Importance of firewalling/fire suit There will be no NAT (NAT does not provide security, btw) Absense of NAT will promote p2p applications Packet filtering at the edge will become very difficult "Fire suit" instead of firewalling - OS vendors must take a security stance Extension header chain makes filtering difficult Need to dig deeper into packet to know the actual protocol being used DoS possibility if the IPv6 stack implemented without care (there's no upper limit to number of extension headers specwise) [IPv6, next=routing] [routing, next=TCP] [TCP] [TCP payload]