LONGEST PREFIX MATCHING OPERATIONS ON A VALUE IN MULTIPLE INTERSPERSED PREFIX LENGTH SEARCH SPACES TO DETERMINE AN OVERALL LONGEST PREFIX MATCHING RESULT IN A PACKET SWITCHING SYSTEM

摘要

In one embodiment, longest prefix matching (LPM) operations are performed on a value in multiple interspersed prefix length search spaces to determine an overall longest prefix matching result in a packet switching system. A first LPM lookup unit performs a first LPM operation on the particular lookup value in a first search space finding a first longest matching prefix, and a second LPM lookup unit performs a second LPM operation on the particular lookup value in a second search space finding a second longest matching prefix. The longer of the first and second longest matching prefixes determines the overall LPM. In one embodiment, the first search space and the second search space include non-default route prefixes with interspersed prefix lengths matching a same value, such as, but not limited to the particular lookup value (e.g., a destination address of a packet).