Upgrading the VPN gateway from VPNGw1 to VPNGw1AZ

Hello @NAKAJIMA Takayuki (中島 隆行) - I translated your question into English and I am answering in English. If English is not comfortable for you, this should translate cleanly into Japanese with a tool like Google Translate.

Yes, it will be migrated automatically. You do not need to do anything. From the retirement notice:

We'll be seamlessly migrating all the gateways on VpnGw1-5 (Non-AZ SKUs) to VpnGw1-5 (AZ SKUs) between April 2025 to October 2026.

The error you are seeing is that migration, not a fault. The retirement date passed on 30 September, so your gateway is now inside the platform migration and will not accept changes while it runs. From VPN Gateway SKU consolidation and migration:

Existing VPN gateways not supported by an availability zone will no longer allow configuration changes. If you attempt any management or configuration operation, you'll get an error message. This is expected behavior after the rollout.

So there is no manual update to perform, and retrying will return the same message.

Your target SKU is VpnGw1AZ, which you had already worked out. The mapping from the same article:

There is no downtime: "This migration is seamless, and there's no expected downtime during migration."

To confirm when it has finished, look for the AZ suffix on the SKU name, either in the portal under Configuration or with:

az network vnet-gateway show --name "vpn-gateway" --resource-group "test-rg" --query "sku.name"

One thing to expect: the new pricing starts only after your gateway is migrated, not before. AZ SKU prices were reduced as part of this consolidation.

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