I ordered a thing from a place in the US some weeks ago. The parcel tracker has now reported it on three different continents, and two of those after it already reached my own country.
Or possibly the parcel tracker is not entirely correct, or maybe it's just misleading me. I don't know, but I sure don't understand physical packet routing either.
@liw A famous (apocryphal?) result says that you can avoid congestion by routing to a random node on the network, then to final destination.
@bremner Interesting. Would you happen to have a reference? (Serious question.)
@liw @bremner I always used to refer to this as the "hot potato algorithm" but searching now tells me that is not quite accurate. But the basic idea is that if a packet comes in one interface and does not have a local address, you simply throw it out another random interface and let the next router do the same.
(Like a hot potato thrown around a group.)
On a small network (with a high TTL) the packet will eventually get there and not require routers to have any knowledge of the wider network.
Lars and friends