Most of the information security training institutions you can see and find are web security, and there are many related training institutions. Because he is relatively simple, has a wide audience and has an immediate effect. But web security is about means and thinking, and it doesn't involve too deep technical content, especially code.
The underlying security emphasizes technology and underlying principles. Because of its high technical content and high threshold, there are few relevant training institutions. In Beijing, the base camp of this training institution, there is only one bottom security, namely 15PB.
As for Guangdong, it is estimated that what can be found is web security, but the underlying security is not.