ARP is for the LAN devices. L2 switches don't rely on ARP to build up their forw...

		10000truths on March 4, 2025 \| parent \| context \| favorite \| on: Let’s code a TCP/IP stack, 1: Ethernet and ARP (20... ARP is for the LAN devices. L2 switches don't rely on ARP to build up their forwarding tables, they can just inspect the source MAC of every Ethernet frame they receive, and correlate it with the port they receive it on. Frames with unknown destination MACs are broadcast, but that stops as soon as every device in the LAN has sent at least one frame.