Allied Telesis AT-S63 - Manual (Page 638)

Chapter 34: Secure Shell (SSH)
638 Section IX: Management Security
Type E to enable the SSH server. Select this value after you have
finished configuring SSH and want to log on to the server. Or, type D to
disable SSH while you are configuring the protocol. SSH must be
disabled while you are configuring the protocol. This is the default.
Note
When there are active SSH connections, you cannot disable the
SSH server. If you attempt to disable the SSH server when it is in
this state, you receive a warning message.
Note
Allied Telesis recommends disabling the Telnet server before you
enable SSH. Otherwise, the security provided by SSH is lost.
8. After making changes, type R to until you return to the Main Menu.
Then type S to select Save Configuration Changes.