As to whether ISP's should install firewalls at every external Internet connection, I think the question would be more appropriately phrased as: Should ISP's have policy enforcement mechanisms at every gateway? The answer to this is "Yes". Much of the problem that exists right now can be attributed to the fact that ISP's and enterprise networks do not have *any* way of enforcing policy between any of the devices on their network, their customers, or anyone elses. Maybe a nice web based interface for customers to alter filters applied by a radius profile for the ISP interface they are connected to would be a start. On Sun, 20 Oct 2002, Sean Donelan wrote: :What may be more interesting to NANOG is what should be the model Internet :security architecture for public network operators? How do you define a :security perimeter? Should ISPs install firewalls at every external :Internet connection? Is there a different between carrier-grade security :and enterprise-grade network security requirements? : :Is the Orange Book really dead? : -- batz