Search for: All records

Since the exhaustion of unallocated IP addresses at the Internet Assigned Numbers Authority (IANA), a market for IPv4 addresses has emerged. In complement to purchasing address space, leasing IP addresses is becoming increasingly popular. Leasing provides a cost-effective alternative for organizations that seek to scale up without a high upfront investment. However, malicious actors also benefit from leasing as it enables them to rapidly cycle through different addresses, circumventing security measures such as IP blocklisting. We explore the emerging IP leasing market and its implications for Internet security. We examine leasing market data, leveraging blocklists as an indirect measure of involvement in various forms of network abuse. In February 2025, leased prefixes were 2.89× more likely to be flagged by blocklists compared to non-leased prefixes. This result raises questions about whether the IP leasing market should be subject to closer scrutiny. 

Abstract Although Internet routing security best practices have recently seen auspicious increases in uptake, Internet Service Providers (ISPs) have limited incentives to deploy them. They are operationally complex and expensive to implement and provide little competitive advantage. The practices with significant uptake protect only against origin hijacks, leaving unresolved the more general threat of path hijacks. We propose a new approach to improved routing security that achieves four design goals: improved incentive alignment to implement best practices; protection against path hijacks; expanded scope of such protection to customers of those engaged in the practices; and reliance on existing capabilities rather than needing complex new software in every participating router. Our proposal leverages an existing coherent core of interconnected ISPs to create a zone of trust, a topological region that protects not only all networks in the region, but all directly attached customers of those networks. Customers benefit from choosing ISPs committed to the practices, and ISPs thus benefit from committing to the practices. We discuss the concept of a zone of trust as a new, more pragmatic approach to security that improves security in a region of the Internet, as opposed to striving for global deployment. We argue that the aspiration for global deployment is unrealistic, since the global Internet includes malicious actors. We compare our approach to other schemes and discuss how a related proposal, ASPA, could be used to increase the scope of protection our scheme achieves. We hope this proposal inspires discussion of how the industry can make practical, measurable progress against the threat of route hijacks in the short term by leveraging institutionalized cooperation rooted in transparency and accountability. 

Network Telescopes, often referred to as darknets, capture unsolicited traffic directed toward advertised but unused IP spaces, enabling researchers and operators to monitor malicious, Internet-wide network phenomena such as vulnerability scanning, botnet propagation, and DoS backscatter. Detecting these events, however,has become increasingly challenging due to the growing traffic volumes that telescopes receive. To address this, we introduce DarkSim,a novel analytic framework that utilizes Dynamic Time Warping to measure similarities within the high-dimensional time series of network traffic. DarkSim combines traditional raw packet processing with statistical approaches, identifying traffic anomalies and enabling rapid time-to-insight. We evaluate our framework against DarkGLASSO, an existing method based on the GraphicalLASSO algorithm, using data from the UCSD Network Telescope.Based on our manually classified detections, DarkSim showcased perfect precision and an overlap of up to 91% of DarkGLASSO’s detections in contrast to DarkGLASSO’s maximum of 73.3% precision and detection overlap of 37.5% with the former. We further demonstrate DarkSim’s capability to detect two real-world events in our case studies: (1) an increase in scanning activities surrounding CVE public disclosures, and (2) shifts in country and network-level scanning patterns that indicate aggressive scanning. DarkSim provides a detailed and interpretable analysis framework for time-series anomalies, representing a new contribution to network security analytics. 

Packet filtering has remained a key network monitoring primitive over decades, even as networking has continuously evolved. In this article we present the results of a survey we ran to collect data from the networking community, including researchers and practitioners, about how packet filtering is used. In doing so, we identify pain points related to packet filtering, and unmet needs of survey participants. Based on analysis of this survey data, we propose future research and development goals that would support the networking community.