NTP client

[bob]

Does anyone know of a really good implementation of an NTP client in Java?

Thanks.

 

[Gunter Herrmann]

Hi!

Does anyone know of a really good implementation of an NTP client in Java?

Why not run a client on the OS?
Works perfectly for me on Windows XP and Linux.

Gunter in Orlando, Fl.

 

[Roedy Green]

Does anyone know of a really good implementation of an NTP client in Java?

If you want something simple, cannibalise the code inside SetClock. It
works at the UDP level. see
http://mindprod.com/products1.html#SETCLOCK.html

For background on NTP see http://mindprod.com/jgloss/ntp.html
including lists of servers.
--
Roedy Green Canadian Mind Products
http://mindprod.com
Controlling complexity is the essence of computer programming.
~ Brian W. Kernighan 1942-01-01
..

 

[Roedy Green]

Why not run a client on the OS?
Works perfectly for me on Windows XP and Linux.

in windows you spawn
w32tm.exe /resync

to resync your clock. From there you can get time via java.

see http://mindprod.com/jgloss/timesources.html
for details.
--
Roedy Green Canadian Mind Products
http://mindprod.com
Controlling complexity is the essence of computer programming.
~ Brian W. Kernighan 1942-01-01
..

 

[Gunter Herrmann]

Hi!

in windows you spawn
w32tm.exe /resync

In a corporate network you should have (at least) 2 servers that run
ntpd getting the time signals from multiple outside sources.
You should ask for permission to use these sources.
Then close the ntp port in the firewall for everyone except these
servers. All your other systems should get the time from your own
time servers.

On Unix/Linux boxes install ntpd and have it point to your
corporate time servers.

Sync your Windows domain controllers with your corporate ntp
servers, all computers in the domain will get their time from there.

Your windows systems that are not part of a domain should get their
time from your ntp servers.

To automate this I use a batch file to set/change the registry entries.

Here the content:

w32tm /register
w32tm /config /manualpeerlist:"Your corporate servers"
reg add HKLM\System\CurrentControlSet\Services\W32Time\Parameters /v "Period" /t REG_DWORD /d 0 /f
reg add HKLM\System\CurrentControlSet\Services\W32Time\Config /v "MaxNegPhaseCorrection" /t REG_DWORD /d 4294967295 /f
reg add HKLM\System\CurrentControlSet\Services\W32Time\Config /v "MaxPosPhaseCorrection" /t REG_DWORD /d 4294967295 /f

Setting the maximum correction to infinity makes sure that a
system with a bad CMOS battery is still synced.

Regards

Gunter