A chronological documentation test project, nothing serious, really!
It is ideal to slow down the SSH dictionary attack when the infested host started to brute force the SSH authentication. There are many scripts/user-land daemons that perform monitoring and blocking. I prefer to use something that has less demand in memory/CPU usage. IPTables module provides a kernel level solution with little overhead.
Dette scriptet er ikke testet samt DoS bør hindres på kernel nivå! A simple rule-based DoS attack-prevention shell script. However, the proposed shell script is not a perfect tool for preventing DoS attacks, but a powerful tool for alleviating DoS attacks overheads of the Linux servers significantly.
In RedHat/Fedora you can define firewall rules in the file /etc/sysconfig/iptables. By adding this line you open ports in the range 5920-5960 -A RH-Firewall-1-INPUT -p tcp –destination-port 5920:5960 -j ACCEPT