A proposal for reducing routes due to multihoming

Wed Oct 30 21:56:42 UTC 1996

Alexis Rosen wrote:

>Bill Simpson claims that this idea is ~10 years old, but if so perhaps
>it's time to air it again....

>It's dead simple, really: Assign address blocks to pairs of providers.
>Both providers announce those blocks all the time, and assign addresses
>out of those blocks to customers who multihome between those two
>providers.

That idea also assumes that providers exchange specifics within
shared blocks.  Otherwise it won't work.

Doesn't sound like big savings...  And is certainly a hell to manage.

I demonstrated some time ago that the lower boundary on the routing
table size given today's Internet topology is about 300 routes.
That was done by analyzing AS-paths -- i.e. the assumption was that
everything can be aggregated down to 1 route per AS.

The result generally indicates that 90% of routes can be eliminated by
renumbering and aggregation.  The rest is simply too few to worry about.

--vadim