[HECnet] HECnet routing costs

[Paul Koning]

> On Jul 31, 2019, at 4:51 PM, Keith Halewood <Keith.Halewood at pitbulluk.org> wrote:
> 
> For broadcast circuits, bridges or not, doesn’t the router priority on a router’s Ethernet circuit play a part too?

Router priority affects only end nodes: it controls which router will advertise itself to the end nodes, so that is the router that will carry out of LAN traffic outbound for those end nodes.  It has no effect on route computation.

Also, if the end nodes are Phase IV-Plus, they keep track of which router delivered an inbound packet and further traffic for the destination will go there.  This is the "previous hop cache", which is a generalization of the "on-NI cache".  With that improvement, off-LAN traffic is routed optimally for end nodes, and the designated router doesn't carry a large extra burden of endnode traffic.

	paul