Quite correct, but nonetheless, that RFC does explore the topic of "why not just mark the traffic?" One basic objection which detaro pointed out is that there's

Quite correct, but nonetheless, that RFC does explore the topic of "why not just mark the traffic?" One basic objection which detaro pointed out is that there's nothing to stop attackers from clearing such marks. As Wikipedia puts it: > The evil bit has become a synonym for all attempts to seek simple technical solutions for difficult human social problems which require the willing participation of malicious actors https://en.wikipedia.org/wiki/Evil_bit https://en.wikipedia.org/wiki/Evil_bit