Abstract: A diagnostic system for a data access networked system (e.g., an Internet/Intranet access networked system) is described. The data access networked system includes a number of data service systems coupled together. Each of the data service systems is independently administrated. The diagnostic system includes a number of diagnostic modules, each running a number of diagnostic tests within one of the data service systems upon receiving a diagnostic request. The diagnostic modules also transmit the diagnostic request and diagnostic results to one another using an open standard communication protocol. The diagnostic system also includes a diagnostic terminal that is coupled to a first diagnostic module of the diagnostic modules to generate the diagnostic request to the first diagnostic module and to display the diagnostic results received from the first diagnostic module. A diagnostic system for a data service system of a data access networked system is also described.