[166227] in North American Network Operators' Group
Re: comcast ipv6 PTR
daemon@ATHENA.MIT.EDU (Lee Howard)
Mon Oct 14 19:28:23 2013
Date: Tue, 15 Oct 2013 02:28:16 +0300
From: Lee Howard <Lee@asgard.org>
To: Barry Shein <bzs@world.std.com>, Chris Adams <cma@cmadams.net>
In-Reply-To: <21078.13971.505553.140013@world.std.com>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On 10/10/13 1:09 AM, "Barry Shein" <bzs@world.std.com> wrote:
>
>On October 9, 2013 at 20:18 cma@cmadams.net (Chris Adams) wrote:
> > Once upon a time, Barry Shein <bzs@world.std.com> said:
> > > It's very useful for blocking spammers and other miscreants -- no
> > > reason at all to accept SMTP connections from troublesome
> > > *.rev.domain.net at all, no matter what the preceding NNN-NNN-NNN-NNN
> > > is.
> >
> > If you are going to block like that, just block anybody without valid
> > reverse DNS. If you don't trust provider foo.net to police their
>users,
> > why trust them to put valid and consistent xx-xx-xx-xx.dyn.foo.net
> > reverse?
>
>Because they do, they just do. This isn't a math proof, it's mostly
>social engineering. The providers aren't trying to fool anyone, in
>general, it's just that clients and websites get botted.
Except the point of this thread is that they don't.
Is it easier to block inbound mail from hosts with certain high-level
domain
names in their PTRs than to block ranges of IP(v6) addresses? Easier for
whom?
Lee
