(Image Credit: iStockPhoto/Thomas_Zsebok_Images)
A few years ago, headlines warned that the internet was running out of IPv4 addresses, threatening the ability to identify devices and connect them to online services. That immediate crisis was largely avoided because many major ISPs still held large reserves of unused IPv4 addresses, easing pressure and delaying any urgent transition.
IPv4 does have a successor: IPv6. It offers an almost unimaginably vast address space (2^128 = 340,282,366,920,938,463,463,374,607,431,768,211,456 addresses), ensuring that address depletion is not a practical concern for the foreseeable future. Despite this, adoption of IPv6 has been gradual. The lack of an urgent need, along with the necessity of maintaining compatibility with IPv4 through dual-stack network setups, has slowed migration.
To stretch their IPv4 inventories, some providers have turned to interim measures such as Carrier Grade NAT (CGNAT), which allows multiple customers to share a single public IPv4 address. While CGNAT helps conserve addresses, it can cause problems for certain services—multiplayer gaming, peer-to-peer applications, and some remote access scenarios often require unique, directly routable addresses and may be disrupted by address sharing.
In the UK, Sky has recently begun customer trials of IPv6. This rollout comes three years after the company initially indicated it was preparing to support IPv6 when needed. The trial has been offered to customers on Sky’s ‘Unlimited’ and ‘Lite’ packages who use specific Sagem-manufactured routers, and the ISP described it as an “exciting” new test.
Moving to IPv6 introduces a number of challenges that Sky will need to address before wider deployment. One significant hurdle is that many other ISPs and parts of the internet are still predominantly IPv4, meaning end-to-end IPv6 connectivity is not yet universal. Equally important, a large amount of consumer hardware—older routers, smart devices, and network equipment—may not fully support IPv6, creating practical compatibility gaps for users.
Because of these compatibility issues, most providers planning a broader IPv6 rollout will likely maintain dual-stack configurations for the foreseeable future. Dual-stack networks run both IPv4 and IPv6 concurrently, allowing devices and services that require IPv4 to continue functioning while enabling native IPv6 connectivity where available. This approach reduces disruption for customers with legacy hardware and helps ensure a smoother transition as IPv6 adoption grows.
Trials like Sky’s are valuable for identifying real-world issues—configuration problems, hardware incompatibilities, or service disruptions—that can be resolved before a full launch. They also help ISPs refine support procedures and communicate requirements to customers, such as whether router firmware updates or hardware replacements are needed to benefit from IPv6.
Ultimately, the long-term benefits of IPv6 are clear: a vastly larger address space, simplified routing in many scenarios, and the potential to reduce reliance on address-sharing workarounds that complicate certain online services. The pace of adoption will depend on coordination across ISPs, equipment manufacturers, and service providers, along with the practicalities of supporting millions of existing devices.
Do you think more ISPs should run IPv6 customer trials? Let us know in the comments.