1. If filtering is used, as suggested by someone, what happens to the small/mid-sized company that is multi-homed out of an ISP's /20 or larger block? In this case, I can see an ISP with a /20 bust that up to /21s smaller to accommodate this user. 2. Wasn't /24 filtering something that a few large ISP's did a few years ago and everyone complained? I don't have a reference here but I seem to remember some flack about that.
Both of these points are why filtering is not a good solution, you just dont know what those netblocks are that you are missing, it needs to be controlled by the ISPs themselves.
3. What happens in the case of a carrier that has given /24s to a downstream out of different blocks?
This is not imho unnecessary deaggregation and not a problem, however where possible the blocks should be contiguous and aggregatable (unlikely), and dont forget each block should be given on the basis that it will last the downstream quite a long time so that over a few years the downstream only accumulates a couple blocks anyhow.
I guess the real question is this:
If X company can not be reached, how/who would you complain to?
If you are company X then its your fault and you should see where you went wrong! If you have a /26 that you're trying to route but no one is accepting it then consider that maybe you arent justifying your being an ISP..
And would this be like the RR and AOL email filtering lists where we all complain, and this filtering is an effort by some to force others to clean up their act?
Yeah kinda, same but different.. :) Steve
Am I out in Left field?
Jim