What should I do if my server is experiencing DDOS?

Question

What should I do if my server is experiencing DDOS?

Answer

If you are experiencing a real DDoS (from multiple IPs), you should communicate with your data center or hosting provider, as they have specialized equipment to put in place to help mitigate the attack until it slows down or dies off. If you are experiencing a smaller-scale attack, you can block the attacking IPs on your server with iptables or with any third-party firewall that you might have installed.

Other options:

• CDN or external firewall services such as like CloudFlare™ can help buffer traffic to the server. They may also offer paid DDOS mitigation services.
• If you are utilizing LiteSpeed™ as your webserver, you can also make use of some of their recommendations here: Mitigating DoS and DDoS Attacks
• In some cases, it might be best to take the service or server offline until the traffic subsides.

Please note that server security and attack mitigation are not services offered by cPanel and, as such, we can only provide limited observational support for those issues. cPanel does not offer a firewall interface and does not support the server's firewall in any way.