If you have looked up the IP that is assigned to your Microsoft Azure deployments using any of the IP geolocation services then you must have noticed that the IP location and deployment location are shown differently. For example if you have a deployment that is hosted in East US datacenter and when you geo lookup the IP address of this deployment, it might show that the VM is located in Brazil. This is not actually accurate.

 

Microsoft has quite a lot of IP address space, and it is assigned to new clusters as they come online. It can also be re-used later if we decommission services that used a specific block of IP space and want to reuse that IP space somewhere else later.

 

The IP address range that you can download from MSDN is the ultimate authority for where the deployment is located.  If you are using one of the several IP geolocation services, be aware that they are not 100% accurate. These services base their information on where the IP address range is registered from. Registration location does not have much to do with where the IP address is being served from.

 

For instance, there is a range of IP address showing as originating from Brazil using the Geolocation services, however per the downloaded document, this is being served from East US. There are also ranges registered in Redmond that are being served out of the EU. 

 

We have already updated many major geo-location databases to ensure customers do not experience any confusion in the future. We apologize for any inconvenience this has caused.

 

Thanks for your patience and understanding.

 

Related Azure Blog: http://azure.microsoft.com/blog/2014/06/11/windows-azures-use-of-non-us-ipv4-address-space-in-us-regions/