What is stateful and stateless IPv6, what does it do?


First of all, I want to quickly answer the question of what is DHCP. DHCP is a service called Dynamic Host Configuration Protocol that allows devices on the network to automatically obtain information such as IP, Default Gateway and DNS. Normally, we now use DHCP with IPv4, but IPv6 introduces two different DHCP services, Stateful and Stateless.


In Stateful DHCP, just like the DHCP server in IPv4, all the necessary information is provided by the DHCP server, and user information (IP and lease, etc.) is stored on the server. In Stateless DHCP, only DNS, etc. information is received from the DHCP server, IP and GW information are automatically generated by the user computer and user information (IP and lease, etc.) is not stored on the server. A computer on an IPv6 network automatically adjusts IP and GW information by utilizing NDP (Neighbor Discovery Protocol) packets from the router on the respective network.


A network can use both stateful and stateless autoconfiguration at the same time, they are not mutually exclusive.