Command to view external IP's connected to port 80

Sometimes apache may be loaded high,this may be due to hugh requset from external IP's to apache . At this time you can use the following command to view the extenal IP's connected to apache (port 80) :

netstat -anp | grep 'http'

When the above command is executed you will see list of IP's connected to apacahe ,when there is hugh number of request from a single IP ,this may considered as DDOS and you can block that IP using CSF