Patent ID: 7684400

Claim:
A method comprising: generating a filter-identifier based, at least in part, on one or more filter elements associated with a data packet header field, wherein the filter-identifier is different from a policy-identifier that identifies a policy applicable to data packets having specified entries in the one or more filter elements; characterizing the specified entries in the filter elements as either a range-based value or an exact value; generating a bit mask from the characterizing, each bit in the bit mask corresponding to a filter element; setting a bit in the bit mask to be a first logical value when its corresponding filter element has a range-based value; setting a bit in the bit mask to be a second, different logical value when its corresponding filter element has an exact value; determining respective sets of one or more filter-identifiers, each set associated with a respective filter element; and producing a result-set of filter-identifiers based on an intersection of the filter-identifier sets.