From owner-freebsd-questions@FreeBSD.ORG Thu Dec 4 16:24:14 2003 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 4E55E16A4CE for ; Thu, 4 Dec 2003 16:24:14 -0800 (PST) Received: from munk.nu (mail.munk.nu [213.152.51.194]) by mx1.FreeBSD.org (Postfix) with ESMTP id 659AB43F93 for ; Thu, 4 Dec 2003 16:24:13 -0800 (PST) (envelope-from munk@munk.nu) Received: from munk by munk.nu with local (Exim 4.24; FreeBSD) id 1AS3lU-000ACt-9a for freebsd-questions@freebsd.org; Fri, 05 Dec 2003 00:24:12 +0000 Date: Fri, 5 Dec 2003 00:24:12 +0000 From: Jez Hancock To: FreeBSD Questions List Message-ID: <20031205002412.GA37507@users.munk.nu> Mail-Followup-To: FreeBSD Questions List Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.1i Sender: User Munk Subject: ipfilter traffic blocking and tcpdump snort etc X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 05 Dec 2003 00:24:14 -0000 Hi, I've blocked a dozen or so addresses using ipfilter: block in quick on fxp0 from 208.186.60.116 to any block in quick on fxp0 from 216.230.149.11 to any etc but I still see a lot of traffic those hosts in trafshow, snort and other packet capturing utils. Why is this? Is there any alternative method of blocking access from certain hosts so that this traffic is not 'seen' by higher level /userland apps? As background, the blocked hosts were part of a denial of service attack which has been going on for a few hours now. The attack was aimed at port 80, although an odd artifact is that no httpd log entries were made for any of the hosts attempting to connect on port 80. A cursory nmap scan of a few of the hosts shows that all hosts had both port 25 and 80 open, but none of the hosts accepted connections on either of those ports. Any idea what kind of attack this could be? -- Jez Hancock - System Administrator / PHP Developer http://munk.nu/