This is my note to build the NTP server on Linux. The note is not intend to cover everything about how to build the NTP environment but only good enough for me to continue my Oracle testing environment .
- Oracle Enterprise Linux 6.3
- Virtual Box 4.2.6
This is main configure file for the NTP daemon.
- restrict: This is to define which subnet allow to connect to this NTP server.
- server: This is to define the upper level NTP server.
In my environment, I set up the NTP server to use public NTP server as the upper level and my other hosts would use my NTP server to sync the time. Below is my client ntp.conf file, it use the “panda” as the source NTP server
After the change, we can bounce the NTP daemon to make it effective.
ntpstat is the command to check whether the time is sync with server. The time sync would not happen immediately, it may take from 15 mins to 1 hour for sync.
ntpq –p show what NTP server this host is connecting.
Below is the output from my NTP server which connect to outside NTP server.
Below is the output from my Linux host which connect to my NTP server.
NTP daemon is connect through port 123. If we have firewall, we have to make sure to let it through.
Timekeeping best practices for Linux guests http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1006427