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=-5.6 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,NICE_REPLY_A,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 E1686C433EA for ; Mon, 13 Jul 2020 13:25:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BD16E206F0 for ; Mon, 13 Jul 2020 13:25:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="IG99Cwzn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730238AbgGMNZT (ORCPT ); Mon, 13 Jul 2020 09:25:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47934 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729822AbgGMNZQ (ORCPT ); Mon, 13 Jul 2020 09:25:16 -0400 Received: from mail-ot1-x344.google.com (mail-ot1-x344.google.com [IPv6:2607:f8b0:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 59B87C061755 for ; Mon, 13 Jul 2020 06:25:16 -0700 (PDT) Received: by mail-ot1-x344.google.com with SMTP id 72so9485235otc.3 for ; Mon, 13 Jul 2020 06:25:16 -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=x0ikcgnusApPQmzUkIF+WMrteE9Av9ac297tKpys05I=; b=IG99CwznfBbGq5WPbt3f3tHpJyAvjk2PVHxVtSnEgtEAOpclYjNyyMEsCTvN6dEkR+ iD1jW26LAk98k1+Lj+ZUzBMIf+fvdOwQvyMs9om6bW504mUAdFYztIZj/eP+kkIuqV4j LQX++XhJCqibhI4W7CZgWYtxv1MXxGigCXlEh3Jt53Vt76p0O3r9EET7b8Vuvd8mXjkL llar8ERA80n3uQ9bzfQAe5idjaFPgcuLcHFTtMFJUE2Db10Kufe6eVBHRdIjPPtQE80x nFnEj8vphTAkwNJ3ehsPL2Z8IQpAQSfXinRiCu8MyZqvQzv1pO97s0DiGcPHROfRdGQq CaTQ== 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=x0ikcgnusApPQmzUkIF+WMrteE9Av9ac297tKpys05I=; b=Vkq8Oq29mTjd+A0PShC9RHFhPI8tGXoz5Y4t9r71l9HyL2uKENdnU8vz1xf8Ecb8JR hEkbWp3h4C321YoY0Xw4HiyYHqhuLU8vuT0aHHeXAUHS/cQb6/e0Mrqqd6OFLMACGo2W nMS+amMBy/Qqp4z7IoEVcfXsGRM4SUOAi/qOkeoxoPm21BV7xhrAh3/axvZJhPamFoc5 uOz4CQdjyTuD/n/zJoDs5H/aJBQMi6A28zfQspv3MrAL6azLX71LntWHHEWl9iLSH+mX 3m/Yh0NICuUXgZkZo8rpR2mAI0dDSEJUWBjXMB1RAqM2qrVKpCDouA+r5R/4p8k5htVK b3pA== X-Gm-Message-State: AOAM532C1NII/pBHIlQWTIc3wyWvtUDg45H0FIXY3fJ//I5lx2V0fHs0 fL+wn2a5S0YgqHzQjW0NJZo= X-Google-Smtp-Source: ABdhPJy8LUnU5vlfTn7CLLWOg4pbBLKIgHJfjkwH/rTL1tjGrZKcuu5vKtV7xTZYHc57L9fU9H0X9Q== X-Received: by 2002:a05:6830:2306:: with SMTP id u6mr71956999ote.104.1594646715780; Mon, 13 Jul 2020 06:25:15 -0700 (PDT) Received: from ?IPv6:2601:284:8202:10b0:a406:dd0d:c1f5:683e? ([2601:284:8202:10b0:a406:dd0d:c1f5:683e]) by smtp.googlemail.com with ESMTPSA id l18sm1883107ooh.5.2020.07.13.06.25.14 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 13 Jul 2020 06:25:14 -0700 (PDT) Subject: Re: [PATCH net-next 1/3] udp_tunnel: allow to turn off path mtu discovery on encap sockets To: Florian Westphal , Stefano Brivio Cc: netdev@vger.kernel.org, aconole@redhat.com References: <20200712200705.9796-1-fw@strlen.de> <20200712200705.9796-2-fw@strlen.de> <20200713003813.01f2d5d3@elisabeth> <20200713080413.GL32005@breakpoint.cc> From: David Ahern Message-ID: Date: Mon, 13 Jul 2020 07:25:13 -0600 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200713080413.GL32005@breakpoint.cc> 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 7/13/20 2:04 AM, Florian Westphal wrote: >> As PMTU discovery happens, we have a route exception on the lower >> layer for the given path, and we know that VXLAN will use that path, >> so we also know there's no point in having a higher MTU on the VXLAN >> device, it's really the maximum packet size we can use. > No, in the setup that prompted this series the route exception is wrong. Why is the exception wrong and why can't the exception code be fixed to include tunnel headers?