Arrangement for searching packet policies using multi-key hash searches in a network switch

A method of identifying a layer 3 switching decision within an integrated network switch having a plurality of network switch ports and switching logic, the method including:

• storing, in a first table, layer 3 switching entries that identify data packet types based on layer 3 information, respectively, each layer 3 switching entry identifying a corresponding layer 3 switching decision to be performed by the integrated network switch;
• generating an entry signature for each of the layer 3 switching entries based on a prescribed hash operation performed on first and second portions of the corresponding layer 3 information based on:
• (1) generating first and second hash keys for the first and second portions of the corresponding layer 3 information in the layer 3 switching entry based on the prescribed hash operation;
• and
• (2) combining the first and second hash keys to form the entry signature;
• generating a packet signature by a network switch port of the integrated network switch for a data packet received at the network switch port based on performing the prescribed hash operation on the first and second portions of the layer 3 information in the corresponding received data packet;
• and
• identifying by the network switch port one of the layer 3 switching entries for switching of the received data packet based on detecting a match between the packet signature and the corresponding entry signature;
• wherein the integrated network switch is implemented on a single chip.

An integrated network switch configured for executing layer 3 switching decisions, comprising:

• an index table that includes addresses of layer 3 switching entries that identify respective data packet types based on layer 3 information, the index table also including for each address entry a corresponding entry signature representing a combination of selected first and second portions of the corresponding layer 3 information hashed according to a prescribed hashing operation;
• a plurality of network switch ports, each comprising:
• (1) a frame identifier configured for obtaining the first and second portions of layer 3 information within a data packet being received by the network switch port, and
• (2) a flow module configured for generating a packet signature by generating first and second hash keys for the first and second portions from the data packet based on a prescribed hash operation, the flow module identifying one of the layer 3 switching entries for execution of the corresponding layer 3 switching decision for the data packet based on a determined correlation between the packet signature and the corresponding entry signature;
• and
• layer 3 switching logic for executing the layer 3 switching decision for the data packet based on the corresponding identified one layer 3 switching entry;
• wherein the integrated network switch is implemented on a single chip.