Cloudflare has released a study revealing a significant issue known as “CGNAT bias,” which affects users sharing IP addresses through Carrier-Grade Network Address Translation (CGNAT). This phenomenon results in internet service providers (ISPs) and online platforms treating traffic from these shared addresses with suspicion, often leading to throttling, blocking, or overall degraded service. Such actions disproportionately impact innocent users, particularly those from lower-income backgrounds who rely on shared connections, thereby exacerbating existing socioeconomic divides.
CGNAT serves as a workaround for the exhaustion of IPv4 addresses, allowing numerous users to share a single public IP address. This practice is prevalent among mobile networks and budget ISPs, especially in regions with limited infrastructure. Cloudflare’s research, detailed in a recent blog post, analyzed global traffic patterns and found that ISPs frequently impose restrictions on CGNAT users, misinterpreting collective online behavior as individual misconduct. For example, if a single user behind a shared IP engages in spam or distributed denial-of-service (DDoS) attacks, the entire group suffers consequences ranging from captcha challenges to outright bans.
Understanding the Mechanism Behind CGNAT Bias
CGNAT operates by translating private IP addresses into a public one at the carrier level. This approach arose from the limited availability of IPv4 addresses. Although IPv6 offers a long-term solution with its vast address space, its adoption remains slow, leaving CGNAT as a temporary fix for billions of users. Cloudflare’s methodology for detecting CGNAT involves monitoring traffic patterns, such as the number of unique users per IP address and variations in connection behaviors.
This detection process is essential because conventional security models view IP addresses as direct representations of user identity. When abuse levels surge from a shared address, automated systems flag the entire IP, resulting in penalties for all users sharing that address. According to reports from The Register on November 3, 2025, innocent users are “dragged down along with bad actors.”
The bias associated with CGNAT extends beyond throttling to hinder access to content. Users on CGNAT frequently experience higher latency or are blocked from services altogether, as platforms like streaming sites and social media apply sweeping restrictions. Cloudflare’s data indicates that this issue is particularly pronounced in mobile networks, affecting vital services such as online education and e-commerce in underserved communities.
Socioeconomic Implications and the Digital Divide
The implications of CGNAT bias are particularly stark when viewed through a socioeconomic lens. In regions such as Southeast Asia and Latin America, where affordable mobile data plans are prevalent, CGNAT users—often from lower-income households—face diminished internet quality. This situation perpetuates a digital divide, a point emphasized in discussions on X (formerly Twitter) by users and analysts in 2025.
Cloudflare’s findings align with broader trends reported by the International Telecommunication Union (ITU), which highlights persistent disparities in internet access. Their Q3 2025 Internet Disruptions Report, referenced by WebProNews, indicates that outages from natural disasters and cyberattacks compound these problems, as CGNAT-heavy networks tend to recover more slowly due to inherent biases.
Industry insiders argue for a need to adapt security measures. Instead of relying on IP-based blocking, there should be a shift toward utilizing user-agent analysis or machine learning to better isolate malicious actors. Critics also suggest that companies like Cloudflare may inadvertently contribute to these disparities by prioritizing enterprise clients over equitable access. Nonetheless, Cloudflare’s transparency efforts, including their updated Transparency Reports from February 2025, demonstrate a commitment to addressing these issues, providing data on government requests and abuse mitigation efforts.
As ISPs and online platforms gradually begin to respond, some are experimenting with more nuanced traffic management strategies. For instance, identifying CGNAT users can lead to more tailored rate-limiting measures, ensuring that a single abuser does not negatively impact the entire user pool. Cloudflare researchers emphasize the need for a shift toward probabilistic models that properly account for shared IP addresses.
The challenges faced by users on shared IPs were highlighted during a turbulent year for Cloudflare, particularly following the global outage on November 18, 2025, attributed to an “unusual traffic spike.” Such incidents underscore the vulnerability of centralized infrastructure, where CGNAT bias amplifies downtime for those most in need of reliable access.
Emerging innovations in networking and cryptography offer potential solutions. Discussions around encrypted client hello (ECH) aim to preserve user privacy while reducing reliance on IP addresses. For industry experts, integrating CGNAT detection into zero-trust architectures could help mitigate bias while enhancing overall security.
As the internet landscape evolves, particularly with increasing reliance on AI-driven models, the risk of alienating users in emerging markets remains. Mobile-first access is critical for economic participation, and Cloudflare’s ongoing research seeks to foster collaboration with academics to refine detection methods.
Regulatory bodies are also beginning to take notice. The EU’s Digital Services Act is influencing transparency measures, potentially requiring bias audits, while discussions in the United States about the digital divide echo statements from the White House in 2021, emphasizing the urgent need for policy interventions to ensure equitable broadband access.
Addressing CGNAT bias requires a comprehensive approach that includes technological advancements, industry standards, and heightened awareness. By exposing these disparities, Cloudflare’s work not only identifies flaws but also charts a pathway towards a more inclusive internet, where users sharing addresses do not face discrimination. As global connectivity continues to expand, closing these gaps will be essential to ensuring that the digital revolution benefits all users rather than deepening existing divides.
