Fighting the worms of mass destruction (Economist)

Fighting the worms of mass destruction (Economist)

IP address spoofing could be largely eliminated, if every router on the net were configured to perform a simple sanity check: don't let packets pass that have an "impossible" source address from the perspective of that router.

That is, if an ISP has sold you a range of static IP addresses, its routers should drop any packets from you that claim a return address outside that range. If everyone did this, spoofing would be much more limited.