A method is provided for constructing a packet classifier for a computer network system. The method includes: receiving a set of rules for packet classification, where a rule sets forth values for fields in a data packet and a decision for data packets having matching field values; representing the set of rules as a directed graph; partitioning the graph into at least two partitions; generating at least one lookup table for each partition of the graph; and instantiating the lookup tables from one partition on a first content-addressable memory and the lookup tables from the other partition on a second content-addressable memory device.