An enterprise hosts their servers (include both Linux and Windows servers) in a traditional IDC Every night hackers with IP addresses from many countries try to crack the password of their servers, making the administrator terribly worried about this However because of work requirements the remote management port of these servers must be opened to public network.

The administrator heard that Alibaba Cloud has solutions that can help customers improve the security of their systems Therefore, he/she wants to migrate the system to Alibaba Cloud. Which of the following functions should the administrator activate in Alibaba Cloud to reduce the possibility of brute force password cracking?