IP addresses can be spoofed. So you’d need some kind of handshake to verify you are the owner of that IP. Which is going to be tough to complete if your network

IP addresses can be spoofed. So you’d need some kind of handshake to verify you are the owner of that IP. Which is going to be tough to complete if your network is completely saturated from the DDoS in progress. I do think your idea has merit though. But it’s still a long way from being a well thought-out solution.