Contents
RHEL
* Open NTP port 123:
vi /etc/sysconfig/iptables
:RH-Firewall-1-INPUT - [0:0] # Open NTP port 123 -I INPUT -p udp -m udp -m multiport --dports 123 -m state --state NEW -j ACCEPT -A INPUT -j RH-Firewall-1-INPUT
* Restart iptables
service iptables restart
* Configure NTP server
vi /etc/ntp.conf
server pool.ntp.org
* Restart ntpd
service ntpd restart
* Check NTP status with ntpstat
ntpstat synchronised to NTP server (198.58.100.237) at stratum 3 time correct to within 97 ms polling server every 64 s
* Check NTP host with ntpq -p
ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== *tux.brhelwig.co 216.218.254.202 2 u 11 128 377 46.408 0.703 0.647 LOCAL(0) .LOCL. 10 l 13 64 377 0.000 0.000 0.001
Windows
* See Windows Time Service Tools and Settings
* NTP time service in Windows 2003
ESXi 5.1
* Login vSphere
* Click host > Configuration > Time Configuration > Properties
* Select NTP Client Enabled
* Click Options > General
– Select Start automatically…
* Click NTP Settings
* Click Add… to add pool.ntp.org
* Check Restart NTP service to apply changes and click OK
