Manage NAT gateway

Article
11/04/2024

Learn how to create and remove a NAT gateway resource from a virtual network subnet. A NAT gateway enables outbound connectivity for resources in an Azure Virtual Network. You can change the public IP addresses and public IP address prefixes associated with the NAT gateway changed after deployment.

This article explains how to manage the following aspects of NAT gateway:

Create a NAT gateway and associate it with an existing subnet.
Remove a NAT gateway from an existing subnet and delete the NAT gateway.
Add or remove a public IP address or public IP prefix.

Prerequisites

An Azure account with an active subscription. Create an account for trial.
An existing Azure Virtual Network and subnet. For more information, see Quickstart: Create a virtual network using the Azure portal.
- The example virtual network that is used in this article is named vnet-1.
- The example subnet is named subnet-1.
- The example NAT gateway is named nat-gateway.

An Azure account with an active subscription. Create an account for trial.
An existing Azure Virtual Network and subnet. For more information, see Quickstart: Create a virtual network using the Azure portal.
- The example virtual network that is used in this article is named vnet-1.
- The example subnet is named subnet-1.
- The example NAT gateway is named nat-gateway.

To use Azure PowerShell for this article, you need:

This article requires the Azure PowerShell module version 5.4.1 or later. Run Get-Module -ListAvailable Az to find the installed version. If you need to upgrade, see Install Azure PowerShell module.

You also need to run Connect-AzAccount -Environment AzureChinaCloud to create a connection with Azure.

Ensure that your Az.Network module is 4.3.0 or later. To verify the installed module, use the command Get-InstalledModule -Name "Az.Network". If the module requires an update, use the command Update-Module -Name Az.Network.
Sign in to Azure PowerShell and select the subscription that you want to use. For more information, see Sign in with Azure PowerShell.

Create a NAT gateway and associate it with an existing subnet

You can create a NAT gateway resource and add it to an existing subnet by using the Azure portal, Azure PowerShell, Azure CLI, or Bicep.

Sign-in to the Azure portal.
In the search box at the top of the Azure portal, enter NAT gateway. Select NAT gateways in the search results.
Select + Create.

Enter or select the following information in the Basics tab of Create network address translation (NAT) gateway.

Setting	Value
Project details
Subscription	Select your subscription.
Resource group	Select your resource group or select Create new to create a new resource group.
Instance details
NAT gateway name	Enter nat-gateway.
Region	Select your region. This example uses China North 3.
Availability zone	Select No Zone. For more information about NAT gateway availability, see NAT gateway and availability zones.
TCP idle timeout (minutes)	Select the default of 4.

Select the Outbound IP tab, or select Next: Outbound IP.
You can select an existing public IP address or prefix or both to associate with the NAT gateway and enable outbound connectivity.
- To create a new public IP for the NAT gateway, select Create a new public IP address. Enter public-ip-nat in Name. Select OK.
- To create a new public IP prefix for the NAT gateway, select Create a new public IP prefix. Enter public-ip-prefix-nat in Name. Select a Prefix size. Select OK.
Select the Subnet tab, or select Next: Subnet.
Select your virtual network. In this example, select vnet-1 in the dropdown list.
Select the checkbox next to subnet-1.
Select Review + create.
Select Create.

Public IP address

To create a NAT gateway with a public IP address, run the following PowerShell commands.

Use the New-AzPublicIpAddress cmdlet to create a public IP address for the NAT gateway.

## Create public IP address for NAT gateway ##
$ip = @{
    Name = 'public-ip-nat'
    ResourceGroupName = 'test-rg'
    Location = 'chinanorth3'
    Sku = 'Standard'
    AllocationMethod = 'Static'
}
New-AzPublicIpAddress @ip

Use the New-AzNatGateway cmdlet to create a NAT gateway resource and associate the public IP address that you created. Use the Set-AzVirtualNetworkSubnetConfig cmdlet to configure the NAT gateway for your virtual network subnet.

