Microsoft Running Out Of IPv4 Address Space In The US To Use For Azure VMs

This is an annoying issue affecting for Microsoft Azure customers. Some Azure customers may have noticed that for a VM deployed in a US region, when they launch a localized page on a web browser it may redirect them to an international site. Microsoft explained the cause of this issue in a blog post yesterday. Microsoft is running out of IPv4 address space in the US as they have used all of them. Microsoft is now trying to use the IPv4 addresses they got in other countries. Microsoft is already working with a few major IP geo-location database companies to update the location of these IPs which should help alleviate the issues this may be causing.

Potential Cause

IPv4 address space has been fully assigned in the United States, meaning there is no additional IPv4 address space available. 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.  It is not possible to transfer registration because the IP space is allocated to the registration authorities by Internet Assigned Numbers Authority.

At times your service may appear to be hosted in a non-US location.

Service and Data are located where deployed

It is important to note that the IP address registration authority does not equate to IP address physical location (i.e., you can have an IP address registered in Brazil but allocated to a device or service physically located in Virginia).  Thus when you deploy to a U.S. region, your service is still hosted in U.S. and your customer data will remain in the U.S. as detailed in our Trust Center:  http://www.windowsazure.com/en-us/support/trust-center/privacy/

Source: Microsoft