It's a great book, I used to have some edition of it and it helped me a lot professionally with setting up firewalls, load balancing, traffic shaping and more.

I also had a book on Designing FreeBSD rootkits that was very educational.

Unfortunately I've given away all my books for more minimalistic living where I am instead dependent on digital information. Not sure how to feel about it.

There are e-readers and DRM-free electronic libraries.