Why IPv4 Still Handles 70% of Internet Traffic – And Will for Decades

IPv6 has been available since 1998, nearly three decades ago. Yet IPv4 continues to dominate production environments worldwide. IPv4 addresses now trade at $45–65 each, up from just $5 in 2011. This isn't a temporary market anomaly. It reflects fundamental operational reality: IPv6 adoption has slowed, and expert consensus projects dual-stack operations will continue until at least 2040–2045.

In this article, I examine five reasons why IPv4 remains essential, what the next two decades look like, and how to build an IPv4 strategy that treats these addresses as the strategic infrastructure assets they've become.

IPv4 Dominance in 2026: The Numbers Tell the Story

The gap between IPv6 availability and IPv6 adoption tells you everything about the state of internet infrastructure today. While IPv6 proponents have been predicting IPv4's obsolescence for decades, the data shows a different picture.

Global Adoption Statistics

Global IPv6 adoption sits at 45–50% according to Google's IPv6 statistics, representing steady but slow growth. Meanwhile, IPv4 still handles 55–70% of total internet traffic. Among Fortune 500 companies, 76% operate primarily on IPv4 infrastructure. Mobile networks show 62% running dual-stack configurations, with 33% remaining IPv4-only.

China leads IPv6 adoption at over 72%, yet even there, massive IPv4 infrastructure remains operational and essential. The pattern holds globally: IPv6 deployment advances incrementally while IPv4 maintains operational dominance.

Why the Transition Remains Slow

Four structural barriers slow IPv6 adoption across enterprises and service providers.

• Legacy system compatibility creates the first barrier. Infrastructure deployed 15–20 years ago was built for IPv4. Replacing or upgrading these systems requires capital investment with minimal operational benefit, making it a low-priority decision for most organizations.

• Migration cost represents the second barrier. Enterprise IPv6 migration typically costs $150K–$2M+ depending on infrastructure complexity. For organizations where IPv4 works perfectly, this expenditure delivers no immediate return.

• Lack of business incentive compounds the problem. IPv4 handles current traffic requirements efficiently. Network operations teams face no burning platform driving urgent migration. When infrastructure works, wholesale replacement becomes hard to justify.

• Training and skillset gaps round out the barriers. Network engineering expertise accumulated over 30+ years favors IPv4. Tools, troubleshooting methodologies, and operational procedures optimize for IPv4 environments. IPv6 requires retooling this expertise.

The Dual-Stack Reality

Dual-stack operation—running IPv4 and IPv6 simultaneously—has become the dominant approach for 95% of ISPs and major enterprises. This isn't a temporary transition state. It's the operational model for the foreseeable future.

Dual-stack environments maintain IPv4 infrastructure while gradually adding IPv6 capability where needed. This approach preserves existing investments, maintains backward compatibility, and allows incremental IPv6 adoption based on actual business requirements rather than theoretical timelines.

The operational complexity of dual-stack environments includes managing two routing tables, two address allocation schemes, two sets of firewall rules, and two troubleshooting methodologies. This complexity has carrying costs, but organizations accept these costs as preferable to wholesale migration risk.

Even Google, a major IPv6 proponent with extensive resources and technical capability, maintains substantial IPv4 infrastructure to ensure service availability and compatibility across global networks.

Why IPv4 Isn't Going Anywhere Soon

Five structural factors ensure IPv4 remains operationally essential for decades, not years.

Legacy Infrastructure Lock-In

Billions of dollars sit invested in IPv4-only hardware across enterprise, industrial, and service provider networks. This installed base creates powerful lock-in effects that extend IPv4 relevance far beyond what protocol designers anticipated.

Enterprise software often has IPv4 addresses hardcoded into configuration files, database schemas, and application logic. Updating these systems requires extensive testing, validation, and often complete application rewrites. The risk and cost rarely justify the effort when systems function properly on IPv4.

Industrial IoT devices present an even more challenging constraint. Manufacturing equipment, building management systems, and industrial control systems typically have 20–30 year operational lifespans. These devices were deployed with IPv4-only capability and cannot be updated with firmware patches. Replacement requires capital equipment expenditure scheduled on decades-long refresh cycles.

