Something that right now confuses *me* is: If I understand this correctly, the 'default-free zone' is meant to be kept below 1000 routes, so routers can be fast.
The hard limit is, IMO, 8192.
Past history has told us that at least some technologists have failed miserably in predicting whether fast routers can be built which handle largish routing tables. If I recall correctly, an argument similar to the above one was one of the arguments the ATM proponents used in their day: you need a short header to do fast lookups, and "fast IP routers cannot be built". History since then has at least told me that this was not entirely accurate. Therefore, I tend to view the above justification and limits with a healthy dose of scepticism. Regards, - HÃ¥vard