## Place the virtual network into a variable. ##
$net = @{
    Name = 'vnet-1'
    ResourceGroupName = 'test-rg'
}
$vnet = Get-AzVirtualNetwork @net

## Place the public IP address you created previously into a variable. ##
$pip = @{
    Name = 'public-ip-nat'
    ResourceGroupName = 'test-rg'
}
$publicIP = Get-AzPublicIPAddress @pip

## Create NAT gateway resource ##
$nat = @{
    ResourceGroupName = 'test-rg'
    Name = 'nat-gateway'
    IdleTimeoutInMinutes = '4'
    Sku = 'Standard'
    Location = 'chinanorth3'
    PublicIpAddress = $publicIP
}
$natGateway = New-AzNatGateway @nat

## Create the subnet configuration. ##
$sub = @{
    Name = 'subnet-1'
    VirtualNetwork = $vnet
    NatGateway = $natGateway
    AddressPrefix = '10.0.0.0/24'
}
Set-AzVirtualNetworkSubnetConfig @sub

## Save the configuration to the virtual network. ##
$vnet | Set-AzVirtualNetwork

Public IP prefix

To create a NAT gateway with a public IP prefix, use these commands.

Use the New-AzPublicIpPrefix cmdlet to create a public IP prefix for the NAT gateway.

## Create public IP prefix for NAT gateway ##
$ip = @{
    Name = 'public-ip-prefix-nat'
    ResourceGroupName = 'test-rg'
    Location = 'chinanorth3'
    Sku = 'Standard'
    PrefixLength ='29'
}
New-AzPublicIpPrefix @ip

Use the New-AzNatGateway cmdlet to create a NAT gateway resource and associate the public IP prefix you created. Use the Set-AzVirtualNetworkSubnetConfig cmdlet to configure the NAT gateway for your virtual network subnet.

## Place the virtual network into a variable. ##
$net = @{
    Name = 'vnet-1'
    ResourceGroupName = 'test-rg'
}
$vnet = Get-AzVirtualNetwork @net

## Place the public IP prefix you created previously into a variable. ##
$pip = @{
    Name = 'public-ip-prefix-nat'
    ResourceGroupName = 'test-rg'
}
$publicIPprefix = Get-AzPublicIPPrefix @pip

## Create NAT gateway resource ##
$nat = @{
    ResourceGroupName = 'test-rgNAT'
    Name = 'nat-gateway'
    IdleTimeoutInMinutes = '4'
    Sku = 'Standard'
    Location = 'chinanorth3'
    PublicIpPrefix = $publicIPprefix
}
$natGateway = New-AzNatGateway @nat

## Create the subnet configuration. ##
$sub = @{
    Name = 'subnet-1'
    VirtualNetwork = $vnet
    NatGateway = $natGateway
    AddressPrefix = '10.0.0.0/24'
}
Set-AzVirtualNetworkSubnetConfig @sub

## Save the configuration to the virtual network. ##
$vnet | Set-AzVirtualNetwork

Public IP address

To create a NAT gateway with a public IP address, use the following commands.

Use az network public-ip create to create a public IP address for the NAT gateway.

az network public-ip create \
    --resource-group test-rg \
    --location chinanorth3 \
    --name public-ip-nat \
    --sku standard

Use az network nat gateway create to create a NAT gateway resource and associate the public IP address that you created.

az network nat gateway create \
    --resource-group test-rg \
    --name nat-gateway \
    --public-ip-addresses public-ip-nat \
    --idle-timeout 4

Use az network vnet subnet update to associate the NAT gateway with your virtual network subnet.

az network vnet subnet update \
    --resource-group test-rg \
    --vnet-name vnet-1 \
    --name subnet-1 \
    --nat-gateway nat-gateway

Public IP prefix

To create a NAT gateway with a public IP prefix, use the following commands.

Use az network public-ip prefix create to create a public IP prefix for the NAT gateway.

az network public-ip prefix create \
    --length 29 \
    --resource-group test-rg \
    --location chinanorth3 \
    --name public-ip-prefix-nat

Use az network nat gateway create to create a NAT gateway resource and associate the public IP prefix that you created.

az network nat gateway create \
    --resource-group test-rg \
    --name nat-gateway \
    --public-ip-prefixes public-ip-prefix-nat \
    --idle-timeout 10

Use az network vnet subnet update to associate the NAT gateway with your virtual network subnet.

az network vnet subnet update \
    --resource-group test-rg \
    --vnet-name vnet-1 \
    --name subnet-1 \
    --nat-gateway nat-gateway


