RE: reverse DNS; RE: [Asrg] RMX proposals and Nash Equilibrium
"Eric D. Williams" <eric@infobro.com> Tue, 06 May 2003 01:03 UTC
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From: "Eric D. Williams" <eric@infobro.com>
To: 'Bob Atkinson' <bobatk@Exchange.Microsoft.com>, Daniel Feenberg <feenberg@nber.org>, "asrg@ietf.org" <asrg@ietf.org>
Subject: RE: reverse DNS; RE: [Asrg] RMX proposals and Nash Equilibrium
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Date: Mon, 05 May 2003 19:32:29 -0400
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I think we concur fully (e.g. incremental). -e On Monday, May 05, 2003 6:19 PM, Bob Atkinson [SMTP:bobatk@Exchange.Microsoft.com] wrote: > Reverse DNS has two quite important situations in which it does not > easily (if ever) give appropriate answers for use in spam deterrence. > > 1) If I host my own DNS servers, and have no DNS relationship with my > ISP, then (typically, if not mostly) the rDNS lookup will ultimately go > to him but have no means by which it can connect to my DNS servers and > thus give a meaningful response. As a result, the rDNS lookup yields > answers like > > dsl-209-123-212-68.myisp.com > > rather than something related to the email domains that I actually send > from. > > 2) If, for one of possibly many reasons, I legitimately relay my > outbound mail through some other domain, then it becomes > administratively very cumbersome (if not logistically impossible, > pragmatically speaking) to have the rDNS lookup resolve to something in > my domain (in addition to the one through which I am relaying, and all > the others he relays for). > > RMX-style proposals, which start their lookup at the domain purportedly > responsible for a message, don't suffer from these shortcomings. > (indeed, they can nicely leverage the existing administrative > infrastructure that I necessarily have to mange my MX records). This is > an important advantage. > > Ultimately, these approaches yield the same information, namely an > answer to the question: "is this IP address authorized by the admin of > this domain to transmit mail on behalf of that domain". While the > spoofing that this prevents is VERY interesting and useful, it is, in > and of itself, of course not something that will eliminate spam. > Additional infrastructure is needed above and beyond RMX. > > Bob > > > -----Original Message----- > From: asrg-admin@ietf.org [mailto:asrg-admin@ietf.org] On Behalf Of Eric > D. Williams > Sent: Saturday, May 03, 2003 6:16 PM > To: 'Daniel Feenberg'; asrg@ietf.org > Subject: RE: [Asrg] RMX proposals and Nash Equilibrium > > All of these are valid points to argue, but without addressing a > fundemental > point (not described in most) RMX proposals from my understanding. That > is, > DNS can also be used to validate an IP reverse map so that not only the > domain > is checked but also the IP. In that case, IMHO, one could argue that an > > additional check for IP origination or relay of delivery would mitigate > the > concerns. > > I could definitely be wrong but that always sticks out to me as a > mis-understanding of that type of proposed solution/strategy. I don't > think > the forwarder of mail has to be penalized for forwarding if they are > properly > registered in the forwarding path (open-relays are another matter in my > opinion) and are no longer used in the historical context (helping a > brother/sister system out). _______________________________________________ Asrg mailing list Asrg@ietf.org https://www1.ietf.org/mailman/listinfo/asrg
- reverse DNS; RE: [Asrg] RMX proposals and Nash Eq… Bob Atkinson
- RE: reverse DNS; RE: [Asrg] RMX proposals and Nas… Eric D. Williams