After installing ESXi first thing to do...by default it is disabled. By enabling it you must strictly know what are you doing. Here are basic steps:
- go to the ESXi console and press alt+F1
- type: unsupported
- enter the root password
- type vi /etc/inetd.conf
- look for the line that starts with #ssh
- uncoment - remove the #
- save /etc/inetd.conf by typing :wq!
- restart the management service /sbin/services.sh restart