Sad but true, it is better to use tcpwrappers to block China bot nets, see for example http://g14n.info/2015/03/server-hardening-tips/#restrict-ssh-access http:

Sad but true, it is better to use tcpwrappers to block China bot nets, see for example http://g14n.info/2015/03/server-hardening-tips/#restrict-ssh-access http://g14n.info/2015/03/server-hardening-tips/#restrict-ssh...