From owner-freebsd-net@FreeBSD.ORG Fri Oct 30 23:19:47 2009 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 9247C106566C for ; Fri, 30 Oct 2009 23:19:47 +0000 (UTC) (envelope-from zibbe@cisko.org) Received: from mail-bw0-f213.google.com (mail-bw0-f213.google.com [209.85.218.213]) by mx1.freebsd.org (Postfix) with ESMTP id 29E2D8FC13 for ; Fri, 30 Oct 2009 23:19:46 +0000 (UTC) Received: by bwz5 with SMTP id 5so4191553bwz.3 for ; Fri, 30 Oct 2009 16:19:45 -0700 (PDT) Received: by 10.204.13.204 with SMTP id d12mr421951bka.61.1256944785690; Fri, 30 Oct 2009 16:19:45 -0700 (PDT) Received: from ?172.17.1.247? (fw.sth1.keff.org [212.247.153.198]) by mx.google.com with ESMTPS id d13sm991843fka.52.2009.10.30.16.19.44 (version=SSLv3 cipher=RC4-MD5); Fri, 30 Oct 2009 16:19:44 -0700 (PDT) Sender: Sebastian Hyrwall Message-ID: <4AEB911E.1070104@keff.org> Date: Sat, 31 Oct 2009 02:21:34 +0100 From: Sebastian Hyrwall User-Agent: Thunderbird 2.0.0.19 (X11/20081209) MIME-Version: 1.0 To: Chuck Swiger References: <4AEB7AE8.5090101@keff.org> <18C758A7-1908-4D1A-BDCA-80FF7FD8BC22@mac.com> <4AEB834D.1050907@keff.org> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-net@freebsd.org Subject: Re: Hi. /31 on ethernet links X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 30 Oct 2009 23:19:47 -0000 Chuck Swiger skrev: > On Oct 30, 2009, at 5:22 PM, Sebastian Hyrwall wrote: >>> A /31 subnet is only defined for point-to-point network links, per: >>> >>> http://www.rfc-editor.org/rfc/rfc3021.txt >>> >>> Ordinary ethernet links have BROADCAST flag set instead of POINTOPOINT. >>> >> >> Well how do I set the POINTOPOINT flag and remove the BROADCAST-flag >> on ethernet links? Or are you implying that it does not belong on >> ethernet links :) Cause Cisco and Linux support /31 (ptp's) on >> ordinary ethernet links. > > Ethernet point-to-point links are normally handled by ppp / pppd in > PPPoE mode, but possibly something like: > > ifconfig en0 inet 192.1.1.10 inet 192.1.1.2 > > ...would give you a POINTOPOINT link instead. If not, you can > probably fake things out by either using a /30 and wrapping the /31 > inside, or using a /32 and an explicit default route via your > ethernet interface. > Unfortunetly that doesn't work. It just sets 192.1.1.2 as broadcast. Well wrapping a /31 inside of a /30 kinda defeats the purpose :) If Cisco,Linux and NetBSD support it so should FreeBSD imho. > Regards,