IPv4
The original internet addressing scheme, with about 4.3 billion possible addresses, now so scarce that providers ration and share them.
IPv4 is the addressing scheme the internet grew up on, written as four numbers separated by dots like 192.0.2.10. Each of those four parts is a byte, which makes the whole address 32 bits and caps the total supply at about 4.3 billion. In the early 1980s that was an unimaginable abundance for a research network connecting a few hundred machines.
It stopped being abundant a long time ago. The regional registries that hand out address space exhausted their free pools years back, and the defining fact about IPv4 today is not a technical limitation but simple scarcity: there are more devices wanting addresses than there are addresses.
Everything awkward about modern addressing follows from that one shortage. Addresses trade on a genuine secondary market for real money, which is why an IPv4 proxy costs what it does. Providers issue fewer than one per customer. And carrier-grade NAT exists specifically to stack many households or many phones behind a single public IPv4, which is why one address so often represents a crowd rather than a person.
The scarcity is also what gives a clean IPv4 address its value in proxy work. If addresses were free and infinite, obtaining a fresh one would be trivial and its reputation would mean nothing, which is very close to the situation with IPv6 and part of why large IPv6 blocks are treated with suspicion. Cost is what makes the reputation worth something.
Despite IPv6 having existed for decades, IPv4 is not going away and is not becoming a legacy concern. Most of the consumer internet still reaches most sites over it, plenty of destinations serve nothing else, and it remains the address type that matters for essentially all proxy work. Planning around its disappearance has been a mistake for twenty years.
Frequently asked questions
Why are IPv4 proxies more expensive than IPv6?
Because the underlying addresses are genuinely scarce and trade for real money, while IPv6 addresses are effectively free and unlimited. The price difference reflects an actual difference in supply cost rather than a difference in service quality, and it is also why IPv4 addresses carry meaningful reputation while a fresh IPv6 block carries almost none.
Has IPv4 actually run out?
The free pools the regional registries handed out from are exhausted, yes. Addresses still change hands, but through a paid transfer market rather than by allocation. That is what turned an administrative resource into a priced asset, and it is why carrier-grade NAT became standard rather than exceptional.
Should I use IPv4 or IPv6 proxies?
IPv4 for almost everything, because it works everywhere. Plenty of destinations do not serve IPv6 at all, and among those that do, a request from a large IPv6 block is often treated with more suspicion precisely because obtaining thousands of such addresses is trivial. IPv6 is worth using when you have confirmed your specific targets both accept it and do not penalise it.
How many IPv4 addresses are there?
About 4.3 billion in total, since the address is 32 bits. The usable figure is meaningfully lower, because large blocks are reserved for private networks, multicast, loopback and other special purposes and never appear on the public internet.
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