Source address validation (was Re: UUNet Offer New Protection

E.B. Dreger eddy+public+spam at noc.everquick.net
Mon Mar 8 01:22:00 UTC 2004


SD> Date: Sun, 7 Mar 2004 17:47:09 -0500 (EST)
SD> From: Sean Donelan


SD> In practice, GWF's ... send reports about packets which have
SD> our IP addresses, but didn't originate here.  The last thing

Probably because someone else failed to implement SAV.  If
$origin_net prevented spoofing your IP space, you'd not have had
the problem.

If other networks prevented spoofed sources, nobody else could
source a packet from your address space.  In this case, a packet
apparently sourced from you network definitely would have come
from your network.  Therefore you'd no longer need to check to
see if a packet was spoofed.

Notice how AS_PATHs and netblock announcements tend to get
filter.  Why?


SD> you want to admit is you do SAV because GWF think SAV means
SD> every packet with that source address must have originated
SD> here.

Uh, no... a spoofed packet from someone else's network means you
had no control over it.  That's pretty obvious.


Eddy
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