Configuring the Network Time Protocol (NTP)

The NTP clock.txt file

The file /pub/ntp/doc/clock.txt on host ftp.udel.edu is your basic source of information on the location of stratum 1 and good quality stratum 2 servers. Among other things, this file also lists:

sources for timecode receivers
sources for precision oscillators and timing receivers
call letters, location, frequencies, and coordinates for timecode transmitters
an algorithm for great-circle distance and bearing computation
information on timecode transmitters in Germany, the United Kingdom, and France

The information on primary and secondary servers in clock.txt has the following format:

   Hostname (IP address)
   Location: organization, geographic location
   Synchronization: machine type, clock type, synchronization protocol
   Service area: networks served
   Access policy: open or closed to the public
   Contact: name and email address of contact person
   Note: miscellaneous information

One way to get the clock.txt file is to use ftp(TC). Below is a sample session showing how you might download this file to your host.

   ftp ftp.udel.edu
   Connected to louie.udel.edu
   220 louie.udel.edu.
   Name (ftp.udel.edu:user): anonymous
   331 Guest login ok, send ident as password.
   Password: guest
   230 Guest login ok, access restrictions apply.
   ftp> cd /pub/ntp/doc
   250 CWD command successful.
   ftp> get clock.txt
   200 PORT command successful.
   150 ASCII data connection for clock.txt (10.0.246.7,1198) (90930 bytes).
   local: clock.txt remote: clock.txt
   58409 bytes received in 8 seconds (7.1 Kbytes/s)
   ftp> quit
   221 Goodbye.