1. Most of these are done by script kiddies. They get a script and run it is tries to connect via standard port 22. 2 Defense in depth. A. Non-standard port. B. Only allow users that require login via ssh which should never be root. C. Require key login no passwords. D. use sudo and sudrestrictions to prevent loading a shell as root.
I changed the port to 6000, restart sshd /etc/init/sshd restart and login via new port 6000 sucessfully. But it takes a longer time to process a command.
eg. default port 22 ps aux takes 2 sec on port 6000 ps aux takes 45 sec. What happened? regards
