Another thing to consider is how long it takes to download into forwarding hardware. Forwarding hardware is optimized for forwarding, not programming. The programming has to wait for time slots when forwarding is not using the memory. When you do smart aggregation, a single changed route could cause a massive change in your aggregates. Then the resulting download could be both long and cause glitches. Glitches, because you remove some aggregates while adding others within a finite time. During this finite time, you may have incorrect routing. Regards, Jakob.