What is NTP (Network Time Protocol)?
NTP is a protocol which helps to computers to synchronize the time to a standard time. It uses UDP on port 123 as its transport layer. NTP uses Marzullo’s algorithm and providing 200 microseconds accuracy on a lan network. NTP is designed to resist the effects of variable latency. NTP is knows as one of the very old Internet protocols. It was firstly designed by Dave Mills and he still maintains it. The current NTP version is 4.
Why NTP is essential in corporate networks?
When you are in an environment where the timestamps plays a major role in the business, it is very essential so that the time will be accurate in every device on the network. Devices such as Routers, Servers, Time recording machines (User login machines) and workstations. If the time on the router is not accurate, while you troubleshoot a router problem it will be uneasy while you examine the router logs as it will not be in proper time stamp.
NTP Official Website http://www.ntp.org/
Here are the standard NTP servers hosted from ntp.org
| Area | Host Name |
| Worldwide | pool.ntp.org |
| Asia | asia.pool.ntp.org |
| Europe | europe.pool.ntp.org |
| North America | north-america.pool.ntp.org |
| Oceania | oceania.pool.ntp.org |
| South America | south-america.pool.ntp.org |
Configuration
On a Domain network it is advised that the NTP should be configured on the Domain Controller so that the clients which are getting authenticated from the DC will get synchronized with the time on the DC.
1. Open the Registry on the DC and navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\W32Time\Parameters
2. On the right hand side you will see NTPServer. Double click on that to edit the key.
3. Now replace “time.windows.com,0×9” with “pool.ntp.org.0×9” ( pool.ntp.org is provided by the Ntp.org)
4. Now open up the Command Prompt windows and execute the following commands to restart the time server on the DC.
net stop w32time
net start w32time
There are many free time servers are available. Even your local ISP will have one, so make sure you configure with the relevant time server according to your area.
