SauRoNZA
Honorary Master
Blocking traffic on your router does not prevent the traffic going down your line, using your bandwidth and congesting your connectivity
Technically yes.
But that's if they know the IP is active and exists and keep knocking at the door as we know has been happening in your case.
But a randomised attack can at least be avoided if you can hide your IP to the best of your ability which is what should happen if you silently drop that traffic and even better if you can kill all ICMP responses.