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

Tue Oct 8 16:41:56 UTC 2002

On Tue, 8 Oct 2002, Jared Mauch wrote:
> 	install this on all your internal, upstream, downstream
> interfaces (cisco router) [cef required]:
>
> "ip verify unicast source reachable-via any"
>
> 	This will drop all packets on the interface that do not
> have a way to return them in your routing table.

Once again, which providers do this?

If c.root-servers.net provider did this, they wouldn't see any RFC1918
traffic because it would be dropped at their provider's border routers.
If c.root-servers.net provider's peer did this, again c.root-servers.net
provider wouldn't see the rfc1918 packets.

So why doesn't c.root-servers.net provider or its peers implement this
"simple" solution?  Its not a rhetorical question.  If it was so simple,
I assume they would have done it already.  PSI wrote one of the original
peering agreements that almost everyone else copied.  If it was a
concern, I imagine PSI could have included the requirement,  most of
their peers would have signed it 10 years ago.  But they didn't.

Does AT&T? Yes
Does UUNET? ?
Does Cable & Wireless? ?
Does Level 3? ?
Does Qwest? ?
Does Genuity? ?
Does Sprint? ?