Accurate time-keeping is extremely important to Windows 2000, partly because the default authentication protocol, Kerberos, uses the system clock on the workstation to generate the authentication tickets. Even if your workstation doesn't participate in a network with Kerberos authentication, having an accurate system clock helps when you schedule automated tasks, and to get correct time stamps on log file events, for example.
However, PC clocks are notoriously imprecise, so you'll need to synchronise them against an accurate time source. You can do this manually, by double-clicking on the clock in the Taskbar, or via a CMD prompt by typing C:\time.
You'll be prompted to enter the correct time (if it's already correct, just press
USE A TIME SERVER
Setting the clock manually is tedious and inaccurate, however. Synchronising the system clock against an atomic or GPS clock over the "Internet is much better. For this, Windows uses the Simple Network Time Protocol (SNTP), so go to www.eecis.udel.edu/~mills/ntp/clock2.htm to find a time server that allows public access. Pick the server(s) located as close to you as possible, to reduce any adverse effects from network delays. You are generally asked to pick a Stratum 2 instead of a Stratum 1 server, as the load on the latter is high, and you won't gain much in terms of accuracy.
Some of the administrators operating the time servers like to be notified via e-mail if you use their service; please "do so, and respect the access policy of the server you choose."Next, you need to tell Windows 2000 which server(s) you want to use. We'll set up two NTP servers, to show how to specify multiple ones for fault tolerance. Again, you do this at the CMD prompt. Type:
C:\net time \\YOUR_MACHINE_NAME /setsntp:""time.deakin.edu.au time.esec.com.au"This writes an entry into the Registry for the W32Time service. Take care when you type the names of the NTP servers, as there is no way to delete incorrect names, short of editing the Registry. To verify that you have the right time servers, type:
C:\net time \\YOUR_MACHINE_NAME /querysntpTo tell Windows 2000 to synchronise the system clock, "type:
C:\net stop w32time
C:\net start w32time
This restarts the Windows Time Service. (You can also do this through the Administrative Tools-Services applet in Control Panel.) Windows 2000 will send a UDP query to the servers (port 123), so you have to allow UDP to pass through your firewall.
IT By default, Windows 2000 checks with the NTP server once every 45 minutes until it has achieved three good synchronisations; after that occurs, it will check once every eight hours.
To set the intervals at which Windows 2000 contacts the NTP server(s) to check the time, start Regedit and go to:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\ParametersEdit the "Period" entry to be one of the values shown in "the table (either for REG_DWORD or REG_SZ types).
While in Regedit, check that the "type" value for W32Time is set to "NTP" (REG_SZ) as well.
The command-line W32TM.EXE utility also allows you to manipulate the frequency at which the synchronisations occur in a similar fashion to the above, and it provides other functions, such as printing out local time zone information, setting the system clock frequency, changing the server port and synchronisation source.
W32TM.EXE with the -v (verbose) flag can be used to synchronise the workstation against the previously set NTP servers - if you don't use the verbose flag, you won't see what's happening. Press
This will synchronise system time. However, in many cases, this only results in an error message: RPC to local server returned 0x0.
Microsoft's Knowledge Base acknowledges the problem, but there is no solution for it yet.
Note that if you're on a network with a Primary Domain Controller (PDC) set up as a time source, you should use "that instead as the master time server, setting it up to synchronise against a public time service; then, synchronise the workstations on the network with:
C:\net time /set
Put this in the login scripts of each workstation for automatic system time adjustment.