If Auto MDI-X is disabled, which type of UTP cable is required to connect a router to a switch?

When Auto MDI-X is disabled on a device, the device will not automatically detect the type of cable being used and will not configure itself accordingly. In such cases, it is important to use the appropriate type of cabling to establish a successful connection.

To connect a router to a switch without Auto MDI-X, a straight-through cable is required. This type of cable is used for connecting devices of different types, such as a router (which is a data terminal equipment or DTE) to a switch (which is a data communication equipment or DCE).

In a straight-through cable, the pinouts on both ends are the same, allowing for the correct configuration of the transmission and reception signals between the two devices. The pinouts typically follow the T568A or T568B standards.

Conversely, a crossover cable would be used to connect similar devices directly, such as a router to another router or a switch to another switch, which is not the case here. Coaxial cables and fiber-optic cables are completely different types of cabling and are not suitable for this particular connection scenario between a router and a switch in a standard ethernet networking setup.