I am studying for my CCNA, and I was wondering why we can't route packets between networks with MAC addresses. Is it theoretically possible to know the location of every computer on the internet, and have switches (possibly at an ISP), that know every MAC address out there, and are able to forward it to the correct switch?
Would a system like this even be practical to implement (if IPs hadn't already been implemented)?
Because that would mean that every node in the network would have to know every mac address everywhere
think of it like this. IP routing is like routing by postal address
123 main st,
Big City
Ohio
USA
This is structured. Post office in California (where I mail this letter) doesnt know about 'main st' at all, but it knows to send to 'Big City' sorting office. They will know
MAC address is just a random number. That would be like mailing using SSN
Imagine a letter that said simply
354-76-8791
as the address, where would the post office send it when I mail it. They would need a registry of every SSN and where they live, updated all the time.