| The Microsoft Windows operating systems from | | | | settings, the service can act as both an SNTP client |
| Windows 2000 onwards has a built-in time | | | | and SNTP server to synchronise other network |
| synchronization service - 'Windows Time'. This article | | | | clients. |
| describes how to configure the Microsoft Windows | | | | Before modifying registry entries it is good a dood |
| 2003 and Windows 2000 time service as a NTP time | | | | idea to backup the registry settings. The registry can |
| server. It shows how to modify registry entries to | | | | then be restored in the event of problems being |
| configure the Microsoft Windows Time Service. The | | | | encountered. |
| Windows Time service allows a Windows network to | | | | The 'Windows Time' service should be present in the |
| provide synchronisation of all machines within a | | | | systems service list. The application executable is |
| domain. | | | | 'w32time.exe'. The parameter list for w32time can be |
| Windows 2003 Server Configuration | | | | found in the registry at: |
| Windows 2003 has expanded on the original | | | | Services\W32Time\Parameters |
| Windows 2000 time service by providing a true NTP | | | | Windows 2000 can operate as an NTP client and |
| implementation. The time service, installed by default, | | | | synchronise to an NTP server by setting parameter |
| can synchronise to a NTP Server. Indeed, by | | | | 'NTP Server' to the IP address of a NTP Server. |
| manipulating registry settings for the service it can | | | | By default, the Microsoft Windows 2000 machine will |
| act as both an NTP server and client to synchronise | | | | synchronise to the specified NTP time server every |
| other network clients in the domain. | | | | 8 hours (or 3 times a day), which may not be |
| The 'Windows Time' service should be present in the | | | | enough to maintain accurate synchronisation. The |
| systems service list. The application executable is | | | | period can be reduced by setting the 'Period' |
| 'w32time.exe'. The parameter list for w32time can be | | | | parameter to how many times a day synchronisation |
| found in the registry at: | | | | is required. Setting the period to 48 will activate |
| Services\W32Time | | | | synchronisation with the NTP server once every half |
| Before modifying registry entries it is good a dood | | | | hour. |
| idea to backup the registry settings. The registry can | | | | Windows 2000 can also be configured to act as an |
| then be restored in the event of problems being | | | | NTP server by setting the 'Local NTP' parameter to |
| encountered. | | | | '1'. |
| To configure a Windows 2003 machine to | | | | After editing any of the registry entries for the |
| synchronise to an external NTP server, edit the | | | | windows time service, the service must be restarted |
| following registry entries: | | | | for the settings to take effect. The services can be |
| Services\W32Time\Config\AnnounceFlags | | | | started or stopped from the service control applet in |
| Set the 'Announce Flags' registry entry to 5, to | | | | 'administrative tools'. Alternatively the service can be |
| indicate a reliable time source. | | | | controlled via the DOS net command thus:net start |
| llInterval | | | | w32timenet stop w32time |
| The 'Special Poll Interval' registry entry defines the | | | | NTP Troubleshooting |
| period in seconds that the Windows 2003 machine | | | | A number of problems can be encountered when |
| should poll the NTP server. A recommended value is | | | | configuring the Windows Time Service. NTP operates |
| 900 seconds, which equates to every 15 minutes. | | | | using the UDP protocol over TCP/IP. Therefore the |
| Services\W32Time\Parameters\NtpServer | | | | TCP/IP network infrastructure must be operational |
| The 'NTP Server' parameter is used to provide a list | | | | for NTP to be effective. Synchronisation issues may |
| of IP addresses or DNS names, separated by a | | | | arise when NTP attempts to synchronise to an |
| space, of NTP servers that the Windows 2003 | | | | inaccurate time reference or if network delays are |
| machine can synchronise to. | | | | excessive. |
| | | | Synchronising Time on Network Devices |
| Changing the 'Enabled' flag to the value 1 enables the | | | | As well as synchronising Microsoft Windows servers |
| NTP Server. | | | | and workstations, NTP can also be used to |
| Services\W32Time\Parameters\Type | | | | synchronise network devices, such as hubs, switches |
| Change the server type to NTP by specifying 'NTP' in | | | | and routers. Any network device that can |
| the 'Type' registry entry. | | | | synchronise to a NTP server can be pointed to the |
| Windows 2000 Time Service Configuration | | | | Windows server to achieve time synchronisation. In |
| Windows 2000 has an integrated time synchronisation | | | | this way the whole network and accompanying |
| service, installed by default, which can synchronise to | | | | infrastructure can be synchronised. |
| a NTP Server. Indeed, by manipulating registry | | | | |