not being a CCNA.... I think that every person in any noc should understand everything in the book. It isnt a hard read and has some basic information about routing and BGP.
Also, I hear that Routing in the Internet is updated and a good book (only read the first version.) it goes into more details on routing and good for a followup book.
For a harder read (but also with significantly more information about routing in larger scales), grab Large-Scale IP Network Solutions by Raza and Turner, ISBN 1578700841. This book talks about more advanced BGP topics and has very good sections on other protocols (IS-IS, OSPF). We actually tend to have most engineers read this book rather than Internet Routing Architectures, but most of our people know at least the basics of BGP (or we can teach them in a day or two). It has enough case studies to put you to sleep for weeks. ...TCB -- Timothy Brown tcb@ga.prestige.net