Networking is no longer just for large corporations and big universities. These days, it's the Internet that's the computer. Hyperlinked online reference manuals are often easier to use than the print version.
Most technical books list a web site for errata and updates.
Networking is now part of the mainstream, both at home and at work. Routing happens under the hood just fine most of the time. Interconnections is a good book for the weekend netadmin, those entering the profession, and for the inquisitive who like to occasionally look under the hood. Although almost no networking protocol follows it exactly, it is useful for comparing protocols. In this book, the data link layer is relevant because bridges operate within it and because the service provided by it is relevant to routers, which operate in the network layers thereby making the network layer also relevant.