I've yet to see what I would consider a satisfactory introduction to networking. Perhaps others will be able to make recommendations for sources they found usef

I've yet to see what I would consider a satisfactory introduction to networking. Perhaps others will be able to make recommendations for sources they found useful. Nevertheless, I can make recommendations on where to focus in case your request is not otherwise fruitful. * Get a concrete picture in your head of devices and protocols associated with layers 2-4 of the OSI model, and ignore the rest. * Care about Ethernet: ARP and DIX (not IEEE 802.3). * Care about IP and TCP/UDP ports--in short, sockets. * Care about TCP, specifically, only if you must. * Fill in the gaps from there, most relevant, first. Networking today is a miserable, architecturally broken mess, and I could bend an ear about the state of the art, but such things are not practical or of wide use, and all I can do here is wish you luck. I sincerely hope you find a good refresher. Good luck to you!