the concept of what IP addresses "can't come from that segment" falls apart when you get into
the core of the Internet where dynamic routing (via BGP) is used. the dynamic routing is
designed so that it can send anyone's traffic anywhere if that's the best way for it to get
there.
Posted Aug 22, 2008 9:07 UTC (Fri) by paulj (subscriber, #341)
[Link]
That's a deficiency in BGP though, or at least a mark of it being designed in days when the internet was a smaller place. It's something which people are trying to address in various ways.