IP assignment

Question

Hello,

We have one virtual machine in azure, which has an interface with a lot of IP Addresses (25 IPs+ as secondary, see please screenshot). Also I have one identical virtual machine (state is down). And in case of failure of first machine I need to turn on second machine and assign all IP-s. How can I do it with scripting(because if i start move IP-s manually it takes a lot of time)? How this script should looks? (P.s There is no another way to failover these machines)

Answer 1

Hello ,

Thanks for reaching out to Microsoft Q and A forum ,

Your Current Cloud Solution 

Single Active VM + Stopped VM (Manual Failover) Downtime is acceptable --> This is your 100% manual current use case 

Recommended Solution :

Standard load balancer, Attach the public Ip's to the Lb + VMSS (scale set) with 1 Always-Running VM --> If you want some automation with similar downtime might be just a few $ more monthly (6$-8$)

But if you want to stick on to current solution only , Here is a PowerShell script which can help you .

Variables

$primaryVMName = "PrimaryVM"

$standbyVMName = "StandbyVM"

$resourceGroupName = "YourResourceGroup"

$location = "YourAzureRegion"

Authenticate to Azure

Connect-AzAccount

Stop the primary VM

Stop-AzVM -Name $primaryVMName -ResourceGroupName $resourceGroupName -Force

Get the NIC of the primary VM

$primaryVM = Get-AzVM -Name $primaryVMName -ResourceGroupName $resourceGroupName

$primaryNIC = Get-AzNetworkInterface -Name $primaryVM.NetworkProfile.NetworkInterfaces[0].Id.Split('/')[-1] -ResourceGroupName $resourceGroupName

Get the NIC of the standby VM

$standbyVM = Get-AzVM -Name $standbyVMName -ResourceGroupName $resourceGroupName

$standbyNIC = Get-AzNetworkInterface -Name $standbyVM.NetworkProfile.NetworkInterfaces[0].Id.Split('/')[-1] -ResourceGroupName $resourceGroupName

Loop through each IP configuration in the primary NIC (excluding the primary IP)

foreach ($ipConfig in $primaryNIC.IpConfigurations) {

    if ($ipConfig.Primary -eq $false) {

        # Remove IP configuration from primary NIC

        $primaryNIC.IpConfigurations.Remove($ipConfig)

        # Add IP configuration to standby NIC

        $standbyNIC.IpConfigurations.Add($ipConfig)

    }

}

Update both NICs

Set-AzNetworkInterface -NetworkInterface $primaryNIC

Set-AzNetworkInterface -NetworkInterface $standbyNIC

Start the standby VM

Start-AzVM -Name $standbyVMName -ResourceGroupName $resourceGroupName

Please don't forget to accept the answer if this was helpful .

Thanks,
Pradeep