IP packets and Ethernet frames are separate animals. Ethernet doesn’t know IP, except for a flag saying “interpret my payload as an IP packet”. It doesn’t have

IP packets and Ethernet frames are separate animals. Ethernet doesn’t know IP, except for a flag saying “interpret my payload as an IP packet”. It doesn’t have src or dst IP addresses. And an IP packet doesn’t know about its physical transport. It doesn’t have src or dst MAC addresses. You can put other things than IP packets inside Ethernet frames. You can put IP packets into non-Ethernet carriers. The short version is that small LANs route frames by MAC addresses and don’t know about IP addresses, and the Internet cares only about IP addresses and not MAC addresses.