DHCPi
DHCPi is not a formal standard in the official DHCP specifications. In some documentation and vendor materials, the term DHCPi is used informally to refer to the DHCP Inform operation, or more broadly to information-request behavior within the DHCP protocol family. The core IPv4 DHCP specification (RFC 2131) defines a DHCPINFORM message type, used by a client that already has an IP address to request additional local configuration parameters from a DHCP server. In IPv6, DHCP is defined separately (DHCPv6), which has its own message flows and information mechanisms; the explicit term DHCPi is not codified in the RFCs for DHCPv6.
In an information-request scenario, the client already holds an IP address (obtained by some means other than
DHCP Inform is commonly used when a device obtains an IP address through another method (static assignment,
DHCP, DHCPINFORM, DHCPv4, DHCPv6, Information-Request (in DHCPv6 context)