- IPv4 leasing is not an innovation but a consequence of structural scarcity and limited exit options.
- What appears as revenue optimisation is, at scale, a signal of deepening dependency in the Internet’s core infrastructure.
IPv4 scarcity and the rise of address rent
The global pool of freely available IPv4 addresses is exhausted. This is not a forecast, nor a temporary condition, but an operating constraint. All five regional Internet registries now allocate IPv4 space primarily through transfers rather than fresh issuance. As a result, IPv4 addresses have shifted from a routing necessity into a rent-bearing asset.
IP leasing emerges naturally from this environment. Organisations that hold unused address blocks can temporarily assign them to others without transferring ownership. The mechanism is simple. The implications are not.
What leasing reflects is not efficiency, but constraint. IPv4 cannot be exited cleanly. IPv6 exists, but interoperability requirements force networks to maintain IPv4 indefinitely. With no viable path to full withdrawal, address holders face a choice: hold idle assets indefinitely, or monetise them. Leasing becomes the default behaviour, not because it is optimal, but because alternatives are limited.
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Incentives change when exit is restricted
IPv4 leasing alters incentives across the Internet’s infrastructure layer. Address holders are no longer merely custodians of routing resources; they become landlords of a finite namespace. For lessees, particularly ISPs and hosting providers, leasing offers access without the capital cost of ownership, but also embeds recurring dependency.
As Bill Woodcock, general manager of Packet Clearing House, has previously noted, Internet number resources function through voluntary coordination rather than enforcement. When scarcity increases and exit options narrow, voluntary systems adapt in ways that prioritise continuity over resilience. Leasing fits this pattern.
The result is a market where addresses circulate without leaving the registry system, reinforcing the relevance of IPv4 rather than diminishing it. The system does not correct itself; it stabilises around scarcity.
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Case study: When unused IPv4 space stops being optional
A regional ISP held a legacy /22 IPv4 allocation obtained years before address exhaustion. Following network consolidation, a significant portion of the block remained unused. Selling the space would have removed future flexibility. Holding it generated no operational benefit.
The ISP opted to lease the addresses through a third-party marketplace. The decision did not reflect strategic foresight so much as structural pressure. IPv4 addresses had become valuable precisely because they could not be replaced.
The outcome was predictable: recurring revenue replaced dormancy, and the addresses re-entered active circulation without changing ownership.
Nothing was fixed. No scarcity was relieved. Instead, the system adapted to its own constraints. Idle resources became financial instruments, and dependency on IPv4 deepened rather than diminished.
IP leasing does not signal transition. It signals entrenchment — a system learning to live with limits rather than escape them.
