Linux commands

How to Do a little with Linux Commands

Some of the useful commands on Linux if you are facing a sudden DDOS attack

Count the number of HTTP processes (it helps to know what your normal count is for comparison):

ps -aux|grep -i HTTP|wc -l

Executing the following command will show the IPs arranged in order of established connections

netstat -lpn|grep :80|awk ‘{print $5}’|sort

It will show a list of the current active connections by IP address and the offending IP is usually the one with a high number of connections:

netstat -ntu | awk ‘{print $5}’ | cut -d: -f1 | sort | uniq -c | sort -n