A method for using inventory rules to identify devices of a computer network includes intercepting data traffic across one or more communication links of the computer network. The intercepted data traffic is analyzed to determine whether one or more of a plurality of inventory rules is satisfied by the intercepted data traffic. Each of the plurality of inventory rules includes one or more conditions indicating the presence of a particular computer network device having a set of parameters. Devices of the computer network are identified using one or more satisfied inventory rules.