I'd suggest a book. I was pretty happy with "Computer Networking: A Top-down Approach" by Jim Kurose. I find it more appealing that it starts with the upper layers (http), because I was more familiar with them.
“You can't buy a hard copy of the 8th edition, but instead can rent (and then choose/pay to keep the hardcopy if you want a hard copy book). You can rent a copy or subscribe to Pearson+ from our publisher, or rent a hard copy or purchase a Kindle version from Amazon, or rent a hard copy from VitalSource.”
That’s just… odd!
It's bullshit.