A DHCP server processes incoming DHCP messages from a client based on
the current state of the binding for that client. A DHCP server can
receive the following messages from a client:
DHCPDISCOVER
DHCPREQUEST
DHCPDECLINE
DHCPRELEASE
DHCPINFORM
Table 3 gives the use of the fields and options in a DHCP message by
a server. The remainder of this section describes the action of the
DHCP server for each possible incoming message.