Wouldn't it be nice if backbones got around to simply charging for annoucements and quit this arbitrary filtering?
thanks geoff. :-)
and how would charging for announcements have ameliorated the 129/8 disaster? ahhh, when they tried to announce those 50k /24s, the check would have bounced!
Thanks Sean! ;-) Let us please be very clear here. There are multiple problems. First, there is the problem of overall size of the routing table (and proportional costs in BGP processing and convergence time, etc.). Second, there is a reasonable requirement for sanity checking and authentication in announcements. Third, there is an alleged correlation between prefix length and route flap. We currently have one hammer (filtering) that has been used to drive the above machine screw, ice piton, and cup hook, respectively. I was not and am not suggesting that anyone stop all filtering. I am suggesting that a sane prefix settlement scheme would allow us to dispense with the filtering policies that are currently in place and would allow the backbone to globally distribute any prefix, regardless of prefix length, if only the originator has paid enough money and informed people first. You want to inject a /32? Go right ahead. Send your check to your provider and it can be made to happen. This is the only sane mechanism to divide up a limited resource (global prefix slots) amongst an otherwise unlimited demand (domains with prefixes). Now I don't claim to be a policy wonk and I don't have the slightest idea of how to make this equitable and fair for all, but I do know that this would result in an outcome that would give us routing tables far smaller than our current 67k entries. I'll also note that this would also decrease the pressure on the address space. No need to go get a /19 if I can get my /23 globally advertised. The sanity checking and policy checking requirements would indeed require filtering, but perhaps this is simply an extension of filtering any advertisements that you haven't received payment for. This will prevent you from accidentally receiving 50k of anything, not just /24's. The correlation with route flap should be re-examined. I suspect that this is no longer a driving force and is more than adequately compensated for by having flap damping parameters that scale geometrically with the prefix length. Regards, Tony