +as defined by RFC 1059 and RFC 1119, +respectively. +.Nm +does most computations in 64-bit floating point arithmetic +and does relatively clumsy 64-bit fixed point operations +only when necessary to preserve the ultimate precision, +about 232 picoseconds. +While the ultimate precision is not achievable +with ordinary workstations and networks of today, +it may be required with future nanosecond CPU clocks and gigabit LANs. +.Pp +The daemon can operate in any of several modes, +including symmetric active/passive, +client/server broadcast/multicast and manycast. +A broadcast/multicast or manycast client can discover remote servers, +compute server-client propagation delay correction factors +and configure itself automatically. +This makes it possible to deploy a fleet of workstations +without specifying configuration details +specific to the local environment. +.Pp +Ordinarily, +.Nm +reads the +.Pa ntp.conf +configuration file at startup time +in order to determine the synchronization sources and operating modes. +It is also possible to specify a working, although limited, +configuration entirely on the command line, +obviating the need for a configuration file. +This may be particularly appropriate +when the local host is to be configured +as a broadcast/multicast client or manycast client, +with all peers being determined +by listening to broadcasts at run time. +.Pp +If NetInfo support is built into +.Nm Ns , +then +.Nm +will attempt to read its configuration from the NetInfo +if the default configuration file cannot be read +and no file is specified by the +.Fl c +option. +.Pp +Various +internal +.Nm +variables can be displayed and configuration options altered +while the daemon is running +through use of the +.Xr ntpq 8 +and +.Xr ntpdc 8 +programs. +.Pp +When +.Nm +starts it looks at the value of +.Xr umask 2 +and if it is zero, +.Nm +will set it to 022. +.Pp +The following command line options are available: +.Bl -tag -width indent +.It Fl a +Enable authentication mode (default). +.It Fl A +Disable authentication mode. +.It Fl b +Synchronize using NTP broadcast messages. +.It Fl c Ar conffile +Specify the name and path of the configuration file. +.It Fl d +Specify debugging mode. +This flag may occur multiple times, +with each occurrence indicating greater detail of display. +.It Fl D Ar level +Specify debugging level directly. +.It Fl f Ar driftfile +Specify the name and path of the drift file. +.It Fl g +Normally, the daemon exits +if the offset exceeds a 1000 s sanity limit. +This option overrides this limit +and allows the time to be set to any value without restriction. +.It Fl k Ar keyfile +Specify the name and path of the file +containing the NTP authentication keys. +.It Fl l Ar logfile +Specify the name and path of the log file. +The default is the system log facility. +.It Fl m +Synchronize using NTP multicast messages +on the IP multicast group address 224.0.1.1 +(requires multicast kernel). +.It Fl p Ar pidfile +Specify the name and path to record the daemon's process ID. +.It Fl P +Override the priority limit set by the operating system. +Not recommended for sissies. +.It Fl r Ar broadcastdelay +Specify the default propagation delay +between the broadcast/multicast server and this computer. +This is necessary +only if the delay cannot be computed automatically by the protocol. +.It Fl s Ar statsdir +Specify the directory path for files created by the statistics +facility. +.It Fl t Ar key +Add a key number to the trusted key list. +.It Fl v Ar variable +.It Fl V Ar variable +Add a system variable listed by default. +.It Fl x +Ordinarily, if the time is to be adjusted more than 128 ms, +it is stepped, not gradually slewed. +This option forces the time to be slewed in all cases. +Note: since the slew rate is limited to 0.5 ms/s, +each second of adjustment requires an amortization interval of 2000 s. +Thus, an adjustment of many seconds can take hours or days to amortize. +.El +.Ss The Configuration File +The +.Nm +configuration file is read at initial startup by the +.Xr ntpd 8 +daemon in order to specify the synchronization sources, +modes and other related information. +Usually, it is installed in the +.Pa /etc +directory, +but could be installed elsewhere +(see the daemon's +.Fl c +command line option). +.Pp +The file format is similar to other Unix configuration files. +Comments begin with a +.Qq # +character and extend to the end of the line; +blank lines are ignored. +Configuration commands consist of an initial keyword +followed by a list of arguments, +some of which may be optional, separated by whitespace. +Commands may not be continued over multiple lines. +Arguments may be host names, +host addresses written in numeric, dotted-quad form, +integers, floating point numbers (when specifying times in seconds) +and text strings. +.Pp +See the following pages for configuration and control options. +While there is a rich set of options available, +the only required option is one or more +.Ic server , +.Ic peer , +.Ic broadcast +or +.Ic manycastclient +commands +described in +.Xr ntp_conf 8 . +.Pp +.Bl -tag -width ntp_clockX8X -compact +.It Xr ntp_conf 8 +Configuration Options +.It Xr ntp_auth 8 +Authentication Options +.It Xr ntp_mon 8 +Monitoring Options +.It Xr ntp_acc 8 +Access Control Options +.It Xr ntp_clock 8 +Reference Clock Options +.It Xr ntp_misc 8 +Miscellaneous Options +.Pp +.El +The +.Qo +Notes on Configuring NTP and Setting up a NTP Subnet +.Qc +page +(available as part of the HTML documentation +provided in +.Pa /usr/share/doc/ntp ) +contains an extended discussion of these options. +.Sh FILES +.Bl -tag -width /etc/ntp.drift -compact +.It Pa /etc/ntp.conf +the default name of the configuration file +.It Pa /etc/ntp.drift +the default name of the drift file +.It Pa /etc/ntp.keys +the default name of the key file +.El +.Sh SEE ALSO +.Xr ntp_acc 8 , +.Xr ntp_auth 8 , +.Xr ntp_clock 8 , +.Xr ntp_conf 8 , +.Xr ntp_misc 8 , +.Xr ntp_mon 8 , +.Xr ntpdate 8 , +.Xr ntpdc 8 , +.Xr ntpq 8 +.Pp +In addition to the manual pages provided, +comprehensive documentation is available on the world wide web +at +.Li http://www.ntp.org/ . +A snapshot of this documentation is available in HTML format in +.Pa /usr/share/doc/ntp . +.Rs +.%A David L. Mills +.%T Network Time Protocol (Version 1) +.%O RFC1059 +.Re +.Rs +.%A David L. Mills +.%T Network Time Protocol (Version 2) +.%O RFC1119 +.Re +.Rs +.%A David L. Mills +.%T Network Time Protocol (Version 3) +.%O RFC1305 +.Re +.Sh HISTORY +Written by +.An Dennis Ferguson +at the University of Toronto. +Text amended by +.An David Mills +at the University of Delaware. +.Sh BUGS +.Nm +has gotten rather fat. +While not huge, it has gotten larger than might +be desireable for an elevated-priority daemon running on a workstation, +particularly since many of the fancy features which consume the space +were designed more with a busy primary server, rather than a high +stratum workstation, in mind. |
