[159458] in North American Network Operators' Group
Re: [SHAME] Spam Rats
daemon@ATHENA.MIT.EDU (Tony Finch)
Fri Jan 11 07:32:41 2013
Date: Fri, 11 Jan 2013 12:32:30 +0000
From: Tony Finch <dot@dotat.at>
To: John Levine <johnl@iecc.com>
In-Reply-To: <20130110205725.90679.qmail@joyce.lan>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
John Levine <johnl@iecc.com> wrote:
> >*.4.4.3.0.5.a.0.0.8.b.d.0.1.0.0.2.ip6.arpa. PTR a.node.on.vlan344.namn.se.
> >...will work just fine, for instance.
>
> Since there is no AAAA record for a.node.on.vlan344.namn.se., this
> won't work fine in any rDNS check I'm aware of.
I believe it's relatively common for mail servers to just check the
existence of a PTR record without any further sanity checking, e.g.
Postfix's reject_unknown_reverse_client_hostname smtpd_client_restrictions
option.
Tony.
--
f.anthony.n.finch <dot@dotat.at> http://dotat.at/
Forties, Cromarty: East, veering southeast, 4 or 5, occasionally 6 at first.
Rough, becoming slight or moderate. Showers, rain at first. Moderate or good,
occasionally poor at first.
