On Wed, Oct 12, 2022 at 7:54 AM Andrey Kostin <ankost@podolsk.ru> wrote:
IMO this line wasn't arbitrary, it was (and it still is) a smallest possible network size allocated by RIRs. So it's just a common sense to receive everything down to /24 to have the complete data about all Internet participants.
Hi Andrey, Filtering routes longer than /24 route filtering came first and is the cause here while the RIR minimum assignment is an effect. The RIRs stay at /24 because it would be implicitly wasteful to assign addresses in units smaller than can be routed on the public Internet. Of the things that would have to change to make longer prefixes routeable on the Internet, the RIR policies are the easiest. The /24 boundary is simply a holdover from pre-CIDR times when the smallest routing unit was a "class C." Folks wanted to make sure CIDR didn't make their routing woes worse, so they filtered and it stuck. Regards, Bill Herrin -- For hire. https://bill.herrin.us/resume/