I recall a supervision question last year along the lines of:
“Are the following addresses hierarchical or flat ?
a) Posrcodes
b) IP addresses
c) MAC addresses ”
Its well know that MAC addresses are flat but what if they where instead hierarchical ? This is the idea behind the MOOSE project by Malcolm Scott. Multi-level Origin-Organised Scalable Ethernet (MOOSE) is an Ethernet switch architecture that rewrites MAC addresses to impose a hierarchy upon the address space so switches no longer need to maintain a large forwarding database.
The context MOOSE is designed for is Ethernet within datacenters