Date: Fri, 28 Nov 1997 00:54:16 -0600 (CST) From: Joel Ray Holveck <joelh@gnu.org> To: grog@lemis.com Cc: jkh@time.cdrom.com, jmb@FreeBSD.ORG, chat@hub.freebsd.org Subject: Re: major push by spammers? Message-ID: <199711280654.AAA01094@detlev.UUCP> In-Reply-To: <19971128164758.02274@lemis.com> (message from Greg Lehey on Fri, 28 Nov 1997 16:47:58 %2B1030) References: <18154.880528164@time.cdrom.com> <199711280604.AAA00737@detlev.UUCP> <19971128164758.02274@lemis.com>
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>>> 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
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