Microsoft Azure’s stock of IPv4 addresses runs dry in US

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Microsoft’s Azure cloud service has run out of IPv4 addresses based in the United States.

Customers of Azure had been noticing that virtual machines deployed in North America were beginning to operate as if they were based in a different continent altogether.

This is because Microsoft had been borrowing from its Latin-American and South American IP databases to make up for the shortage.

Web browsers on the VMs, as a result, were bringing up the international versions of websites rather than the American one.

The issue comes amid the shift from IP version 4 over to IP version 6, which will allow Micrsoft to offer more addresses to new customers.

"IPv4 address space has been fully assigned in the United States, meaning there is no additional IPv4 address space available," said Ganesh Srinivasan, senior program manager at Microsoft, in a blog post.

“This requires Microsoft to use the IPv4 address space available to us globally for the addressing of new services.

"The result is that 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 added.

"It is not possible to transfer registration because the IP space is allocated to the registration authorities by Internet Assigned Numbers Authority."

The servers, stresses Microsoft, are still based in the US, despite the VM convincing itself that it’s based in Brazil or Mexico. IP address registration location does not equate to its physical location.

“Your service is still hosted in the US and your customer data will remain in the US,” wrote Srinivason.

Microsoft is working with its IP databases to alleviate the problem.