Quickstart: Create a public load balancer to load balance VMs using Azure PowerShell

Get started with Azure Load Balancer by using Azure PowerShell to create a public load balancer and two virtual machines. Also, you deploy other resources including Azure Bastion, NAT Gateway, a virtual network, and the required subnets.

• An Azure account with an active subscription. Create an account for free

• 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.

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

Create a resource group with New-AzResourceGroup:

$rg = @{
    Name = 'CreatePubLBQS-rg'
    Location = 'westus2'
}
New-AzResourceGroup @rg

Use New-AzPublicIpAddress to create a public IP address.

$publicip = @{
    Name = 'myPublicIP'
    ResourceGroupName = $rg.name
    Location = 'westus2'
    Sku = 'Standard'
    AllocationMethod = 'static'
    Zone = 1,2,3
}
New-AzPublicIpAddress @publicip

To create a zonal public IP address in zone 1, use the following command:

$publicip = @{
    Name = 'myPublicIP'
    ResourceGroupName = $rg.name
    Location = 'westus2'
    Sku = 'Standard'
    AllocationMethod = 'static'
    Zone = 1
}
New-AzPublicIpAddress @publicip

This section details how you can create and configure the following components of the load balancer:

• Create a frontend IP with New-AzLoadBalancerFrontendIpConfig for the frontend IP pool. This IP receives the incoming traffic on the load balancer

• Create a backend address pool with New-AzLoadBalancerBackendAddressPoolConfig for traffic sent from the frontend of the load balancer. This pool is where your backend virtual machines are deployed

• Create a health probe with Add-AzLoadBalancerProbeConfig that determines the health of the backend VM instances

• Create a load balancer rule with Add-AzLoadBalancerRuleConfig that defines how traffic is distributed to the VMs

• Create a public load balancer with New-AzLoadBalancer

## Place public IP created in previous steps into variable. ##
$pip = @{
    Name = 'myPublicIP'
    ResourceGroupName = $rg.name
}
$publicIp = Get-AzPublicIpAddress @pip

## Create load balancer frontend configuration and place in variable. ##
$fip = @{
    Name = 'myFrontEnd'
    PublicIpAddress = $publicIp 
}
$feip = New-AzLoadBalancerFrontendIpConfig @fip

## Create backend address pool configuration and place in variable. ##
$bepool = New-AzLoadBalancerBackendAddressPoolConfig -Name 'myBackEndPool'

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

## Create the load balancer rule and place in variable. ##
$lbrule = @{
    Name = 'myHTTPRule'
    Protocol = 'tcp'
    FrontendPort = '80'
    BackendPort = '80'
    IdleTimeoutInMinutes = '15'
    FrontendIpConfiguration = $feip
    BackendAddressPool = $bePool
}
$rule = New-AzLoadBalancerRuleConfig @lbrule -EnableTcpReset -DisableOutboundSNAT

## Create the load balancer resource. ##
$loadbalancer = @{
    ResourceGroupName = $rg.name
    Name = 'myLoadBalancer'
    Location = 'westus2'
    Sku = 'Standard'
    FrontendIpConfiguration = $feip
    BackendAddressPool = $bePool
    LoadBalancingRule = $rule
    Probe = $healthprobe
}
New-AzLoadBalancer @loadbalancer

Before you deploy VMs and test your load balancer, create the supporting virtual network resources.

Create a virtual network for the backend virtual machines.

Create a network security group to define inbound connections to your virtual network.

Create an Azure Bastion host to securely manage the virtual machines in the backend pool.

Use a NAT gateway to provide outbound internet access to resources in the backend pool of your load balancer.

• Create a virtual network with New-AzVirtualNetwork

• Create a network security group rule with New-AzNetworkSecurityRuleConfig

• Create an Azure Bastion host with New-AzBastion

• Create a network security group with New-AzNetworkSecurityGroup

• Create the NAT gateway resource with New-AzNatGateway

• Use New-AzVirtualNetworkSubnetConfig to associate the NAT gateway to the subnet of the virtual network

## Create public IP address for NAT gateway ##
$ip = @{
    Name = 'myNATgatewayIP'
    ResourceGroupName = $rg.name
    Location = 'westus2'
    Sku = 'Standard'
    AllocationMethod = 'Static'
}
$publicIP = New-AzPublicIpAddress @ip

## Create NAT gateway resource ##
$nat = @{
    ResourceGroupName = $rg.name
    Name = 'myNATgateway'
    IdleTimeoutInMinutes = '10'
    Sku = 'Standard'
    Location = 'westus2'
    PublicIpAddress = $publicIP
}
$natGateway = New-AzNatGateway @nat

## Create backend subnet config ##
$subnet = @{
    Name = 'myBackendSubnet'
    AddressPrefix = '10.1.0.0/24'
    NatGateway = $natGateway
}
$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 = $rg.name
    Location = 'westus2'
    AddressPrefix = '10.1.0.0/16'
    Subnet = $subnetConfig,$bastsubnetConfig
}
$vnet = New-AzVirtualNetwork @net

## Create public IP address for bastion host. ##
$ip = @{
    Name = 'myBastionIP'
    ResourceGroupName = $rg.name
    Location = 'westus2'
    Sku = 'Standard'
    AllocationMethod = 'Static'
}
$publicip = New-AzPublicIpAddress @ip

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

## Create rule for network security group and place in variable. ##
$nsgrule = @{
    Name = 'myNSGRuleHTTP'
    Description = 'Allow HTTP'
    Protocol = '*'
    SourcePortRange = '*'
    DestinationPortRange = '80'
    SourceAddressPrefix = 'Internet'
    DestinationAddressPrefix = '*'
    Access = 'Allow'
    Priority = '2000'
    Direction = 'Inbound'
}
$rule1 = New-AzNetworkSecurityRuleConfig @nsgrule

## Create network security group ##
$nsg = @{
    Name = 'myNSG'
    ResourceGroupName = $rg.name
    Location = 'westus2'
    SecurityRules = $rule1
}
New-AzNetworkSecurityGroup @nsg

In this section, you create the two virtual machines for the backend pool of the load balancer.

