if err := i.applyIstiodGateway(c, i.primaryIOP.spec.Revision); err != nil {
			return fmt.Errorf("failed applying istiod gateway for cluster %s: %v", c.Name(), err)
		}
		if err := waitForIstioReady(i.ctx, c, i.cfg); err != nil {
			return err
		}
	} else {
		// configure istioctl to run with an external control plane topology.
		istiodAddress, err := i.RemoteDiscoveryAddressFor(c)
		if err != nil {