Very much a work in progress, the most recent update brings it up to 125 pages and it's pretty good. The author is involved in the development and deployment of DNSSEC.
Network Programming by Jan Newmarch
Golang (aka Google Go) is ideal for servers and to that extent you need to know about programming. If you want to learn network programming in Go, this ebook is a very good place to start. There are 15 chapters most with code.