Oops, I misread dhcp as dns, my bad. I haven't played with setting up a dhcp server in linux, so I can't help you with that. But it sounds like a configuration issue from what you describe. Is the laptop the only dhcp server on your network, and if you have a router, you would need to disable the dhcp server on the router so you don't get conflicts. Also, if you have a firewall of any sort running on the laptop, you need to open a hole for dhcp packets to pass thru both ways in the firewall configuration, I forget what ports dhcp uses, possibly 69?