From owner-freebsd-security Mon Jul 27 01:07:19 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id BAA27237 for freebsd-security-outgoing; Mon, 27 Jul 1998 01:07:19 -0700 (PDT) (envelope-from owner-freebsd-security@FreeBSD.ORG) Received: from ns0.fast.net.uk (ns0.fast.net.uk [194.207.104.1]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id BAA27222 for ; Mon, 27 Jul 1998 01:07:14 -0700 (PDT) (envelope-from netadmin@fastnet.co.uk) Received: from bofh.fast.net.uk (bofh.fast.net.uk [194.207.104.22]) by ns0.fast.net.uk (8.9.0/8.8.7) with ESMTP id JAA16446; Mon, 27 Jul 1998 09:06:44 +0100 (BST) Received: from localhost (localhost [127.0.0.1]) by bofh.fast.net.uk (8.8.8/8.8.5) with SMTP id JAA11139; Mon, 27 Jul 1998 09:06:45 +0100 (BST) Date: Mon, 27 Jul 1998 09:06:45 +0100 (BST) From: Jay Tribick X-Sender: netadmin@bofh.fast.net.uk To: Jesse cc: freebsd-security@FreeBSD.ORG Subject: Re: ipfw rules to allow DNS activity In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org | I'm thinking of changing one of my boxes which is running bind (performing | primary secondary DNS functions) from | allow-anything-except-things-specifically-denied ipfw rules to | deny-everything-except-things-specifically-allowed rules (open vs closed? | hehe). Anyway, I was wondering what are the minimum rules necessary to | allow DNS queries/transfers from other servers to my server, and also to | allow queries from my server to other servers. | | I tried a variety of rules from the rc.firewall file, but it's still | blocking some traffic, so there must be something I'm missing. AFAIR you should just be able to explicitly allow data from port 53 (udp & tcp) to pass through. i.e ipfw add 0 deny ip from any to ip.ip.ip.ip:255.255.255.255 ipfw add 1 allow tcp from any to ip.ip.ip.ip:255.255.255.255 53 ipfw add 1 allow udp from any to ip.ip.ip.ip:255.255.255.255 53 (Don't quote me on the above.. I don't tend to use ipfw and there's probably a better way of defining the above rules, for example, you may not want to deny packets but simly drop/reject them - depends how much info. you want to give out to script kiddies ;) Regards, Jay Tribick -- [| Network Administrator | FastNet International | http://fast.net.uk/ |] [| Finger netadmin@fastnet.co.uk for contact information |] [| T: +44 (0)1273 677633 F: +44 (0)1273 621631 e: netadmin@fast.net.uk |] To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe security" in the body of the message