ExpressRoute gateway to a zone-redundant SKU and the public IP to a Standard SKU

Hello @Middlewick, David

Yes, the migration path still exists, but there's an important current status that likely explains why you're getting through Validate without being able to progress.

Microsoft's current ExpressRoute migration documentation states:

ExpressRoute gateway migrations are temporarily paused. Don't initiate migrations at this time. You will be notified when migrations can resume.

So if Gateway SKU Migration → Validate succeeds, but the workflow doesn't proceed into Prepare/Migrate, I wouldn't assume there's a configuration problem with your gateways yet.

Under the normal migration workflow, Microsoft supports moving legacy Standard, HighPerformance, or UltraPerformance ExpressRoute gateways to availability-zone-enabled SKUs such as ErGw1Az, ErGw2Az, or ErGw3Az. The process creates a second gateway in the existing GatewaySubnet and provisions the replacement public IP as part of the migration.

The normal portal sequence is:

Validate → Prepare → Migrate → Commit

During Prepare, Azure creates the replacement gateway, and Microsoft manages/provisions its public IP. The Prepare operation can take up to approximately 45 minutes.

Regarding the Basic Public IP: ExpressRoute gateways using Basic SKU public IPs require the ExpressRoute gateway migration process rather than attempting to upgrade the public IP independently. Microsoft's Basic-to-Standard guidance still explicitly directs ExpressRoute customers to the ExpressRoute Gateway migration workflow.

Therefore, I wouldn't delete/recreate the gateway or manually attempt to replace its public IP simply because Azure Advisor continues showing: Implement Zone Redundant ExpressRoute Gateways

The recommendation is consistent with the gateway still being on the legacy configuration.

Since Microsoft previously advised that your two gateways would be upgraded, I'd suggest checking whether you received a Service Health/advisory notification specific to those resources. If not, and the portal continues stopping after successful validation, opening an Azure Networking support case would be appropriate. Provide the gateway resource IDs and mention specifically that:

Gateway SKU Migration validation succeeds, but the migration cannot progress to the Prepare stage.

Support can confirm whether those particular gateways are currently blocked by the temporary migration pause or are part of a Microsoft-managed migration wave.

One other point: Microsoft now also offers ErGwScale. Existing Standard/HighPerformance/UltraPerformance gateways require the migration tool to move to ErGwScale, while existing ErGw1Az/2Az/3Az gateways can upgrade directly. ErGwScale also doesn't support Basic Public IPs.

So based on the current documentation, I would not make a disruptive change to these production gateways simply to clear the Advisor recommendation. Successful validation is encouraging; the workflow not proceeding may align with Microsoft's documented temporary migration pause.

Sharing these references with you:

Microsoft - ExpressRoute Gateway migration

Microsoft - Migrate an ExpressRoute gateway using the Azure portal

Microsoft - ExpressRoute Scalable Gateway

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