A switching apparatus provides an address extension for an environment, such as I²C, that uses devices with a limited address configurability. The switching apparatus provides connection between a main bus and one or more secondary busses to which additional devices are connected. The switching apparatus detects an address on the main bus, and determines whether it is intended for a device on a secondary bus. If so, it connects the main bus to the proper secondary bus where the device in question is located. It then translates the address to an address within the limited configurability of the devices, and places the translated address on the secondary bus where the addressed device is located.