From owner-freebsd-security Sun Jun 13 13:29: 4 1999 Delivered-To: freebsd-security@freebsd.org Received: from trooper.velocet.ca (trooper.velocet.net [209.167.225.226]) by hub.freebsd.org (Postfix) with ESMTP id 4DD1214EB1 for ; Sun, 13 Jun 1999 13:29:00 -0700 (PDT) (envelope-from dgilbert@trooper.velocet.ca) Received: (from dgilbert@localhost) by trooper.velocet.ca (8.8.7/8.8.7) id QAA27002; Sun, 13 Jun 1999 16:28:52 -0400 (EDT) From: David Gilbert MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <14180.5252.211630.750974@trooper.velocet.ca> Date: Sun, 13 Jun 1999 16:28:52 -0400 (EDT) To: Jay Nelson Cc: "Ed P." , security@FreeBSD.ORG Subject: Re: Fwd: [linux-security] Re: Port 7 scan In-Reply-To: References: <99061312495500.02641@MOLTEN.R0CK.COM> X-Mailer: VM 6.71 under 20.4 "Emerald" XEmacs Lucid Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org >>>>> "Jay" == Jay Nelson writes: Jay> This explains what is going on. Thank you. It does, though, raise Jay> a couple of other questions: Jay> The echo service is, AFIK, a peculiarly Unix service. Why do you Jay> suppose they chose echo for the latency test as opposed to a Jay> simple ping? Nearly everything with an ethernet card will respond Jay> to a ping returning, I would think, more useful latency Jay> information than a refused connect. Jay> Since echo is Unixcentric and most new admins leave echo open, Jay> echo will reveal far more about a machine than a ping. Could it Jay> be that this is the intent? Actually, this is probably caused by a desire to subvert an 'optimization' made at major routers on the net. In general, most busy routers 'de-prioritize' ping traffic. This is largely due to the face that the worse the network gets, the higher the amount of ping traffic (coming from people who wonder why it's slow). So the latency from a ping connection isn't as accurate as trying to open a tcp connection. Dave. -- ============================================================================ |David Gilbert, Velocet Communications. | Two things can only be | |Mail: dgilbert@velocet.net | equal if and only if they | |http://www.velocet.net/~dgilbert | are precisely opposite. | =========================================================GLO================ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message