Configuring interface ath0=lan2 (inet)
run-parts --verbose /etc/network/if-pre-up.d
Starting WPA wireless connection...
ifconfig $IFACE up
dhclient3 -cf /etc/dhcp3/dhclient.$LOGICAL.conf -pf /var/run/dhclient.$IFACE.pid -lf /var/run/dhclient.$IFACE.leases $IFACE
Internet Systems Consortium DHCP Client V3.0.4
Copyright 2004-2006 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/

Listening on LPF/ath0/00:15:af:b5:ab:a4
Sending on LPF/ath0/00:15:af:b5:ab:a4
Sending on Socket/fallback
DHCPDISCOVER on ath0 to 255.255.255.255 port 67 interval 7
DHCPDISCOVER on ath0 to 255.255.255.255 port 67 interval 7
DHCPDISCOVER on ath0 to 255.255.255.255 port 67 interval 15
DHCPDISCOVER on ath0 to 255.255.255.255 port 67 interval 2
No DHCPOFFERS received.
No working leases in persistent database - sleeping.
run-parts --verbose /etc/network/if-up.d
Where is linux driver for DHCP???

Hi lailan, I probably know less about linux and networking than you do, but once when I was googling around for something else I found that on ubuntu only the dhcp client is installed by default, not the server. If you want to assign IP addresses using dhcp, you'll have to go to synaptic and install dhcp-server. I don't know if this is what you are looking for, and if you feel that my suggestion does not have any merits, just ignore it.

I think there is a bit of a concept problem here. First, what is it you are trying to achieve? Are you running a Linux client (desktop / laptop) or are you trying to run a server that will provide DHCP functionality?

The output you have posted shows that you are trying to configure a wireless device, which suggests a laptop/client but that it is not able to connect to a DHCP server, which indicates that you have the interface configured to receive its information dynamically. Is this what you are trying to do?

When you mention driver, there is no DHCP driver, but there are wireless drivers. Normally, these are installed automatically. Depending on the distribution you are using you may need a wireless manager, like wicd, which may or may not have been installed automatically.

Linux is capable of running a DHCP server, but I don't think that this is what you want. Please elaborate on what you are trying to do and provide specifics such as distribution, wireless adapter information, driver installed, etc. If you need help determining these things, we can provide that too.