IPv4 Exhaustion Timeline: How We Got Here and What It Means for Your Business
IPv4 exhaustion is no longer a future scenario—it’s the reality that shapes how businesses get and use IP addresses today. Regional registries have largely run out of free IPv4 space, so IPv4 address depletion has pushed demand into the secondary market: buying, leasing, and renting from existing holders. This post walks through the IPv4 exhaustion timeline, what it means for your operations, and how you can still get the addresses you need.
The IPv4 Exhaustion Timeline
IPv4 uses a 32-bit address space: about 4.3 billion addresses. That seemed ample in the 1980s, but the growth of the internet made depletion inevitable.
2011: IANA runs out. The Internet Assigned Numbers Authority (IANA) allocated its last large blocks to the five Regional Internet Registries (RIRs)—ARIN, RIPE NCC, APNIC, LACNIC, and AFRINIC. From that point, no new IPv4 space existed at the top level; each RIR had only what was left in its pool.
2011–2019: RIRs exhaust one by one. APNIC was first to reach its own exhaustion phase. Others followed. RIPE NCC’s pool effectively ran out in November 2019, which made headlines across Europe and beyond. By 2020, the idea of “getting free IPv4 from the RIR” was largely over for most organizations.
The outcome: if you need IPv4 today, you typically get it from the secondary market—buying, leasing, or renting from someone who already holds space.
Why IPv4 Address Depletion Matters for Your Business
When RIRs stop handing out new IPv4, three things happen.
Supply is fixed. The total number of IPv4 addresses in use or held is roughly fixed. New needs are met by reusing or reallocating existing space (transfers, leases, rentals), not by creating new addresses.
Demand keeps growing. Cloud, hosting, VPN/proxy, remote work, and IoT keep demand high. So IPv4 exhaustion doesn’t mean “no one needs IPv4”—it means “new need is met from a finite pool,” which supports a liquid secondary market and stable or rising prices in many regions.
Your options are buy, lease, or rent. You can buy IPv4 addresses and own them after an RIR transfer, lease IPv4 for medium- to long-term use, or rent IPv4 for short-term or flexible needs. Choosing the right option depends on your timeline, budget, and how much control you need.
What Happens After an RIR Runs Out?
When a regional registry exhausts its pool, it doesn’t “close shop.” It keeps maintaining the registry, processing transfers (between parties within its region or under its policies), and supporting existing holders. New allocations from the RIR’s free pool stop; everything else moves to transfer and market mechanisms.
That’s why post-exhaustion, the focus shifts to:
- Transfers: Moving ownership or rights between organizations under RIR rules.
- Leasing and renting: Holders who don’t need all their space lease out IPv4 or offer it for rent, so others can use it without a full transfer.
So “run-out” really means “no more free lunch”—not “no more IPv4.”
How Companies Are Responding
Organizations have responded in a few main ways.
Buying IPv4. Companies with long-term needs and budget often buy IPv4 blocks and complete an RIR transfer. They get full control and an asset that can hold or increase in value.
Leasing IPv4. Others lease IPv4 for one to several years. Lower upfront cost, predictable monthly or annual payments, and no need to manage a transfer if they only need use rights.
Renting IPv4. For short projects, campaigns, or burst capacity, renting IPv4 is an option. Shorter commitment, often more flexible terms.
Carrier-grade NAT (CGNAT) and IPv6. Many networks use CGNAT to stretch fewer IPv4 addresses across more users, and push new services onto IPv6. That reduces but doesn’t eliminate the need for IPv4, especially for outbound compatibility and B2B requirements.
What You Should Do Next
If you’re planning capacity, launching a service, or expanding into new regions:
- Assume IPv4 won’t come from the RIR. Treat the secondary market as the normal path.
- Decide whether you need to own or just use. Ownership (buy) vs medium-term use (lease) vs short-term (rent) drives which pillar to use—how to buy IPv4, how to lease IPv4, or how to rent IPv4.
- Get current numbers. Pricing and availability vary by region and block size. Use a marketplace or broker to get quotes and see what’s available.
IPv4 exhaustion and address depletion have made the secondary market the default. Understanding the timeline and your options—buy, lease, or rent—puts you in a better position to secure the IPv4 you need.