Dormant IPv4 Addresses: The Market's Invisible Supply
All 4.3 billion IPv4 addresses are allocated — but allocation is not usage. Dormant blocks are the market's invisible supply: an inventory opportunity, an abuse magnet and idle capital all at once.
Allocation is not usage
All roughly **4.3 billion IPv4 addresses are already allocated**. The free pools ran out between 2011 and 2020, and every transfer since has moved space that was already owned by someone. Yet allocation is a registry fact, not a usage fact. A large share of that allocated space answers nothing. It is not announced in routing tables, it does not respond to probes, and it has not carried production traffic in years. It is registered, it is owned — and it is dormant. The market's visible supply is what brokers list; the invisible supply is what sits quietly in the registries.
Why good space goes dormant
Dormancy is rarely a decision. It is usually drift: - **Mergers and acquisitions.** Two companies become one, each with its own address space. The duplicate blocks are never consolidated, and the acquired space is simply forgotten. - **Closed projects and decommissioned services.** A product dies, the servers are returned, and the /20 that supported it stays registered to a legal entity that no longer knows why it holds it. - **Migration behind NAT.** Whole offices collapse thousands of public addresses into a handful, and the original allocations quietly stop being used. - **Forgotten legacy allocations.** Space registered decades ago — before current staff, current policy, sometimes before the current company name. None of this is malicious. It is ordinary corporate entropy, and it happens at a scale the market never sees.
Three things at once
A dormant block is simultaneously three different assets, depending on who is looking at it. **An inventory opportunity.** Dormant blocks are the best source of supply because they have never been listed. The **RIPE region — Europe and Türkiye — carries the highest transfer volume in the world**, and much of that market runs on exactly this kind of space: clean, quiet, and moving directly from owner to buyer without ever appearing in a public listing. **An abuse magnet.** Unmonitored space is recycled space. Dormant prefixes attract spam and scanning because nobody is watching them — and by the time the owner looks, the block carries a reputation that makes it harder to sell or lease. **A balance sheet item.** A /24 is 256 addresses. At roughly **$27 per IP** that is about **$6,900** sitting idle; a /20, at roughly **$16 per IP**, is about **$65,500**; a /19, at roughly **$14 per IP**, is about **$114,700**. Meanwhile leasing runs at about **$0.40 per IP per month**, and cloud providers charge about **$44 per address per year** for the same resource. The market peaked near **$60 per IP in 2021** — this is an asset class with a history, and idle blocks are capital that is not working.
Why the registry won't tell you
A registry query tells you who holds a block. It does not tell you whether the block does anything. A prefix can be registered and announced, registered and silent, announced and unregistered — every combination exists in the wild. That is why finding dormant space requires measurement, not just lookup. Passive observation of routing tables and address-level activity separates "registered" from "used" and turns a static registry snapshot into live market intelligence. The difference between "allocated" and "available" is exactly what measurement produces.
Turning dormant space into supply
For owners, dormant space is a three-way choice: consolidate it, lease it, or sell it — all preferable to holding a block that generates nothing and attracts abuse. For buyers, dormant blocks are the cheapest clean supply on the market, at a moment when **AI infrastructure, IoT, VPN services and clean-block email reputation** keep demand firm. The first step is the same for both sides: find the space. IPDORM maps the dormant internet with passive scanning, turning silent blocks into visible supply — before anyone else lists them. --- *Explore the dormant side of the address space on the IPDORM map — [ipdorm.com](https://ipdorm.com).*