> What we call a "router" is in other-speak an "intermediate
> system".  There is no "strong intermediate system model", such
> a thing makes no sense at all, a router would simply route the
> packet from the "incorrect" interface it arrived on, to the
> correct interface, and then deliver it.  That's what routers
> do, after all.

Hm, if I have understood what the "strong host model" is about, I
think there is a place for a "strong router model" too.  The
corresponding function in a router would be to refuse to forward
a packet entering an interface if the router did not have a route
for the source address in the packet pointing back out the same
interface the packet entered on.

Having such a function in place could reduce the problems caused
by the fact that spoofing source IP addresses is often quite
simple and can be used in various "undesireable contexts".

- H=E5vard