Our app’s DNS record points to a public IP handled by an Azure Application Gateway.

We need to switch over to a different public IP with zero downtime.

It would seem that each App Gateway can only handle a single public IP, see ApplicationGatewayFrontendIPConfiguration. Is that correct? Or is there a way to temporarily have the App Gateway serve two public IPs?

If not possible to serve two IPs, just updating that IP in-place and immediately updating the DNS record would cause a temporary outage during the DNS caching period – right?

So, would a zero downtime solution require temporarily adding a second Application Gateway (identical to the existing one, just different public IP), then cutting over the DNS record, then (after a few days) cleaning up the old Application Gateway? Or is there an easier solution?