Stands for "Dynamic Host Configuration Protocol." DHCP is a protocol that automatically assigns a unique IP address to each device that connects to a network. With DHCP, there is no need to manually assign IP addresses to new devices. Therefore, no user configuration is necessary to connect to a DHCP-based network. Because of its ease of use and widespread support, DHCP is the default protocol used by most routers and networking equipment.
- When a client detects it has connected to a DHCP server, it sends a DHCPDISCOVER request.
- The router either receives the request or redirects it to the appropriate DHCP server.
- If the server accepts the new device, it will send a DHCPOFFER message back to the client, which contains the client device's MAC address and the IP address being offered.
- The client returns a DHCPREQUEST message to the server, confirming it will use the IP address.
- Finally, the server responds with a DHCPACK acknowledgement message that confirms the client has been given access (or a "lease") for a certain amount of time.
DHCP works in the background when you connect to a network, so you will rarely see any of the above steps happen. The time it takes to connect via DHCP depends on the type of router and the size of the network, but it usually takes around three to ten seconds. DHCP works the same way for both wired and wireless connections, which means desktop computers, tablets, and smartphones can all connect to a DHCP-based network at the same time.
Updated: August 19, 2014