6Hit: A reinforcement learning-based approach to target generation for internet-wide IPv6 scanning

Fast Internet-wide network measurement plays an important role in cybersecurity analysis and network asset detection. The vast address space of IPv6, however, makes it infeasible to apply a brute-force approach for scanning the entire network. Even worse, the extremely uneven distribution of IPv6 active addresses results in a low hit rate for active scanning. To address the problem, we propose 6Hit, a reinforcement learning-based target generation method for active address discovery in the IPv6 address space. It first divides the IPv6 address space into different regions according to the structural information of a set of known seed addresses. Then, it allocates exploration resources according to the reward of the scanning on each region. Based on the evaluative feedback from existing scanning results, 6Hit optimizes the subsequent search direction to regions that have a higher density of activity addresses. Compared with other state-of-the-art target generation methods, 6Hit achieves better performance on hit rate. Our experiments over real-world networks show that 6Hit achieves 3.5% - 11.5% hit rate for the eight candidate datasets, which is 7.7% - 630% improvement over the state-of-the-art methods. © 2021 IEEE.