Abstract: Devices and techniques are generally described for network device failure testing. In some examples, first data may be received describing a network topology. The network topology may describe a plurality of network components arranged in communication with one another. A first set of equivalent network components and a second set of equivalent network components may be determined from the network topology. A first network performance may be determined for the network topology by simulating network communication while a first network component of the first set of equivalent network components is in an inoperable state. A first test coverage percentage may be determined for the network topology. The first test coverage percentage may be a ratio of a first number of network components of the first set of equivalent network components to a total number of the plurality of network components.