Nice addition to my /etc/ssh/sshd_config to deal with the script kiddies:
PerSourcePenalties authfail:1h crash:1d grace-exceeded:1h noauth:1h

If you edit your config, before restarting sshd, don't forget to open a second session just in case and then check the config with: `sshd -t` – if that does not output anything, all is ok and you can restart sshd.