1. A computer readable memory device having computer executable instructions that when executed by a processor of a computing system perform a method comprising: accessing a target response of a target system, the target response comprising at least a portion of a reply to a test probe; determining a service supported by the target system by comparing the target response with a signature response; comparing the service supported by the target system with one or more roles associated with the service supported to determine at least one role of the target system; and determining a confidence level of the target system functioning in the at least one role of the target system; wherein the confidence level is a function of a number of roles to which the target response corresponds; and wherein the confidence level is indicated with a confidence level indicator comprising a numerical weight value.