Reserved IP addresses (classic deployment)

IP addresses in Azure fall into two categories: dynamic and reserved. Public IP addresses managed by Azure are dynamic by default. That means that the IP address used for a given cloud service (VIP) or to access a VM or role instance directly (ILPIP) can change from time to time, when resources are shut down or stopped (deallocated).

To prevent IP addresses from changing, you can reserve an IP address. Reserved IPs can be used only as a VIP, ensuring that the IP address for the cloud service remains the same, even as resources are shut down or stopped (deallocated). Furthermore, you can convert existing dynamic IPs used as a VIP to a reserved IP address.

To learn more about IP addresses in Azure, read the IP addresses article.

When do I need a reserved IP?

• You want to ensure that the IP is reserved in your subscription. If you want to reserve an IP address that is not released from your subscription under any circumstance, you should use a reserved public IP.
• You want your IP to stay with your cloud service even across stopped or deallocated state (VMs). If you want your service to be accessed by using an IP address that doesn't change, even when VMs in the cloud service are shut down or stop (deallocated).
• You want to ensure that outbound traffic from Azure uses a predictable IP address. You may have your on-premises firewall configured to allow only traffic from specific IP addresses. By reserving an IP, you know the source IP address, and don't need to update your firewall rules due to an IP change.

FAQs

• Can I use a reserved IP for all Azure services? No. Reserved IPs can only be used for VMs and cloud service instance roles exposed through a VIP.
• How many reserved IPs can I have? For details, see the Azure limits article.
• Is there a charge for reserved IPs? Sometimes. For pricing details, see the Reserved IP Address Pricing Details page.
• How do I reserve an IP address? You can use PowerShell, the Azure Management REST API, or the Azure portal to reserve an IP address in an Azure region. A reserved IP address is associated to your subscription.
• Can I use a reserved IP with affinity group-based VNets? No. Reserved IPs are only supported in regional VNets. Reserved IPs are not supported for VNets that are associated with affinity groups. For more information about associating a VNet with a region or affinity group, see the About Regional VNets and Affinity Groups article.

Manage reserved VIPs

Using Azure PowerShell (classic)

Before you can use reserved IPs, you must add it to your subscription. Create a reserved IP from the pool of public IP addresses available in the Central US location as follows:

  New-AzureReservedIP –ReservedIPName MyReservedIP –Location "Central US"

Notice, however, that you cannot specify what IP is being reserved. To view what IP addresses are reserved in your subscription, run the following PowerShell command, and notice the values for ReservedIPName and Address:

Get-AzureReservedIP

Expected output:

ReservedIPName       : MyReservedIP
Address              : 23.101.114.211
Id                   : d73be9dd-db12-4b5e-98c8-bc62e7c42041
Label                :
Location             : Central US
State                : Created
InUse                : False
ServiceName          :
DeploymentName       :
OperationDescription : Get-AzureReservedIP
OperationId          : 55e4f245-82e4-9c66-9bd8-273e815ce30a
OperationStatus      : Succeeded

Once an IP is reserved, it remains associated to your subscription until you delete it. Delete a reserved IP as follows:

Remove-AzureReservedIP -ReservedIPName "MyReservedIP"

Using Azure CLI (classic)

Create a reserved IP from the pool of public IP addresses available in the Central US location as Using Azure classic CLI follows:

Command:

azure network reserved-ip create <name> <location>

Example:

azure network reserved-ip create MyReservedIP centralus

You can view what IP addresses are reserved in your subscription using Azure CLI as follows:

Command:

azure network reserved-ip list

Once an IP is reserved, it remains associated to your subscription until you delete it. Delete a reserved IP as follows:

Command:

azure network reserved-ip delete <name>

Example:

azure network reserved-ip delete MyReservedIP

Reserve the IP address of an existing cloud service

You can reserve the IP address of an existing cloud service by adding the -ServiceName parameter. Reserve the IP address of a cloud service TestService in the Central US location as follows:

• Using Azure PowerShell (classic):

  New-AzureReservedIP –ReservedIPName MyReservedIP –Location "Central US" -ServiceName TestService
  

• Using Azure CLI (classic):

  Command:

   azure network reserved-ip create <name> <location> -r <service-name> -d <deployment-name>
  

  Example:

    azure network reserved-ip create MyReservedIP centralus -r TestService -d asmtest8942
  

Associate a reserved IP to a new cloud service

The following script creates a new reserved IP, then associates it to a new cloud service named TestService.

