Implementing anti-abuse techniques on ISP networks....

Greg A. Woods woods at
Wed Aug 6 22:48:06 UTC 1997

[ On Wed, August 6, 1997 at 18:01:36 (-0400), Christopher Masto wrote: ]
> Subject: Re: Implementing anti-abuse techniques on ISP networks....
> I don't know about the "huge players", but we're an Internet Service
> Provider, not an Internet Blockage Provider.  We don't allow spoofing,
> and we don't allow relaying, but we're not about to put filters
> to prevent dialup customers from connecting wherever they want.

This is one of those more-or-less political answers that I was hoping
not to see on the NANOG list!  ;-)

In any case it does give me a bit of an opportunity to define more
clearly what I meant by "huge players", which I should have done in the
first place.

The primary benefit to the world at large from filtering dial-up access
to arbitrary SMTP ports will be from those ISPs who have either weak
AUPs (in this respect); or who offer low-cost initiation accounts with
easily, or nearly, anonymous quick, or automatic, registration; or both.

If you have a strong AUP and you let your users know you will enforce
it, and if you can find some happy balance between making it easy for
new users to open accounts and ensuring you have enough of a fix on
them that you can track them down should they violate your AUP, then I
would agree that there's no need for you to filter your customer's
ability to make legitimate connections wherever they want.

However if you're one of those "huge players" that has a black-hole
abuse mailbox (or even one that only results in account cancellation
long past when there's any benefit to taking such action) and invites
new users to sign up for the first month for some tiny amount of money
paid with the mere presentation of a vaild credit card then I *really*
want you to think very seriously about the business benefits of such
filtering vs. the minor operational annoyance of implementing these

Note that if you do have a strong AUP that effectively tells your
customers that they must use your e-mail gateway and only your e-mail
gateway, then are not such filters merely a good strong technological
way to enforce that part of your AUP with full and equal fairness to
all?  ;-)

BTW, I have it on good word that <isp-mail-filter at>
would be a good place to discuss some of the non-operational aspects of
this issue.....  I've Cc'd this message there in hopes of striking up
that discussion over there and in hopes of avoiding further
non-operations related discussion on the NANOG list!  ;-)

[[ I can forward copies of my original post to isp-mail-filter too if
that's desired.... ]]

							Greg A. Woods

+1 416 443-1734      VE3TCP      <gwoods at>      <robohack!woods>
Planix, Inc. <woods at>; Secrets of the Weird <woods at>

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