From owner-freebsd-security Mon Jul 15 7:25:44 2002 Delivered-To: freebsd-security@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3039137B400 for ; Mon, 15 Jul 2002 07:25:40 -0700 (PDT) Received: from flood.ping.uio.no (flood.ping.uio.no [129.240.78.31]) by mx1.FreeBSD.org (Postfix) with ESMTP id BD60443E4A for ; Mon, 15 Jul 2002 07:25:39 -0700 (PDT) (envelope-from des@ofug.org) Received: by flood.ping.uio.no (Postfix, from userid 2602) id D11E1534A; Mon, 15 Jul 2002 16:25:37 +0200 (CEST) X-URL: http://www.ofug.org/~des/ X-Disclaimer: The views expressed in this message do not necessarily coincide with those of any organisation or company with which I am or have been affiliated. To: "Dmitry S. Rzhavin" Cc: security@FreeBSD.ORG Subject: Re: ipfw and keep-state References: <3D32D849.E3D8F2BE@rt.ru> From: Dag-Erling Smorgrav Date: 15 Jul 2002 16:25:36 +0200 In-Reply-To: <3D32D849.E3D8F2BE@rt.ru> Message-ID: Lines: 19 User-Agent: Gnus/5.0808 (Gnus v5.8.8) Emacs/21.2 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org "Dmitry S. Rzhavin" writes: > 10 pass tcp from any to ip2 in keep-state setup > ... nothing interesting here > 20 deny tcp from any to ip2 > > > Or, in other words, I want to pre-auth some packet with rile 10 to > check it later. Then, I decide to drop it. > But ipfw creates dynamic rule "inet <-> ip1" and passes this > session. I think this is not good. Why does ipfw works this way? That's what you asked it to do. Rule 10 basically says "if the packet is a tcp SYN packet destined for ip2, stop examining it, let it through, and remember to let all similar packets through in the future" DES -- Dag-Erling Smorgrav - des@ofug.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message