From owner-freebsd-questions@FreeBSD.ORG Sat Mar 6 16:26:58 2010 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6F238106564A for ; Sat, 6 Mar 2010 16:26:58 +0000 (UTC) (envelope-from merlyn@stonehenge.com) Received: from blue.stonehenge.com (blue.stonehenge.com [209.223.236.162]) by mx1.freebsd.org (Postfix) with ESMTP id 5137E8FC0C for ; Sat, 6 Mar 2010 16:26:58 +0000 (UTC) Received: by blue.stonehenge.com (Postfix, from userid 1001) id 950F61DE3AF; Sat, 6 Mar 2010 08:26:27 -0800 (PST) To: Matthew Seaman References: <20100305185135.DD214106576C@hub.freebsd.org> <20100306172517.Q17960@sola.nimnet.asn.au> <4B922207.3090404@infracaninophile.co.uk> From: merlyn@stonehenge.com (Randal L. Schwartz) x-mayan-date: Long count = 12.19.17.2.19; tzolkin = 10 Cauac; haab = 17 Kayab Date: Sat, 06 Mar 2010 08:26:27 -0800 In-Reply-To: <4B922207.3090404@infracaninophile.co.uk> (Matthew Seaman's message of "Sat, 06 Mar 2010 09:36:07 +0000") Message-ID: <86y6i5xvpo.fsf@blue.stonehenge.com> User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.4 (berkeley-unix) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Ian Smith , freebsd-questions@freebsd.org Subject: Re: Thousands of ssh probes X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 06 Mar 2010 16:26:58 -0000 >>>>> "Matthew" == Matthew Seaman writes: Matthew> On the whole, I don't see the value in having a high-numbered MX to Matthew> dumbly accept, queue and forward messages like this. High-numbered MX came from a time where an internal machine could only be delivered from outside via an external gateway. If you want to deliver to internal.example.com, you tried its lowest MX first, and failing to connect, you fall back to the next MX, external.example.com. The idea is that external.example.com would then be able to see the next hop, and forward the mail. The modern recommendation is to avoid MX altogether, and rely on split-horizon DNS and SMTP delivery reattempts. But a lot of people are still stuck in the old ways. -- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion