Microsoft's Azure cloud service has run out of IPv4 addresses in the US, and it's borrowing from its Latin-American IP block.

Microsoft said that Azure customers may have noticed that virtual machines deployed in North America might think they are elsewhere, with web browsers bringing up international versions of a website, rather than the American one.

This is because IPv4 address space has been fully assigned in the United States, meaning there is no additional IPv4 address space available.

Ganesh Srinivasan, senior program manager, in a Microsoft blog post this means Microsoft has to use the IPv4 address space available to us globally for the addressing of new services.

“We will have to use IPv4 address space assigned to a non-US region to address services which may be in a US region," he said. "It is not possible to transfer registration because the IP space is allocated to the registration authorities by Internet Assigned Numbers Authority."

Microsoft said it's working with IP databases to help deal with the issue. The company bought a tranche of IPv4 addresses three years ago for $7.5 million, but they don't appear to have lasted long. Perhaps it is time that they came up with a service that used IPv6?