Design Options for IP Address Management
Applies To: Windows Server 2008
Consider the following solutions for central management of client IP configurations:
Address Allocation Option 1: Manually Configured IP Addresses
Address Allocation Option 2: BOOTP This is a host configuration protocol originally specified in 1985 in RFC 951. It is a client-server protocol designed to allow a client device to receive an IP address automatically and have an operating system booted and loaded from a server. It is typically used to configure operating systems of diskless workstations and to assign IP addresses to such workstations.
Address Allocation Option 3: DHCP This is an IP standard for simplifying the management of host IP configurations. DHCP servers manage the dynamic allocation of IP addresses and other related configuration details for DHCP-enabled clients. DHCP was designed to support the configuration of frequently relocated networked computers that have local hard disks and full startup capabilities, such as laptops.
It is likely that DHCP will be the most appropriate technology for address management. However, there are a number of situations for which manual configuration or BOOTP might be more appropriate. Manually configured IP addresses are assigned by configuring a set of properties for the network device to provide the appropriate information. BOOTP and DHCP allocate and distribute IP addresses, and possibly other IP-related parameters, such as default gateway addresses, in response to a request from a networked client.
If BOOTP or DHCP are used for centralized allocation, there are several design options for implementing and managing these services that are described in Design Options for DHCP on Routed Networks. For example, the DHCP design must address options for integration and interoperability with other services, such as DNS.
Best practice recommendation
For a typical enterprise, the best practice is to use manual IP addresses for DHCP servers and IP router interfaces, DHCP address allocation to reserved IP addresses for most server interfaces, and dynamically assigned addresses for all other devices. DHCP is a core service in large enterprise environments, and fault tolerance for this service is critical. A DHCP server can be managing thousands of clients at a central site, so failure of the service must be avoided. Unlike the other core services, the DHCP service does not have any native fault tolerance. For example, Active Directory Domain Services (AD DS) uses multiple domain controllers that communicate with each other and WINS uses secondary and primary servers; DHCP does not have an equivalent mechanism.