3.2.8 Automatic IP addressing
If you have never entered an IP address on any of your personal devices, it is because the IP address information is automatically assigned to any end device by the Dynamic Host Configuration Protocol for IPv4 (DHCP).
Imagine the amount of time it would take if every end device connected to the network required IP addressing information to be entered manually. Multiply that by every user, every mobile device, and every IP-enabled device on the network, and it becomes overwhelming. With DHCP, end users walk into areas served by a given network, plug in an Ethernet cable or enable a wireless connection, and they are immediately allocated the IP address information.
As shown in the figure, to configure DHCP on a Windows PC, the Obtain an IP address automatically option is selected. Your device is assigned information from an IP address pool and associated IP information set up on the DHCP server.
When deploying IPv6, there are other methods that allow a device to obtain its IPv6 addressing information. Stateless Address Autoconfiguration (SLAAC) is a method that allows a device to obtain information from an IPv6 router. Dynamic Host Configuration Protocol for IPv6 (DHCPv6) is similar to DHCP for IPv4, allowing a device to receive information from a DHCPv6 server.