What is DHCP?

DHCP (Dynamic Host Configuration Protocol) is a protocol that provides a central and automatic management for the distribution of IP addresses to the devices in a network. In other words, DHCP is the protocol that assigns a device its IP address. DHCP is also used to configure other parameters such as the subnet mask, default gateway, and the DNS server information on connected devices.

How it works

In most small networks, the network router acts as a DHCP server. In larger networks, however, a DHCP server can be a stand-alone computer.

When a device (the client) connects to a router, it requests an IP address from the router. This is called a DHCP discover request. Once the request reaches the DHCP server (the router in this case), it allocates an IP address from its list of available IP addresses for the connected device to use. The server responds to the device with its IP address and a DHCP offer message.

The device accepts the first offer it receives and responds with another request to verify that the offer has been accepted. The DHCP server then updates itself with the device’s IP address and other configuration information.

Note that the DHCP is dynamic. This means that instead of having just one fixed IP address, new devices will be assigned addresses that are available from a subnet or “pool” that is assigned to the network.