DDoS site through active connections (ISP). How to set a limit on the number of requests?

Question

Apache HTTP Server

There is a site on OVH. Their antiddos catches big attacks. But somehow they manage to zaddosit us.

httpd.itk becomes 256 and that's it. And all connections with 1 IP.
How can I do something to distribute the load?
CentOS 6.6 (64bits)
Processor Intel(R) Xeon(R) CPU W3530 @ 2.80GHz 1600.000 Mhz X 8
RAM 16 GB

Answer 1

In Iptables add a line. Limit of 10 connections from one IP to port 80
Another option. The gist is the same:

iptables -A INPUT -p tcp --syn --dport 80 -m recent --name radiator --set
iptables -A INPUT -p tcp --syn --dport 80 -m recent --name radiator --update --seconds 120 --hitcount 10 -j REJECT

Answer 2

Hire an admin if such tasks are a problem
Or remove apache from the front

Answer 3

Um, what about blocking an IP?
I recommend CloudFlare .