Question: What IP ranges does Windows Azure use? We want to add these IP ranges to our firewall exceptions.
Answer: Windows Azure IP ranges are not regularly published and are subject to change without prior notice. We do not recommend your service depend on whitelisting specific IP rangers on the Windows Azure Platform as this could result in breaking your application and causing downtime when the IP ranges are changed.
Alternatives to enabling IP filtering in your applications are to look into the Windows Azure AppFabric Service Bus, use lightweight authentication , or enable a secure connection between on-premise servers and the Windows Azure Platform withWindows Azure Connect .
Windows Azure Platform Support persona