Q: How can I guarantee the virtual IP address of my Azure cloud service for the life of my subscription?
A: Each cloud service in Azure has a virtual IP. A VIP is an Internet-accessible IP address that can be used to contact virtual machines running in the cloud service through defined endpoints that publish ports on the virtual machine via ports on the VIP. The VIP of a cloud service will never change as long as it has a provisioned virtual machine within the cloud service. One way to ensure the VIP is never lost is to keep a small virtual machine provisioned. However, Microsoft has created a better option: the ability to actually reserve VIPs for an Azure subscription. These VIPs can then be used with cloud services. In addition, the VIPs are kept for a particular customer for the life of the customer's Azure subscription.
You can use PowerShell to create a reservation. For example, to reserve an IP address I might use the following command:
New-AzureReservedIP –ReservedIPName "SavSiteVIP" –Label "SavSiteVIP" –Location "East US"
This IP address would then be used when creating a new virtual machine in a new cloud service via the -ReservedIPName parameter. Reserved IP addresses can also be used with Web and Worker PaaS roles by modifying the Service Configuration Schema.
You can use the Get-AzureReservedIP command to view all reserved IP addresses. You can use the Remove-AzureReservedIP command to release an IP address that you no longer need.
Pricing for reserved IP addresses is available on Microsoft's Reserved IP Address Pricing Details page.