You can have network segments which do not use ethernet and therefor have no MAC addresses, but still use IP addressing and need to be routable. It doesn't make sense to tie the next-hop in a table to MAC addresses which are an implementation detail on a lower layer. A good, popular, example of this you can test yourself without obscure hardware is wireguard.
Comments
You can have network segments which do not use ethernet and therefor have no MAC addresses, but still use IP addressing and need to be routable. It doesn't make sense to tie the next-hop in a table to MAC addresses which are an implementation detail on a lower layer. A good, popular, example of this you can test yourself without obscure hardware is wireguard.