Goals from former Norwich striker Lewis Grabban either side of an Aiden McGeady strike helped the Black Cats to all three points from their trip to Carrow Road, leaving Farke's side still searching for their first win of the campaign following a draw at Fulham last weekend.
"First of all, we are really disappointed," Farke, who took charge over the summer, told the Norwich website. "We wanted to win the game and in football it's all about the result. It's not about philosophy, ideas or performance.
"We were the better team in the first half but it's about being good in the small things. For two situations we defended very sloppily and that was the reason we lost.
"Although it was a good performance we are not content. We're disappointed we lost the game. Sunderland were very compact and defence-orientated. The biggest problem was being disciplined and defending everything well.
"You have to do your defence stuff. We defended a goal-kick sloppily which was a simple situation. In the second half we put more pressure on them. We had a lot of chances but we have to learn from today.
"I'm not angry with the guys, I'm angry with the two situations. You have to be good in the small situations to win games which we will work on."
Next up for Norwich is a home tie with Queens Park Rangers on Wednesday evening.