13. Transmission of Messages by a Client

13. Transmission of Messages by a Client

Unless otherwise specified in this document or in documents describing how IPv6 is carried over specific types of links (for link types that do not support multicast), a client sends DHCP messages to All_DHCP_Relay_Agents_and_Servers.

A client uses multicast to reach all servers or a single server. A single server is indicated by specifying that server's DUID in the Server Identifier option (see section 22.3) in the client message (all servers will receive this message, but only the indicated server will respond). All servers are indicated by not providing this option.

A client can use unicast to send some messages directly to a server, as described in section 22.12.