Tutorial: Create a gateway load balancer using the Azure CLI

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:

• If you prefer to run CLI reference commands locally, install the Azure CLI. If you're running on Windows or macOS, consider running Azure CLI in a Docker container. For more information, see How to run the Azure CLI in a Docker container.

  • If you're using a local installation, sign in to the Azure CLI by using the az login command. To finish the authentication process, follow the steps displayed in your terminal. For other sign-in options, see Sign in with the Azure CLI.

  • When you're prompted, install the Azure CLI extension on first use. For more information about extensions, see Use extensions with the Azure CLI.

  • Run az version to find the version and dependent libraries that are installed. To upgrade to the latest version, run az upgrade.

• This tutorial requires version 2.0.28 or later of the Azure CLI. If using Azure local Shell, the latest version is already installed.

• An Azure account with an active subscription.Create a trial subscription.

• An existing public standard SKU Azure Load Balancer. For more information on creating a load balancer, see Create a public load balancer using the Azure CLI.

  • For the purposes of this tutorial, the existing load balancer in the examples is named myLoadBalancer.

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

Create a resource group with az group create:

  az group create \
    --name TutorGwLB-rg \
    --location chinanorth3

A virtual network is needed for the resources that are in the backend pool of the gateway load balancer.

Use az network vnet create to create the virtual network.

  az network vnet create \
    --resource-group TutorGwLB-rg \
    --location chinanorth3 \
    --name myVNet \
    --address-prefixes 10.1.0.0/16 \
    --subnet-name myBackendSubnet \
    --subnet-prefixes 10.1.0.0/24

Use az network public-ip create to create a public IP address for the Azure Bastion host

az network public-ip create \
    --resource-group TutorGwLB-rg \
    --name myBastionIP \
    --sku Standard \
    --zone 1 2 3

Use az network vnet subnet create to create the bastion subnet.

az network vnet subnet create \
    --resource-group TutorGwLB-rg \
    --name AzureBastionSubnet \
    --vnet-name myVNet \
    --address-prefixes 10.1.1.0/27

Use az network bastion create to deploy a bastion host for secure management of resources in virtual network.

az network bastion create \
    --resource-group TutorGwLB-rg \
    --name myBastionHost \
    --public-ip-address myBastionIP \
    --vnet-name myVNet \
    --location chinanorth3

It can take a few minutes for the Azure Bastion host to deploy.

Hourly pricing starts from the moment that Bastion is deployed, regardless of outbound data usage. For more information, see Pricing and SKUs. If you're deploying Bastion as part of a tutorial or test, we recommend that you delete this resource after you finish using it.

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 az network nsg create to create the NSG.

  az network nsg create \
    --resource-group TutorGwLB-rg \
    --name myNSG

Use az network nsg rule create to create rules for the NSG.

  az network nsg rule create \
    --resource-group TutorGwLB-rg \
    --nsg-name myNSG \
    --name myNSGRule-AllowAll \
    --protocol '*' \
    --direction inbound \
    --source-address-prefix '0.0.0.0/0' \
    --source-port-range '*' \
    --destination-address-prefix '0.0.0.0/0' \
    --destination-port-range '*' \
    --access allow \
    --priority 100

  az network nsg rule create \
    --resource-group TutorGwLB-rg \
    --nsg-name myNSG \
    --name myNSGRule-AllowAll-TCP-Out \
    --protocol 'TCP' \
    --direction outbound \
    --source-address-prefix '0.0.0.0/0' \
    --source-port-range '*' \
    --destination-address-prefix '0.0.0.0/0' \
    --destination-port-range '*' \
    --access allow \
    --priority 100

In this section, you'll create the configuration and deploy the gateway load balancer.

To create the load balancer, use az network lb create.

  az network lb create \
    --resource-group TutorGwLB-rg \
    --name myLoadBalancer-gw \
    --sku Gateway \
    --vnet-name myVNet \
    --subnet myBackendSubnet \
    --backend-pool-name myBackendPool \
    --frontend-ip-name myFrontEnd

An internal interface is automatically created with Azure CLI with the --identifier of 900 and --port of 10800.

You'll use az network lb address-pool tunnel-interface add to create external tunnel interface for the load balancer.

  az network lb address-pool tunnel-interface add \
    --address-pool myBackEndPool \
    --identifier '901' \
    --lb-name myLoadBalancer-gw \
    --protocol VXLAN \
    --resource-group TutorGwLB-rg \
    --type External \
    --port '10801'

A health probe is required to monitor the health of the backend instances in the load balancer. Use az network lb probe create to create the health probe.

  az network lb probe create \
    --resource-group TutorGwLB-rg \
    --lb-name myLoadBalancer-gw \
    --name myHealthProbe \
    --protocol http \
    --port 80 \
    --path '/' \
    --interval '5' \
    --threshold '2'

Traffic destined for the backend instances is routed with a load-balancing rule. Use az network lb rule create to create the load-balancing rule.

  az network lb rule create \
    --resource-group TutorGwLB-rg \
    --lb-name myLoadBalancer-gw \
    --name myLBRule \
    --protocol All \
    --frontend-port 0 \
    --backend-port 0 \
    --frontend-ip-name myFrontEnd \
    --backend-pool-name myBackEndPool \
    --probe-name myHealthProbe

Deploy NVAs through the Azure Marketplace. Once deployed, add the virtual machines to the backend pool with az network nic ip-config address-pool add.

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

  az group delete \
    --name TutorGwLB-rg

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.