[NTLUG:Discuss] CentOS server not keeping correct time

[Ralph Green]

Neil,
  If you think it is upstream from you, and you ant a different port,I
read that the answer is to add a new iptables rule on your machine.
The command redirects standard ntp traffic to an unpriviledged port.
Something like:
  iptables -A PREROUTING -t nat -i eth0 -p udp --dport 123 -j REDIRECT
--to-ports 1194

 ntpdate can do this with the -u option, as you found.  There is also
another ntp daemon you can install that has an option of using
unpriviledged ports.  It  is called OpenNTPD.  I have not used it
myself, so I'd want to do some vulnerability research before putting
it on a production server.
Good luck,
Ralph