Fwd: Re: Digital Island sponsors DoS attempt?

Sun Oct 28 23:20:48 UTC 2001

> > That way lies madness.  Senders have no such rights, and the
> > determination of a message's legitimacy lies with recipients (and
> > perhaps infrastructure owners) NOT senders.
> 
> How is the recipient of a message that has been blocked before he sees it to
> decide whether it was legitimate?

Why would you care, unless you are the receiver?  If I decide that all ICMP
traffic from IP addresses that have an odd number of "1" bits in it is not
legitimate and shall not be allowed to reach my web server, then that seems
to be a matter between me and my psychotherapist.  I'm not sure why it would
matter to anyone else, including rebuffed senders or NANOG's philosophers.

What this all begs for is a reference standard for "presumed legitimacy" so
that senders can know without waiting for complaints nor seeking explicit
permission, just what kind of traffic they ought or ought not send.  As I
said in another note here, such a standard would have to be written in terms
of assertions rather than negations.  A peering or transit agreement is quite
explicit since the parties and their specific concerns are known: it can
therefore be of the form "All is permitted except X, Y, and Z."  Presumptive
traffic legitimacy or "implicit welcome" is between unspecified parties who
can by definition have no specific concerns and so the standard must take the
form "All is prohibited, except A, B, and C."