A method of identifying targets for monitoring includes: obtaining a user-defined filter map, the user-defined filter map having one or more filter rules for matching against network traffic when the user-defined filter map is used by a network system to process the network traffic; and determining a set of one or more targets by a processing unit based at least in part on the user-defined filter map, wherein the processing unit comprises a target selection module configured to access a list of available targets from a database, and select the one or more targets from the list of available targets based at least in part on the user-defined filter map.