The SSH connection error that you are facing while importing HDP 2.5 to the virtual box, check if the SSH service is running inside the VM with the service sshd status. Starting the service usually fixes it. There are many different causes for it, such as:- 1) SSH Service not running 2) Firewall blocking SSH port 3) Incorrect SSH Configuration 4) Network issues 5) Server Overload  6) SSH Key Authentication issues, etc You need to understand all the causes thoroughly and also the different ways to fix the error in detail, so it might help solve it. SSH is a method of securely getting access to the remote device or server over an insecure network, usually over the Internet. Therefore, SSH is very important for conveying sensitive information, especially where security is of the utmost importance. ... View more