DHCPv4 Overview

The Dynamic Host Configuration Protocol for IPv4 (DHCPv4) enables DHCP servers to pass configuration parameters to IPv4 hosts.

DHCPv4 is based on the Bootstrap Protocol and provides configuration parameters to DHCP clients on request:

DHCP enables the automatic configuration of client systems. DHCP removes the need to configure devices individually. Instead, clients set network properties by connecting to the DHCP server. This protocol consists of two components: a protocol to deliver host-specific configuration parameters from a DHCP server to a host and a mechanism to allocate network addresses to hosts.

DHCP has a client-server model, where designated DHCP server hosts allocate network addresses and deliver configuration parameters to dynamically configured hosts. DHCP uses a four-message exchange between client and server: DISCOVER, OFFER, REQUEST, and ACKNOWLEDGE.

DHCP uses MAC addresses to identify a client and uses broadcast IPv4 messages on the LAN.

When you enable DHCP on a router, the router can automatically obtain an Ethernet IP address, prefix length, and default gateway address from the DHCP server.