nivesh@hellbound:~$ sudo dhclient wlan0
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/

wmaster0: unknown hardware address type 801
SIOCSIFFLAGS: No such file or directory
SIOCSIFFLAGS: No such file or directory
wmaster0: unknown hardware address type 801
Listening on LPF/wlan0/00:1a:73:6b:7c:02
Sending on   LPF/wlan0/00:1a:73:6b:7c:02
Sending on   Socket/fallback
receive_packet failed on wlan0: Network is down
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 8
send_packet: Network is down
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 9
send_packet: Network is down
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 19
send_packet: Network is down
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 17
send_packet: Network is down
DHCPDISCOVER on wlan0 to 255.255.255.255 port 67 interval 8
send_packet: Network is down
No DHCPOFFERS received.
No working leases in persistent database - sleeping.