Instruct: Classify a given Amazon review as either positive or negative.
Query: An excellent book about the BGP4 protocol.

This book is about the BGP4 protocol - there's a brief chapter about IP & IP routing, which serves to refresh one's memory, and the rest of the book is about the protocl itself.This book is not tied to any specific router implementation, but rather describes the protocol 'academicaly' in a clear language and with all the needed details.It's an excellent book for two purposes - people who want to study the protocol academicaly, e.g. for a course in computer networks or Internet Protocols, and arent into studying the RFCs that sink into the details, and for people who manage routers/networks and want to understand the protocol before reading a lengthier text specific to some implementation.