From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8D00C433FF for ; Wed, 14 Aug 2019 18:36:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD7492133F for ; Wed, 14 Aug 2019 18:36:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728782AbfHNSgi (ORCPT ); Wed, 14 Aug 2019 14:36:38 -0400 Received: from mail-a05.ithnet.com ([217.64.83.100]:42786 "EHLO mail-a05.ithnet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726522AbfHNSgi (ORCPT ); Wed, 14 Aug 2019 14:36:38 -0400 X-Greylist: delayed 401 seconds by postgrey-1.27 at vger.kernel.org; Wed, 14 Aug 2019 14:36:36 EDT Received: (qmail 8432 invoked by uid 0); 14 Aug 2019 18:29:54 -0000 Received: from skraw.ml@ithnet.com by mail-a05 (Processed in 2.051755 secs); 14 Aug 2019 18:29:54 -0000 X-Virus-Status: No X-ExecutableContent: No Received: from unknown (HELO ithnet.com) (217.64.64.14) by mail-a05.ithnet.com with ESMTPS (ECDHE-RSA-AES256-GCM-SHA384 encrypted); 14 Aug 2019 18:29:52 -0000 X-Sender-Authentication: SMTP AUTH verified Date: Wed, 14 Aug 2019 20:29:51 +0200 From: Stephan von Krawczynski To: linux-kernel@vger.kernel.org Subject: VLAN tag stacking with bridge/tap device ? Message-ID: <20190814202951.20d7dff1@ithnet.com> Organization: ith Kommunikationstechnik GmbH X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello all, I try to do a setup with qemu and tap devices attached to bridges where 802.1Q vlan packets that are tag stacked are running through the tap device/bridge where the outer tag is stripped. But it seems on the way back out of qemu/guest and back through the tap and bridge no additional vlan tags are added back. The very same setup with only one vlan tag that is stripped and added back works as expected. Is there something in the tap device or bridge code that prevents stacking? Can this be done by configuration or by additional coding in the tap or bridge? -- Regards, Stephan PS: please add me as cc in reply