Replace [PORT] & [CON_NUM] with respected values.
iptables -I INPUT -p tcp --syn --dport [PORT] -m connlimit --connlimit-above [CON_NUM] --connlimit-mask 0 -j REJECT --reject-with tcp-reset
October 23, 2019
How to limit the number of incoming connections to a specific port
July 14, 2009
Limit Connections per IP using mod_limitipconn on cPanel
one of the problems I had on one of my cPanel servers was that some people were using download managers to download files from server , so hundreds of connections were being ESTABLISHED to Apache and it was becoming like a dos attack and causing Apache to become non responsive.
so here is what I did to limit connections per IP in a cPanel hosting server :
there is an Apache module named mod_limitipconn which will take care of it for us.
first download the latest version of mod_limitipconn from this site : http://dominia.org/djao/limitipconn2.html
decompress and install it.
at current time the latest version is 0.23.
wget http://dominia.org/djao/limit/mod_limitipconn-0.23.tar.bz2 tar jxvf mod_limitipconn-0.23.tar.bz2 cd mod_limitipconn-0.23 /usr/local/apache/bin/apxs -cia mod_limitipconn.c
next step is to add the required configuration to the Apache config file , we can add this directly to the end of httpd.conf file but the problem is that if we do this , the httpd.conf will be overwritten by easyapache so we will use include files to add our config.
login into your WHM panel , and follow the following menu items :
Main >> Service Configuration >> Apache Configuration >> Include Editor
on the Post VirtualHost Include section , choose All Versions from drop down menu and add the following config into it :
<IfModule mod_limitipconn.c> <Location /> MaxConnPerIP 10 NoIPLimit images/* </Location> </IfModule>
then click on update and restart Apache server.
now We are all set 🙂