I moved into a new apartment a few months ago. There are ethernet jacks all over the place, and hidden in a closet is an Airplay101 8-way ethernet switch that connects all of those jacks. I am wondering what the switch actually does, at a packet level. One end is plugged into my router, another to a PC, and the rest are unused for now. Do all packets sent in get forwarded to all other ports? Does the switch know the IP address of each connected device and forward things only to the correct port (and if so, how is that different from a router)? Or is it something else?
Somebody on another forum (before the question was closed as off-topic) started to explain that an Ethernet switch does frame-level switching, meaning it's based on MAC address, and doesn't care about the embedded IP packets. So does every device hooked up to the switch use ARP to learn IP/MAC mapping, and then add the correct destination MAC address, which gets sorted by the switch?
For reference, my background is in EE, I've been working in chip design for 15 years, and though I never took a networking class in school, I've worked on some networking chips, read some books, and at one point had a decent understanding of what a router does (and I could probably still design an Infiniband HCA with enough time). But I'm not sure what's in a standalone switch.