So... I have studied for CCNA and such and been working with IP networking at the least the past 8 years or so. I have always seen and been told that the network address for a subnet is not a valid host address. Now first I will start by saying I know this is true. My question is more... is there a technical reason it can not be used or was it just arbitrarily agreed upon when the specification was designed? I understand why a broadcast address can not be used (because it is ACTUALLY used). The thing is when I see a network address used it is normally only in routing which is specifically using NETWORK addresses. This being the case, (network addresses being used only when you are expecting a network address) is there some technical reason that they could not have the network address be an actual valid host address?