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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 283E0C433DF for ; Wed, 24 Jun 2020 02:14:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EDA2420874 for ; Wed, 24 Jun 2020 02:14:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="oRGvUhBs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387982AbgFXCOe (ORCPT ); Tue, 23 Jun 2020 22:14:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50508 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730898AbgFXCOd (ORCPT ); Tue, 23 Jun 2020 22:14:33 -0400 Received: from mail-io1-xd43.google.com (mail-io1-xd43.google.com [IPv6:2607:f8b0:4864:20::d43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A4333C061573 for ; Tue, 23 Jun 2020 19:14:31 -0700 (PDT) Received: by mail-io1-xd43.google.com with SMTP id y2so498028ioy.3 for ; Tue, 23 Jun 2020 19:14:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=Ln6jmHb6P2/um7MStjIOZ+1MO+YVQKOf+KBBOqTJ0Jw=; b=oRGvUhBsR2yuOhGODTZ+NS/FzmqBtJPGZwu5A5/C4mpguS8y+0o8Z3OMReRgG9IwLQ anHJnqomJbaorTYimntonTF13VlDErcrClibNj1wQBHFs6M6vbJZRWmtwonyi6iNkkOF K/gSmBAj+GDD86Sel7iNpUaE7Vpbmnhw3Zk6Hs4sNMoc4eu95abtMhGws6dOpRJttAUr Ah7aFr+IKsyNxYqjg1qkjxxK3AxKy8Ds0+2lo9EA8eJtG5Q8J4sZRuje2KpL2UYdY2Jv bGil0hn+crTjvzfv3co1CWpnlLAXDSypLIljExKV92H6kB87cIWNIvep4MgTRoD0F8Fx c4Lg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=Ln6jmHb6P2/um7MStjIOZ+1MO+YVQKOf+KBBOqTJ0Jw=; b=Q1dccB4lwDQ9s6ZyfJYjDaADqJPRN7lxOR7HB3JyHaqIAGyWOtzwfGI16FAdrWQSzG VBX87IFxRwxVn6XKkbGKtVr40j8dGx/hhi91DZhYOBsw4O1hx/KDeEOZVjjjIIdOz0g1 VZAQwMorvJCSNOVy15Dlhbp/0+27Ttok1DE/sw+mtCfApkKPWQ+pNMRt662BO1wxznZw 618YnN5C3D1Tv2y52v7psfOMBM4T0ReuLqiYYd/1YxEm6dHHN/GjoW/214ytQvFJLSA/ EJDio59XvsNS9Yi3jxp4kMx/xJvAj0diTJ9LgzijQdPKWg5d0OWJUw5E+YCGSaLOaZb2 yayw== X-Gm-Message-State: AOAM533rSh1ore9JFzYPiNN3I26K+wpB2kSsdoJRXHesXE2K77HbotMR HofN1BpMqg7KkhXtbqpsvSMbySFu X-Google-Smtp-Source: ABdhPJxs/p8WIIxdkc9oZlE7Yhp/o4QEZixv5bf/qXIV1yOlBNZErrtV4wHcHtCFuw/5iX2Tqp0akw== X-Received: by 2002:a05:6638:a0a:: with SMTP id 10mr27152324jan.30.1592964870683; Tue, 23 Jun 2020 19:14:30 -0700 (PDT) Received: from [10.254.22.15] ([138.68.32.133]) by smtp.googlemail.com with ESMTPSA id y8sm3765798ilq.21.2020.06.23.19.14.29 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 23 Jun 2020 19:14:30 -0700 (PDT) Subject: Re: Multicast routing: wrong output interface selected unless VRF default route is added To: Ido Schimmel , Qiwei Wen Cc: netdev@vger.kernel.org References: <20200623183835.GA69452@shredder> From: David Ahern Message-ID: <891caeb6-9c1f-d79d-caa6-23aba7e4d0c7@gmail.com> Date: Tue, 23 Jun 2020 19:14:28 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <20200623183835.GA69452@shredder> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 6/23/20 11:38 AM, Ido Schimmel wrote: >> >> My questions are: >> 1. is fib_lookup supposed to work with multicast daddr? If so, has >> multicast routing been working for the wrong reason? yes; it is a quirk with Linux routing. see the code after fib_lookup in ip_route_output_key_hash_rcu. perf can show you the call chain that gets to that lookup if you want the details. >> 2. Why does the addition of a unicast default route affect multicast >> routing behaviour? > > I believe this was discussed in the past. See: > https://lore.kernel.org/netdev/20200115191920.GA1490933@splinter/#t >