China's "IPv9" was real — and even Vint Cerf confused it with an April Fools' joke

By the early 2000s, it had become clear that the 4.3 billion addresses of IPv4 would soon be exhausted. What once seemed an unimaginably large pool was running out, and the standardization of IPv6 had been underway from the mid-1990s until its final publication in 1998. Yet just a few years later, in the mid-2000s, rumors began circulating that China was working on its own protocol — IPv9.

The problem was that no international body recognized this protocol, and it appeared drastically different from the rest of the global internet. But the confusion ran deeper. In 1994, on April Fools' Day, the Internet Engineering Task Force published RFC 1606, titled "A Historical Perspective On The Usage Of IP Version 9." This was a detailed parody memo, complete with absurd technical descriptions — such as the claim that broadcast storms could make patients' blood boil, and that wearing a "silly satellite dish hat" had become a trend in California.

When reports of China's actual IPv9 emerged a decade later, many people — including Vint Cerf, often called one of the "fathers of the internet" — initially thought it was just a reference to that old joke. In an email to figures within the Chinese internet community, Cerf expressed confusion: was this a real protocol, or another April Fools' prank? The line between parody and reality had blurred.

Ultimately, IPv9 never gained international recognition and failed to become a standard. It remains a curious footnote in internet history — a genuine technical effort that was mistaken for an elaborate engineering joke, and a reminder of how easily fact and fiction can mix in the world of network protocols.