Authoritative server and support for DHCP inform packets

The server message DHCPinformmay be received when the server is already configured for static IPv4 addresses so that the server can to get configuration parameters dynamically.

NOTE:

RFC 2131 states that if a client has obtained a network address through some other means (e.g., manual configuration), it may use a DHCPinform request message to obtain other local configuration parameters. Servers receiving a DHCPinform message construct a DHCPACK message with any local configuration parameters appropriate for the client without: allocating a new address, checking for an existing binding, filling in yiaddr or including lease time parameters.