From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.17.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 31C043B2A4 for ; Tue, 24 Apr 2018 03:57:08 -0400 (EDT) Received: from [172.16.11.125] ([134.76.241.253]) by mail.gmx.com (mrgmx102 [212.227.17.168]) with ESMTPSA (Nemesis) id 0MYtId-1exJsw21hL-00VcrG; Tue, 24 Apr 2018 09:57:05 +0200 Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 11.3 \(3445.6.18\)) From: Sebastian Moeller In-Reply-To: <6A13BD7F-D682-4864-B5DB-2352C1C3F529@eventide.io> Date: Tue, 24 Apr 2018 09:56:35 +0200 Cc: Jonathan Morton , cake@lists.bufferbloat.net Content-Transfer-Encoding: quoted-printable Message-Id: References: <871sf6xqne.fsf@toke.dk> <003D19B8-73F8-46D4-8FC8-95F6E518D3B5@eventide.io> <311BE3FC-9211-4B33-AD46-444F21E2A38A@gmail.com> <6A13BD7F-D682-4864-B5DB-2352C1C3F529@eventide.io> To: Pete Heist X-Mailer: Apple Mail (2.3445.6.18) X-Provags-ID: V03:K1:8YjvF+yTBH1o27oLyJqwrq9B7UsrRTNjh8GTUYWhVtx8ncUz6Ws t1QfHQj0OqiSBaGnERuUiayAiZn/5spk0+rOKvKWupI9GWyDf0XHfCKeAm/7pXff7NCWovH y934FacOYZDA6oHhYXklvA71d9LEKtip/U8zivxiBw4x72NgmAz2QxQyW9URCaXIi26AKgG D50apx+L0LmUqbLaKa+/g== X-UI-Out-Filterresults: notjunk:1;V01:K0:/jabDrpjLsQ=:8skItGPj7TL7IT7dal5+T4 uNplWHQV8H7eYdxWbTqeYwHn+uzODWZpPsXcmCKzKQBBMsU8pTFWVz7G6thjzazl+ztXLOPRX 4ZLjx+6yWyTNsYOw56yBGy6cUGCAJvMplHorEUvEsypwXZK9wtDetind9STzB4Y5MutSzChu+ ugQPEg1Nc1s6QyVAT6Cw5yagx4ACVErUq9w+nQ1Wu+l2MFh7KUyBPNk9u0hE0CrNXNS12714O +UHPoGOy3N3jJX6ekioy2KTt/Mh5Hp7KJQ9t0f1KABq3LDghOMszAXQjNly0jod79H2DIxVct 8ua81VWGvEghR9mCvncKWR+Likm+WqL4d3PHlZZPNeZjjcbz/+tT6aR4eQidKH/buMNBH60jW iL9nw3U/7z52J2abqaCTYYZJTu0kGCc0EkPfj5vS96hMRQdOPlPVrrrUS4xx09jAUQRyK95SZ a2MyzOuUILv0dcBuDW3WLUbCC9a6TBeb1XI9nC8ll5SJAVAJWDdDq+m86gDIP/za4GTxHIu03 1rX3VhLKI3Fo1+crafZ9maBspZ5jSvIuu0aiPBaNcbI+U9v5UgYY4T2MwOVnNTivasliwZVqj 2ygMRRI+P9G7Z0P3znDEvcskycO7JURc17RqyEXDrr+MqomD/zHYdqbCS3c+ebtUYFQzcRfTI eSVEm94TmZni6zVale6M0ysz/nlFqFICWCSDSiSvD8b7PayAgkiW37ttqWKfvw4pT7gS8DVQr vrLSeg+eJxlwq9gkRbd1H4QYDvU35en/d4SqKE38iedGLivEh5osnhjJr3cZZh6AhLMyJ7Rle 7F/WYkP8qggOViDqO+QeK/nO/Hgoe5+pqeCt7KryhPrceqUGwY= Subject: Re: [Cake] Pre-print of Cake paper available X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 24 Apr 2018 07:57:08 -0000 > On Apr 24, 2018, at 09:15, Pete Heist wrote: >=20 >=20 >> On Apr 24, 2018, at 7:58 AM, Jonathan Morton = wrote: >>=20 >> Turning NAT support on by default might actually be reasonable, since = it doesn't really break anything if it's not needed - it just eats a bit = of CPU with unnecessary conntrack lookups. >=20 > I would be for it, if it eats say < 1% additional CPU, and preferably = less. I expect the impact to increase with packet rates. >=20 >> For the flowmodes, basically triple-isolate's raison d'=C3=AAtre is = to be a reasonable default which (usually) gives most of the benefits of = the "dual" modes, without needing to know a-priori anything about = network topology. In the most typical application, the distinction can = be seen in whether the qdisc is attached to an IFB or a physical = interface, but in deployments that we'd *like* to see, the opposite = cases easily occur. To do anything more sophisticated, we'd need to = watch some traffic and guess after a while, and that doesn't feel right. >=20 > Yeah, I see. The same could be done with nat. There could be an = auto-detect phase where nat lookups are performed and not to determine = if it=E2=80=99s needed. But if these detections didn=E2=80=99t work with = near-perfect reliability, it would complicate troubleshooting. IMHO, auto-detection would at least require a dedicated keyword, like = "detect-nat" that would be reported in the tc -s qdisc output for cake = as long as the detection phase is active and would be replaced by the = appropriate "nat" or "nonat" keyword in the tc -s qdisc output after the phase is done (there should = be no ambiguity). But overall I believe that this is adding more = confusion. That said I am all for making nat the default, even though it = would be nice to have measurements showing its cost.=20 > _______________________________________________ > Cake mailing list > Cake@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/cake