The UK switched to BST (British Summer Time) on the 27th March and while the idea of altering the time dependent on the position of the planet in its orbit around the sun can be questioned the need for servers and other networked devices to show the correct time is important.
NTP is the protocol used to synchronise clocks across data networks. Normally, for Windows Servers, you will set your domains operational master to check the time from a master source and the domain members will check time with the domain operational master.
Of course if you have a standalone server or a different network device you can usually configure them to check directly. The NTP Pool project (http://www.pool.ntp.org) is a distributed collection of machines that exist to provide accurate time service to machines worldwide.
For the UK they offer local time servers, the full list available here http://www.pool.ntp.org/zone/uk
Settings for Windows 7 & Server 2008 to use pool.ntp.org servers
The above administrative command prompt shows the default settings for a non-domain Windows 7 machine. If you look at the section NtpServer: time.windows.com, this shows that my machine is checking the time with the default server provided by Microsoft.
Steps to change to alternative time server
- Stop the W32Time service.
- Edit the config.
- For operational master domain controllers, make a reliable time source.
- Start the W32Time service.
- C:\>net stop w32time
- C:\>w32tm /config /syncfromflags:manual /manualpeerlist:0.uk.pool.ntp.org,1.uk.pool.ntp.org,2.uk.pool.ntp.org
- C:\>w32tm /config /reliable:yes
- C:\>net start w32time
Once set make sure you open UDP port 123 on your firewall to allow NTP traffic in and out. If your applying these settings on your home Windows 7 machine or other non-domain server you can omit step 3.
If you’re interested in seeing what settings you have applied first you can check the configuration like so:
C:\>w32tm /query /configuration
Checking domain members time subscriptions
To check that a domain member is syncing time with the Active Directory master you can check here in the registry
If Type is set to Nt5DS then the member machine should be checking with the domain controller for its time. If Type is set to NTP it will be checking on its own.
You can see what time server the machine is checking with using the /monitor command
Running this command on non-domain machines will result in an error.