dhcp_release (1) Linux Manual Page
dhcp_release – Release a DHCP lease on a the local dnsmasq DHCP server.
Synopsis
dhcp_release <interface> <address> <MAC address> <client_id>Description
A utility which forces the DHCP server running on this machine to release a DHCP lease.Send a DHCPRELEASE message via the specified interface to tell the local DHCP server to delete a particular lease.
The interface argument is the interface in which a DHCP request _would_ be received if it was coming from the client, rather than being faked up here.
The address argument is a dotted-quad IP addresses and mandatory.
The MAC address is colon separated hex, and is mandatory. It may be prefixed by an address-type byte followed by -, eg
10-11:22:33:44:55:66
but if the address-type byte is missing it is assumed to be 1, the type for ethernet. This encoding is the one used in dnsmasq lease files.
The client-id is optional. If it is "*" then it treated as being missing.