@description('Name of the NAT gateway')
param natgatewayname string = 'nat-gateway'

@description('Name of the NAT gateway public IP')
param publicipname string = 'public-ip-nat'

@description('Name of resource group')
param location string = resourceGroup().location

var existingVNetName = 'vnet-1'
var existingSubnetName = 'subnet-1'

resource vnet 'Microsoft.Network/virtualNetworks@2023-05-01' existing = {
  name: existingVNetName
}
output vnetid string = vnet.id

resource publicip 'Microsoft.Network/publicIPAddresses@2023-06-01' = {
  name: publicipname
  location: location
  sku: {
    name: 'Standard'
  }
  properties: {
    publicIPAddressVersion: 'IPv4'
    publicIPAllocationMethod: 'Static'
    idleTimeoutInMinutes: 4
  }
}

resource natgateway 'Microsoft.Network/natGateways@2023-06-01' = {
  name: natgatewayname
  location: location
  sku: {
    name: 'Standard'
  }
  properties: {
    idleTimeoutInMinutes: 4
    publicIpAddresses: [
      {
        id: publicip.id
      }
    ]
  }
}
output natgatewayid string = natgateway.id

resource updatedsubnet01 'Microsoft.Network/virtualNetworks/subnets@2023-06-01' = {
  parent: vnet
  name: existingSubnetName
  properties: {
    addressPrefix: vnet.properties.subnets[0].properties.addressPrefix
    natGateway: {
      id: natgateway.id
    }
  }
}

Remove a NAT gateway from an existing subnet and delete the resource

To remove a NAT gateway from an existing subnet, complete the following steps.

Sign-in to the Azure portal.
In the search box at the top of the Azure portal, enter NAT gateway. Select NAT gateways in the search results.
Select nat-gateway.
Under Settings, select Subnets.
Select Disassociate to remove the NAT gateway from the configured subnet.

You can now associate the NAT gateway with a different subnet or virtual network in your subscription. To delete the NAT gateway resource, complete the following steps.

In the search box at the top of the Azure portal, enter NAT gateway. Select NAT gateways in the search results.
Select nat-gateway.
Select Delete.
Select Yes.

Use Set-AzVirtualNetworkSubnetConfig to remove the NAT gateway association from the subnet by setting the value to $null. Use Set-AzVirtualNetwork to update the virtual network configuration.

# Specify the resource group and NAT gateway name
$resourceGroupName = "test-rg"

# Specify the virtual network name and subnet name
$virtualNetworkName = "vnet-1"
$subnetName = "subnet-1"

# Get the virtual network
$vnet = @{
    Name = $virtualNetworkName
    ResourceGroupName = $resourceGroupName
}
$virtualNetwork = Get-AzVirtualNetwork @vnet

# Get the subnet
$subnet = $virtualNetwork.Subnets | Where-Object {$_.Name -eq $subnetName}

# Remove the NAT gateway association from the subnet
$subnet.NatGateway = $null

# Update the subnet configuration
$subConfig = @{
    Name = $subnetName
    VirtualNetwork = $virtualNetwork
    AddressPrefix = $subnet.AddressPrefix         
}
Set-AzVirtualNetworkSubnetConfig @subConfig

# Update the virtual network
Set-AzVirtualNetwork -VirtualNetwork $virtualNetwork

Use Remove-AzNatGateway to delete the NAT gateway resource.

# Specify the resource group and NAT gateway name
$resourceGroupName = "test-rg"
$natGatewayName = "nat-gateway"

$nat = @{
    Name = $natGatewayName
    ResourceGroupName = $resourceGroupName
}
Remove-AzNatGateway @nat

Use az network vnet subnet update to remove the NAT gateway from the subnet.

az network vnet subnet update \
      --resource-group test-rg \
      --vnet-name vnet-1 \
      --name subnet-1 \
      --remove natGateway

Use az network nat gateway delete to delete the NAT gateway resource.

az network nat gateway delete \
    --name nat-gateway \
    --resource-group test-rg

@description('Name of resource group')
param location string = resourceGroup().location

var existingVNetName = 'vnet-1'
var existingSubnetName = 'subnet-1'

resource vnet 'Microsoft.Network/virtualNetworks@2023-05-01' existing = {
  name: existingVNetName
}
output vnetid string = vnet.id

resource updatedsubnet01 'Microsoft.Network/virtualNetworks/subnets@2023-06-01' = {
  parent: vnet
  name: existingSubnetName
  properties: {
    addressPrefix: vnet.properties.subnets[0].properties.addressPrefix
  }
}

Note

When you delete a NAT gateway, the public IP address or prefix associated with it isn't deleted.

