func resourceNetworkingSubnetV2Update(d *schema.ResourceData, meta interface{}) error {
	config := meta.(*Config)
	networkingClient, err := config.networkingV2Client(d.Get("region").(string))
	if err != nil {
		return fmt.Errorf("Error creating OpenStack networking client: %s", err)
	}

	// Check if both gateway_ip and no_gateway are set
	if _, ok := d.GetOk("gateway_ip"); ok {
		if _, ok2 := d.GetOk("no_gateway"); ok2 {
			return fmt.Errorf("Both gateway_ip and no_gateway cannot be set.")
		}
	}

	var updateOpts subnets.UpdateOpts

	if d.HasChange("name") {
		updateOpts.Name = d.Get("name").(string)
	}

	if d.HasChange("gateway_ip") {
		updateOpts.GatewayIP = d.Get("gateway_ip").(string)
	}

	if d.HasChange("no_gateway") {
		updateOpts.NoGateway = d.Get("no_gateway").(bool)
	}

	if d.HasChange("dns_nameservers") {
		updateOpts.DNSNameservers = resourceSubnetDNSNameserversV2(d)
	}

	if d.HasChange("host_routes") {
		updateOpts.HostRoutes = resourceSubnetHostRoutesV2(d)
	}

	if d.HasChange("enable_dhcp") {
		v := d.Get("enable_dhcp").(bool)
		updateOpts.EnableDHCP = &v
	}

	log.Printf("[DEBUG] Updating Subnet %s with options: %+v", d.Id(), updateOpts)

	_, err = subnets.Update(networkingClient, d.Id(), updateOpts).Extract()
	if err != nil {
		return fmt.Errorf("Error updating OpenStack Neutron Subnet: %s", err)
	}

	return resourceNetworkingSubnetV2Read(d, meta)
}
func resourceNetworkingSubnetV2Update(d *schema.ResourceData, meta interface{}) error {
	config := meta.(*Config)
	networkingClient, err := config.networkingV2Client(d.Get("region").(string))
	if err != nil {
		return fmt.Errorf("Error creating OpenStack networking client: %s", err)
	}

	var updateOpts subnets.UpdateOpts

	if d.HasChange("name") {
		updateOpts.Name = d.Get("name").(string)
	}

	if d.HasChange("gateway_ip") {
		updateOpts.GatewayIP = d.Get("gateway_ip").(string)
	}

	if d.HasChange("dns_nameservers") {
		updateOpts.DNSNameservers = resourceSubnetDNSNameserversV2(d)
	}

	if d.HasChange("host_routes") {
		updateOpts.HostRoutes = resourceSubnetHostRoutesV2(d)
	}

	if d.HasChange("enable_dhcp") {
		edRaw := d.Get("enable_dhcp").(string)
		if edRaw != "" {
			ed, err := strconv.ParseBool(edRaw)
			if err != nil {
				return fmt.Errorf("enable_dhcp, if provided, must be either 'true' or 'false'")
			}
			updateOpts.EnableDHCP = &ed
		}
	}

	log.Printf("[DEBUG] Updating Subnet %s with options: %+v", d.Id(), updateOpts)

	_, err = subnets.Update(networkingClient, d.Id(), updateOpts).Extract()
	if err != nil {
		return fmt.Errorf("Error updating OpenStack Neutron Subnet: %s", err)
	}

	return resourceNetworkingSubnetV2Read(d, meta)
}