Joe Provo wrote:

Any policing effort will require co-ordination and to be stated publicly (here and elsewhere) that it is a Good Thing. ... A direct cookbook provided and lots of folks will still think you are asking too much of them.

Some of the networks this would help may be skittish of testing the concept themselves. And no Tier-2 operator would want to be perceived as making a cheap "hack", or of using a non-standard routing policy. Documenting the practice (e.g. "RFCxxxx: filtering BGP route tables using RIR allocations") would help the network operator answer customer inquiries (and auditors' questions). The approach could create a different kind of Tier-1/Tier-2 structure: default-free networks and "default-enabled networks" ;) . A default-enabled network, which lets its customers advertise long prefixes out of its own allocations to other ISPs, would need to purchase transit from default-free ISPs, or else coordinate holes in the filters with their default-enabled upstream. Default-enabled Tier-2's would need to be clear about this limitation when selling transit to a BGP-speaking customer; and would be unable to use other default-enabled ISPs as "carrier of last resort". -Bradley Urberg-Carlson