Why won't providers source-filter attacks? Simple.

[randy at psg.com (Randy Bush)]

> No, you write a law requiring something, e.g. BCP 38 filtering by
> ISPs, and you audit it.  You also make the ISPs directors liable
> for the impact that results from spoofed traffic from them.
> 
> Making it law puts all the ISP's in the country on a equal footing
> with respect to implementation costs.

you have done this in your network, the isp for which you are an
engineer?

randy