Hash-based Address Matching

A packet switching device, comprising:

• off-lookup chip memory;
• and
• a lookup chip including one or more processors and on-lookup chip memory;
• wherein the lookup chip is configured to determine processing information for packets including performing a longest prefix match on a destination address of each particular packet of said packets using progressive, exact matching of one or more single prefix length hash keys generated from said particular packet with entries in one or more hash tables until a matching hash table entry is found, with the matching hash table entry associated with particular processing information for said particular packet, wherein an entry of said one or more hash tables is distributed between said on-lookup chip memory and said off-lookup chip memory.

A method, comprising:

• determining, by a packet switching device, processing information for a packet;
• and
• processing, by the packet switching device, the packet according to said processing information;
• wherein said determining processing information includes:
• performing a longest prefix match on a destination address of the packet using progressive, exact matching of single prefix length hash keys generated from the packet with entries in one or more hash tables until a matching hash table entry is found, with the matching hash table entry associated with said processing information, wherein the matching hash table entry is found when one or more signatures of a particular hash key of said of single prefix length hash keys and all fields of the particular hash key match corresponding values in the matching hash table entry.