The first paragraph of this book’s afterword reads:
“You now know more about SSH, OpenSSH and Putty than the vast majority of IT professionals! Congratulations”.
That claim will be true for any reader of SSH Mastery who has read the book up to that point and has incorporated at least some of the elements of the configurations it describes into their own environments.
“But why a book dedicated to a single command?”, you might ask. Almost all Unixes and Unix-likes have incorporated OpenSSH, the free SSH that is developed as part of the OpenBSD project, and OpenSSH comes with excellent documentation in the form of several extensive man pages.