[SOLVED] Does anyone know how to secure Port Mapper?

Issue

I recently got the message from my hoster that my portmapper is not secured! What can I do about this?

iptables -A INPUT -p tcp -s! 192.168.0.0/24  --dport 111 -j DROP

I already tried this code but I get the message that the IP is a bad argument.

Thanks in advance.

Solution

The proper syntax is:

iptables -A INPUT -p tcp ! -s 192.168.0.0/24  --dport 111 -j DROP

Answered By - user12974465

Answer Checked By - Dawn Plyler (WPSolving Volunteer)