Systems and methods for packet filtering

The invention relates to the field of data networking. In particular, the invention relates to technologies for packet and flow identification in networks. Systems and methods are described for converting priority based rules into isomorphic longest match rules. Rules for packet processing may be presented to a networking device in priority order, through an interface such as a Command Line Interface (CLI) or from networking applications which may reside on the networking device. The networking device may include hardware and/or software layers for accelerating packet processing; a forwarding layer may include hardware and/or software designed to perform longest match searches on packets. Prioritized rules may be converted into a data structure for the forwarding layer, so that a longest match search performed by the forwarding layer on the data structure is equivalent to a priority order search on the prioritized rules.