add posh article for Lb vmss

Author: asudbring

articles/load-balancer/configure-vm-scale-set-powershell.md

@@ -0,0 +1,85 @@
+---
+title: Configure virtual machine scale set with an existing Azure Load Balancer - Azure PowerShell
+description: Learn how to configure a virtual machine scale set with an existing Azure Load Balancer.
+author: asudbring
+ms.author: allensu
+ms.service: load-balancer
+ms.topic: article
+ms.date: 03/26/2020
+---
+
+# Configure a virtual machine scale set with an existing Azure Load Balancer using the Azure PowerShell
+
+In this article, you'll learn how to configure a virtual machine scale set with an existing Azure Load Balancer. 
+
+## Prerequisites
+
+- An Azure subscription.
+- An existing Azure Load Balancer in the subscription where the virtual machine scale set will be deployed.
+- An Azure Virtual Network for the virtual machine scale set.
+
+[!INCLUDE [cloud-shell-try-it.md](../../includes/cloud-shell-try-it.md)] 
+
+[!INCLUDE [updated-for-az](../../includes/updated-for-az.md)]
+
+## Sign in to Azure CLI
+
+Sign into Azure.
+
+```azurepowershell-interactive
+Connect-AzAccount
+```
+
+## Deploy a virtual machine scale set with existing load balancer
+
+Replace the values in brackets with the names of the resources in your configuration.
+
+```azurepowershell-interactive
+
+$rsg = <resource-group>
+$loc = <location>
+$vms = <vm-scale-set-name>
+$vnt = <virtual-network>
+$sub = <subnet-name>
+$lbn = <load-balancer-name>
+$pol = <upgrade-policy-mode>
+
+$lb = Get-AzLoadBalancer -ResourceGroupName $rsg -Name $lbn
+
+New-AzVmss -ResourceGroupName $rsg -Location $loc -VMScaleSetName $vms -VirtualNetworkName $vnt -SubnetName $sub -LoadBalancerName $lb -UpgradePolicyMode $pol
+
+```
+
+The below example deploys a virtual machine scale set with:
+
+- Virtual machine scale set named **myVMSS**
+- Azure Load Balancer named **myLoadBalancer**
+- Load balancer backend pool named **myBackendPool**
+- Azure Virtual Network named **myVnet**
+- Subnet named **mySubnet**
+- Resource group named **myResourceGroup**
+
+```azureppowershell-interactive
+
+$rsg = "myResourceGroup"
+$loc = "East US 2"
+$vms = "myVMSS"
+$vnt = "myVnet"
+$sub = "mySubnet"
+$pol = "Automatic"
+$lbn = "myLoadBalancer"
+
+$lb = Get-AzLoadBalancer -ResourceGroupName $rsg -Name $lbn
+
+New-AzVmss -ResourceGroupName $rsg -Location $loc -VMScaleSetName $vms -VirtualNetworkName $vnt -SubnetName $sub -LoadBalancerName $lb -UpgradePolicyMode $pol
+```
+> [!NOTE]
+> After the scale set has been created, the backend port cannot be modified for a load balancing rule used by a health probe of the load balancer. To change the port, you can remove the health probe by updating the Azure virtual machine scale set, update the port and then configure the health probe again.
+
+## Next steps
+
+In this article, you deployed a virtual machine scale set with an existing Azure Load Balancer.  To learn more about virtual machine scale sets and load balancer, see:
+
+- [What is Azure Load Balancer?](load-balancer-overview.md)
+- [What are virtual machine scale sets?](../virtual-machine-scale-sets/overview.md)
+