Scanning the large-scale topology of the IPv6 internet presents a significant challenge in network engineering, particularly for understanding the underlying network structure and assessing network security. The sheer size of the IPv6 address space makes traditional brute-force scanning techniques, such as traceroute, inefficient and impractical. Existing methodologies are often unable to cope with the inherent complexity of IPv6’s network structure and its probing requirements, leading to issues such as redundant probes, ICMPv6 rate limits, and network congestion. To address these challenges, this paper introduces 6Trace, an innovative solution that mitigates the impact of rate-limiting and congestion by distributing scanning traffic across the network. Furthermore, 6Trace incorporates a stateless, asynchronous scanning approach combined with a bisection-like dynamic probing strategy, significantly reducing redundancy. Experimental results demonstrate that 6Trace enhances scanning efficiency by 70% over current solutions, discovering the maximum number of interface addresses while minimizing probing time. Notably, this paper also provides the first comprehensive analysis of topology probing results across different types of target networks. The insights gained from this study will inform future research on optimal target selection and IPv6 internet measurement techniques.

In network protocol fuzzing, effective seed scheduling plays a critical role in improving testing efficiency. Traditional state-driven seed scheduling methods in network protocol fuzzing are often limited by imbalanced seed selection, monolithic scheduling strategies, and ineffective power allocation. To overcome these limitations, we propose SCFuzz, specifically by employing a multi-armed bandit model to dynamically balance exploration and exploitation across multiple fuzzing phases. The fuzzing process is divided into initial, middle, and final phases with seed selection strategies adapted at each phase to optimize the discovery of new states, paths, and code coverage. Additionally, SCFuzz employs a power allocation method based on state weights, focusing power on high-potential messages to improve the overall fuzzing efficiency. Experimental evaluations on open-source protocol implementations show that SCFuzz significantly improves state and code coverage, achieving up to 17.10% more states, 22.92% higher state transitions, and 7.92% greater code branch coverage compared to AFLNet. Moreover, SCFuzz improves seed selection effectiveness by 389.37% and increases power utilization by 45.61%, effectively boosting the overall efficiency of fuzzing.

The rapid development of low-Earth-orbit (LEO) satellite constellations has not only provided global users with low-latency and unrestricted high-speed data services but also presented researchers with the challenge of understanding dynamic changes in global network behavior. Unlike geostationary satellites and terrestrial internet infrastructure, LEO satellites move at a relative velocity of 7.6 km/s, leading to frequent alterations in their connectivity status with ground stations. Given the complexity of the space environment, current research on LEO satellite internet primarily focuses on modeling and simulation. However, existing LEO satellite network simulators often overlook the global network characteristics of these systems. We present SatScope, a data-driven simulator for LEO satellite internet. SatScope consists of three main components, space segment modeling, ground segment modeling, and network simulation configuration, providing researchers with an interface to interact with these models. Utilizing both space and ground segment models, SatScope can configure various network topology models, routing algorithms, and load balancing schemes, thereby enabling the evaluation of optimization algorithms for LEO satellite communication systems. We also compare SatScope’s fidelity, lightweight design, scalability, and openness against other simulators. Based on our simulation results using SatScope, we propose two metrics—ground node IP coverage rate and the number of satellite service IPs—to assess the service performance of single-layer satellite networks. Our findings reveal that during each network handover, on average, 38.94% of nodes and 83.66% of links change.

Fast large-scale network scanning is an important way to understand internet service configurations and security in real time, among which stateless scan is representative. Existing stateless scanners can perform single-packet scans for internet-wide network measurements but are limited to host discovery or port scanning. To obtain further information over TCP, slower stateful scanners must be used in conjunction which spend more time and memory because of connection state maintenance. Through simplifying TCP finite state machine, this paper proposes a novel stateless scanning model, which can establish TCP connections and obtain further responses in a completely stateless manner. Based on this model, we implement ZBanner, an improved modular stateless scanner that utilizes user-defined probes for identifying services and versions, fingerprinting TLS servers, etc. We present unique design of ZBanner and experimentally characterize its feasibility and performance. Experiments show that ZBanner performs better than current state-of-the-art solutions in terms of scan rate and memory usage. ZBanner achieves at least three times faster than current tools for generic ports and over 90 times faster for open ports while keeping a minimum and stable memory usage.

Fast large-scale network scanning is an important way to understand internet service configurations and security in real time, among which stateless scan technology is representative. Existing stateless scanners can perform single-packet scans for internet-wide network measurements but are limited to host discovery or port scanning. To obtain further information over TCP, slower stateful scanners must be used in conjunction, which spend more time and memory because of connection state maintenance. Through the simplification of the TCP finite state machine (FSM), this paper proposes a novel stateless scanning model, which can establish TCP connections and obtain further responses in a completely stateless manner. Based on this model, we implement ZBanner, an improved modular stateless scanner that utilizes user-defined probes for identifying services and versions, fingerprinting TLS servers, etc. We present the unique design of ZBanner and experimentally characterize its feasibility and performance. Experiments show that ZBanner performs better than current state-of-the-art solutions in terms of scan rate and memory usage. ZBanner achieves a scan rate that is at least three times faster than current tools for generic ports and over 90 times faster for open ports while keeping a minimum and stable memory usage.