Authentication issue when setting up F5

davidy2001you are receiving the "Authentication failure" because you have to enter the default password again and after that it will prompt you for the new password. Notice that it says "(current)" next to "UNIX password:" meaning the password that you entered when you first logged in. UNIX does this as a safe guard essentially so that if for some reason a user was left logged in you couldn't just change the password to a new one without knowing what the current password is.