The most common cause of an Ethernet splitter not working is a faulty connection. By enabling multiple devices to share a single Ethernet connection, they offer a cost-effective solution for those seeking to connect various devices to the internet. Connecting a Wi-Fi router to a splitter involves using an Ethernet cable. An Ethernet splitter, also known as an Ethernet switch or network switch, is designed to allow multiple devices to. Ethernet splitters are a handy tool for expanding a network connection in situations where you need to connect multiple devices to a single Ethernet cable. However, they aren't without their issues.