According to Gartner research, 66% of enterprise applications remain IPv4-only as of 2025. The average enterprise infrastructure refresh cycle runs 7–10 years. Hardware replacement costs run $50–$200 per device, creating significant barriers for large-scale infrastructure updates.

A Fortune 500 manufacturer we consulted estimated $18M to upgrade factory floor networking to IPv6-compatible hardware. The analysis showed no operational benefit justifying this investment. Production equipment runs reliably on IPv4. The business case for migration simply doesn't close when existing infrastructure meets operational requirements.

IPv4 Actually Works Better for Many Use Cases

IPv4 offers practical advantages that keep it preferable for many production environments, independent of IPv6's theoretical benefits.

NAT and CGNAT technologies extend IPv4 address space efficiently. While NAT was originally a workaround for address scarcity, it became a powerful network architecture tool. NAT provides implicit security benefits by hiding internal network topology and creates clean separation between internal and external addressing schemes.

Troubleshooting complexity favors IPv4. Network engineers debug IPv4 issues faster because tools, methodologies, and expertise have refined over three decades. IPv4 troubleshooting averages 23 minutes compared to 48 minutes for equivalent IPv6 issues, based on operational data from large service providers.

Enterprise security tools show better IPv4 support. Research indicates 91% of network security tools, SIEM platforms, and monitoring solutions have more mature, feature-complete IPv4 capabilities compared to IPv6. Security operations teams work with tools optimized for IPv4 traffic analysis, threat detection, and incident response.

Engineer familiarity represents a significant operational advantage. The global network engineering workforce has universal IPv4 expertise. IPv6 expertise is growing but remains less widespread, creating operational risk for organizations dependent on specialized skills.

IPv4 vs IPv6: Practical Operational Differences

The Economics Favor IPv4 Retention

IPv4 addresses have become appreciating assets, fundamentally changing the economic calculus around migration and retention strategies.

IPv4 prices increased 900% since 2011. Addresses traded at $5 in 2011, $15 in 2015, $45 in 2023, and now exceed $55 in 2026. This price trajectory reflects genuine scarcity in a market where demand continues growing while supply remains fixed.

The IPv4 transfer market now exceeds $1B annually according to RIPE NCC transfer statistics. Organizations holding unused IPv4 blocks increasingly view these as balance sheet assets rather than operational overhead.

Compare migration costs against IPv4 leasing costs over a five-year planning horizon. IPv6 migration costs $150K–$2M upfront for typical enterprises. IPv4 leasing runs $0.40–0.50 per IP per month. A company leasing a /22 block (1,024 addresses) pays approximately $5,000–6,000 monthly, or $300K–360K over five years. This cost sits well below typical migration expenses while preserving capital flexibility.

Organizations now monetize unused IPv4 inventory. Companies that over-provisioned IPv4 addresses in earlier eras lease excess capacity through platforms like IPbnb. This creates new revenue streams from existing assets while maintaining strategic reserves for future growth.

IPbnb data shows 380% growth in IPv4 lease inquiries from 2023 to 2026, indicating strong demand-side pressure that keeps IPv4 economically relevant.

Curious what your unused IPv4 blocks are worth? Calculate potential revenue →

IPv6 Adoption Slowed to a Crawl

IPv6 adoption rates tell a story of momentum loss rather than inevitable transition. The adoption curve has flattened significantly over the past three years.

IPv6 traffic share grew from 45% to 50% over three years, representing 2–3% annual growth. This contrasts sharply with 8% annual growth rates seen from 2015–2018. The slowdown reflects diminishing returns as easier adoption targets get addressed, leaving more complex infrastructure challenges.

Current projections place 80% IPv6 adoption somewhere between 2040–2045, not the 2030 target often cited in earlier forecasts. The "full transition" timeline now extends to 2045–2050, representing a 15–20 year shift from earlier projections.

The chicken-and-egg problem persists. Content providers won't prioritize IPv6 without user base justification. Users won't demand IPv6 without content availability driving the need. This dynamic creates a stable equilibrium around dual-stack operation rather than forcing rapid transition.

Regional disparities widen rather than narrow. China leads at 72% IPv6 adoption while Africa sits at 11%. Europe and North America show 45–50% adoption. These gaps reflect different infrastructure investment cycles, regulatory environments, and economic priorities.

According to W3Techs data, 63% of websites don't support IPv6 as of 2026. This statistic alone illustrates the magnitude of work remaining before IPv6 becomes truly universal.

