My "wire" / not yours I am looking for a way to secure DHCP. I have a network with all the frills; DCHP, DNS, DOMAIN, Etc. I know how to use DHCP to the point of settings address ranges etc.. What I would like to do is make it so that machines that aren't know to me. Such as users laptops and WiFi devices aren't allowed access to the network and obtain an IP address unless I am notified and allow it. Right now on the 2nd floor someone could just "jack" in and poof. they have an IP. Another thing I could do is this . I would set ISA to now allow network access outside of the network (somehow) if they don't have a domain user-id/password. This being all said. Why would I want to even get an IP. If I don't know you I don't know you . then again I don't know you why do I want you on my wire!