You certainly need to do that in the killingfloor.ini file. If you are hosting from home, you have probably set up port-forwarding, so you'll need to adjust those ports as well.

i need to do that in the killingfloor.ini or in my router as usual?

By default, the game & query ports are 7707 and 7708. Make them different. For example, 40007 and 40008.

thanks, but killing floor 1 has unique ports right? where's the different ones?

Yes, what you've shown looks like DDoS, indeed. More specifically, reflection-based amplification type of DDoS attacks, where the target is something else, and it's your server that becomes the attacker. Your KF 1 server is not the only one that has been affected. The simple and immediate solution is to change the game ports to a different number. That should stop the attacks until the new ports are discovered again. The more complicated solutions rely on rate-limiting, and are best used on Linux servers.

Tu é mito

esse cara sabe jogar muito bem l2d2 eo 1 tambem

+rep great and helpful tf2 medic

Muito bom no l4d2 +rep