Packets received at a network element are filtered according to a plurality of filtering rules, where each filtering rule includes filtering data associated with one or more fields of a received packet. Rule groups are defined to include a plurality of filtering rules having common associated fields. For each rule group, global filter masks are generated, where bit positions in the global filter mask indicate whether each filtering rule in the rule group has a predetermined value at a corresponding bit position. As packets are received, comparing the global filter masks to one or more fields in the packets to determine whether there is a possibility that one of the rules in a corresponding rule group will match data in the fields.