Towards a Non-Binary View of IPv6 Adoption

TL;DR

This work reframes IPv6 adoption from a binary question of accessibility to a non-binary inquiry into actual usage across three ecosystem layers: clients, servers, and cloud providers. Through nine months of client-side data from five residences, a browser-based crawl of the Top 100k websites, and cloud-domain analyses, it reveals wide variability in IPv6 usage, with only about $12.6\%$ of reachable sites being fully IPv6-enabled and substantial portions relying on IPv4-only resources. The findings highlight that human-driven activity, service composition, and cloud deployment policies strongly influence IPv6 uptake, with diurnal patterns at the client level and inconsistent tenant adoption in the cloud. The study concludes with practical recommendations for cloud providers and CDN operators to adopt default-on IPv6 and for the measurement community to emphasize usage-based metrics to accelerate broader IPv6 deployment.

Abstract

Twelve years have passed since World IPv6 Launch Day, but what is the current state of IPv6 deployment? Prior work has examined IPv6 status as a binary: can a user do any IPv6? As deployment increases, we must consider a more nuanced, non-binary perspective on IPv6: how much and often can a user or a service use IPv6? We consider this question as a client, server, and cloud provider. Considering the client's perspective, we observe user traffic. We see that the fraction of IPv6 traffic a user sends varies greatly, both across users and day-by-day, with a standard deviation of over 15%. We show this variation occurs for two main reasons. First, IPv6 traffic is primarily human-generated, thus showing diurnal patterns. Second, some services lead with full IPv6 adoption, while others lag with partial or no support, so as users do different things their fraction of IPv6 varies. We look at server-side IPv6 adoption in two ways. First, we expand analysis of web services to examine how many are only partially IPv6 enabled due to their reliance on IPv4-only resources. Our findings reveal that only 12.6% of top 100k websites qualify as fully IPv6-ready. Finally, we examine cloud support for IPv6. Although all clouds and CDNs support IPv6, we find that tenant deployment rates vary significantly across providers. We find that ease of enabling IPv6 in the cloud is correlated with tenant IPv6 adoption rates, and recommend best practices for cloud providers to improve IPv6 adoption. Our results suggest IPv6 deployment is growing, but many services lag, presenting a potential for improvement.

Figures (18)

• Figure 1: Fraction of per-day IPv6 bytes and flows (vs. IPv4) at three residences, by external (solid lines) and internal (dashed lines).
• Figure 2: Fraction of IPv6 bytes at residence A (top graph), with MSTL decomposition into trend, daily, weekly, and residual components.
• Figure 3: Cumulative distribution of IPv6 byte fractions across 35 ASes observed at three or more residences. Each point $(x,y)$ on a curve indicates that the IPv6 byte fractions of $y$ fraction of ASes at that location was at or below $x$.
• Figure 4: Distribution of IPv6 byte fractions for 35 ASes observed at three or more locations, grouped by function. Within each category, ASes are sorted by median IPv6 byte fraction. Boxes show the interquartile range (25th-75th percentiles), and whiskers extend to 1.5$\times$IQR. Dots represent outliers.
• Figure 5: Sankey diagram and tabular breakdown of the Tranco top 100,000 websites, classified into IPv4-only, IPv6-partial, or IPv6-full.