Big cloud providers are desperate for blocks of old IPv4 addresses, and this is creating opportunity for companies such as Hilco Streambank, which brokers those sought-after assets.

The company today announced, for example, it is offering RadioShack’s internal and unused IPv4 addresses to the public market. RadioShack filed for bankruptcy in March 2017, leaving more than 32,000 addresses that Hilco Streambank is listing for auction. The bankruptcy court has pre-approved the sale of the addresses.

The free pool of IPv4 addresses reached exhaustion in September 2015, and the American Registry for Internet Numbers (ARIN) has since been issuing free IPv6 addresses. But the transition is more complicated than just switching from one protocol to another.

Hilco Streambank CEO Gabe Fried explained that millions of devices such as routers, which run the Internet all over the world, are assigned IPv4 addresses. In addition, millions of Internet users have older devices that also are assigned IPv4 addresses. It’s going to take quite some time for a complete transition from IPv4 to IPv6. In the meantime, companies are having to run dual-stack IPv4/IPv6.

“It’s hard to find people spinning up networks that are IPv6 only,” said Fried. “There’s not enough traffic on IPv6 for people to give up IPv4 at this point. They have to do something.”

The most immediate solution “involves a lot of dual stacking,” said Fried. “Or you need some kind of translation going on inside networks. There are a variety of software solutions to get traffic compatible on both protocols.”

This problem is especially pressing for big cloud providers that need to deliver cloud services to their enterprise customers regardless of where they’re located and how updated the networks are in their regions. Hilco Streambank sees the biggest demand for IPv4 addresses from cloud providers, hosting companies, and Internet Service Providers (ISPs).

The company finds large blocks of unused IPv4 addresses and connects the owners of those addresses with prospective buyers.

“There was a lot of IPv4 allocated inefficiently in the early days to large companies and government organizations,” said Fried. He cited MIT as an example. The school received huge blocks of IPv4, which it never used. In April, MIT announced it was selling about 8 million of those addresses.

“There are companies like ours who are mining the globe for allocated but unused addresses,” said Fried. “A private market has emerged. It’s an opportunity for cloud networks to find additional addresses."