> Traffic appears at core routers because it already gets send there by peripheral routers as a gateway. Sharing routing information between peer routers is not

> Traffic appears at core routers because it already gets send there by peripheral routers as a gateway. Sharing routing information between peer routers is not unsolvable nor likely onerous. Strawman solutions (flood constantly) are being deliberately dense. If by "sharing routing information between peer routers" you mean that, when a router learn of a new host, it shares that information with its peer routers, which then share that information with their peer routers, that is flooding. Without flooding, the traffic would not appear at every core router, which means most routers would not know of your host. > I suspect because, folks are so very comfortable with what they know, and so very unwilling to extend themselves. I once seriously considered how to make an Internet-scale non-hierarchical routing protocol, where the host identifier was a cryptographic hash of its cryptographic public key. The reverse path is easy; once A has successfully sent a packet to B, all routers in the middle know how to get from B to A. The forward path (from A to B) is the hard one. Every router knowing every host is non-viable; consider, for instance, what happens when my phone roams from the WiFi to the LTE and back (which happens many times per day) - if every router had to know of that change, for every roaming phone in the world, it would be enough to overwhelm all the links between them, not to mention their CPUs. I came to the conclusion that the amount of propagation of the route updates must be limited for it to be viable, so having every router know of every host is not possible. Either the routing information must be summarized somehow (which is what the hierarchical routing used with IPv4 and IPv6 does), or some other way which does not involve the routers (for instance, path routing, like MPLS) must be used. That is, I'm not rejecting your idea because I "feel comfortable" with hierarchical routing, I'm rejecting your idea because I've already given it (or something like it) serious consideration, and found it harder than what I had initially thought.