Installation

sudo apt-get install ntp

Konfiguration

Changing Time Servers

Your system will use Ubuntu's NTP server at ntp.ubuntu.com by default. This is OK, but you might want to use several servers to increase accuracy and resilience, and you may want to use time servers that are geographically closer to you. For ntpd edit

vi /etc/ntp.conf to include additional server lines:

server swisstime.ethz.ch
server 0.ch.pool.ntp.org
server 1.ch.pool.ntp.org
server 2.ch.pool.ntp.org
server 3.ch.pool.ntp.org

You may notice pool.ntp.org in the examples above. This is a really good idea which uses round-robin DNS to return an NTP server from a pool, spreading the load between several different servers. Even better, they have pools for different regions - for instance, if you are in New Zealand, so you could use nz.pool.ntp.org instead of pool.ntp.org . Look at http://www.pool.ntp.org/ for more details.

Restarting NTP

/etc/init.d/ntp restart

Testing NTP

ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
 swisstime.ee.et 129.132.2.22     2 u   18   64    7   11.964   -2.756   2.057
 77.109.137.140  129.132.2.21     3 u   19   64    7   10.105   -3.295   4.209
 2b3w.ch         62.2.104.140     3 u   23   64    7   13.176   -3.198  18.182
 magma.woody.ch  130.60.75.53     3 u   22   64    7   12.059  -47.851  19.174
 ns2.xplo-re.net 94.23.99.153     3 u   25   64    7   24.139    3.603   2.614