"Frank Ellermann" <nobody(_at_)xyzzy(_dot_)claranet(_dot_)de> wrote:
Seth wrote:
The theory is that customers impacted by such a listing will apply
pressure on the provider to take action against the customer which
is the source of the abusive email.
Whose theory is that?
It's implied.
It's implied that there _is_ a theory.
If IPv4 aaa.bbb.ccc.ddd is the source of net abuse,
and a DNSBL recording it lists more than only this IPv4, then it
has a theory why listing aaa.bbb.ccc.* is better than say listing
*.bbb.ccc.ddd. And that theory might be wrong if it is based on
obsolete concepts of classes or assumptions about /24 ranges.
Maybe the theory is "IP addresses owned by entities that don't kick
off spammers are more likely to accumulate spammers than those owned
by entities that do kick off spammers. Therefore, since <company>
didn't kick off the spammer at aaa.bbb.ccc.ddd, its other addresses
are more likely to have spammers than most IP addresses (Bayes
Theorem)."
Such a DNSBL policy is highly controversial, and discussion of
its appropriateness is beyond the scope of this document.
So why bring it up in the first place?
Maybe an explanation why simply progressing from listing the IPv4,
then the /31, and so on, is an oversimplification and at some
point doomed, is better. With a note that "some point" can be
smaller or bigger than /24 depending on the IPv4.
Maybe we shouldn't get into claiming that some policies are better
than others, and only specify that the policy should be explicit and
followed.
"This DNSBL lists all IP addresses if the number of spam-emitting
IPs in their /24 exceeds 10." To anybody who can read, that
discloses whether it may include an IP address that didn't emit
spam.
That misses the point, when the assumption that all IPs in a /24
are administratively related, is dubious.
That assumption might not be correct. But it's irrelevant: it's the
policy stated, that's all. I think DNSBLs should be allowed to have
whatever policies they want. It's up to the user of the DNSBL to
decide whether it has policies he wants to apply.
Readers of a listing policy could arrive at arbitrary conclusions
based on the wrong assumption.
All anyone can do is tell the truth. People will draw arbitrary
incorrect conclusions from anything.
Seth
_______________________________________________
Asrg mailing list
Asrg(_at_)ietf(_dot_)org
https://www.ietf.org/mailman/listinfo/asrg