Ranieri took over at Fulham on Wednesday following the sacking of Slavisa Jokanovic, and he inherits a defence that has conceded 31 goals in 12 games.
"You know as an Italian manager, for us that the defensive way is the best element for the team. It is important to have a strong vision of the defensive way," he said to 'fulhamfctv'.
"But it is not only the full back or the goalkeeper, it is all the team. When you attack, you attack in an 11; when you defend, you have to defend in an 11.
"Always I look forward and want more. I hope to make a very good job here."