From owner-freebsd-questions@FreeBSD.ORG Tue Jun 10 04:08:46 2008 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 26E911065671 for ; Tue, 10 Jun 2008 04:08:46 +0000 (UTC) (envelope-from jeffrey@goldmark.org) Received: from out1.smtp.messagingengine.com (out1.smtp.messagingengine.com [66.111.4.25]) by mx1.freebsd.org (Postfix) with ESMTP id E93D18FC1D for ; Tue, 10 Jun 2008 04:08:45 +0000 (UTC) (envelope-from jeffrey@goldmark.org) Received: from compute2.internal (compute2.internal [10.202.2.42]) by out1.messagingengine.com (Postfix) with ESMTP id 40631111BD0; Tue, 10 Jun 2008 00:08:45 -0400 (EDT) Received: from heartbeat1.messagingengine.com ([10.202.2.160]) by compute2.internal (MEProxy); Tue, 10 Jun 2008 00:08:45 -0400 X-Sasl-enc: Z5upst6rTKzakbz9qZs1r9+P1pyXIvrqr4BcCi5uM9fI 1213070924 Received: from hagrid.ewd.goldmark.org (n114.ewd.goldmark.org [72.64.118.114]) by mail.messagingengine.com (Postfix) with ESMTPSA id C0FD5D09E; Tue, 10 Jun 2008 00:08:44 -0400 (EDT) Message-Id: <9145C6E6-4C2F-4DA3-B953-4A91DC4C476B@goldmark.org> From: Jeffrey Goldberg To: Jake Evans In-Reply-To: <20080609205426.N23640@awww.jeah.net> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v924) Date: Mon, 9 Jun 2008 23:08:43 -0500 References: <20080609205426.N23640@awww.jeah.net> X-Mailer: Apple Mail (2.924) Cc: freebsd-questions@freebsd.org Subject: Re: no reverse DNS causing connectivity problems 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: Tue, 10 Jun 2008 04:08:46 -0000 [mailed and posted] On Jun 9, 2008, at 8:57 PM, Jake Evans wrote: > I've had a few people complain that when they telnet/ssh/ftp/web to > our server, it's slow... I've traced the problem to them having no > reverse on their IPs. You should configure your servers to not do the reverse lookup. Not resolving is certainly the default for Apache. For sshd, set UseDNS to "no" in /etc/ssh/sshd_config. As for telnet and ftp, I don't know where that might be configured. Of course I don't know your needs and situation, but some people might consider it a reasonable policy to disallow ssh and telnet (and certainly mail) from hosts that don't have proper PTR records. -j -- Jeffrey Goldberg http://www.goldmark.org/jeff/