From owner-freebsd-ipfw@freebsd.org Mon Aug 1 05:22:28 2016 Return-Path: Delivered-To: freebsd-ipfw@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id AA5C5BABF61 for ; Mon, 1 Aug 2016 05:22:28 +0000 (UTC) (envelope-from julian@freebsd.org) Received: from vps1.elischer.org (vps1.elischer.org [204.109.63.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "vps1.elischer.org", Issuer "CA Cert Signing Authority" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 8312713BB for ; Mon, 1 Aug 2016 05:22:28 +0000 (UTC) (envelope-from julian@freebsd.org) Received: from Julian-MBP3.local (ppp121-45-226-8.lns20.per1.internode.on.net [121.45.226.8]) (authenticated bits=0) by vps1.elischer.org (8.15.2/8.15.2) with ESMTPSA id u715MN6W094317 (version=TLSv1.2 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Sun, 31 Jul 2016 22:22:26 -0700 (PDT) (envelope-from julian@freebsd.org) Subject: Re: ipfw divert filter for IPv4 geo-blocking To: "Dr. Rolf Jansen" , freebsd-ipfw@freebsd.org References: <61DFB3E2-6E34-4EEA-8AC6-70094CEACA72@cyclaero.com> <4D047727-F7D0-4BEE-BD42-2501F44C9550@obsigna.com> <9641D08A-0501-4AA2-9DF6-D5AFE6CB2975@obsigna.com> <4d76a492-17ae-cbff-f92f-5bbbb1339aad@freebsd.org> <677900fb-c717-743f-fcfe-86b603466e33@freebsd.org> <0D3C9016-7A4A-46BA-B35F-3844D07562A8@obsigna.com> <1E1DB7E0-D354-4D7A-B657-0ECF94C12CE0@obsigna.com> <50d405a4-3f8f-a706-9cac-d1162925e56a@freebsd.org> <9222BB10-C700-4DE7-83A3-BE7A38A11713@obsigna.com> <1B36CAD7-A139-436B-B7EC-0FFF232F9C6A@obsigna.com> From: Julian Elischer Message-ID: Date: Mon, 1 Aug 2016 13:22:17 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <1B36CAD7-A139-436B-B7EC-0FFF232F9C6A@obsigna.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-ipfw@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: IPFW Technical Discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 01 Aug 2016 05:22:28 -0000 On 30/07/2016 10:17 PM, Dr. Rolf Jansen wrote: > > I am still a little bit amazed how ipfw come to accept incorrect CIDR ranges and arbitrarily moves the start/end addresses in order to achieve CIDR conformity, and that without any further notice, and that given that ipfw can be considered as being quite relevant to system security. Or, may I assume that ipfw knows always better than the user what should be allowed or denied. Otherwise, perhaps I am the only one ever who input incorrect CIDR ranges for processing by ipfw. it's not so amazing when you think about it. The code comes from the routing table.. In this context a.b.c.d/N means "the range of addresses containing a.b.c.d, masked to a length of N". there is no specification that a.b.c.d is the first address of the range. I have relied upon this behaviour many times. > > Best regards > > Rolf > > _______________________________________________ > freebsd-ipfw@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-ipfw > To unsubscribe, send any mail to "freebsd-ipfw-unsubscribe@freebsd.org" >