Somewhere I read that to grasp the technology of the internet, computers and networking, you really only needed to understand: TCP/IP, the end to end principle, object-oriented programming and service based APIs.
This summary of 10 serious networking papers is useful to have and also points to Blumenthal/Clark's key paper on the architecture of the internet: M. Blumenthal, D. Clark, “Rethinking the Design of the Internet: the End-to-end Arguments vs. the Brave New World,” ACM Transactions on Internet Technology, Vol. 1 , No. 1 (August 2001) pp. 70-109.