dhcp_release(1)

dhcp_release1

Release a dhcp lease on a the local dnsmasq dhcp server.

Usage

dhcp_release <interface> <address> <MAC address> <client_id>

Overview

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.

Notes

MUST be run as root - will fail otherwise.

Limitations

Only usable on IPv4 DHCP leases.

Releases

8 releases since Debian 7 (Wheezy); the text changed 1 time.

  1. 7
  2. 8–Arch

Author

This manual page was written by Simon Kelley <[email protected]>.

From dnsmasq 2.93-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.