Using Azure PowerShell (classic)

New-AzureReservedIP –ReservedIPName MyReservedIP –Location "Central US"

$image = Get-AzureVMImage|?{$_.ImageName -like "*RightImage-Windows-2012R2-x64*"}

New-AzureVMConfig -Name TestVM -InstanceSize Small -ImageName $image.ImageName `
| Add-AzureProvisioningConfig -Windows -AdminUsername adminuser -Password MyP@ssw0rd!! `
| New-AzureVM -ServiceName TestService -ReservedIPName MyReservedIP -Location "Central US"

Remove a reserved IP from a running deployment

Remove a reserved IP added to a new cloud service as follows:

Using Azure PowerShell (classic)

Remove-AzureReservedIPAssociation -ReservedIPName MyReservedIP -ServiceName TestService

Using Azure CLI (classic)

Command:

azure network reserved-ip disassociate <name> <service-name> <deployment-name>

Example:

azure network reserved-ip disassociate MyReservedIP TestService asmtest8942

To remove a reserved IP completely from a subscription, run the following command:

Command:

azure network reserved-ip delete <name>

Example:

azure network reserved-ip delete MyReservedIP

Associate a reserved IP to a running deployment

Using Azure PowerShell (classic)

The following commands create a cloud service named TestService2 with a new VM named TestVM2. The existing reserved IP named MyReservedIP is then associated to the cloud service.

$image = Get-AzureVMImage|?{$_.ImageName -like "*RightImage-Windows-2012R2-x64*"}

New-AzureVMConfig -Name TestVM2 -InstanceSize Small -ImageName $image.ImageName `
| Add-AzureProvisioningConfig -Windows -AdminUsername adminuser -Password MyP@ssw0rd!! `
| New-AzureVM -ServiceName TestService2 -Location "Central US"

Set-AzureReservedIPAssociation -ReservedIPName MyReservedIP -ServiceName TestService2

Using Azure CLI (classic)

You can associate a new reserved IP to your running cloud service deployment using Azure CLI as follows:

Command:

azure network reserved-ip associate <name> <service-name> <deployment-name>

Example:

azure network reserved-ip associate MyReservedIP TestService asmtest8942

Associate a reserved ip to a cloud service by using a service configuration file

You can also associate a reserved IP to a cloud service by using a service configuration (CSCFG) file. The following sample xml shows how to configure a cloud service to use a reserved VIP named MyReservedIP:

   <?xml version="1.0" encoding="utf-8"?>
    <ServiceConfiguration serviceName="ReservedIPSample" xmlns="https://schemas.microsoft.com/ServiceHosting/2008/10/ServiceConfiguration" osFamily="4" osVersion="*" schemaVersion="2014-01.2.3">
      <Role name="WebRole1">
        <Instances count="1" />
        <ConfigurationSettings>
          <Setting name="Microsoft.WindowsAzure.Plugins.Diagnostics.ConnectionString" value="UseDevelopmentStorage=true" />
        </ConfigurationSettings>
      </Role>
      <NetworkConfiguration>
        <AddressAssignments>
          <ReservedIPs>
           <ReservedIP name="MyReservedIP"/>
          </ReservedIPs>
        </AddressAssignments>
      </NetworkConfiguration>
    </ServiceConfiguration>

Next steps

• Understand how IP addressing works in the classic deployment model.
• Learn about reserved private IP addresses.
• Learn about Instance Level Public IP (ILPIP) addresses.