[tor-relays] botnet? abusing/attacking guard nodes

[Logforme]

My relay ran out of connections once and also crashed once so I followed 
the suggestions in the "DoS attacks are real (probably)" thread and 
implemented connection limits in my firewall. Everything have run 
smoothly since.

My only concern is how low I can set the number of connections per IP 
address. Someone wrote a legit client will only open max 2 tcp 
connections. I'd like this verified before I lower my limits further.