Re: Who does source address validation? (was Re: what's that smell?)

In addition to the bandwidth savings, there is also a support cost reduction and together, I believe backbone providers can see this on the bottom line of their balance sheets.

If the backbone providers bill their customers for traffic, then filtering out those packets would let them bill less. Since their costs are fixed, and the amount of billable traffic decreases, the break-even price per meg goes up, not down. They wont filter up until it would be more expensive not to filter. Alex