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=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 78848C49EA6 for ; Thu, 24 Jun 2021 13:39:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 53D98613DC for ; Thu, 24 Jun 2021 13:39:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231608AbhFXNlm (ORCPT ); Thu, 24 Jun 2021 09:41:42 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:51748 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229995AbhFXNll (ORCPT ); Thu, 24 Jun 2021 09:41:41 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1624541960; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=9vLK98PdEnpyQ/nS6/7YJpw/gmVqIJdAagVZW4uCkYo=; b=hH40r3nxhE480aJAjea+7jZRIp4WZw91yRNuo5g/HhnzchiGnuoy8kYeOnB7JqUse8GFGg UI3UrNpb0fTVGBAriqCtf0fkCKyQDZep7CsC6OHUIEgMXlKqVBVwDWa0QJ/E3Y8N7CvOB3 ZcTvqg3hjNAzOtHofR5kOaXY/sjIi2E= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-532-s8-a7UoTMOC2w2wXKj0p-g-1; Thu, 24 Jun 2021 09:39:19 -0400 X-MC-Unique: s8-a7UoTMOC2w2wXKj0p-g-1 Received: by mail-wm1-f70.google.com with SMTP id j2-20020a05600c1c02b02901cecbe55d49so573882wms.3 for ; Thu, 24 Jun 2021 06:39:19 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=9vLK98PdEnpyQ/nS6/7YJpw/gmVqIJdAagVZW4uCkYo=; b=iLwE+qSVFWY3HyyyW90FvrzD5eguBj2iZ57CzgiarnqXzuFR5X939PfpSSeCuj+48F DuvPXvf0Nms+IHPmE+RLeTLI0Hl84lN8i9iRq7HsTOAakg70V/xvI1+PSEpBhfX/q9CF FLZUQaZp9jUZ/Hr+Nazp+7nNK92Lwo9w9Nizy3eIaZ86bnV9cwJ5pK6uhTsZP3m7bbVi 11TXo1CGwDNbZR50SgAaSOQ1Z2Ii7sGU1Lc0qcRQ2F2W2WykYy0T2GIalDMVsvj3Vi9s Je8G/0byv5jl8/s0TM5ztQrDJ8k72SKDyLCVUJanvFwgxOB+XAGd/PXdY3jnXCg6KeM3 kBWQ== X-Gm-Message-State: AOAM532tSh0RxdnbafGflAnkpSpnXTyc6+SrXYLQBa5Kjn4KBTv/689B cWxVEA3WgEn+Gqvic5XJjApSE0wuxHJslTTqS3xVjU9EQmhsOQaBSPLhORSneDDFXEHKzA44OqD 4luQPkHkMsHZL/eU0 X-Received: by 2002:a5d:4a01:: with SMTP id m1mr4658206wrq.51.1624541958186; Thu, 24 Jun 2021 06:39:18 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzAJF2wUKvYOPeRb1CAsZgVlgHOPr4wgvdb504Sg1whYhBbruwbvWgntrHJxJYp0n/StAFHkA== X-Received: by 2002:a5d:4a01:: with SMTP id m1mr4658188wrq.51.1624541958066; Thu, 24 Jun 2021 06:39:18 -0700 (PDT) Received: from pc-32.home (2a01cb058918ce00dd1a5a4f9908f2d5.ipv6.abo.wanadoo.fr. [2a01:cb05:8918:ce00:dd1a:5a4f:9908:f2d5]) by smtp.gmail.com with ESMTPSA id u18sm2798608wmj.15.2021.06.24.06.39.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 24 Jun 2021 06:39:17 -0700 (PDT) Date: Thu, 24 Jun 2021 15:39:15 +0200 From: Guillaume Nault To: David Ahern Cc: Jakub Kicinski , davem@davemloft.net, netdev@vger.kernel.org, yoshfuji@linux-ipv6.org, dsahern@kernel.org, vfedorenko@novek.ru Subject: Re: [PATCH net] ip6_tunnel: fix GRE6 segmentation Message-ID: <20210624133915.GA4606@pc-32.home> References: <20210622015254.1967716-1-kuba@kernel.org> <33902f8c-e14a-7dc6-9bde-4f8f168505b5@gmail.com> <20210622152451.7847bc24@kicinski-fedora-PC1C0HJN.hsd1.ca.comcast.net> <592a8a33-dfb8-c67f-c9e6-0e1bab37b00d@gmail.com> <20210623091458.40fb59c6@kicinski-fedora-PC1C0HJN.hsd1.ca.comcast.net> <5011b8aa-8bbf-9172-0982-599afed69c5d@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5011b8aa-8bbf-9172-0982-599afed69c5d@gmail.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Jun 23, 2021 at 12:28:05PM -0600, David Ahern wrote: > On 6/23/21 10:14 AM, Jakub Kicinski wrote: > > Noob question, why do we need that 2 sec wait with IPv6 sometimes? > > I've seen it randomly in my local testing as well I wasn't sure if > > it's a bug or expected. > > It is to let IPv6 DAD to complete otherwise the address will not be > selected as a source address. That typically results in test failures. > There are sysctl settings that can prevent the race and hence the need > for the sleep. But Jakub's script uses "nodad" in the "ip address add ..." commands. Isn't that supposed to disable DAD entirely for the new address? Why would it need an additional "sleep 2"?