In newer version of ESX such as version 5, you have the option to enable the SSH daemon from the console menu (console directly from the host). However for older version like version 3, you need to do some tricks for it to happen:
- At the console, hit Alt+F1
- You will enter into console terminal, but you won’t see any prompt. Just key in “unsupported” (without quote) and press enter.
- Now you can see the prompt, edit
/etc/inetd.confusing any editor (vi or nano)
- Look for the line with ssh, uncomment it.
- Exit from editor, then you need to stop the inetd process by killing it.
- Find out the inetd process id and kill it using
kill <process id>
- Start the inetd daemon by issuing the command
Now you should able to connect the ESX host through SSH.
Reference: Get full control over your ESXi Server