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Tutorial: Connect to Virtual Machine Scale Set instances using the Azure CLI

  • Article

A Virtual Machine Scale Set allows you to deploy and manage a set of virtual machines. Throughout the lifecycle of a Virtual Machine Scale Set, you may need to run one or more management tasks. In this tutorial you learn how to:

  • List connection information
  • Connect to individual instances using SSH

If you don't have an Azure subscription, create an Azure free account before you begin.

Prerequisites

This article requires version 2.0.29 or later of the Azure CLI. If using Azure Cloud Shell, the latest version is already installed.

List instances in a scale set

If you do not have a scale set already created, see Tutorial: Create and manage a Virtual Machine Scale Set with the Azure CLI

List all the instances in your Virtual Machine Scale Set.

az vmss list-instances \
  --resource-group myResourceGroup \
  --name myScaleSet \
  --output table

Location    Name                 ResourceGroup
----------  -------------------  ---------------
eastus      myScaleSet_0e7d4d21  myResourceGroup
eastus      myScaleSet_39379fc3  myResourceGroup

Get NIC information

Use az vm nic list and the name of the individual VM instance to find the NIC name.

az vm nic list \
  --resource-group myResourceGroup
  --vm-name myScaleSet_0e7d4d21

[
  {
    "deleteOption": "Delete",
    "id": "/subscriptions/resourceGroups/myResourceGroup/providers/Microsoft.Network/networkInterfaces/mysca2215Nic-828c525a",
    "primary": true,
    "resourceGroup": "myResourceGroup"
  }
]

Using the VM name and NIC name, get the private IP address of the NIC, the Inbound NAT rule name and load balancer name using az vm nic show.

az vm nic show --resource-group myResourceGroup --vm-name myScaleSet_0e7d4d21 --nic mysca2215Nic-828c525a

{
  "enableAcceleratedNetworking": false,
  "id": "/subscriptions/resourceGroups/myResourceGroup/providers/Microsoft.Network/networkInterfaces/mysca2215Nic-828c525a",
  "ipConfigurations": [
    {
      "id": "/subscriptions/resourceGroups/myResourceGroup/providers/Microsoft.Network/networkInterfaces/mysca2215Nic-828c525a/ipConfigurations/mysca2215IPConfig",
      "loadBalancerBackendAddressPools": [
        {
          "id": "/subscriptions/resourceGroups/myResourceGroup/providers/Microsoft.Network/loadBalancers/myScaleSetLB/backendAddressPools/myScaleSetLBBEPool",
        }
      ],
      "name": "mysca2215IPConfig",
      "primary": true,
      "privateIpAddress": "10.0.0.5",
      "privateIpAddressVersion": "IPv4",
      "privateIpAllocationMethod": "Dynamic",
      "provisioningState": "Succeeded",
      "resourceGroup": "myResourceGroup",
      "subnet": {
        "id": "/subscriptions/resourceGroups/myResourceGroup/providers/Microsoft.Network/virtualNetworks/myScaleSetVNET/subnets/myScaleSetSubnet",
        "resourceGroup": "myResourceGroup",
      },
      "type": "Microsoft.Network/networkInterfaces/ipConfigurations",
    }
  ],
  "location": "eastus",
  "name": "mysca2215Nic-828c525a",
  "networkSecurityGroup": {
    "id": "/subscriptions/resourceGroups/myResourceGroup/providers/Microsoft.Network/networkSecurityGroups/myScaleSetNSG",
    "resourceGroup": "myResourceGroup",
  },
  "nicType": "Standard",
  "primary": true,
  "provisioningState": "Succeeded",
  "resourceGroup": "myResourceGroup",
  "tapConfigurations": [],
  "type": "Microsoft.Network/networkInterfaces",
  "virtualMachine": {
    "id": "/subscriptions/resourceGroups/myResourceGroup/providers/Microsoft.Compute/virtualMachines/myScaleSet_0e7d4d21",
    "resourceGroup": "myResourceGroup"
  },
}

Get backend pool details

Using the backend pool name and load balancer name, get the port for the private IP address of the instance you want to connect to with az network lb list-mapping.

az network lb list-mapping --backend-pool-name myScaleSetLBBEPool --resource-group myResourceGroup --name myScaleSetLB --request ip=10.0.0.5

{
  "inboundNatRulePortMappings": [
    {
      "backendPort": 22,
      "frontendPort": 50001,
      "inboundNatRuleName": "NatRule",
      "protocol": "Tcp"
    }
  ]
}

Get public IP of load balancer

Get the public IP of the load balancer using az network public-ip list.

az network public-ip list --resource-group myResourceGroup

[
  {
    "id": "/subscriptions/resourceGroups/myResourceGroup/providers/Microsoft.Network/publicIPAddresses/myScaleSetLBPublicIP",
    "idleTimeoutInMinutes": 4,
    "ipAddress": "20.172.211.239",
    "ipConfiguration": {
      "id": "/subscriptions/resourceGroups/myResourceGroup/providers/Microsoft.Network/loadBalancers/myScaleSetLB/frontendIPConfigurations/loadBalancerFrontEnd",
      "resourceGroup": "myResourceGroup"
    },
    "ipTags": [],
    "location": "eastus",
    "name": "myScaleSetLBPublicIP",
    "provisioningState": "Succeeded",
    "publicIPAddressVersion": "IPv4",
    "publicIPAllocationMethod": "Static",
    "resourceGroup": "myResourceGroup",
    "sku": {
      "name": "Standard",
      "tier": "Regional"
    },
    "tags": {},
    "type": "Microsoft.Network/publicIPAddresses"
  }
]

Connect to your instance

SSH to the machine using the load balancer IP and the port of the machine you want to connect to.

ssh azureuser@20.172.211.239 -p 50000

Next steps

In this tutorial, you learned how to list the instances in your scale set and connect via SSH to an individual instance.

  • List and view instances in a scale set
  • Gather networking information for individual instances in a scale set
  • Connect to individual VM instances inside a scale set

Modify a scale set