Any server you put on the Internet will be subject automated and targeted attacks. If you look at your auth.log file you would see that your servers are constantly scanned and attacked. %99 of the attacks are automated and targeting standard ssh port (22). Try this command on your server. You can change the date [...]

I am working on a KVM based virtualized environment.  All my virtual machines are sitting behind a virtual firewall appliance. Here comes the challenge. I need to identify and open up required ports for each individual appliance. What are the ports a mailserver would need? Here is the list of ports you need to open [...]