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=-2.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 7937FC4338F for ; Tue, 24 Aug 2021 04:57:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4A7C861248 for ; Tue, 24 Aug 2021 04:57:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229848AbhHXE6l (ORCPT ); Tue, 24 Aug 2021 00:58:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57644 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229701AbhHXE6k (ORCPT ); Tue, 24 Aug 2021 00:58:40 -0400 Received: from mail-lj1-x231.google.com (mail-lj1-x231.google.com [IPv6:2a00:1450:4864:20::231]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E4ACDC061575 for ; Mon, 23 Aug 2021 21:57:56 -0700 (PDT) Received: by mail-lj1-x231.google.com with SMTP id y6so35403956lje.2 for ; Mon, 23 Aug 2021 21:57:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to; bh=bU+QKR/jrdY7YoIA73vKkOY7YY3CxR7uor1mOZjxtso=; b=KSCrddLs6U68zIzkZLhPXI0oGJ0cuu2RycTKqzFWIOBG26Uk9onw3Oy1ndB3O34duG ZPdiaGe4mLs3EYpv0CeEEVsdgksAAWJhko1zmCT36FhyfJTfaNXCtfjdRAkJY7TKlWRY /fMZtNtkBaJ0k3254dGikJ4DDCirxMHiO9WBFYLj4uJqmWuuQpIj/PEwOzictp5f7v5E 5EkogzE/8UGj5YzP8NJugE+mS/dYGbokjiCAfv+Ok3kxIFLTQL/tXqmMJRL8P30XYMvJ 48UtC3QY73ZL1/j47CplD3URrCqu9ZKCTKHOi7Pn0HNVOCkP+4I2N28SBJLT8NPRdwcC m18Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=bU+QKR/jrdY7YoIA73vKkOY7YY3CxR7uor1mOZjxtso=; b=t0K/XFofkBKqjG9O8UGyuUac9pqgqq/GxfrmDZR+DUF0zKbY3HR0prGlyhqTJBs4Hw TxYhEGoFK8tMXVIKs9isYbAjJH3LKxKIVEXq7KuHnZ4F4+PT4p9MLXmbYTelS7iqzc0K /yia0qQSzNYK3atbRiGnuD3oYy0pyxi/rEuDgw+LgL98m2V3O9TuwJo8h6vSBMNiRsnp 5FrBH82RE+rclxtZRO3651zpJFmmCNx/OWqUviFYe9LVB66RyeZ6nAz1ZZob+ddBwNB0 1hp7TokdeLOgTfDwXQbFec/v8xIBgjtvCeUA7dsxThkKIZ3Eqwg8D06CyZ4U6A3lVr1o CLUw== X-Gm-Message-State: AOAM5318MRkNTufFXdvPU85V1y7byE4dxYetexH8Uew9QwYElEQqQnck T4PDEwoAA1ATexdnjEjWaAsnDRqDmH+sLmmpRH+XLlp+TuALTA== X-Google-Smtp-Source: ABdhPJzk81eyke+yJkjvHKNLzzSdNpHW6OkSWfxQz+TvpTpvGJBfExAhRH9QSq+EQ+n1POZnKE3K1FMhsfNe71jAjKc= X-Received: by 2002:a05:651c:11c7:: with SMTP id z7mr30052469ljo.87.1629781075128; Mon, 23 Aug 2021 21:57:55 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Tom Yan Date: Tue, 24 Aug 2021 12:57:44 +0800 Message-ID: Subject: Re: Bridged passthru MACVLAN breaks IPv6 multicast? To: netdev@vger.kernel.org, davem@davemloft.net Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Never mind. I made a mistake. Turns out only Neighbor Solicitation from a LAN host does not "walk across" the MACVLAN. ping ff02::1%some_dev and Neighbor Solicitation from a bridge tap host actually do. (I forgot to change the ether saddr for them: the underlying link is a wireless NIC) Btw Neighbor Advertisement from a LAN host "walks across" the MACVLAN as well. I can see it on this host. I guess I can workaround the problem by re-enabling IPv6LL on the MACVLAN. Still wonder why that is broken though. On Tue, 24 Aug 2021 at 12:12, Tom Yan wrote: > > Hi, > > I've further investigated the problem: > > What "walk across": > ping ff02::1%bridge and Neighbor Solicitation from this host (tcpdump > multicast on a LAN host can see them) > ping ff02::1%some_dev from a LAN host (tcpdump multicast on this host > or a bridge tap host can see them) > > What do not "walk across": > Neighbor Solicitation from a LAN host (both tcpdump multicast on this > host and on a bridge tap host cannot see them) > ping ff02::1%some_dev and Neighbor Solicitation from a bridge tap host > (tcpdump multicast on this host can see them, but that on a LAN host > cannot) > > There is no problem with ARP (or IPv4 multicast, apparently). > > P.S. I've filed a bug report on: > https://bugzilla.kernel.org/show_bug.cgi?id=214153 > > Regards, > Tom > > On Mon, 23 Aug 2021 at 02:07, Tom Yan wrote: > > > > Hi, > > > > Normally when a NIC is (directly) enslaved as a bridge port, the NIC > > itself does not need to have a IPv6 link-local address configured on > > it for IPv6 multicast / NDP to work properly (instead the address can > > simply be configured on the bridge like IPv4 addresses). > > > > Yet it appears that if the bridge port is instead a passthru mode > > MACVLAN, IPv6 multicast traffics from (the link/"side" of) it cannot > > reach the host (as in, cannot even be captured with tcpdump) unless > > either the MACVLAN or its underlying link has a/the[1] IPv6 link-local > > address configured. > > > > Is it an expected behavior? Or is it a bug? > > > > [1]: In my configuration, the bridge, the bridged passthru MACVLAN and > > its underlying link have the same MAC address and hence (at least by > > default) their IPv6 link-local addresses are identical. > > > > Regards, > > Tom