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diff --git a/contrib/ntp/html/ntpd.htm b/contrib/ntp/html/ntpd.htm new file mode 100644 index 0000000..a90dfcb --- /dev/null +++ b/contrib/ntp/html/ntpd.htm @@ -0,0 +1,183 @@ +<HTML><HEAD><TITLE> +<TT>ntpd</TT> - Network Time Protocol (NTP) daemon +</TITLE></HEAD><BODY><H3> +<TT>ntpd</TT> - Network Time Protocol (NTP) daemon +</H3><HR> + +<H4>Synopsis</H4> + +<TT>ntpd [ -aAbdm ] [ -c <I>conffile</I> ] [ -f <I>driftfile</I> ] [ -k +<I>keyfile</I> ] [ -l <I>logfile</I> ] [ -p <I>pidfile</I> ] [ -r +<I>broadcastdelay</I> ] [ -s <I>statsdir</I> ] [ -t <I>key</I> ] [ -v +<I>variable</I> ] [ -V +<I>variable</I> ]</TT> + +<H4>Description</H4> + +<TT>ntpd</TT> is an operating system daemon which sets and maintains the +system time-of-day in synchronism with Internet standard time servers. +<TT>ntpd</TT> 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. <TT>ntpd</TT> does most computations in 64-bit +floating point arithmetic and does relatively clumsy 64-bit fixed point +operations only when necessary to preserve the unltimate 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. + +<P>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. + +<P>Ordinarily, <TT>ntpd</TT> reads the <TT>ntp.conf</TT> 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. + +<P>If NetInfo support is built into <TT>ntpd</TT>, then <TT>ntpd</TT> will +attempt to read its configuration from the NetInfo if the default ntp.conf +file cannot be read and no file is specified by the <TT>-c</TT> option. + +<P>Various internal <TT>ntpd</TT> variables can be displayed and +configuration options altered while the daemon is running using the +<TT><A HREF="ntpq.htm">ntpq</A></TT> and <TT><A +HREF="ntpdc.htm">ntpdc</A></TT> utility programs. + +<P>When <TT>ntpd</TT> starts it looks at the value of <TT>umask</TT>, +and if it's zero <TT>ntpd</TT> will set the <TT>umask</TT> to +<TT>022</TT>. + +<H4>Command Line Options</H4> + +<DL> + +<DT><TT>-a</TT></DT> +<DD>Enable authentication mode (default).</DD> + +<DT><TT>-A</TT></DT> +<DD>Disable authentication mode.</DD> + +<DT><TT>-b</TT></DT> +<DD>Synchronize using NTP broadcast messages.</DD> + +<DT><TT>-c <I>conffile</I></TT></DT> +<DD>Specify the name and path of the configuration file.</DD> + +<DT><TT>-d</TT></DT> +<DD>Specify debugging mode. This flag may occur multiple times, with +each occurrence indicating greater detail of display.</DD> + +<DT><TT>-D <I>level</I></TT></DT> +<DD>Specify debugging level directly.</DD> + +<DT><TT>-f <I>driftfile</I></TT></DT> +<DD>Specify the name and path of the drift file.</DD> + +<DT><TT>-g</TT></DT> +<DD>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.</DD> + +<DT><TT>-k <I>keyfile</I></TT></DT> +<DD>Specify the name and path of the file containing the NTP +authentication keys.</DD> + +<DT><TT>-l <I>logfile</I></TT></DT> +<DD>Specify the name and path of the log file. The default is the system +log facility.</DD> + +<DT><TT>-m</TT></DT> +<DD>Synchronize using NTP multicast messages on the IP multicast group +address 224.0.1.1 (requires multicast kernel).</DD> + +<DT><TT>-p <I>pidfile</I></TT></DT> +<DD>Specify the name and path to record the daemon's process ID.</DD> + +<DT><TT>-P</TT></DT> +<DD>Override the priority limit set by the operating system. Not +recommended for sissies.</DD> + +<DT><TT>-r <I>broadcastdelay</I></TT></DT> +<DD>Specify the default propagation delay from the broadcast/multicast +server and this computer. This is necessary only if the delay cannot be +computed automatically by the protocol.</DD> + +<DT><TT>-s <I>statsdir</I></TT></DT> +<DD>Specify the directory path for files created by the statistics +facility.</DD> + +<DT><TT>-t <I>key</I></TT></DT> +<DD>Add a key number to the trusted key list.</DD> + +<DT><TT>-v <I>variable</I></TT></DT> +<DT><TT>-V <I>variable</I></TT></DT> +<DD>Add a system variable listed by default.</DD> + +<DT><TT>-x</TT></DT> +<DD>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.</DD> + +</DL> + +<H4>The Configuration File</H4> + +The <TT>ntpd</TT> configuration file is read at initial startup in order +to specify the synchronization sources, modes and other related +information. Usually, it is installed in the <TT>/etc</TT> directory, +but could be installed elsewhere (see the <TT>-c <I>conffile</I></TT> +command line option). The file format is similar to other Unix +configuration files - comments begin with a <TT>#</TT> 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. +Optional arguments are delimited by <TT>[ ]</TT> in the following +descriptions, while alternatives are separated by <TT>|</TT>. The +notation <TT>[ ... ]</TT> means an optional, indefinite repetition of +the last item before the <TT>[ ... ]</TT>. + +<P>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 <TT>server, peer,</TT> <TT>broadcast</TT> or +<TT>manycastclient </TT>commands described in the Configuration Options +page. The <A HREF="notes.htm">Notes on Configuring NTP and Setting up a +NTP Subnet </A>page contains an extended discussion of these options. + +<P><A HREF="confopt.htm">Configuration Options</A> +<BR><A HREF="authopt.htm">Authentication Options</A> +<BR><A HREF="monopt.htm">Monitoring Options</A> +<BR><A HREF="accopt.htm">Access Control Options</A> +<BR><A HREF="clockopt.htm">Reference Clock Options</A> +<BR><A HREF="miscopt.htm">Miscellaneous Options</A> + +<H4>Files</H4> + +<TT>/etc/ntp.conf</TT> - the default name of the configuration file +<BR><TT>/etc/ntp.drift</TT> - the default name of the drift file +<BR><TT>/etc/ntp.keys</TT> - the default name of the key file + +<H4>Bugs</H4> + +<TT>ntpd</TT> 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. + +<hr><a href=index.htm><img align=left src=pic/home.gif></a><address><a +href=mailto:mills@udel.edu> David L. Mills <mills@udel.edu></a> +</address></a></body></html> |
