From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753596Ab1G0Dwj (ORCPT ); Tue, 26 Jul 2011 23:52:39 -0400 Received: from mail-gw0-f46.google.com ([74.125.83.46]:52350 "EHLO mail-gw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752792Ab1G0Dwh (ORCPT ); Tue, 26 Jul 2011 23:52:37 -0400 Message-ID: <4E2F8B7B.80906@signal11.us> Date: Tue, 26 Jul 2011 23:52:27 -0400 From: Alan Ott User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.14) Gecko/20110223 Thunderbird/3.1.8 MIME-Version: 1.0 To: linux-kernel@vger.kernel.org, linux-net@vger.kernel.org Subject: IP over 802.2 with LLC/SNAP Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, What I have is a fairly straight-forward question, but takes a little background to get there. I have an ancient computer (Gould 3267) that I'm trying to interface with both a Windows computer and an embedded Linux computer over UDP/Ethernet. Since the Gould doesn't have any IP support, I have to make the IP packet myself. Also, because of the way the Gould's Ethernet driver works, sent packets all use the type/length field in the Ethernet header to represent the length and therefore are unable to specify that the packet contains IP data in the Ethernet header. To get around this, I added an 802.2 LLC/SNAP header to my packet[1]. My packet looks good in Wireshark, and I have it working well communicating with the Windows PC. However, I can't seem to get Linux to recognize the packet as IP, and thus I am unable to receive it using the normal socket interface on the Linux system. So the question is, does Linux support IP over 802.2 with LLC/SNAP? Is there a sysfs/proc entry that I have to turn on to make this work (I didn't find one)? I have the LLC2 module loaded, and I believe my packet to be correct, since Windows recognizes it and since Wireshark doesn't give any red flags on it. I've been unable to find anything about this kind of thing in my searching. I put a sample capture file of the packets I'm sending at [2] for those interested. Alan. [1] So the packet looks like this: Ethernet Header LLC/SNAP header IP Header UDP Header data [2] www.signal11.us/~alan/testraw.pcap