The present invention provides a method and apparatus for internal network device dynamic health monitoring. To increase network device availability, internal network device evaluations of resource attributes are conducted against threshold expressions and network managers are notified of any threshold events to allow them to address issues before failures occur. Flexibility is added by allowing users to select between various predefined threshold expressions, and flexibility is further increased by allowing users to input new threshold expressions. The user provided threshold expressions are dynamically incorporated into the network device's threshold evaluations while the network device is running. Thus, network managers may change threshold expressions at any time in accordance with their needs. The types of threshold expressions that may be used are practically limitless and may include any operand and multiple variables, including the time of day. In addition, multiple threshold expressions may be cascaded together. Network managers may be notified of threshold events in multiple manners as well. Moreover, the types of resource attributes that may be evaluated is extended by assigning unique identifiers to network device resources and allowing threshold evaluations for any identifiable resource and associated attributes.