DNS DDoS via multiple exit relays causing performance issues?

[gus]

Hello, yes, some exit operators reported that issue last year.
You may find this project by Artikel10 useful:

GitHub - artikel10/surgeprotector: Block Tor Exit traffic to flooded IP...

From tor-relays mailing list:

[tor-relays] Performance issues/DoS from outgoing Exit connections

Hello, on the evening of 2022-10-18, we (Artikel10) started getting alerts about our Tor servers, while our traffic declined sharply. When we investigated, we found that there were hundreds of thousands of TCP connections (per server) open to a single address, orders of magnitude more than any other address. We blocked this address via “ExitPolicy reject”, then another one, and since then things seem to have improved. I have thrown together a small Python script to detect this and generate “Ex…