What Does Medium Dependent Interface Crossover (MDIX) Mean?
A medium dependent interface crossover (MDIX) is a version of the medium dependent interface (MDI) enabling a connection between corresponding devices. An MDI port or uplink port is a port on a switch, router or network hub connecting to another switch or hub using a straight-through cable rather than an Ethernet crossover cable. Generally there are one to two ports on a switch or hub with an uplink switch, which can be used to alter between an MDI and MDIX interface.
Techopedia Explains Medium Dependent Interface Crossover (MDIX)
Generally switches and hubs use an MDIX interface. Routers use an MDI interface in a workstation or PC environment. Newer technology for hubs, switches and routers automatically detect the appropriate cable connection type by the use of automatic medium-dependent interface crossover (Auto-MDIX) or Auto Uplink. With Auto-MDIX straight-through cable and Ethernet, crossover cable can be used. Switches and hubs not having Auto-MDIX will typically have one port that will not cross the line or crossover.
