 Part-2:
Part-2: NTP Server & Client settings.
2.1 : Install ntp package using yum
[root@loadb1 ~]# ssh ntp [root@ntp ~]# yum install -y ntp Loaded plugins: fastestmirror, presto Loading mirror speeds from cached hostfile * base: ftp.cc.uoc.gr * extras: ftp.cc.uoc.gr * updates: ftp.cc.uoc.gr Setting up Install Process Resolving Dependencies --> Running transaction check ---> Package ntp.i686 0:4.2.4p8-2.el6.centos will be installed --> Finished Dependency Resolution Dependencies Resolved ======================================================================================================================================================================= Package Arch Version Repository Size ======================================================================================================================================================================= Installing: ntp i686 4.2.4p8-2.el6.centos base 436 k Transaction Summary ======================================================================================================================================================================= Install 1 Package(s) Total download size: 436 k Installed size: 1.1 M Downloading Packages: Setting up and reading Presto delta metadata Processing delta metadata Package(s) data still to download: 436 k ntp-4.2.4p8-2.el6.centos.i686.rpm | 436 kB 00:01 Running rpm_check_debug Running Transaction Test Transaction Test Succeeded Running Transaction Installing : ntp-4.2.4p8-2.el6.centos.i686 1/1 Installed: ntp.i686 0:4.2.4p8-2.el6.centos Complete!
2.2 : Edit /etc/ntp.conf file for server’s configurations.
[root@ntp ~]# vi /etc/ntp.conf # For more information about this file, see the man pages # ntp.conf(5), ntp_acc(5), ntp_auth(5), ntp_clock(5), ntp_misc(5), ntp_mon(5). driftfile /var/lib/ntp/drift # Permit time synchronization with our time source, but do not # permit the source to query or modify the service on this system. #restrict default kod nomodify notrap nopeer noquery #restrict -6 default kod nomodify notrap nopeer noquery # Permit all access over the loopback interface. This could # be tightened as well, but to do so would effect some of # the administrative functions. restrict 127.0.0.1 # BroExperts NTP Server #restrict -6 ::1 # Hosts on local network are less restricted. #restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap # Use public servers from the pool.ntp.org project. # Please consider joining the pool (http://www.pool.ntp.org/join.html). #server 0.centos.pool.ntp.org #server 1.centos.pool.ntp.org #server 2.centos.pool.ntp.org #broadcast 192.168.1.255 autokey # broadcast server #broadcastclient # broadcast client #broadcast 224.0.1.1 autokey # multicast server #multicastclient 224.0.1.1 # multicast client #manycastserver 239.255.254.254 # manycast server #manycastclient 239.255.254.254 autokey # manycast client # Undisciplined Local Clock. This is a fake driver intended for backup # and when no outside source of synchronized time is available. server 127.127.1.0 # local clock # BroExperts NTP Server #fudge 127.127.1.0 stratum 10 # Enable public key cryptography. #crypto includefile /etc/ntp/crypto/pw # Key file containing the keys and key identifiers used when operating # with symmetric key cryptography. keys /etc/ntp/keys # Specify the key identifiers which are trusted. #trustedkey 4 8 42 # Specify the key identifier to use with the ntpdc utility. #requestkey 8 # Specify the key identifier to use with the ntpq utility. #controlkey 8 # Enable writing of statistics records. #statistics clockstats cryptostats loopstats peerstats
2.3 : start ntpd service and make it available on startup.
[root@ntp ~]# service ntpd start && chkconfig ntpd on Starting ntpd: [ OK ]
2.4 : verify your server. ( * ) is sign of your server working fine it will take sometime to appear.
[root@ntp ~]# watch ntpq -p -n Every 2.0s: ntpq -p -n wed Jun 6 15:46:32 2012 romote refid st t when poll reach delay offset jitter =============================================================================== *127.127.1.0 .LOCL. 5 l - 2 64 377 0.000 0.000
2.5 : Clients Settings.
yum -y install ntp
2.6 : edit /etc/ntp.conf
[root@loadb1 ~]# vi /etc/ntp.conf driftfile /var/lib/ntp/drift # Permit time synchronization with our time source, but do not # permit the source to query or modify the service on this system. restrict default kod nomodify notrap nopeer noquery restrict -6 default kod nomodify notrap nopeer noquery # Permit all access over the loopback interface. This could # be tightened as well, but to do so would effect some of # the administrative functions. #restrict 127.0.0.1 #restrict -6 ::1 # Hosts on local network are less restricted. #restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap # Use public servers from the pool.ntp.org project. # Please consider joining the pool (http://www.pool.ntp.org/join.html). #server 0.centos.pool.ntp.org #server 1.centos.pool.ntp.org #server 2.centos.pool.ntp.org server 192.168.2.31 #broadcast 192.168.1.255 autokey # broadcast server #broadcastclient # broadcast client #broadcast 224.0.1.1 autokey # multicast server #multicastclient 224.0.1.1 # multicast client #manycastserver 239.255.254.254 # manycast server #manycastclient 239.255.254.254 autokey # manycast client # Undisciplined Local Clock. This is a fake driver intended for backup # and when no outside source of synchronized time is available. #server 127.127.1.0 # local clock #fudge 127.127.1.0 stratum 10 # Enable public key cryptography. #crypto includefile /etc/ntp/crypto/pw # Key file containing the keys and key identifiers used when operating # with symmetric key cryptography. keys /etc/ntp/keys # Specify the key identifiers which are trusted. #trustedkey 4 8 42 # Specify the key identifier to use with the ntpdc utility. #requestkey 8 # Specify the key identifier to use with the ntpq utility. #controlkey 8 # Enable writing of statistics records. #statistics clockstats cryptostats loopstats peerstats
2.7 : start ntpd service and make it available on startup.
[root@loadb1 ~]# service ntpd start && chkconfig ntpd on Starting ntpd: [ OK ]
2.8 : Copy this file to all other clients using scp
[root@loadb1 ~]# scp /etc/ntp.conf loadb2:/etc/ ntp.conf 100% 1950 1.9KB/s 00:00 [root@loadb1 ~]# scp /etc/ntp.conf websrv1:/etc/ ntp.conf 100% 1950 1.9KB/s 00:00 [root@loadb1 ~]# scp /etc/ntp.conf websrv2:/etc/ ntp.conf 100% 1950 1.9KB/s 00:00 [root@loadb1 ~]# scp /etc/ntp.conf dbase1:/etc/ ntp.conf 100% 1950 1.9KB/s 00:00 [root@loadb1 ~]# scp /etc/ntp.conf dbase2:/etc/ ntp.conf 100% 1950 1.9KB/s 00:00 [root@loadb1 ~]# scp /etc/ntp.conf dns:/etc/ ntp.conf 100% 1950 1.9KB/s 00:00
2.9 : Run this command on all clients
service ntpd start && chkconfig ntpd on
2.10 : sync your time with your ntp server on all clients
[root@loadb1 ~]# ntpdate -u 192.168.2.31 6 Jun 13:06:26 ntpdate[10904]: adjust time server 192.168.2.31 offset -0.000111 sec
Part-3: Bind Server Installation + configurations.