In a network device, a hash calculator generates a lookup hash value from data fields associated with a packet received by the network device. A compressed lookup key generator generates a compressed lookup key for the packet using the lookup hash value. A content addressable memory (CAM) stores compressed patterns corresponding to compressed lookup keys, uses the compressed lookup key received from the compressed lookup key generator to determine if the received compressed lookup key matches any stored compressed patterns, and outputs an index corresponding to a stored compressed pattern that matches the compressed lookup key. A memory stores uncompressed patterns corresponding to the compressed patterns stored in the CAM, and retrieves an uncompressed pattern using the index output by the CAM. A comparator generate a signal that indicates whether the uncompressed pattern retrieved from the memory matches the data fields associated with the packet.