Add or remove a public IP address

Complete the following steps to add or remove a public IP address from a NAT gateway.

Sign-in to the Azure portal.
In the search box at the top of the Azure portal, enter Public IP address. Select Public IP addresses in the search results.
Select Create.

Enter the following information in Create public IP address.

Setting	Value
Subscription	Select your subscription.
Resource group	Select your resource group. The example uses test-rg.
Region	Select a region. This example uses China North 3.
Name	Enter public-ip-nat2.
IP version	Select IPv4.
SKU	Select Standard.
Availability zone	Select the default of Zone-redundant.
Tier	Select Regional.

Select Review + create and then select Create.
In the search box at the top of the Azure portal, enter NAT gateway. Select NAT gateways in the search results.
Select nat-gateway.
Under Settings, select Outbound IP.
The IP addresses and prefixes associated with the NAT gateway are displayed. Next to Public IP addresses, select Change.
Next to Public IP addresses, select the dropdown for IP addresses. Select the IP address that you created to add to the NAT gateway. To remove an address, unselect it.
Select OK.
Select Save.

Add public IP address

To add a public IP address to the NAT gateway, add it to an array object along with the current IP addresses. The PowerShell cmdlets replace all the addresses.

In this example, the existing IP address associated with the NAT gateway is named public-ip-nat. Replace this value with an array that contains both public-ip-nat and a new IP address. If you have multiple IP addresses already configured, you must also add them to the array.

Use New-AzPublicIpAddress to create a new IP address for the NAT gateway.

## Create public IP address for NAT gateway ##
$ip = @{
    Name = 'public-ip-nat2'
    ResourceGroupName = 'test-rg'
    Location = 'chinanorth3'
    Sku = 'Standard'
    AllocationMethod = 'Static'
}
New-AzPublicIpAddress @ip

Use Set-AzNatGateway to add the public IP address to the NAT gateway.

## Place NAT gateway into a variable. ##
$ng = @{
    Name = 'nat-gateway'
    ResourceGroupName = 'test-rg'
}
$nat = Get-AzNatGateway @ng

## Place the existing public IP address associated with the NAT gateway into a variable. ##
$ip = @{
    Name = 'public-ip-nat'
    ResourceGroupName = 'test-rg'
}
$publicIP1 = Get-AzPublicIPaddress @ip

## Place the public IP address you created previously into a variable. ##
$ip = @{
    Name = 'public-ip-nat2'
    ResourceGroupName = 'test-rg'
}
$publicIP2 = Get-AzPublicIPaddress @ip

## Place the public IP address variables into an array. ##
$pipArray = $publicIP1,$publicIP2

## Add the IP address to the NAT gateway. ##
$nt = @{
    NatGateway = $nat
    PublicIpAddress = $pipArray
}
Set-AzNatGateway @nt

Remove public IP address

To remove a public IP from a NAT gateway, create an array object that doesn't contain the IP address you want to remove. For example, you have a NAT gateway configured with two public IP addresses. You want to remove one of the IP addresses. The IP addresses associated with the NAT gateway are named public-ip-nat and public-ip-nat2. To remove public-ip-nat2, create an array object for the PowerShell command that contains only public-ip-nat. When you apply the command, the array is reapplied to the NAT gateway, and public-ip-nat is the only associated public IP address.

Use Set-AzNatGateway to remove a public IP address from the NAT gateway.

