Oh ok, cloudfare is a good option and I don't understand why this forum doesn't use it.
It's ok. But, you have to rely on a third party which is the dealbreaker in my opinion. Cloudfare? I don't think we need that service for this forum tbh. It's just that the forum software is a little bit outdated but can still stand some security threats. The last time I remember that we experienced similar issue was dated January. Hope this attack doesn't persist and the forum may once again be stable.
Well, even with new forum software it won't really improve protection against DDOS attacks. More/better hardware will, there's certain things you can do, but theymos has pretty much already covered most of the little things you can do to prevent DDOS attack. There's been plenty of discussion on this previously where theymos has asked for advice on protection from DDOS. I can't seem to find the thread yet. 
