Tutorial: Create a gateway load balancer using Azure PowerShell

Azure Load Balancer consists of Standard, Basic, and Gateway SKUs. Gateway Load Balancer is used for transparent insertion of Network Virtual Appliances (NVA). Use Gateway Load Balancer for scenarios that require high performance and high scalability of NVAs.

In this tutorial, you learn how to:

  • Create virtual network.
  • Create network security group.
  • Create a gateway load balancer.
  • Chain a load balancer frontend to gateway load balancer.

Prerequisites

  • An Azure account with an active subscription.Create an account for free.
  • An existing public standard SKU Azure Load Balancer. For more information on creating a load balancer, see Create a public load balancer using Azure PowerShell.
    • For the purposes of this tutorial, the existing load balancer in the examples is named myLoadBalancer.
  • Azure PowerShell installed locally or Azure Cloud Shell

If you choose to install and use PowerShell locally, 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. If you're running PowerShell locally, you also need to run Connect-AzAccount to create a connection with Azure.

Create a resource group

An Azure resource group is a logical container into which Azure resources are deployed and managed.

Create a resource group with New-AzResourceGroup:

New-AzResourceGroup -Name 'TutorGwLB-rg' -Location 'eastus'

Create virtual network

A virtual network is needed for the resources that are in the backend pool of the gateway load balancer. Use New-AzVirtualNetwork to create the virtual network. Use New-AzBastion to deploy a bastion host for secure management of resources in virtual network.

## Create backend subnet config ##
$subnet = @{
    Name = 'myBackendSubnet'
    AddressPrefix = '10.1.0.0/24'
}
$subnetConfig = New-AzVirtualNetworkSubnetConfig @subnet 

## Create Azure Bastion subnet. ##
$bastsubnet = @{
    Name = 'AzureBastionSubnet' 
    AddressPrefix = '10.1.1.0/24'
}
$bastsubnetConfig = New-AzVirtualNetworkSubnetConfig @bastsubnet

## Create the virtual network ##
$net = @{
    Name = 'myVNet'
    ResourceGroupName = 'TutorGwLB-rg'
    Location = 'eastus'
    AddressPrefix = '10.1.0.0/16'
    Subnet = $subnetConfig,$bastsubnetConfig
}
$vnet = New-AzVirtualNetwork @net

## Create public IP address for bastion host. ##
$ip = @{
    Name = 'myBastionIP'
    ResourceGroupName = 'TutorGwLB-rg'
    Location = 'eastus'
    Sku = 'Standard'
    AllocationMethod = 'Static'
}
$publicip = New-AzPublicIpAddress @ip

## Create bastion host ##
$bastion = @{
    ResourceGroupName = 'TutorGwLB-rg'
    Name = 'myBastion'
    PublicIpAddress = $publicip
    VirtualNetwork = $vnet
}
New-AzBastion @bastion -AsJob

Create NSG

Use the following example to create a network security group. You'll configure the NSG rules needed for network traffic in the virtual network created previously.

Use New-AzNetworkSecurityRuleConfig to create rules for the NSG. Use New-AzNetworkSecurityGroup to create the NSG.

## Create rule for network security group and place in variable. ##
$nsgrule1 = @{
    Name = 'myNSGRule-AllowAll'
    Description = 'Allow all'
    Protocol = '*'
    SourcePortRange = '*'
    DestinationPortRange = '*'
    SourceAddressPrefix = '0.0.0.0/0'
    DestinationAddressPrefix = '0.0.0.0/0'
    Access = 'Allow'
    Priority = '100'
    Direction = 'Inbound'
}
$rule1 = New-AzNetworkSecurityRuleConfig @nsgrule1

$nsgrule2 = @{
    Name = 'myNSGRule-AllowAll-TCP-Out'
    Description = 'Allow all TCP Out'
    Protocol = 'TCP'
    SourcePortRange = '*'
    DestinationPortRange = '*'
    SourceAddressPrefix = '0.0.0.0/0'
    DestinationAddressPrefix = '0.0.0.0/0'
    Access = 'Allow'
    Priority = '100'
    Direction = 'Outbound'
}
$rule2 = New-AzNetworkSecurityRuleConfig @nsgrule2

## Create network security group ##
$nsg = @{
    Name = 'myNSG'
    ResourceGroupName = 'TutorGwLB-rg'
    Location = 'eastus'
    SecurityRules = $rule1,$rule2
}
New-AzNetworkSecurityGroup @nsg

Create Gateway Load Balancer

In this section, you'll create the configuration and deploy the gateway load balancer. Use New-AzLoadBalancerFrontendIpConfig to create the frontend IP configuration of the load balancer.

You'll use New-AzLoadBalancerTunnelInterface to create two tunnel interfaces for the load balancer.

Create a backend pool with New-AzLoadBalancerBackendAddressPoolConfig for the NVAs.

A health probe is required to monitor the health of the backend instances in the load balancer. Use New-AzLoadBalancerProbeConfig to create the health probe.

Traffic destined for the backend instances is routed with a load-balancing rule. Use New-AzLoadBalancerRuleConfig to create the load-balancing rule.

To create the deploy the load balancer, use New-AzLoadBalancer.

