From owner-freebsd-net@FreeBSD.ORG Sun Feb 10 09:24:45 2013 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id 143BE24C for ; Sun, 10 Feb 2013 09:24:45 +0000 (UTC) (envelope-from garmitage@swin.edu.au) Received: from gpo4.cc.swin.edu.au (gpo4.cc.swin.edu.au [136.186.1.33]) by mx1.freebsd.org (Postfix) with ESMTP id 96B5110F for ; Sun, 10 Feb 2013 09:24:44 +0000 (UTC) Received: from [136.186.229.37] (garmitage.caia.swin.edu.au [136.186.229.37]) by gpo4.cc.swin.edu.au (8.14.3/8.14.3) with ESMTP id r1A9OEDq020597 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sun, 10 Feb 2013 20:24:36 +1100 Message-ID: <5117673E.3020203@swin.edu.au> Date: Sun, 10 Feb 2013 20:24:14 +1100 From: grenville armitage User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:16.0) Gecko/20121107 Thunderbird/16.0.2 MIME-Version: 1.0 To: freebsd-net@freebsd.org Subject: Re: [PATCH] Add a new TCP_IGNOREIDLE socket option References: <201301221511.02496.jhb@freebsd.org> <50FF06AD.402@networx.ch> <061B4EA5-6A93-48A0-A269-C2C3A3C7E77C@lakerest.net> <201302060746.43736.jhb@freebsd.org> <511292C9.4040307@mu.org> <51166019.9040104@mu.org> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 10 Feb 2013 09:24:45 -0000 I'm somewhat sympathetic to the purity of TCP. Nevertheless... On 02/10/2013 16:05, Kevin Oberman wrote: [..] > What I would like to see is a way to have it available, but make it > unlikely to be enabled except in a way that would put up flashing red > warnings and sound sirens to warn people that it is very dangerous and > can be a way to blow off a few of one's own toes. +1 I rather doubt the Internet will be crushed by adding a non-default option that allows FreeBSD TCP to behave More Aggressively Than It Really Should(tm) under certain circumstances. I'm certainly not denying that the sky would likely fall if everyone turned on John's proposed socket option all the time. (Such might also be said of allowing UDP applications to be free of any CC at all, or allowing new TCP CC algorithms that deviate from the prevalent norm.) But I think that FreeBSD benefits from adding more special-case knobs for the cognoscenti to twiddle, on the basis that most end-users wont bother. > One idea that popped into my head (and may be completely ridiculous, > is to make its availability dependent on a kernel option and have > warning in NOTES about it contravening normal and accepted practice > and that it can cause serious problems both for yourself and for > others using the network. Perhaps also require a sysctl to be set before John's per-socket TCP_IGNOREIDLE option has any effect. (Thus requiring a sending host's administrator to at least be complicit in enabling any subsequent ruination of their nearest bottleneck.) cheers, gja