DHCP stands for Dynamic Host Configuration Protocol, which is a network management protocol used on Internet Protocol (IP) networks. It 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. DHCP allows hosts to obtain required TCP/IP configuration information from a DHCP server. When a computer or other device connects to a network, the DHCP client software sends a DHCP broadcast query requesting the necessary information. Any DHCP server on the network may service the request. DHCP can be implemented on networks ranging in size from residential networks to large campus networks and regional ISP networks.
DHCP servers manage a pool of unique IP addresses, as well as information about client configuration parameters such as default gateway, domain name, the name servers, and time servers. DHCP-enabled clients send a request to the DHCP server whenever they connect to a network. DHCP minimizes configuration errors caused by manual IP address configuration. DHCP servers provide logging and management interfaces that aid administrators manage their IP address scopes. DHCP servers can provide redundancy and high availability.
It is important to note that DHCP lacks any built-in mechanism that enables clients and servers to authenticate each other. Both are vulnerable to deception -- one computer pretending to be another -- and to attack, where rogue clients can exhaust a DHCP servers IP address pool.