## Place virtual network configuration in a variable for later use. ##
$net = @{
    Name = 'myVNet'
    ResourceGroupName = 'TutorGwLB-rg'
}
$vnet = Get-AzVirtualNetwork @net

## Create load balancer frontend configuration and place in variable. ## 
$fe = @{
    Name = 'myFrontend'
    SubnetId = $vnet.subnets[0].id
}
$feip = New-AzLoadBalancerFrontendIpConfig @fe

## Create backend address pool configuration and place in variable. ## 
$int1 = @{
    Type = 'Internal'
    Protocol = 'Vxlan'
    Identifier = '800'
    Port = '10800'
}
$tunnelInterface1 = New-AzLoadBalancerBackendAddressPoolTunnelInterfaceConfig @int1

$int2 = @{
    Type = 'External'
    Protocol = 'Vxlan'
    Identifier = '801'
    Port = '10801'
}
$tunnelInterface2 = New-AzLoadBalancerBackendAddressPoolTunnelInterfaceConfig @int2

$pool = @{
    Name = 'myBackendPool'
    TunnelInterface = $tunnelInterface1,$tunnelInterface2
}
$bepool = New-AzLoadBalancerBackendAddressPoolConfig @pool

## Create the health probe and place in variable. ## 
$probe = @{
    Name = 'myHealthProbe'
    Protocol = 'http'
    Port = '80'
    IntervalInSeconds = '360'
    ProbeCount = '5'
    RequestPath = '/'
}
$healthprobe = New-AzLoadBalancerProbeConfig @probe

## Create the load balancer rule and place in variable. ## 
$para = @{
    Name = 'myLBRule'
    Protocol = 'All'
    FrontendPort = '0'
    BackendPort = '0'
    FrontendIpConfiguration = $feip
    BackendAddressPool = $bepool
    Probe = $healthprobe
}
$rule = New-AzLoadBalancerRuleConfig @para

## Create the load balancer resource. ## 
$lb = @{
    ResourceGroupName = 'TutorGwLB-rg'
    Name = 'myLoadBalancer-gw'
    Location = 'eastus'
    Sku = 'Gateway'
    LoadBalancingRule = $rule
    FrontendIpConfiguration = $feip
    BackendAddressPool = $bepool
    Probe = $healthprobe
}
New-AzLoadBalancer @lb

Add network virtual appliances to the Gateway Load Balancer backend pool

Deploy NVAs through the Azure Marketplace. Once deployed, add the virtual machines to the backend pool with Add-AzVMNetworkInterface

Chain load balancer frontend to Gateway Load Balancer

In this example, you'll chain the frontend of a standard load balancer to the gateway load balancer.

You'll add the frontend to the frontend IP of an existing load balancer in your subscription.

Use Set-AzLoadBalancerFrontendIpConfig to chain the gateway load balancer frontend to your existing load balancer.

## Place the gateway load balancer configuration into a variable. ##
$par1 = @{
    ResourceGroupName = 'TutorGwLB-rg'
    Name = 'myLoadBalancer-gw'
}
$gwlb = Get-AzLoadBalancer @par1

## Place the existing load balancer into a variable. ##
$par2 = @{
    ResourceGroupName = 'CreatePubLBQS-rg'
    Name = 'myLoadBalancer'
}
$lb = Get-AzLoadBalancer @par2

## Place the existing public IP for the existing load balancer into a variable.
$par3 = @{
    ResourceGroupName = 'CreatePubLBQS-rg'
    Name = 'myPublicIP'
}
$publicIP = Get-AzPublicIPAddress @par3

## Chain the gateway load balancer to your existing load balancer frontend. ##
$par4 = @{
    Name = 'myFrontEndIP'
    PublicIPAddress = $publicIP
    LoadBalancer = $lb
    GatewayLoadBalancerId = $gwlb.FrontendIpConfigurations.Id
}
$config = Set-AzLoadBalancerFrontendIpConfig @par4

$config | Set-AzLoadBalancer

Chain virtual machine to Gateway Load Balancer

Alternatively, you can chain a VM's NIC IP configuration to the gateway load balancer.

You'll add the gateway load balancer's frontend to an existing VM's NIC IP configuration.

Use Set-AzNetworkInterfaceIpConfig to chain the gateway load balancer frontend to your existing VM's NIC IP configuration.

 ## Place the gateway load balancer configuration into a variable. ##
$par1 = @{
    ResourceGroupName = 'TutorGwLB-rg'
    Name = 'myLoadBalancer-gw'
}
$gwlb = Get-AzLoadBalancer @par1

## Place the existing NIC into a variable. ##
$par2 = @{
    ResourceGroupName = 'MyResourceGroup'
    Name = 'myNic'
}
$nic = Get-AzNetworkInterface @par2

## Chain the gateway load balancer to your existing VM NIC. ##
$par3 = @{
    Name = 'myIPconfig'
    NetworkInterface = $nic
    GatewayLoadBalancerId = $gwlb.FrontendIpConfigurations.Id
}
$config = Set-AzNetworkInterfaceIpConfig @par3

$config | Set-AzNetworkInterface

Clean up resources

When no longer needed, you can use the Remove-AzResourceGroup command to remove the resource group, load balancer, and the remaining resources.

Remove-AzResourceGroup -Name 'TutorGwLB-rg'

Next steps

Create Network Virtual Appliances in Azure.

When creating the NVAs, choose the resources created in this tutorial:

  • Virtual network

  • Subnet

  • Network security group

  • Gateway Load Balancer

Advance to the next article to learn how to create a cross-region Azure Load Balancer.