Definition & steps
DHCP stands for Dynamic Host Configuration Protocol. When DHCP assigns an IP address, it actually leases that connection identifier to the user’s computer for a specific amount of time. The default lease is five days.
- Because there is certain lease duration, if not using after the duration, they will automatically collect it after the lease. So, it can be used for other computer.
- Because you don’t need to set the IP one by one, if you move to other office and connect to the that network, it will automatically assign an IP for you.
How DHCP works
- Discover: client computer sends a broadcast request looking for a DHCP server to answer.
- Router directs the DISCOVER packet to the correct DHCP server.
- The server receives the DISCOVER packet. Based on availability and usage policies set on the server, the server determines an appropriate address (if any) to give to the client.
- Offer: The server then temporarily reserves that address for the client and sends back to the client an OFFER packet, with that address information.
- Request: Letting the server know that it intends to use the address.
- ACK: Confirming that the client has a been given a lease on the address for a server-specified period of time.