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=-2.3 required=3.0 tests=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 D65D2C2BB1D for ; Mon, 13 Apr 2020 06:04:55 +0000 (UTC) Received: from vger.kernel.org (unknown [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3844F2073E for ; Mon, 13 Apr 2020 06:04:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3844F2073E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=si6networks.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=netdev-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728214AbgDMGEx (ORCPT ); Mon, 13 Apr 2020 02:04:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.18]:46698 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726967AbgDMGEw (ORCPT ); Mon, 13 Apr 2020 02:04:52 -0400 Received: from fgont.go6lab.si (fgont.go6lab.si [91.239.96.14]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 06D6CC0A3BE0 for ; Sun, 12 Apr 2020 23:04:51 -0700 (PDT) Received: from [192.168.0.10] (unknown [181.45.84.85]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by fgont.go6lab.si (Postfix) with ESMTPSA id 8A743804D5; Mon, 13 Apr 2020 08:04:45 +0200 (CEST) Subject: Re: [PATCH net-next] Implement draft-ietf-6man-rfc4941bis To: Stephen Hemminger Cc: netdev@vger.kernel.org, David Miller References: <20200408104458.GA15473@archlinux-current.localdomain> <20200412222205.04cb37cc@hermes.lan> From: Fernando Gont Message-ID: <2999c2d5-77f2-c69f-7fab-d5b01b30a65f@si6networks.com> Date: Mon, 13 Apr 2020 03:04:29 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.1 MIME-Version: 1.0 In-Reply-To: <20200412222205.04cb37cc@hermes.lan> Content-Type: text/plain; charset=utf-8; format=flowed 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 13/4/20 02:22, Stephen Hemminger wrote: > On Wed, 8 Apr 2020 07:44:58 -0300 > Fernando Gont wrote: > >> Implement the upcoming rev of RFC4941 (IPv6 temporary addresses): >> https://tools.ietf.org/html/draft-ietf-6man-rfc4941bis-09 >> [...] >> >> temp_valid_lft - INTEGER >> valid lifetime (in seconds) for temporary addresses. >> - Default: 604800 (7 days) >> + Default: 172800 (2 days) > > You can't change defaults for existing users without a really good > argument. The number of extra addresses you get when the Valid Lifetime is 7 days tends to exacerbate the stress caused on network elements/devices. There are references in the I-D. Additionally, the motivation of temporary addresses is indeed privacy and reduced exposure. With a default VL of 7 days, and address that becomes revealed is reachable for one whole week. That's not very "temporary" as the name would imply. The only use case for a VL of 7 days could be some application that is expecting to have long lived connections. But if you want to have a long lived connections, you probably shouldn't be using a temporary address. And even more in the era of mobile devices, I'd argue that general applications should be prepared and robust to address changes (nodes swaps wifi <-> 4G, etc.) This is, of the top of my head, the reason why we decided to modify the default valid lifetime in the upcoming revision of the standard. Thoughts? Thanks, -- Fernando Gont SI6 Networks e-mail: fgont@si6networks.com PGP Fingerprint: 6666 31C6 D484 63B2 8FB1 E3C4 AE25 0D55 1D4E 7492