An entry adapter allows downstream and upstream external signals to be conducted to a server interface of an internal client-server network and allows downstream and upstream external signals to be conducted to a client interface of the internal client-server network. The adapter also includes frequency band separation and blocking means for separating the client signals from the external signals based on the client signals having a higher frequency than the external signals, allowing the external signals to be conducted to only the server interface, allowing the client signals to be conducted through the second port means and the third port means, blocking the client signals from being conducted to the external network, and allowing the client signals to be conducted between the server interface and the client interface.