vaillan@ireq.hydro.qc.ca (C.Vaillancourt Hydro-Quebec QC 514-652-8238) (03/21/90)
On our network of 150 Sun we use rdate to set the time on all our systems.
This is a simple way to synchronize them all once a day with crontab.
But we need a good source of time to use with the rdate command.
NOW THE SURPRISE: rdate works with other Sun on the net, try:
rdate titan.rice.edu (in su on your station, it works...)
My question is: Is there any installation of Sun on the net synchronized
with a receiver to the Universal Coordinated Time?
I think it would be a non-expensive way to synchronize many systems when
an accuracy of about 10 sec. is required.
[[Ed's Note: With the time to reach a remote site across far across the
network, I'm not sure you really get many advantages from using a site
that is synchronized with UCT. -bdg]]
Clement Vaillancourt, | Institut de Recherche d'Hydro-Quebec
Analyste, | 1800 Montee Ste-Julie, Varennes
Responsable du Reseau Ethernet | P. Quebec, Canada, J3X 1S1
(Analyst, Network Manager) | Tel: 514-652-8238 Fax: 514-652-8309
| vaillan@ireq.hydro.qc.calibes@cme.nist.gov (Don Libes) (03/21/90)
In article <5933@brazos.Rice.edu> vaillan@ireq.hydro.qc.ca (C.Vaillancourt Hydro-Quebec QC 514-652-8238) writes: >My question is: Is there any installation of Sun on the net synchronized >with a receiver to the Universal Coordinated Time? Our lab in Boulder maintains the civilian Time-Of-Day. They have a computer which they guarantee is within 30 milliseconds of the correct time. (At the moment it is 17 msecs off.) It happens to be a Sun running UNIX, so naturally it runs 'rdate'. The hostname is india.colorado.edu. (Don't ask what it's doing in .edu) This means you can put 'rdate' into your server's rc.local. To reduce network traffic, the 'rdate' in your client's rc.local should point to your server. (See rdate(8) for more info.) Of course, 'rdate' makes no guarantees of accuracy, but sample tests we ran indicated the results were less than a second off. (We're in Gaithersburg, Maryland!) Boulder is working on a server to provide time service to better than millisecond accuracy taking into account network and OS latency, but it is not yet available. They seemed disappointed when I said "within a couple of seconds would be just fine." Don Libes libes@cme.nist.gov ...!uunet!cme-durer!libes
pml@cacs.usl.edu (03/21/90)
[[Ed's Note: About 2 dozen people sent in replies along this vein, so my apologies to those of you whose articles were not printed. -bdg]] There is a standard network protocol defined and tools available to do this. The programs are based on NTP (Network Time Protocol). I know of two version which run on suns: ntp and xntp. Both are available via anonymous ftp from trantor.umd.edu 128.8.10.14 I have installed and used both. patrick pml@cacs.usl.edu