Which DHCP message type does the DHCP server send to a client to confirm its allocated IP address?

DHCPACK (DHCP Acknowledgment) is the message sent by the DHCP server to the client that confirms the client's requested IP address, grants the lease, and provides all necessary configuration parameters, concluding the DHCP DORA process.

DHCPOFFER is sent by the DHCP server to propose an available IP address to a client in response to a DHCPDISCOVER message.

DHCPDISCOVER is the initial broadcast message sent by a client to locate DHCP servers on the network.

DHCPREQUEST is sent by the client to formally request the offered IP address from a specific DHCP server.