This is one of those things that, when you see happening, makes you immediately jump to the wrong conclusion and makes you lose time troubleshooting. Today I tried to connect to my XenServer box as I have done countless times in the past, only this time I was greeted by the following error message:

I immediately thought about having entered the wrong password. Instead, this time it was a network issue: I was using the wrong network adapter in this VM that I use to connect to XenServer. Consequently, the VM was getting an IP address in a different subnet than the one XenServer is configured on, and the connection was failing.

So, when you see this error message, it doesn’t necessarily mean that SSH is disabled on the machine or that you are entering the wrong password. Have a look at your network adapter settings first.