Help stopping DoS attack Ubuntu 16.04
 

Hi, Does anyone know how to stop DoS attacks? Have you any good tutorial?

We're having a lot of problems 'cause of brazilians :/

Re: Help stopping DoS attack Ubuntu 16.04
 

get a host with good ddos protection, but that might be very expensive depending on your location

Re: Help stopping DoS attack Ubuntu 16.04
 

Right, but it's no DDoS, it's DoS, so I don't know very well how to use iptables to limit the connections from some potential attacker

Re: Help stopping DoS attack Ubuntu 16.04
 

Did you have wireshark pcap file on that server?

Re: Help stopping DoS attack Ubuntu 16.04
 

sudo iptables -t nat -A INPUT -p tcp -m tcp --tcp-flags FIN,SYN,RST,ACK SYN -m connlimit --connlimit-above 15 --connlimit-mask 32 --connlimit-saddr -j DROP
sudo iptables -t nat -A INPUT -p udp -m connlimit --connlimit-above 15 --connlimit-mask 32 --connlimit-saddr -j DROP

Run this. It will drop any IP that makes more than 15 conections (you can lower it if you want)

Re: Help stopping DoS attack Ubuntu 16.04
 

this works only if the flood comes from the same ip address (which is a very rare case), but not for ddos flood, which can be mitigated only upstream.

Re: Help stopping DoS attack Ubuntu 16.04
 

No way to defend udp spoofing (faked ip)
apart from white ip list

Re: Help stopping DoS attack Ubuntu 16.04
 

hello,

send me log i help you.

Re: Help stopping DoS attack Ubuntu 16.04
 

Unfortunately this is the answer.

There are definitely more robust systems out there in other games such as the one which ARK Survival uses where it uses a steam relay. The downside is that it adds additional latency.