Thanks for the command. There were around 2k ips attacking the server and those who think cloudflare can protect their sites should reconsider their statements 8-)You can use the following command to identify the network of IPs which caused the problem.
nestat -plan | grep 80 | awk {'print $5'} | cut -d: -f1 | sort | uniq -c | sort -n
Thanks for the command. There were around 2k ips attacking the server and those who think cloudflare can protect their sites should reconsider their statements 8-)