NETWORK TIME SYNCHRONIZATION


Current Time: UTC

The NTP Home Page, Univ. Delaware

For instructions on the installation of NTP, go here


For links to software for setting time on various computers, see

Here is Explanation of Network Timekeeping by Hal Stern for SunWorld.

Here are lists of Network Time Protocol stratum 1 and stratum 2 servers, from Dave Mills, University of Delaware.

Network Time Protocol Installation

from the Ntp3-5.90 distribution by D. Mills.

RFC-1305 NETWORK TIME PROTOCOL

SIPRNET NETWORK TIME PROTOCOL SERVERS

The U.S. Naval Observatory now provides NTP service on the Secret Internet Protocol Routing Network (SIPRNET).
 140.49.183.70		ntp-usno.sipr.smil.mil USNO Time Service, Washington, DC
 140.49.231.138 	ntp-amc.sipr.smil.mil  USNO Alternate Master Clock,
 Falcon AFB, Colorado.

Contact Richard Schmidt, Time Service Dept., US Naval Observatory, res@tuttle.usno.navy.mil , for details.

NIPRNET NETWORK TIME PROTOCOL SERVERS

The U.S. Naval Observatory operates three stratum 1 time servers located in Washington, DC:
ntp2.usno.navy.mil	192.5.41.209
tick.usno.navy.mil	192.5.41.40
tock.usno.navy.mil	192.5.41.41
These systems are synchronized to USNO Master Clocks 1 and 2 (hydrogen masers) and to GPS. They to all NTP stratum 2 servers in the Eastern Time Zone, and to others by request.

USNO also operates two stratum-1 servers from its Alternate Master Clock Facility at Falcon AFB, CO, near Colorado Springs. These servers are linked to the Alternate Master Clock (hydrogen maser):
navobs1.usnogps.navy.mil   204.34.198.40 (CNAME tick.usnogps.navy.mil)
navobs2.usnogps.navy.mil   204.34.198.41 (CNAME tock.usnogps.navy.mil)


A USNO GPS network time server is now in operation at OARnet, Ohio State University, Columbus, Ohio, with open access to stratum 2 servers and to OARnet clients:

 navobs1.oar.net 198.30.92.2  	 (CNAME ntp-oar.usno.navy.mil)


A USNO GPS network time server is now in operation at Columbia University, New York City, with open access to stratum 2 servers and to CU clients:
 gnomon.cc.columbia.edu 128.59.39.48 	 (CNAME ntp-cu.usno.navy.mil)


A USNO GPS network time server is now in operation at the Georgia Institute of Technology, Atlanta Georgia, with open access to stratum 2 servers and to GATECH clients:

tick.gatech.edu 130.207.244.240 	 (CNAME ntp-gatech.usno.navy.mil)


A USNO GPS network time server is now in operation at the University of Washington, Seattle, Washington,with open access to stratum 2 servers and to UW clients:
 bigben.cac.washington.edu   140.142.16.34	 (CNAME ntp-uw.usno.navy.mil)


A USNO GPS network time server is now in operation at the University of California, Los Angeles, with open access to stratum 2 servers and to UCLA clients:
tick.ucla.edu  164.67.62.194 	 (CNAME ntp-ucla.usno.navy.mil)


A USNO GPS network time server is now in operation at Digital Equipment Corporation, Palo Alto, CA This is an open-access stratum-1 for the Pacific Timezone:
usno.pa-x.dec.com	 204.123.2.72 (CNAME ntp-dec.usno.navy.mil)


A USNO GPS network time server is now in operation at Washington University, in St. Louis, Missouri. This is an open-access stratum-1 for the Central Timezone:
navobs1.wustl.edu	128.252.19.1 (CNAMES ntp-wustl.usno.navy.mil, tick.wustl.edu)

A USNO GPS network time server is now in operation at the University of Houston, Houston, Texas, with open access to stratum 2 servers and to UH clients:

tick.uh.edu	 129.7.1.66 (CNAME ntp-uh.usno.navy.mil)


A USNO GPS network time server is now in operation at MIT, Cambridge, MA. Service region is Northeast US and Canada. Access is open to stratum-2 servers and to MIT clients.
navobs1.mit.edu	18.145.0.30 (CNAMES ntp-mit.usno.navy.mil, tick.mit.edu)


For access information contact Richard Schmidt, Time Service Dept., USNO

ABOUT NETDATE

We get inquiries about the "netdate" program. We do not support it. Netdate fails to perform the simplest error checks on input. If we are not running inetd, as on occasion we do not, netdate seems to run but returns garbage. So, if you use netdate, please don't point it to us.

TELNET ASCII TIME

This service, on telnet port 13, has been discontinued.

TIME SETTING VIA BERKELEY INTERNET STREAM SOCKETS:

This service has been discontinued.

RFC 868 TIME PROTOCOL

THIS SERVICE HAS BEEN DISCONTINUED . The "time" protocol [RFC-868] was formerly supported on TCP and UDP port 37. This service returns a 32-bit binary number, in network byte order, representing the number of seconds of time since 1 Jan. 1900 UT. We provide provide the UDP service only.
The "rdate" program operated over TCP port 37. This service has also been discontinued.

RFC 867 DAYTIME PROTOCOL

The ASCII "daytime" protocol is now supported on UDP port 13.

For links to software for setting time on personal computers, see
Time Synchronization Software

(Revised 3/97)

Richard Schmidt (res@tuttle.usno.navy.mil)

Back to Time Service Home Page "The inaudible and noiseless foot of Time." --W. S. Time Service Dept., U.S. Naval Observatory, Washington, DC