No network can be rendered impenetrable through access control alone. Networks should ideally demonstrate an absence of reaction to malicious access [52]. The system itself should
therefore be configured to minimise the effects of malicious access to the system. Unused ports on switches and routers should be disabled, as should data access capabilities of USB ports on computers within the network. User accounts and passwords should also be in place on all the equipment, to prevent unauthorised operation of the device should either physical or electronic access to it be gained.