I’ve read an article which describes how to simulate the close ports as open in Linux by eBPF. That is, an outside port scanner, malicious actor, will get tricked to observe that some ports, or all of them, are open, whereas in reality they’ll be closed.
How could this be useful for the owner of a server? Wouldn’t it be better to pretend otherwise: open port -> closed?
indeed, a service on a port would no longer properly work. However, pretending that an open port is closed is possible the same way when pretending that’s open