NTP Server configuration for Oracle RAC in RHEL 5

Resources:

http://oracle-base.com/articles/linux/linux-ntp-configuration.php
http://www.tecmint.com/install-ntp-server-in-centos/
http://www.cyberciti.biz/faq/rhel-fedora-centos-configure-ntp-client-server/

Hostname	NAT	Host-only	Host-only	NTP
rac5.example.com	1.0.1.5	1.0.2.5	1.0.9.5	Server
rac6.example.com	1.0.1.6	1.0.2.6	1.0.9.6	Client

NTP Server configure:       

chkconfig ntpd on

vim /etc/ntp.conf

restrict 1.0.1.0 mask 255.255.255.0 nomodify notrap

server  0.centos.pool.ntp.org

server  1.centos.pool.ntp.org

server  2.centos.pool.ntp.org
server  1.0.1.5

fudge   1.0.1.5 stratum 10

driftfile /var/lib/ntp/drift

keys /etc/ntp/keys

  

vim /etc/sysconfig/ntpd

OPTIONS="-x -u ntp:ntp -p /var/run/ntpd.pid -g"

SYNC_HWCLOCK=no

iptables -A INPUT -p udp --dport 123 -j ACCEPT

iptables save

/etc/init.d/iptables save

/etc/init.d/iptables restart

/etc/init.d/ntpd start

ntpq -p

NTP Client settings

chkconfig ntpd on

vim /etc/ntp.conf

server  1.0.1.5

fudge   1.0.1.5 stratum 10

driftfile /var/lib/ntp/drift

keys /etc/ntp/keys

  

vim /etc/sysconfig/ntpd

OPTIONS="-x -u ntp:ntp -p /var/run/ntpd.pid -g"

SYNC_HWCLOCK=no

/etc/init.d/ntpd start

ntpdate -u 1.0.1.5  

ntpq -p