New Technologies Still Demand IPv4

Emerging technology categories drive continued IPv4 demand rather than accelerating migration to IPv6.

AI datacenters require IPv4 for compatibility with existing infrastructure. Machine learning workloads integrate with data sources, APIs, and services running on IPv4 infrastructure. While new AI infrastructure could theoretically deploy IPv6-only, practical integration requirements demand IPv4 connectivity.

The IoT device explosion creates sustained IPv4 demand. Projections indicate 75 billion IoT devices by 2030. Many IoT devices use IPv4 because implementation is simpler, cheaper, and better supported by existing development tools and platforms. The economics of low-cost IoT devices favor proven, well-understood protocols.

Cloud service providers maintain massive IPv4 pools and allocate IPv4 by default. AWS, Azure, and GCP recognize that customers expect IPv4 connectivity for compatibility with existing infrastructure. While these providers support IPv6, IPv4 remains the default allocation for new resources.

Email deliverability continues favoring IPv4. Approximately 85% of email reputation systems, blacklist services, and spam filtering infrastructure focuses on IPv4. Email sent from IPv6 addresses often faces deliverability challenges as reputation systems have incomplete IPv6 coverage. For businesses where email represents a critical channel, IPv4 remains operationally essential.

IPv4 Roadmap: What to Expect from 2026–2045

Understanding the next two decades requires abandoning the myth of sudden transition and accepting the reality of gradual coexistence. I've mapped out this timeline based on current market data, infrastructure refresh cycles, and RIR policy trends—not wishful thinking about protocol superiority.

2026–2030: Dual-Stack Consolidation Era

The next four years see continued IPv4 price appreciation with addresses projected to reach $65–$85 per IP by 2030. This reflects sustained demand against fixed supply as organizations compete for limited address space.

IPv6 adoption reaches approximately 65% by 2030, representing steady but unspectacular growth. Most enterprises finalize dual-stack infrastructure during this period, achieving stable configurations that support both protocols efficiently.

The IPv4 transfer market matures with clearer regulatory frameworks. Regional Internet Registries refine transfer policies, reducing friction and improving market efficiency. This maturation supports more sophisticated approaches to IPv4 as an asset class, including leasing arrangements, fractional ownership models, and address-backed financing instruments.

2030–2040: The Gradual Shift Period

IPv6 becomes the majority protocol during this decade, handling 70–80% of traffic by 2040. However, "majority" doesn't mean "exclusive." IPv4 remains critical for legacy infrastructure, email delivery, and specific operational requirements.

IPv4 transitions toward "premium" infrastructure status. Organizations maintain IPv4 for critical systems while routing commodity traffic through IPv6. This bifurcation creates different value tiers for different address blocks based on routing quality and reputation.

NAT and CGNAT technologies reach peak efficiency as service providers optimize these architectures for long-term operation rather than viewing them as temporary bridges to IPv6.

2040–2045: IPv4 as Legacy Infrastructure

By the early 2040s, IPv6 handles 80–85% of internet traffic. IPv4 persists for critical legacy systems that cannot be migrated economically or where replacement risk exceeds operational tolerance.

IPv4 blocks trade as "digital real estate" with pricing based on routing characteristics, reputation, and strategic value rather than simple scarcity. Well-maintained address space with clean reputation commands premium pricing.

Certain industries—manufacturing, healthcare, critical infrastructure—remain heavily IPv4-dependent due to equipment lifecycles and regulatory constraints around infrastructure changes.

IPv4 Strategy for Different Business Types

The right IPv4 approach depends on business size, industry, and growth trajectory. One-size-fits-all guidance misses critical context.

For Startups and SMBs

Recommendation: Lease IPv4, adopt IPv6 where possible

Why: Capital efficiency matters more than asset ownership at early stages. IPv4 leasing converts large capital expenditure into predictable OpEx, preserving cash for core business growth.

Action: Calculate lease versus purchase ROI over a 3–5 year horizon. Factor in growth projections and potential pivot scenarios. Leasing maintains flexibility if business requirements shift.

Key consideration: Preserve capital for differentiation and growth rather than locking funds into infrastructure assets with uncertain future value at your scale.

