Synchronize Time with NTP Server

In Windows 2008 R2 Standard Environment:

Time synchronization is an important aspect in network. For example, if time is not synchronized then you may receive mail in future time, many software installation requires time synchronization.

• AD (Active Directory), uses Windows Time service for clock synchronization: W32Time

• All client machines synchronizes time from domain controller

• In Domain Controller Environment all domain controller synchronizes from the PDC

• Thus PDC must synchronize from external source e.g. NTP Server

To locate PDC:

netdom /query fsmo

Sample Output:

Schema master               DC2.abc.com.bd

Domain naming master        DC2.abc.com.bd

PDC                         DC2.abc.com.bd

RID pool manager            DC2.abc.com.bd

Infrastructure master       DC2.abc.com.bd

The command completed successfully.

Stop W32Time service:

net stop w32time

Setting up external source (assume: NTP IP is 192.168.220.80)

w32tm /config /syncfromflags:manual /manualpeerlist:192.168.220.80

Make PDC a reliable time source for clients:

w32tm /config /reliable:yes

Start the w32time service

net start w32time

In RHEL 6.5:

Edit ntp.conf file and add below line

#vim /etc/ntp.conf

# IP Address of your NTP Server

server 192.168.100.200

Save & Exit.


Add cronjob for update time from NTP

0 0 * * * /usr/sbin/ntpdate -u 192.168.100.200


Cheers!!!