Load Avarage High What to do? UDP/SYN might be the problem Firewall

[StefanNET]

So I have cPanel and installed csf, but clearly someone's abuse my server and load avarage is high which slowdown my server.

I have installed and started csf and firewall csf -s, and it doesnt help, cause in the first place I thought that someone's ddosing server, but it isnt, so I think its someone inside the hosting which do ddos syn/udp flood attack on other's.

How can I check it and how to determinate it, and once i resolve who it is, where to report that IP?

[LinuxTechie]

Hello,

With the help of proper configuration of CSF, we can limit ddos. Deflate/Evasive may also give good results.

[cPanelTristan]

If it is not a DoS attack and you suspect it's a user on the system, then please check in WHM > Daily Process Logs for any high CPU, memory or MySQL usage users.

Do you know how to use top in root SSH to check the processes running and determine what is going on at the time of high load? If not, then please try running the command "top" in root SSH and watch the processes for around 5-15 minutes time. The more you use top to get an idea of what processes are running and what is happening, the more familiar you will get with that command. The top command is a vital component to understanding and troubleshooting system load issues.

[StefanNET]

Yes I have been resolved this with top command, but 30 mins after that, someone's start's massive ddos attack on my 100mbps server, and now is down for 1 day and counting, I cant access neither ssh or http, I dont know what to do.

[cPanelTristan]

If you cannot access SSH, then only your hosting provider, datacenter or NOC can assist at this time. Anyone who has physical access to your machine to reboot it or log into it to check what is happening. The datacenter or NOC should also be able to filter traffic to the machine so that the attack is mitigated.