What i would say is that, you will read all networking books and attend alll online course as much as you want but you still won't learn much beyond the OSI model and difference between IPv4 and IPv6.
My advice, get a Cisco course near you, they are always pretty short course, then learn as you do. Networking is a hands on work, not a read-a-book-be-an-expert kinda work. Leave that to the programmers.