IgNiTeD SoUL

The core function of DHCP is to assign addresses. DHCP functions at the Application Layer of the Open System Interconnection (OSI) reference model, as defined by the International Organization for Standardization (ISO) and the Telecommunication Standards Section of the International Telecommunications Union (ITU-T).

The OSI model is used for reference and teaching purposes; it divides computer networking functions into seven layers. From top to bottom, the seven layers are application, presentation,

session, transport, network, data-link, and physical

In brief, DHCP provides four key benefits to those managing and maintaining a TCP/IP network:

• Centralized administration of IP configuration—DHCP IP configuration information can be stored in a single location and enables the administrator to centrally manage all IP configuration information. A DHCP server tracks all leased and reserved IP addresses and lists them in the DHCP console. You can use the DHCP console to determine the IP addresses of all DHCP-enabled devices on your network. Without DHCP, not only would you need to manually assign addresses, you would also need to devise a method of tracking and updating them.
• Dynamic host configuration—DHCP automates the host configuration process for key configuration parameters. This eliminates the need to manually configure individual hosts when TCP/IP is first deployed or when IP infrastructure changes are required.
• Seamless IP host configuration—the use of DHCP ensures that DHCP clients get accurate and timely IP configuration parameters, such as the IP address, subnet mask, default gateway, IP address of the DNS server, and so on, without user intervention. Because the configuration is automatic, troubleshooting of misconfigurations, such as mistyped numbers, is largely eliminated.
• Flexibility and scalability—Using DHCP gives the administrator increased flexibility, allowing the administrator to more easily change IP configurations when the infrastructure changes. DHCP also scales from small to large networks. DHCP can service networks with ten clients as well as networks with thousands of clients. For very small, isolated networks, Automatic Private IP Addressing (APIPA) can be used.