Example approaches for authenticating a device are described. In an example, a category, from a plurality of categories, is identified for a device, based on data packets exchanged between the device and a network element. The category is indicative of operational capabilities of the device. Based on the category identified for the device, an authentication order for the device is determined. The authentication order is indicative of a sequence in which a set of authentication tests is to be executed for authentication of the device.