Upgrading Load Balancer from Basic to Standard SKU

Hi Pooja Dahivalkar

Thanks for using the Q&A platform.

Upgrading from Basic to Standard SKU Load Balancer in Azure is not a direct in-place upgrade; it requires recreating the resource with the desired SKU. However, preserving the same private IP and minimizing downtime are key challenges.

The first approach would be to deploy a new Standard SKU ILB with a temporary private IP. Migrate backend pools and health probes, delete the old Basic SKU ILB to release the original IP, and create a new Standard SKU ILB again using the original IP.

Another approach, if backend VMs support it, is to use an additional NIC or a temporary IP. Register this with the Standard ILB backend pool, gradually move traffic to Standard ILB, and once cutover is complete, decommission the Basic ILB and reuse the IP.

Regarding the validate-only error, you will need to consolidate VMs into the same availability set if possible, recreate VMs in a Virtual Machine Scale Set (VMSS) for compatibility, and use individual NIC-based backend pool configuration.

Find additional documentation:
https://learn.microsoft.com/en-us/azure/load-balancer/skus#backend-pool-configuration
https://learn.microsoft.com/en-us/azure/load-balancer/upgrade-basic-standard-with-powershell

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Regards,

Obinna.