Methods and apparatus to implement except condition during data packet classification

An apparatus, comprising:

• a memory configured to store a policy vector database including a plurality of policy vectors, each policy vector from the plurality of policy vectors being represented by a bit sequence and associated with a set of keys, each policy vector from the plurality of policy vectors being associated with at least one action triggering instruction in a switch fabric based on a bit value of each bit element in that policy vector;
• a processor operatively coupled to the memory,
• the processor configured to produce an indicator associated with an availability of a policy vector from the plurality of policy vectors, the policy vector from the plurality of policy vectors being associated with a set of keys including a key, associated with a portion of a data packet received at a multi-stage switch;
• and
• the processor configured to produce a composite policy vector, the composite policy vector being a logical bit combination of a first default policy vector from the plurality of policy vectors with one of, based on the indicator, the policy vector from the plurality of policy vectors or a second default policy vector from the plurality of policy vectors, the first default policy vector being associated with a default set of keys, the second default policy vector being associated with an excepted set of keys, the excepted set of keys including a second set of keys to be excepted from the default set of keys.

A method, comprising:

• receiving a key based on a portion of a data packet received at a multi-stage switch;
• accessing a first policy vector associated with one of a first set of keys including the key or a default set of keys, the first policy vector having a plurality of bit elements, each bit element from the plurality of bit elements of the first policy vector being uniquely associated with an action triggering instruction in a switch fabric of the multi-stage switch;
• accessing a second policy vector based on the first set of keys or the default set of keys, the second policy vector being associated with an excepted set of keys including a second set of keys associated with an except condition, the second policy vector having a plurality of bit elements, each bit element from the plurality of bit elements of the second policy vector being uniquely associated with an action triggering instruction in the switch fabric;
• and
• producing a composite policy vector based on a logical combination of the first policy vector with the second policy vector.