• Create two network interfaces with New-AzNetworkInterface

• Set an administrator username and password for the VMs with Get-Credential

• Create the virtual machines with:

  • New-AzVM

  • New-AzVMConfig

  • Set-AzVMOperatingSystem

  • Set-AzVMSourceImage

  • Add-AzVMNetworkInterface

# Set the administrator and password for the VMs. ##
$cred = Get-Credential

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

## Place the load balancer into a variable. ##
$lb = @{
    Name = 'myLoadBalancer'
    ResourceGroupName = $rg.name
}
$bepool = Get-AzLoadBalancer @lb  | Get-AzLoadBalancerBackendAddressPoolConfig

## Place the network security group into a variable. ##
$ns = @{
    Name = 'myNSG'
    ResourceGroupName = $rg.name
}
$nsg = Get-AzNetworkSecurityGroup @ns

## For loop with variable to create virtual machines for load balancer backend pool. ##
for ($i=1; $i -le 2; $i++){

    ## Command to create network interface for VMs ##
    $nic = @{
        Name = "myNicVM$i"
        ResourceGroupName = $rg.name
        Location = 'westus2'
        Subnet = $vnet.Subnets[0]
        NetworkSecurityGroup = $nsg
        LoadBalancerBackendAddressPool = $bepool
    }
    $nicVM = New-AzNetworkInterface @nic

    ## Create a virtual machine configuration for VMs ##
    $vmsz = @{
        VMName = "myVM$i"
        VMSize = 'Standard_DS1_v2'  
    }
    $vmos = @{
        ComputerName = "myVM$i"
        Credential = $cred
    }
    $vmimage = @{
        PublisherName = 'MicrosoftWindowsServer'
        Offer = 'WindowsServer'
        Skus = '2019-Datacenter'
        Version = 'latest'    
    }
    $vmConfig = New-AzVMConfig @vmsz `
        | Set-AzVMOperatingSystem @vmos -Windows `
        | Set-AzVMSourceImage @vmimage `
        | Add-AzVMNetworkInterface -Id $nicVM.Id

    ## Create the virtual machine for VMs ##
    $vm = @{
        ResourceGroupName = $rg.name
        Location = 'westus2'
        VM = $vmConfig
        Zone = "$i"
    }
    New-AzVM @vm -AsJob
}

The deployments of the virtual machines and bastion host are submitted as PowerShell jobs. To view the status of the jobs, use Get-Job:

Get-Job

Id     Name            PSJobTypeName   State         HasMoreData     Location             Command
--     ----            -------------   -----         -----------     --------             -------
1      Long Running O… AzureLongRunni… Completed     True            localhost            New-AzBastion
2      Long Running O… AzureLongRunni… Completed     True            localhost            New-AzVM
3      Long Running O… AzureLongRunni… Completed     True            localhost            New-AzVM

Ensure the State of the VM creation is Completed before moving on to the next steps.

Use Set-AzVMExtension to install the Custom Script Extension.

The extension runs PowerShell Add-WindowsFeature Web-Server to install the IIS webserver and then updates the Default.htm page to show the hostname of the VM:

## For loop with variable to install custom script extension on virtual machines. ##
for ($i=1; $i -le 2; $i++)
{
$ext = @{
    Publisher = 'Microsoft.Compute'
    ExtensionType = 'CustomScriptExtension'
    ExtensionName = 'IIS'
    ResourceGroupName = $rg.name
    VMName = "myVM$i"
    Location = 'westus2'
    TypeHandlerVersion = '1.8'
    SettingString = '{"commandToExecute":"powershell Add-WindowsFeature Web-Server; powershell Add-Content -Path \"C:\\inetpub\\wwwroot\\Default.htm\" -Value $($env:computername)"}'
}
Set-AzVMExtension @ext -AsJob
}

The extensions are deployed as PowerShell jobs. To view the status of the installation jobs, use Get-Job:

Get-Job

Id     Name            PSJobTypeName   State         HasMoreData     Location             Command
--     ----            -------------   -----         -----------     --------             -------
8      Long Running O… AzureLongRunni… Running       True            localhost            Set-AzVMExtension
9      Long Running O… AzureLongRunni… Running       True            localhost            Set-AzVMExtension

Ensure the State of the jobs is Completed before moving on to the next steps.

Use Get-AzPublicIpAddress to get the public IP address of the load balancer:

$ip = @{
    ResourceGroupName = $rg.name
    Name = 'myPublicIP'
}  
Get-AzPublicIPAddress @ip | select IpAddress

Copy the public IP address, and then paste it into the address bar of your browser. The default page of IIS Web server is displayed on the browser.

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 $rg.name

In this quickstart, you:

• Created an Azure Load Balancer

• Attached 2 VMs to the load balancer

• Tested the load balancer

To learn more about Azure Load Balancer, continue to: