From owner-freebsd-security Mon Jun 12 18:42:49 2000 Delivered-To: freebsd-security@freebsd.org Received: from web210.mail.yahoo.com (web210.mail.yahoo.com [128.11.68.110]) by hub.freebsd.org (Postfix) with SMTP id EA99F37BCA6 for ; Mon, 12 Jun 2000 18:42:41 -0700 (PDT) (envelope-from hho321@yahoo.com) Received: (qmail 10943 invoked by uid 60001); 13 Jun 2000 01:42:37 -0000 Message-ID: <20000613014237.10942.qmail@web210.mail.yahoo.com> Received: from [207.172.11.148] by web210.mail.yahoo.com; Mon, 12 Jun 2000 18:42:37 PDT Date: Mon, 12 Jun 2000 18:42:37 -0700 (PDT) From: Hugh Ho Subject: IPFW rules for DNS? To: freebsd-security@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org I need to do nslookup quite often, and I have the following IPFW rules which allow nslookup to talk to my ISP's DNS server: allow udp from ${my_ip} to ${dns_server} 53 allow udp from ${dns_server} 53 to ${my_ip} Problem with the above rules is that people can pass IPFW if they use UDP port 53 with a spoofed IP that matches my ISP's DNS server. Is there a way to fix my problem? Thanks. -Hugh __________________________________________________ Do You Yahoo!? Yahoo! Photos -- now, 100 FREE prints! http://photos.yahoo.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message