Found this, if it helps:
If your Ethernet router only has 1 network port, or you want to connect more devices to the network than there are available ports, an Ethernet switch/hub can be used in combination with a crossover cable to extend the size of your network. A point to note is that a crossover cable usage is dependent on the LAN switch. Many LAN switches either have a separate uplink port, or auto-detect polarity on its ports. Therefore in many cases, a normal “straight” RJ45 cables as opposed to a crossover cable is needed
