Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Limited but concise

I used this book to teach the matter to a group of novices, and I can say that it accomplished its mission. It gave to the students the backgroud they needed to undertand the technology, while orienting them through some basic hands-on labs. There are topics for which they needed further reference, specially when I came to ACS and VPNs.Naturally, it wasn't made as an exam preparation reference (at least it is what I find out), though it has some knowledge assessment questions that help in the learning process.If you are new to PIX Firewalls, this could be a good starting point.