The Dynamic Host Configuration Protocol (DHCP) is a protocol extension of the BOOTP protocol, which provides automated IP address assignment (among other things) to client systems on a network. It handles IP address allocation in one of three ways:
- Dynamic allocation
In this scheme, a DHCP server maintains a preset list of IP addresses designated by the system administrator. IP addresses are assigned as clients request an address from the available addresses in the pool. The address can be used, or leased, for a limited period of time. The client must continually renegotiate the lease with the server to maintain use of the address beyond the allotted period. When the lease expires, the IP address is placed back into the pool for use by other requesting clients and a new IP address is assigned.
- Manual allocation
The system administrator may wish to designate specific IP addresses to specific network interfaces (for example, to an Ethernet MAC address) while still using DHCP to deliver the address to the client. This allows the convenience of automated address setup and assures the same address each time.
- Automatic allocation
This method assigns a permanent address to a client. Typically DHCP is used to assign a temporary address (either dynamically or statically assigned) to a client, but a DHCP server can allow an infinite lease time.
DHCP can be configured to assign not only the IP address to the client but also such things as name servers, gateways, and architecture-specific parameters. ...