@NekkoDroid …distinguish between very high number of attempts because of misconfiguration or because of valid connection attempts.
Now, the this ratelimit was configurable since a long long time, people just never bothered to. You can simply turn it off in the socket unit via TriggerLimitIntervalSec=/TriggerLimitBurst=.
So, the DoS never really was a DoS, it was at best a misconfiguration.
With v255 we added a separate ratelimit to socket units that behaves differently, btw.