1.1 Secure Login and Telnet Disabling - Enable SSH server
From the perspective of security, the management plane should support at least the SSH/SSL login mode. Ordinary plain text Telnet/ftp login is vulnerable to attack, and such secure login modes as SSH and SFTP should be supported. The session validity period must be limited.
It is recommended to enable ssh server Enable SSH server by running: ZXR10 (config)#ssh server enable