From owner-freebsd-questions@FreeBSD.ORG Thu Oct 7 19:16:08 2004 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 D681516A4CE for ; Thu, 7 Oct 2004 19:16:08 +0000 (GMT) Received: from advmail.lsn.net (advmail.lsn.net [66.90.138.148]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7712543D31 for ; Thu, 7 Oct 2004 19:16:06 +0000 (GMT) (envelope-from norm@etherealconsulting.com) Received: from [127.0.0.1] (24-155-40-125.ip.grandenetworks.net [24.155.40.125]) by advmail.lsn.net (8.12.8/8.12.4) with ESMTP id i97JG90A021382 for ; Thu, 7 Oct 2004 14:16:10 -0500 Message-ID: <416595F3.1030601@etherealconsulting.com> Date: Thu, 07 Oct 2004 14:16:03 -0500 From: Norm Vilmer User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.3) Gecko/20040910 X-Accept-Language: en-us, en MIME-Version: 1.0 To: freebsd-questions@freebsd.org Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-AntiVirus: checked by Vexira Milter 1.0.6; VAE 6.28.0.3; VDF 6.28.0.7 Subject: nmap'ing myself 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: Thu, 07 Oct 2004 19:16:09 -0000 If there a better forum for discussing IPFW, please direct me there. I have a firewall machine running FreeBSD 4.10 connected between my DSL modem and my office switch. It does nat and has a basic set of IPFW rules. It is somewhat locked down (kern_securelevel = 1, other recommendations typical for this configuration). My question is: from a "well" configured firewall, "Should" I be able to nmap the public interface using a console session on the firewall itself? Will allowing this compromising security of the machine? Basically, should I even attempt to make this work? What's a good way to test your own firewall without driving down the road (and hacking into an unsecured linksys wireless router.... just kidding)? Additional info: I am still reading "Network Security Hacks" by Andrew Lockhart; not sure if this is covered..... nmap -v -O -sS my.firewall.com .... sendto in send_ip_raw: sendto(4, packet, 28, 0, n.n.n.n, 16) => Permission denied. I can nmap to other machine inside and outside my firewall. Machines inside my firewall can nmap machines inside(duh) and outside the firewall. Although doing an nmap from a machine inside my firewall to a machine outside causes the net.inet.ip.fw.dyn_count to grow rather large so I avoid doing this. Same thing if I try to nmap my firewall from a machine inside the firewall. Tried opening up the firewall, still does not work (slightly different error though).