Abstract: A test instrument and method for testing switched LANs using a set of available MIBs in a switch is provided. The test instrument is designed for the characterization, diagnosis, and testing of a LAN having at least one switch which divides the network traffic into segments. A network device such as a switch will have a set of available MIBs, usually determined by the vendor, which may be accessed via an SNMP agent in the switch. Using the information selectively gathered from this set of available MIBs, various reports may be generated and displayed as reports which allow for a detailed analysis of switch parameters and traffic patterns. For any given report, optimal data items are chosen according to a predetermined hierarchy which provide the most pertinent, detailed information for each given report.