root@client:~# dhclient eth0
There is already a pid file /var/run/dhclient.pid with pid 4478
killed old client process, removed PID file
Internet Systems Consortium DHCP Client V3.0.6
Copyright 2004-2007 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/Listening on LPF/eth0/00:22:cb:ze:95:sh
Sending on LPF/eth0/00:22:cb:ze:95:sh
Sending on Socket/fallback
DHCPREQUEST of 192.168.0.101 on eth0 to 255.255.255.255 port 67
DHCPACK of 192.168.0.101 from 192.168.0.1
bound to 192.168.0.101 — renewal in 284384 seconds.
root@client:~#
You could want to restart your leas for a variety of reasons. You just set up a static DHCP lease and you want to computer to pick up the new ip. If you are logged in via SSH make sure when you connection is dropped that you know what the new ip will be before hand or at least have a log in to the router so you can find out what it was assigned.