## Place NAT gateway into a variable. ##
$ng = @{
    Name = 'nat-gateway'
    ResourceGroupName = 'test-rg'
}
$nat = Get-AzNatGateway @ng

## Place the existing public IP address associated with the NAT gateway into a variable. ##
$ip = @{
    Name = 'public-ip-nat'
    ResourceGroupName = 'test-rg'
}
$publicIP1 = Get-AzPublicIPaddress @ip

## Place the second public IP address into a variable. ##
$ip = @{
    Name = 'public-ip-nat2'
    ResourceGroupName = 'test-rg'
}
$publicIP2 = Get-AzPublicIPAddress @ip

## Place ONLY the public IP you wish to keep in the array. ##
$pipArray = $publicIP1

## Add the public IP address to the NAT gateway. ##
$nt = @{
    NatGateway = $nat
    PublicIpAddress = $pipArray
}
Set-AzNatGateway @nt

Add public IP address

In this example, the existing public IP address associated with the NAT gateway is named public-ip-nat.

Use az network public-ip create to create a new IP address for the NAT gateway.

az network public-ip create \
    --resource-group test-rg \
    --location chinanorth3 \
    --name public-ip-nat2 \
    --sku standard

Use az network nat gateway update to add the public IP address that you created to the NAT gateway. The Azure CLI command replaces the values. It doesn't add a new value. To add the new IP address to the NAT gateway, you must also include any other IP addresses associated to the NAT gateway.

az network nat gateway update \
    --name nat-gateway \
    --resource-group test-rg \
    --public-ip-addresses public-ip-nat public-ip-nat2

Remove public IP address

Use az network nat gateway update to remove a public IP address from the NAT gateway. The Azure CLI command replaces the values. It doesn't remove a value. To remove a public IP address, include any IP address in the command that you want to keep. Omit the value that you want to remove. For example, you have a NAT gateway configured with two public IP addresses. You want to remove one of the IP addresses. The IP addresses associated with the NAT gateway are named public-ip-nat and public-ip-nat2. To remove public-ip-nat2, omit the name of the IP address from the command. The command reapplies the IP addresses listed in the command to the NAT gateway. It removes any IP address not listed.

az network nat gateway update \
    --name nat-gateway \
    --resource-group test-rg \
    --public-ip-addresses public-ip-nat

Add or remove a public IP prefix

Complete the following steps to add or remove a public IP prefix from a NAT gateway.

Sign-in to the Azure portal.
In the search box at the top of the Azure portal, enter Public IP prefix. Select Public IP Prefixes in the search results.
Select Create.

Enter the following information in the Basics tab of Create a public IP prefix.

Setting	Value
Project details
Subscription	Select your subscription.
Resource group	Select your resource group. This example uses test-rg.
Instance details
Name	Enter public-ip-prefix-nat.
Region	Select your region. This example uses China North 3.
IP version	Select IPv4.
Prefix size	Select a prefix size. This example uses /28 (16 addresses).

Select Review + create, then select Create.
In the search box at the top of the Azure portal, enter NAT gateway. Select NAT gateways in the search results.
Select nat-gateway.
Under Settings, select Outbound IP.
The page displays the IP addresses and prefixes associated with the NAT gateway. Next to Public IP prefixes, select Change.
Next to Public IP Prefixes, select the dropdown box. Select the IP address prefix that you created to add the prefix to the NAT gateway. To remove a prefix, unselect it.
Select OK.
Select Save.

Add public IP prefix

To add a public IP prefix to the NAT gateway, add it to an array object along with the current IP prefixes. The PowerShell cmdlets replace all the IP prefixes.

In this example, the existing public IP prefix associated with the NAT gateway is named public-ip-prefix-nat. Replace this value with an array that contains both public-ip-prefix-nat and a new IP address prefix. If you have multiple IP prefixes already configured, you must also add them to the array.

Use New-AzPublicIpPrefix to create a new public IP prefix for the NAT gateway.

## Create public IP prefix for NAT gateway ##
$ip = @{
    Name = 'public-ip-prefix-nat2'
    ResourceGroupName = 'test-rg'
    Location = 'chinanorth3'
    Sku = 'Standard'
    PrefixLength = '29'
}
New-AzPublicIpPrefix @ip

Use Set-AzNatGateway to add the public IP prefix to the NAT gateway.

