$ sudo ifdown eth0
Internet Systems Consortium DHCP Client V3.0.3
Copyright 2004-2005 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/products/DHCP

Listening on LPF/eth0/00:11:2f:96:bb:0f
Sending on   LPF/eth0/00:11:2f:96:bb:0f
Sending on   Socket/fallback