From owner-freebsd-questions Fri Apr 5 10:15:47 2002 Delivered-To: freebsd-questions@freebsd.org Received: from tninet.se (lennier.tninet.se [195.100.94.105]) by hub.freebsd.org (Postfix) with ESMTP id 0E6EB37B417 for ; Fri, 5 Apr 2002 10:15:40 -0800 (PST) Received: from cs.umu.se (h16n1c1o1023.bredband.skanova.com [213.64.164.16]) by lennier.tninet.se (BMR ErlangTM/OTP 3.0) with ESMTP id 988674.30534.1018.1s19292339lennier ; Fri, 05 Apr 2002 20:15:34 +0200 Message-ID: <3CADE9C7.4EA2A22D@cs.umu.se> Date: Fri, 05 Apr 2002 20:15:35 +0200 From: Paul Everlund X-Mailer: Mozilla 4.77 [en] (Windows NT 5.0; U) X-Accept-Language: sv,en MIME-Version: 1.0 To: Marc Hunter Cc: freebsd-questions@FreeBSD.ORG Subject: Re: Newbie: Telnet and FTP reverse DNS References: <4.2.0.58.20020405095217.00c912f0@192.168.0.64> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Marc Hunter wrote: > > I am continually plagued by somewhat random delays due to reverse lookup > issues with the standard FreeBSD telnet and ftp (sometimes the ISP DNS > returns promptly, sometimes it does the timeout thing...). Every answer I > can fine online to this question seems to be: Set up a DNS or tweak your > hosts file. I'm not interested in running a DNS, and it's a pain to > maintain the hosts file... > > So my question is: Why does FTP and Telnet go through this whole > rigamarole? It seems to me (in my ignorance) to be redundant and > unnecessary seeing as it lets me in whether it succeeds or > fails.... Shouldn't this just be disabled? Or at very least, shouldn't > there be an easy configuration option to disable it? Maybe there is and I > just can't find it? I'm not 100% sure, but it probably makes this check to come up with a match in /etc/hosts.allow, as inetd uses TCP-wrappers (the -w -W switches). As this file contains a default to allow all in, it works even if your reverse DNS lookup fails. If you on the other hand make changes this file I'm not sure you're able to connect if the reverse DNS lookup fails. As I stated first, I'm not 100% sure about this. Best regards, Paul To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message