$ sudo /etc/init.d/networking restart
 * Reconfiguring network interfaces...                                          
There is already a pid file /var/run/dhclient.eth1.pid with pid 13197
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/eth1/00:14:c1:32:4b:8c
Sending on   LPF/eth1/00:14:c1:32:4b:8c
Sending on   Socket/fallback
DHCPRELEASE on eth1 to 192.168.1.1 port 67
There is already a pid file /var/run/dhclient.eth1.pid with pid 134519072
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/eth1/00:14:c1:32:4b:8c
Sending on   LPF/eth1/00:14:c1:32:4b:8c
Sending on   Socket/fallback
DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 8
DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 19
DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 4
No DHCPOFFERS received.
No working leases in persistent database - sleeping.
 * Stopping NTP server ntpd
   ...done.
                                                                         [ OK ]
$  * Starting NTP server ntpd
   ...done.