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.TH "ntptrace" "1M" "" "" "System Administration Commands"
.SH NAME
ntptrace \- trace a chain of NTP hosts back to their master time source
.SH SYNOPSIS
.LP
.nf
\fB/usr/sbin/ntptrace\fR [\fB-n\fR] [\fB-m\fR \fImaxhosts\fR] [\fIserver\fR]
.fi
.SH DESCRIPTION
.LP
\fBntptrace\fR determines from where a given Network Time Protocol (\fBNTP\fR) server gets its time, and follows the chain of  \fBNTP\fR servers back to their master time source. If given no arguments, it starts with  \fIlocalhost\fR.
.SH OPTIONS
.LP
The following options are supported:
.sp
.ne 2
.mk
.na
\fB\fB-n\fR\fR
.ad
.RS 14n
.rt  
Turns off the printing of host names; instead, host IP addresses are given.
.RE

.sp
.ne 2
.mk
.na
\fB\fB-m\fR \fImaxhosts\fR\fR
.ad
.RS 14n
.rt  
Sets the maximum number of levels up the chain that will be followed.
.RE

.SH EXAMPLES
.LP
\fBExample 1 \fRSample Output From the \fBntptrace\fR Command
.LP
The following example shows the output from the \fBntptrace\fR command:

.sp
.in +2
.nf
% \fBntptrace\fR


 localhost: stratum 4, offset 0.0019529, synch distance 0.144135
 server2.bozo.com: stratum 2, offset 0.0124263, synch distance 0.115784
 usndh.edu: stratum 1, offset 0.0019298, synch distance 0.011993, refid 'WWVB'
.fi
.in -2
.sp

.LP
On each line, the fields are (left to right):

.RS +4
.TP
.ie t \(bu
.el o
The server's host name
.RE
.RS +4
.TP
.ie t \(bu
.el o
The server's stratum
.RE
.RS +4
.TP
.ie t \(bu
.el o
The time offset between that server and the local host (as measured by \fBntptrace\fR; this is why it is not always zero for  \fIlocalhost\fR)
.RE
.RS +4
.TP
.ie t \(bu
.el o
The host's synchronization distance
.RE
.RS +4
.TP
.ie t \(bu
.el o
The reference clock \fBID\fR (only for stratum-1 servers)
.RE
.LP
All times are given in seconds. Synchronization distance is a measure of the goodness of the clock's time.
.SH SEE ALSO
.LP
\fBntpq\fR(1M), \fBntpd\fR(1M), \fBntpdc\fR(1M), \fBattributes\fR(5))