There is another mitigation: everyone here should commit to filtering
customer packets at the customer premesis router (or at the dial in for
PPP/SLIP) such that it is not possible for a customer to send a packet into
the network that has an IP source address on it that is not assigned to
that customer. That is, no more lying about source addresses.Every time I show a customer of mine how to configure a router, I
try to educate them on this. We need some kind of massive marketing
effort to get this out to people though. People would do it, but nobody
knows about it.
Why not include it as part of "their" contractual obligations by placing
it in the text of the contract as well as by including an instructional
whitepaper. You can't really enforce it but at least you get the coverage
you want. Besides, if the customer is as clueless as most (and I say that
in a benign way) they may not know that you can't or wouldn't really enforce
it.