From owner-freebsd-chat Thu Nov 27 22:56:05 1997 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.7/8.8.7) id WAA25163 for chat-outgoing; Thu, 27 Nov 1997 22:56:05 -0800 (PST) (envelope-from owner-freebsd-chat@FreeBSD.ORG) Received: from detlev.UUCP (ppp42.wcc.net [208.6.232.42]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id WAA25137; Thu, 27 Nov 1997 22:55:44 -0800 (PST) (envelope-from detlev!joelh) Received: (from joelh@localhost) by detlev.UUCP (8.8.7/8.8.7) id AAA01094; Fri, 28 Nov 1997 00:54:16 -0600 (CST) (envelope-from joelh) Date: Fri, 28 Nov 1997 00:54:16 -0600 (CST) Message-Id: <199711280654.AAA01094@detlev.UUCP> To: grog@lemis.com CC: jkh@time.cdrom.com, jmb@FreeBSD.ORG, chat@hub.freebsd.org In-reply-to: <19971128164758.02274@lemis.com> (message from Greg Lehey on Fri, 28 Nov 1997 16:47:58 +1030) Subject: Re: major push by spammers? From: Joel Ray Holveck Reply-to: joelh@gnu.org References: <18154.880528164@time.cdrom.com> <199711280604.AAA00737@detlev.UUCP> <19971128164758.02274@lemis.com> Sender: owner-freebsd-chat@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org >>> 2 ways: The first, if reverse DNS lookup fails, accounts for about 90% >>> of the rejects. When I first started doing this, I worried that >> Now tell me, how does the reverse DNS lookup work? Does it perform a >> reverse DNS against the IP source vs. the line sent in EHLO, or what? > A reverse lookup takes the IP address and looks through the BIND > hierarchy for a corresponding PTR record (more specifically, for > address 192.109.197.137, it will look for a PTR record which matches > 137.197.109.192.in-addr.arpa). A lot of systems don't have their > reverse delegation set up correctly, so I suspect a number of innocent > people are also being rejected. Yes, but what IP address is it looking for? The one in the TCP header? -- Joel Ray Holveck - joelh@gnu.org - http://www.wp.com/piquan Fourth law of programming: Anything that can go wrong wi sendmail: segmentation violation - core dumped