(Before watching the network administrator tutorial, I hope you can calm down and learn slowly. Everything is difficult at the beginning, so don't ignore some small difficulties. In a word, persistence is a victory. In many cases, it is a kind of essence of perseverance to get results. It is also a key stage to improve knowledge. Most of the time, we have to have the attitude of always making that thing if we can't make it. I believe everyone will have good results!)