Arista Networks, Inc.
Resilient Hashing With Compression

Abstract:

Techniques for implementing resilient hashing with compression are provided. In one set of embodiments, a network device can maintain a compressed partition and an uncompressed partition for a logical hash table, where (1) the logical hash table comprises a first set of mappings between bucket identifiers and active next-hop destinations, (2) the compressed partition comprises a second set of mappings between compressed indices and the active next-hop destinations, each compressed index in the second set addressing C consecutive bucket identifiers in the first set, and (3) the uncompressed partition comprises a third set of mappings between uncompressed indices and the active next-hop destinations, each uncompressed index in the third set addressing a single bucket identifier in the first set. Upon receiving a network packet, the network device can compute a hash value using a portion of the packet. When the hash value is addressed by a compressed index of a first mapping in the compressed partition, the network device can send the network packet to the first mapping's active next-hop destination, and when the hash value is addressed by an uncompressed index of a second mapping in the uncompressed partition, the network device can send the network packet to the second mapping's active next-hop destination.