The *benefit* of "/48 multihoming" is that you can filter those routes if you don't want to see them - then your routers will send packets down the /32 road, and eventually hit a router that knows about the /48 (which is why I consider this approach superior to "everybody gets a independent prefix", which I can't properly aggregate).
This does _not_ work in at least two cases:
- If someone implements RPF checks and someone else filters.
RPF will most likely break with most of the proposed multi6 solutions.
- If the primary ISP (the one that announces the /32) dies. The site is dead as well. This is the #1 reason why organizations do multihome: they want to be up even if their primary ISP tanks.
You mean if /48s where filtered? So don't filter ;-) That was the original idea with the proposal... - kurtis -