Our household wireless network is provided by a Linksys WRT54G. Just two laptops, a laser printer and a network-attached drive I use for backups. I have UPnP disabled at the router and can not connect to the NAS device from the outside Internet, which is exactly what I want. That device is just for backing up our two laptops and I don't want anyone to be able to access it. Can someone point to a tool or methodology for testing to make sure there are no ports (or whatever) open to that device from the big, bad world out there? And I'd welcome any suggestions for additional filters or settings I should use on the WRT54G to lock down that device completely Internet-wise while keeping it visible to our internal wireless network?