1.\" $NetBSD: ntptrace.8,v 1.1 2010/08/28 15:42:45 kardel Exp $ 2.\" Converted from HTML to mandoc by ntp-html2mdoc.pl 3.\" 4.Dd March 29, 2000 5.Dt NTPTRACE 8 6.Os 7.Sh NAME 8.Nm ntptrace 9.Nd "trace a chain of NTP servers back to the primary source" 10.Sh SYNOPSIS 11.Nm 12.Op Fl vdn 13.Op Fl r Ar retries 14.Op Fl t Ar timeout 15.Op Ar server 16.Sh DESCRIPTION 17.Nm 18determines where a given Network Time Protocol (NTP) 19server gets its time from, and follows the chain of NTP servers back to 20their master time source. If given no arguments, it starts with 21.Pa localhost . 22Here is an example of the output from 23.Nm : 24.Pp 25.nf 26% ntptrace 27localhost: stratum 4, offset 0.0019529, synch distance 0.144135 28server2ozo.com: stratum 2, offset 0.0124263, synch distance 0.115784 29usndh.edu: stratum 1, offset 0.0019298, synch distance 0.011993, refid 'WWVB' 30.fi 31.Pp 32On each line, the fields are (left to right): the host name, the host stratum, 33the time offset between that host and the local host (as measured by 34.Nm 35; 36this is why it is not always zero for 37.Pa localhost 38), the host synchronization 39distance, and (only for stratum-1 servers) the reference clock ID. All 40times are given in seconds. Note that the stratum is the server hop count 41to the primary source, while the synchronization distance is the estimated 42error relative to the primary source. These terms are precisely defined 43in RFC-1305. 44.Sh OPTIONS 45.Bl -tag -width indent 46.It Fl d 47Turns on some debugging output. 48.It Fl n 49Turns off the printing of host names; instead, host IP addresses are given. 50This may be useful if a nameserver is down. 51.It Fl r Ar retries 52Sets the number of retransmission attempts for each host (default = 5). 53.It Fl t Ar timeout 54Sets the retransmission timeout (in seconds) (default = 2). 55.It Fl v 56Prints verbose information about the NTP servers. 57.El 58.Sh AUTHORS 59David L. Mills (mills@udel.edu) 60.Sh BUGS 61This program makes no attempt to improve accuracy by doing multiple samples. 62