Dominate Method  Attack is a New method of DDoS Attack on Layer4 of Network. the method is able to drop servers from ddos protected networks such as OVH, Voxility by bypassing their firewall and sending the attack straight to the server itself, therefore causing it crash completely.

As for the moment, as a server owner with a limited to no access to the firewall (internal or external), there is nothing in your hands. This attack should be blocked by the ddos protection network that you are in.