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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 DA969C2D0DC for ; Thu, 2 Jan 2020 12:54:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A25E12072C for ; Thu, 2 Jan 2020 12:54:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="vSBfzZ3n" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728336AbgABMyZ (ORCPT ); Thu, 2 Jan 2020 07:54:25 -0500 Received: from vps0.lunn.ch ([185.16.172.187]:45118 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728278AbgABMyZ (ORCPT ); Thu, 2 Jan 2020 07:54:25 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=O6e4CuOBxyrYTSDbzpg+4CY5EG8a5QAk50cY/URZTIo=; b=vSBfzZ3nkjaeybChC0/tEtSYD9 dqBXCnBbxJ3bl0+uyZ6wrEi5p0BZA0EIpqYSbLnfXj4awaXBvWl51HXkoZGDaLIQ83UDFBB7uKX8r Ek2TYdMWXZB0CGdv/MS1KAsedUyFY6E6zDOI2h6JK/x3AEJEn+0YVEXkPkCqLXwdO/50=; Received: from andrew by vps0.lunn.ch with local (Exim 4.93) (envelope-from ) id 1imzzV-000607-CH; Thu, 02 Jan 2020 13:54:17 +0100 Date: Thu, 2 Jan 2020 13:54:17 +0100 From: Andrew Lunn To: Russell King - ARM Linux admin Cc: Pali =?iso-8859-1?Q?Roh=E1r?= , Ido Schimmel , netdev@vger.kernel.org, Jiri Pirko , Ivan Vecera , Vivien Didelot Subject: Re: [RFC 0/3] VLANs, DSA switches and multiple bridges Message-ID: <20200102125417.GA22789@lunn.ch> References: <20191222192235.GK25745@shell.armlinux.org.uk> <20191231161020.stzil224ziyduepd@pali> <20191231180614.GA120120@splinter> <20200101011027.gpxnbq57wp6mwzjk@pali> <20200101173014.GZ25745@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200101173014.GZ25745@shell.armlinux.org.uk> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org > # tcpdump -enXXi $host_dsa_interface > > Here's an example ping packet received over the vlan with the above > configuration, captured from the host DSA interface (ether mac > addresses obfuscated): > > 0x0000: DDDD DDDD DDDD SSSS SSSS SSSS dada 0000 .PC.....[h:..... > ^^^^^^^^^ > 0x0010: c020 0000 8100 0080 0800 4500 0054 ec40 ..........E..T.@ > ^^^^^^^^^ ^^^^^^^^^ ^^^^ > 0x0020: 4000 4001 c314 c0a8 0502 c0a8 0501 0800 @.@............. > 0x0030: 8784 0c85 0001 32c8 0c5e 0000 0000 59fc ......2..^....Y. > 0x0040: 0c00 0000 0000 1011 1213 1415 1617 1819 ................ > 0x0050: 1a1b 1c1d 1e1f 2021 2223 2425 2627 2829 .......!"#$%&'() > 0x0060: 2a2b 2c2d 2e2f 3031 3233 3435 3637 *+,-./01234567 > > dada 0000 c020 0000 - EDSA tag > 8100 0080 - VLAN ethertype, vlan id > 0800 - IPv4 ethertype, and what follows is the ipv4 > packet. > > That way it would be possible to know whether the DSA switch is > forwarding the packets, and in what manner it's forwarding them. Hi Russell Try upgrading your tcpdump and pcap library. It now understands DSA headers, will dump them in a semi human readable way, and also the rest of the frame. Andrew