Network Configuration Technologies
Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2
Network configuration is vital to the proper operation of any network infrastructure. Administrators must be able to configure IP addresses as well as other configuration information, such as options configured by using Dynamic Host Configuration Protocol (DHCP) or the Windows Time service. These services offer administrators scalable solutions to configure client computers on the network.
Network Configuration Components
Microsoft Windows Server 2003 provides DHCP and the Windows Time service for network configuration.
DHCP is a client/server protocol that automatically provides an IP host with its IP address and other related configuration information such as the subnet mask and default gateway. RFC 2131 and RFC 2132 define DHCP as an Internet Engineering Task Force (IETF) standard based on the Bootstrap Protocol (BOOTP), with which it shares many implementation details. DHCP allows hosts to obtain all necessary TCP/IP configuration information from a DHCP server.
All Microsoft Windows Server 2003 products (including Standard Edition, Enterprise Edition, Web Edition, and Datacenter Edition) include a DHCP Server service, which is an optional networking component. All Windows clients include the DHCP Client as part of TCP/IP, including Windows Server 2003, Windows XP, Windows 2000, Windows NT 4.0, Windows Millennium Edition (Windows Me), and Windows 98.
DHCP simplifies the administrative management of IP address configuration by automating this process for network clients. The DHCP servers, which are computers running the DHCP Server service, allocate IP addresses and related TCP/IP configuration settings to DHCP-enabled clients on the network. DHCP relay agents help forward DHCP messages between DHCP clients and DHCP servers.
Windows Time Service
The Windows Time service (W32Time) in Windows Server 2003 synchronizes the date and time for all computers running on a Windows Server 2003 network. Time synchronization is critical for the proper operation of many Windows services and line-of-business applications. The Windows Time service uses the Network Time Protocol (NTP) to synchronize computer clocks on the network so that an accurate clock value, or time stamp, can be assigned to network validation and resource access requests. The service integrates NTP and time providers, making it a reliable and scalable time service for enterprise administrators.
Network Configuration Scenarios
Every device on a TCP/IP-based network must have a unique unicast IP address to access the network and its resources. Without DHCP, IP addresses must be configured manually on each computer on the network, changes must be tracked so that unused addresses can be reused by other computers, and computers must be manually reconfigured each time they move between subnets.
DHCP allows this entire process to be automated and centrally managed. The DHCP server maintains a pool of IP addresses and leases an address to any DHCP-enabled client when it starts on the network. Because the IP addresses are dynamic (leased) rather than static (permanently assigned), addresses no longer in use are automatically returned to the pool for reallocation.
DHCP also allows the network administrator to centrally manage additional configuration settings by specifying DHCP options, which pass additional information to the DHCP client when it obtains a lease.
The Windows Time service is essential to the successful operation of Kerberos authentication. It is therefore essential for authentication based on Active Directory. Any application that uses Kerberos, including most security services, relies on time synchronization between the computers that are participating in the authentication request. Active Directory domain controllers must also have synchronized clocks to help ensure accurate data replication.
Although Windows Time service was originally designed to provide clock synchronization for Kerberos authentication, many current applications use timestamps to ensure transactional consistency, to record the time of important events, and other time-sensitive information.