From owner-freebsd-arch@FreeBSD.ORG Tue Oct 28 07:40:23 2003 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 2B36F16A4CF; Tue, 28 Oct 2003 07:40:23 -0800 (PST) Received: from basie.internet2.edu (basie.internet2.edu [207.75.164.22]) by mx1.FreeBSD.org (Postfix) with ESMTP id 38E3543F85; Tue, 28 Oct 2003 07:40:22 -0800 (PST) (envelope-from boote@internet2.edu) Received: from localhost (localhost.localdomain [127.0.0.1]) by basie.internet2.edu (Postfix) with ESMTP id A36353F8; Tue, 28 Oct 2003 10:40:21 -0500 (EST) Received: from internet2.edu (unknown [127.0.0.1]) by basie.internet2.edu (Postfix) with ESMTP id 2B8AC32A; Tue, 28 Oct 2003 10:40:20 -0500 (EST) Message-ID: <3F9E8DE3.61A5D814@internet2.edu> Date: Tue, 28 Oct 2003 08:40:19 -0700 From: "Jeff W. Boote" X-Mailer: Mozilla 4.79 [en] (Windows NT 5.0; U) X-Accept-Language: en MIME-Version: 1.0 To: Hajimu UMEMOTO References: <20031028063802.GC10818@canolog.ninthwonder.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Virus-Scanned: by mail.internet2.edu virus scanner cc: arch@FreeBSD.org cc: current@FreeBSD.org cc: net@FreeBSD.org Subject: Re: Forward: HEADS UP! Default value of ip6_v6only changed X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 28 Oct 2003 15:40:23 -0000 Hajimu UMEMOTO wrote: > > Hi, > > Our default of net.inet6.ip6.v6only was off in 4.X, and was changed to > on on 5.X to follow NetBSD's practice. This behavior on 5.X breaks > RFC2553/3493, and the change was intentional from security > consideration. But, NetBSD changed it off by default. > How do you think our default of on? As long as it is documented well, and the workaround (setting the IPV6_V6ONLY sockopt "off") is referenced, I don't think it really matters. Application programmers realize they have *some* work to do when porting applications to V6. A single sockopt call is not unreasonable. I think "on" for the security reasons outlined is the right call - it will at least make people think about those issues, and most would not without something bringing it up. (That said, it would be nice if NetBSD would pick a direction and keep it.) jeff