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INSTALLING AND CONFIGURING A WINDOWS 2003 DOMAIN TIME SERVER
Computers have integral Real Time Clock chips (RTC) that provide
time and date information. The real
time clock chips are battery backed so that even during power
outages, they can maintain time. The
function of the Real Time Clock is to provide accurate time and
date information to operating system
processes and user applications. For many applications, this is
adequate, however, quite often
applications may need time to be synchronised with other PC's on
the network.
For transaction processing in a networked environment or for
scheduling purposes, the system time and
date may need to be synchronised with every other PC on the
local network. Microsoft Windows 2003
has an integrated time service that provides synchronisation
between PC's in a domain.
This article describes how the Windows 2003 Time Service
synchronises time and date information on
servers to a domain controller. It also discuses how the Windows
2003 time synchronisation service uses
NTP to synchronise servers in a domain.
Networked computers require an automated time synchronisation
service which can automatically
synchronise time on each client to an accurate master clock. The
Microsoft Windows 2003 time
synchronisation service was developed to fulfill this function.
The service is installed by default on any
Windows 2000, XP and Server 2003 machine.
On power-up, the Windows 2003 time service starts automatically
and attempts to synchronise time
and date information with a domain controller using the NTP
protocol. NTP is an Internet protocol
developed for the transfer of accurate time. The Network Time
Protocol provides accurate time
information along with network transmission delay information,
so that a precise time can be obtained.
A domain controller can be configured as either a trusted or an
un-trusted time reference. A Windows
Time Client will always attempt to synchronise time periodically
with a trusted domain controller. In this
manner networked Windows 2003 servers maintain synchronisation
with a domain controller and each
other.
The Windows 2003 time synchronisation service configuration
settings are contained in a global group
policy. The settings are obtained from registry entries, which
are located in
HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32Time. A
breif description of the more
useful time service configuration settings is contained
below.
The AnnounceFlags' registry entry indicates whether the server
is a trusted time reference. This flag
should be set to the value 5 indicating that this PC is a
trusted time source. The Type' registry entry
specifies which network peers to accept synchronisation. Set the
Type' registry entry to NTP' to specify
synchronization to a NTP time server.
