About OopsCrasher, I tried it on two servers I own. One is Squirrel and is the Vice Legends TDM server. The other is Pawn and is the Vice Legends A/D server. I ran a packet sniffer while I was doing this. The Pawn server, as you would've expected, crashed. The Squirrel server was still available. Why? This is my theory:
The packets being sent are SAMP packets, which are also compatible with VCMP since they're both made from the same code base as of 0.3z r2. However, the packets that this version of OopsCrasher were sending seem to be invalid packets. The server does not "crash." However, the server will spend eternity trying to read a packet that's not even valid; and the connection is lost.
Squirrel, on the other hand, seems to drop or ignore these invalid packets. This allows it to stay up during an OopsCrasher bombing. While it may not be able to handle a botnet of millions, that's a highly unlikely scenario, so you should be safe from most, if not all, VC:MP DDoS kiddies.
If you couldn't understand that, well, your loss.