## Place NAT gateway into a variable. ##
$ng = @{
    Name = 'nat-gateway'
    ResourceGroupName = 'test-rg'
}
$nat = Get-AzNatGateway @ng

## Place the existing public IP prefix associated with the NAT gateway into a variable. ##
$ip = @{
    Name = 'public-ip-prefix-nat'
    ResourceGroupName = 'test-rg'
}
$prefixIP1 = Get-AzPublicIPPrefix @ip

## Place the public IP prefix you created previously into a variable. ##
$ip = @{
    Name = 'public-ip-prefix-nat2'
    ResourceGroupName = 'test-rg'
}
$prefixIP2 = Get-AzPublicIPprefix @ip

## Place the public IP address variables into an array. ##
$preArray = $prefixIP1,$prefixIP2

## Add the IP address prefix to the NAT gateway. ##
$nt = @{
    NatGateway = $nat
    PublicIpPrefix = $preArray
}
Set-AzNatGateway @nt

Remove public IP prefix

To remove a public IP prefix from a NAT gateway, create an array object that doesn't contain the IP address prefix that you want to remove. For example, you have a NAT gateway configured with two public IP prefixes. You want to remove one of the IP prefixes. The IP prefixes associated with the NAT gateway are named public-ip-prefix-nat and public-ip-prefix-nat2. To remove public-ip-prefix-nat2, create an array object for the PowerShell command that contains only public-ip-prefix-nat. When you apply the command, the array is reapplied to the NAT gateway, and public-ip-prefix-nat is the only prefix associated.

Use the Set-AzNatGateway cmdlet to remove a public IP prefix from the NAT gateway.

## Place NAT gateway into a variable. ##
$ng = @{
    Name = 'nat-gateway'
    ResourceGroupName = 'test-rg'
}
$nat = Get-AzNatGateway @ng

## Place the existing public IP prefix associated with the NAT gateway into a variable. ##
$ip = @{
    Name = 'public-ip-prefix-nat'
    ResourceGroupName = 'test-rg'
}
$prefixIP1 = Get-AzPublicIPPrefix @ip

## Place the secondary public IP prefix into a variable. ##
$ip = @{
    Name = 'public-ip-prefix-nat2'
    ResourceGroupName = 'test-rg'
}
$prefixIP2 = Get-AzPublicIPprefix @ip

## Place ONLY the prefix you wish to keep in the array. DO NOT ADD THE SECONDARY VARIABLE ##
$preArray = $prefixIP1

## Add the IP address prefix to the NAT gateway. ##
$nt = @{
    NatGateway = $nat
    PublicIpPrefix = $preArray
}
Set-AzNatGateway @nt

Add public IP prefix

In this example, the existing public IP prefix associated with the NAT gateway is named public-ip-prefix-nat.

Use az network public-ip prefix create to create a public IP prefix for the NAT gateway.

az network public-ip prefix create \
    --length 29 \
    --resource-group test-rg \
    --location chinanorth3 \
    --name public-ip-prefix-nat2

Use az network nat gateway update to add the public IP prefix that you created to the NAT gateway. The Azure CLI command replaces values. It doesn't add a value. To add the new IP address prefix to the NAT gateway, you must also include any other IP prefixes associated to the NAT gateway.

az network nat gateway update \
    --name nat-gateway \
    --resource-group test-rg \
    --public-ip-prefixes public-ip-prefix-nat public-ip-prefix-nat2

Remove public IP prefix

Use az network nat gateway update to remove a public IP prefix from the NAT gateway. The Azure CLI command replaces the values. It doesn't remove a value. To remove a public IP prefix, include any prefix in the command that you wish to keep. Omit the one you want to remove. For example, you have a NAT gateway configured with two public IP prefixes. You want to remove one of the prefixes. The IP prefixes associated with the NAT gateway are named public-ip-prefix-nat and public-ip-prefix-nat2. To remove public-ip-prefix-nat2, omit the name of the IP prefix from the command. The command reapplies the IP prefixes listed in the command to the NAT gateway. It removes any IP address not listed.

az network nat gateway update \
    --name nat-gateway \
    --resource-group test-rg \
    --public-ip-prefixes public-ip-prefix-nat

Next steps

To learn more about Azure Virtual Network NAT and its capabilities, see the following articles:

Manage NAT gateway

Prerequisites

Create a NAT gateway and associate it with an existing subnet

Remove a NAT gateway from an existing subnet and delete the resource

Add or remove a public IP address

Add or remove a public IP prefix

Next steps

Additional resources