Its a hard question to answer because at the base is semantic word games.
Unix to me, represents a design philosophy. This philosophy is a one that all computer input and output should be stream based and have human interface-able commands through the terminal. This also includes the idea that each program, should do only one task. This philosophy, practiced by engineers of the day, was efficient because it encourages code reuse, because of the dependability of other's work.
Linux to me, represents a distribution philosophy. This philosophy is one one shared ownership and copyright. It represents the core fundamentals behind what we call the Apache Foundation. The shared copyright concept, is akin to who owns this discussion on forums.linuxmint.com.... 1) Clem? 2) Users? 3) Both Contributers or 4)Everyone.
To understand what Linux is, we must know what it is not. It is not BSD. Because BSD is like Linux in that it looks and acts like it. It even has many of the same programs. So if it looks like linux, acts like Linux, performs like Linux, but yet is BSD, its due to the fact the the code is not shared in ownership, but rather granted exception from prosecution from the owner.
Linux in the simplest form, is the Kernel. Android is Linux, Linux is Linux. Half the cellphones in the word are use Linux, because they use memory management code from the Linux kernel, but they themselves are not Linux, because the cellphone OS is proprietary.
What we understand as Linux, is the distribution of Linux, for example Linux Mint, Red-Hat, Ubuntu, CentOS. We call them Linux, because they adhere to the Linux philosophy of free-to-own (not free to use).
If your still reading this, you should now understand that Unix is an ideological design framework. And Linux memory management code from the kernel, and potentially all the way up the distribution code, as long as it continues to use the Linux philosophy.
So unix networking, most likely will use protocols from when people developed on unix. Sure people still develop for unix/BSD but they often don't share their code. If you want to start a simple network using technologies supported by BSD, then try looking into the NFS (network file system) and how to use export file to setup shares.
So linux networking, will use free-to-own protocols, which are most likely reverse engineered commercial protocols. I've given up on samba and NFS shares and have switched exclusively to sshfs file shares.