[Zack9764]

I know it causes high ping, lag spikes, data loss, but how can you tell if someone's DDOS'ing your server and how can you tell who it is?

[Krx17]

There's only a couple of symptoms, and those are the ones you already know about. There is no way to tell since it's a DDOS, because it's distributed, meaning lots of different connections from different IPs.

[PowerPC603]

http://en.wikipedia.org/wiki/Denial-of-service_attack