From owner-freebsd-questions@FreeBSD.ORG Mon Jun 11 03:16:18 2012 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 421B4106564A for ; Mon, 11 Jun 2012 03:16:18 +0000 (UTC) (envelope-from bycn82@gmail.com) Received: from mail-vb0-f54.google.com (mail-vb0-f54.google.com [209.85.212.54]) by mx1.freebsd.org (Postfix) with ESMTP id EB61E8FC0C for ; Mon, 11 Jun 2012 03:16:17 +0000 (UTC) Received: by vbmv11 with SMTP id v11so2362858vbm.13 for ; Sun, 10 Jun 2012 20:16:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=6vpthSQN5kf6VvIKDEe/WQrWvkN/szl0uoezJqeGLFI=; b=S6c2pNlZ/0zBHLq7ML/egQFBgorIDhpKB8MvsiGR5MHHWilGN+b9uQGBoxJszznKOB 8Cykeo/OqTA2N+Q0FsWJ6NKMx2gdg7ztZS9loGA22yymga3VmzyJCFmLmr6UY9muOcTx B6YgEbE8XnCWO+7pR1jWkiTDafV4RRoA+iBixQP+76SkoPiVmiHczfK3VvCvLfbZZum8 0knoXbz9YNybAOY1eWbLF2ouHgin9yfYWUkhyylGvnOKg2mFcm5CLE4OjwTPKQdURKEM dDl8B4KIozRNqfqmdXhIvNfhEXY+CYbCxepAKCIL1mTUiyQ9ssCT6sPbYWeGxR1ztMHu cIrg== MIME-Version: 1.0 Received: by 10.52.65.80 with SMTP id v16mr10139807vds.9.1339384577268; Sun, 10 Jun 2012 20:16:17 -0700 (PDT) Received: by 10.220.214.70 with HTTP; Sun, 10 Jun 2012 20:16:17 -0700 (PDT) In-Reply-To: <20120611025332.N46641@sola.nimnet.asn.au> References: <20120610120041.4D0F610657C3@hub.freebsd.org> <20120611025332.N46641@sola.nimnet.asn.au> Date: Mon, 11 Jun 2012 11:16:17 +0800 Message-ID: From: Bill Yuan To: Ian Smith Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-questions@freebsd.org Subject: Re: how to allow by MAC X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 11 Jun 2012 03:16:18 -0000 Hi Lan, Thanks for your reply, I am reading some old emails which you sent in 2008 while other place asked a same question as mine, On Mon, Jun 11, 2012 at 1:53 AM, Ian Smith wrote: > In freebsd-questions Digest, Vol 418, Issue 18, Message: 1 > On Sun, 10 Jun 2012 17:43:39 +0800 Bill Yuan wrote: > > > how to allow by MAC in ipfw > > > > currently i set the rule like below > > > > 1 allow ip from any to any MAC any to > > 1 allow ip from any to any MAC any > > 2 deny all from any to any > > > > i want to only allow the mac address to go through the freebsd firewall, > > > > but I found it is not working on my freebsd but it works on pfsense! > > > > so maybe that means the environment is not the same ? and how to setup > the > > ipfw properly to support this ? > > Bill, you did get some good clues in the earlier thread, but it's not > clear if you took note of them. There's also been some confusion .. > > Firstly, read up on layer2 (ethernet, MAC-level) filtering options in > ipfw(8). Thoroughly, several times, until you've got it. Seriously. > > After enabling sysctl net.link.ether.ipfw=1 (add it to /etc/sysctl.conf) > ipfw will be invoked 4 times instead of the normal 2, on every packet. > > Read carefully ipfw(8) section 'PACKET FLOW', and see that only on the > inbound pass invoked from ether_demux() and the outbound pass invoked > from ether_output_frame() can you test for MAC addresses (or mac-types); > the 'normal' layer3 passes examine packets that have no layer2 headers. > > You could just add 'layer2' to any rules filtering on MAC addresses, and > omit MAC addresses from all layer 3 (IP) rules, but I'd recommend using > a method like shown there to separate layer2 and layer3 flows early on: > > # packets from ether_demux > ipfw add 10 skipto 1000 all from any to any layer2 in > # packets from ip_input > ipfw add 10 skipto 2000 all from any to any not layer2 in > # packets from ip_output > ipfw add 10 skipto 3000 all from any to any not layer2 out > # packets from ether_output_frame > ipfw add 10 skipto 4000 all from any to any layer2 out > > So at (eg) 1000 and 4000 place your incoming and outgoing MAC filtering > rules (remembering the reversed order of MAC addresses vs IP addresses, > and to allow broadcasts as well), pass good guys and/or block bad guys, > then deal with your normal IPv4|v6 traffic in a separate section(s). > > Or you could just split the flows into two streams, one for layer2 for > your MAC filtering, the other for layer3, ie the rest of your ruleset. > > HTH, Ian [please cc me on any reply] >