Michael, On Sep 20, 2006, at 2:17 AM, Michael.Dillon@btradianz.com wrote:
Simply, PI to network topological leaves doesn't scale.
On the contrary, PI *DOES* scale and it has scaled because there is no direct one-to-one connection between issuing a PI assignment and consuming a global routing table slot.
Yes, pedantically, if you don't insert a prefix into the routing system, it scales quite well. I'm not sure this distinction has much value though.
Those things have greater impact on global routing table size than the number of new PI blocks.
More specific announcement for TE may have a greater impact _today_ but given the pattern of liberalization of PI policies in all the RIRs, it isn't clear to me this will be the case in the future. What's worse is that more specifics can be filtered while still potentially providing routability (albeit perhaps sub-optimally) through the supernet. If you apply filters that affect PI prefixes, those prefixes are simply gone. Rgds, -drc