For Enterprises

Recommendation: Secure IPv4 reserves, implement dual-stack strategically

Why: IPv4 represents long-term asset appreciation and operational continuity. Large organizations benefit from holding strategic reserves while gradually building IPv6 capability.

Action: Audit current IPv4 holdings. Identify underutilized blocks for monetization through leasing. Calculate optimal reserve levels based on 10-year growth projections. Implement dual-stack in new deployments while maintaining IPv4 for critical systems.

Key consideration: Treat IPv4 as infrastructure capital with both carrying cost and yield potential. Optimize the balance between operational requirements and asset monetization.

For Network Operators/ISPs

Recommendation: Maintain IPv4 infrastructure, accelerate IPv6 deployment

Why: Customer demand requires IPv4 availability while competitive positioning demands IPv6 capability. Service quality differentiates in mature markets.

Action: Implement CGNAT to extend IPv4 efficiency. Optimize allocation strategies to maximize utilization of existing inventory. Aggressively deploy IPv6 to support customers with IPv6 requirements.

Key consideration: Dual-stack operational excellence differentiates service quality and customer satisfaction in competitive markets.

Your IPv4 Strategy by Business Profile

Building Your Dual-Stack IPv4/IPv6 Strategy

Effective IP infrastructure strategy requires systematic assessment and planning across four key areas.

Step 1 – Audit Your Current IPv4 Resources

Start with complete visibility into current IPv4 holdings. Identify all allocated blocks, utilization rates, and assignment patterns. Many organizations discover significant unused capacity during systematic audits.

Calculate potential leasing revenue from underutilized blocks. Even partially unused address space generates yield when leased through efficient marketplaces. Organizations often find that strategic reserves exceed actual operational requirements.

Assess infrastructure dependencies to understand which systems require IPv4 and which could migrate to IPv6 or dual-stack configurations. This mapping informs both near-term optimization and long-term planning.

Step 2 – Calculate IPv4 Needs (2026–2035)

Project growth requirements over a realistic planning horizon. Consider customer growth, geographic expansion, new product launches, and potential M&A activity. Build scenarios rather than single-point forecasts.

Evaluate lease versus purchase scenarios across different growth trajectories. Leasing offers flexibility for uncertain growth while purchasing locks in current pricing for long-term needs. The optimal mix depends on your specific situation.

Consider geographic expansion needs early. Different regions have different IPv4 availability and pricing through Regional Internet Registries. Planning multi-region architecture requires understanding these dynamics.

Step 3 – Implement IPv6 Where It Makes Sense

Start IPv6 deployment with new infrastructure where integration costs are lowest. New data centers, new application deployments, and new service launches offer natural opportunities for IPv6 adoption without disruptive migration.

Prioritize user-facing services for IPv6 support. Customer-facing applications benefit most from broad IPv6 availability. Internal systems can remain IPv4 longer without impacting user experience.

Maintain IPv4 for critical systems where migration risk exceeds benefits. Core infrastructure components with proven reliability and deep operational integration should migrate last, if at all.

Step 4 – Monitor the Market

Track IPv4 pricing trends through transfer market data and marketplace pricing. Understanding price movements helps optimize timing for purchases, sales, or leasing arrangements.

Stay informed on Regional Internet Registry policy changes. RIR policies affect transfer eligibility, allocation procedures, and administrative requirements. Policy changes can create opportunities or constraints for your IPv4 strategy.

Evaluate emerging technologies like improved CGNAT implementations that extend IPv4 efficiency. Technology evolution may change the economic calculation around migration timelines.

The Bottom Line: IPv4 Isn't Going Anywhere

Let me summarize what this means for your infrastructure planning.

IPv4 remains operationally essential through at least 2045. Legacy infrastructure, economic factors, and slow adoption dynamics guarantee continued relevance for decades. Smart businesses treat IPv4 as strategic assets, not technical debt. This shift in perspective enables better capital decisions and unlocks revenue from underutilized address blocks.

Dual-stack isn't temporary – it's the next 20 years. Stop planning for IPv4 sunset. Start optimizing for long-term dual-stack efficiency. The IPv4 market is maturing fast. Price discovery improves. Transfer mechanisms become more efficient. Sophisticated asset management approaches emerge.

The question isn't whether you need an IPv4 strategy. It's whether you're treating IPv4 as the long-term asset it has become.