[Discuss] anti-spam.

[Alan W. Irwin]

On 2006-05-26 09:54-0700 pw wrote:

> Most home systems are DHCP addresses from a providers block.
> All the box needs to do is request a new lease with a different
> address each time it sends bunch of spam.

By having a quick look at the DHCP-related man pages, I cannot confirm or
deny your assumption that dhcp clients can request a large variety of
specific IP addresses from a DHCP server.  The shoe is normally on the other
foot; users want consistent IP addresses if at all possible.  For this
reason, my IP address changes roughly once a year with Shaw.  In any case
even if your assumption is true, I believe constant requests for IP address
changes would immediately identify my box to the ISP as a spam server. Of
course, there are presumably malevolent ISP's that grant such spam server
requests for many IP address changes, but then I would think such ISP's
would get blacklisted as a whole.

Thus, I still cannot see how spammers could effectively use fixed spam
servers.  Thus, we are back to the model of spammers generally needing to
gain outside control of user-owned boxes to turn them into temporary spam
servers, and that is why it should be emphasized that the the best long-term
strategy against spam is to encourage user-adoption of OS's that have the
largest resistance to such outside takeover attempts.

>
> There is also drive-by spam where the 'perp' uses some hapless
> users home wireless router as a gateway outgoing mail DHCP lease
> or through some, newly enthralled, redhat users open relay somewhere
> beyond that router.
>

Sounds possible, but I doubt this is the principal source of spam (unless
every other car you see on the road is one of these guys looking for
victims).


> This is probably why blacklisting doesn't work so well.
> Especially on Shaw where every once in a while you can't
> send email.

That's a different issue which I mentioned previously in this thread. One of
the usual black-list rules is no "temporary" IP addresses can be used for
SMTP servers, but apparently those lists of what are temporary IP addresses
and what are not are badly maintained. For example, whenever I follow up on
problems where Shaw cannot send e-mail, it always turns out that Shaw's SMTP
server IP address had been misclassified as a temporary IP address by the
black-listers.

>
> I suggest that everyone redirect thier viagra mail to
> Glaxo-Smith-Klein or whoever manufactures it, since they
> benefit from those sales. A kind of viagra internet tax
> on the drug companies after the fact

Sounds like a good strategy as well. :-)

Alan
__________________________
Alan W. Irwin

Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).

Programming affiliations with the FreeEOS equation-of-state implementation
for stellar interiors (freeeos.sf.net); PLplot scientific plotting software
package (plplot.org); the Yorick front-end to PLplot (yplot.sf.net); the
Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project
(lbproject.sf.net).
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Linux-powered Science
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