From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vincent Bernat Subject: Re: nonlocal_bind and IPv6 Date: Sat, 17 Dec 2011 11:52:01 +0100 Message-ID: References: <20111216.020600.1695776769736304587.davem@davemloft.net> <20111216.131833.2127398230815526406.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: zenczykowski@gmail.com, netdev@vger.kernel.org, yoshfuji@linux-ipv6.org To: David Miller Return-path: Received: from bart.luffy.cx ([78.47.78.131]:52635 "EHLO bart.luffy.cx" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751923Ab1LQKwG convert rfc822-to-8bit (ORCPT ); Sat, 17 Dec 2011 05:52:06 -0500 In-Reply-To: <20111216.131833.2127398230815526406.davem@davemloft.net> (David Miller's message of "Fri, 16 Dec 2011 13:18:33 -0500 (EST)") Sender: netdev-owner@vger.kernel.org List-ID: OoO Pendant le repas du vendredi 16 d=C3=A9cembre 2011, vers 19:18,= David Miller disait=C2=A0: >> Moreover, I am just adding the IPv6 version of this setting. The IPv= 4 >> version already exists. > I don't think the ipv4 feature was a wise thing to add, so just becau= se > ipv4 has something doesn't automatically make it appropriate to suppo= rt > it in ipv6 too. So please don't use arguments like that. Here are my arguments against using IP_FREEBIND: 1. It needs to be applied to all services, this will take years. Al= l services will need an option just for that (because usually a use= r does not want to be able to bind to a non local IP). We could us= e some hacks with LD_PRELOAD, but that's just an hack. 2. This option may just be unavailable because it is too low-level. Fo= r example, it is not available in Python socket implementation (but = I can still hardcode the numerical value). If I use some we= b framework, I will also have hard time to set this option. 3. This is a Linux only option. Here are the arguments for a sysctl: 1. It is a system-wide configuration: you configure VRRP on you= r system, you enable this sysctl, nothing else to do. 2. This is essentially a one-line modification. This will be quite eas= y to maintain for years. 3. This is the natural option for many people. See for example: http://thread.gmane.org/gmane.comp.web.haproxy/7317/focus=3D7318 4. Without it, people just do horrible things: http://thread.gmane.org/gmane.comp.web.haproxy/7317/focus=3D7321 Did I convince you? --=20 Vincent Bernat =E2=98=AF http://vincent.bernat.im /* * We used to try various strange things. Let's not. */ 2.2.16 /usr/src/linux/fs/buffer.c