Heuristic Binary Search: Adaptive and Fast IPv6 Route Lookup With Incremental Prefix Updates

The advent of Software Defined Networking (SDN) and Network Function Virtualization (NFV) has revolutionized the deployment of software-based routing and forwarding devices in cloud and network systems. Yet, the performance of IPv6 route lookup in these devices remains a significant challenge due to two main factors: 1) the longer IPv6 addresses, which hinder high-speed lookup, and 2) the huge IPv6 IP address space, necessitates adaptability to varied length-based prefix distributions across various network scenarios. Existing IP lookup algorithms fall short in addressing these IPv6-specific challenges. To address these challenges, this paper proposes a novel Heuristic Binary Search (HBS) scheme. Building on the classical “Binary Search on Prefix Lengths” scheme, HBS employs three innovative techniques to achieve adaptive and fast IPv6 lookups with incremental updates: 1) a heuristic binary search method for fast lookup; 2) a tree rotation method for dynamic adjustment of binary search tree shapes in response to changes in prefix distribution; and 3) the introduction of the Associated Marker List (AML), a new data structure aimed at facilitating rapid incremental prefix updates. Our theoretical proofs and comprehensive evaluations demonstrate HBS’s superiority in lookup performance, dynamic adaptability, update speed, and memory efficiency.