Abstract: An address-transparent device is disclosed that couples between two network interfaces in a semiconductor fab for communicating packets between a host coupled to a first network interface and a tool coupled to a second network interface. Alternatively, the address-transparent device couples between two networks in a semiconductor fab for communicating packets between a host on a first network and a tool on a second network. In a first aspect of the invention, the address-transparent device routes packets between the first network and the second network that is independent of any protocol. The address-transparent device couples to the host through the first network and couples to the tool through the second network where the address-transparent device having a first port with no IP address and a second port with a subnet IP address.