From owner-freebsd-net@FreeBSD.ORG Wed May 17 01:20:40 2006 Return-Path: X-Original-To: freebsd-net@freebsd.org Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 5CC3D16A401 for ; Wed, 17 May 2006 01:20:40 +0000 (UTC) (envelope-from kim@tinker.com) Received: from tinker.com (tinker2-3.august.net [66.228.55.4]) by mx1.FreeBSD.org (Postfix) with SMTP id 00ADC43D45 for ; Wed, 17 May 2006 01:20:39 +0000 (GMT) (envelope-from kim@tinker.com) Received: (qmail 91084 invoked by uid 27); 17 May 2006 01:20:39 -0000 Received: from 204.10.126.26.tinker.com(204.10.126.26), claiming to be "[192.42.172.22]" via SMTP by pop.tinker.com, id smtpdeClu09; Tue May 16 20:20:34 2006 In-Reply-To: <20060517010927.GA656@gremlin.foo.is> References: <001301c67946$604b7f70$aa00000a@cloe> <20060517005546.GJ65555@funkthat.com> <20060517010927.GA656@gremlin.foo.is> Mime-Version: 1.0 (Apple Message framework v750) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: Content-Transfer-Encoding: 7bit From: Kim Shrier Date: Tue, 16 May 2006 19:20:30 -0600 To: Unix-Solutions - Steven X-Mailer: Apple Mail (2.750) Cc: freebsd-net@freebsd.org Subject: Re: /31 on 2 interfaces 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: Wed, 17 May 2006 01:20:40 -0000 A /31 is not a point-to-point link. A /32 is. A /31 is a network with nothing but a loopback and broadcast address. You have to go to a /30 to have a block of addresses that is useful or configure a point-to-point link where you specify the address at each end of the link. Kim On May 16, 2006, at 7:09 PM, Baldur Gislason wrote: > /31 is common practice today. You don't need broadcast on a point- > to-point link. > The only broadcast you need is ARP and that's on layer 2. > > Baldur > > On Tue, May 16, 2006 at 05:55:46PM -0700, John-Mark Gurney wrote: >> Unix-Solutions - Steven wrote this message on Wed, May 17, 2006 at >> 02:10 +0200: >>> I have 2 servers with both 2x 'em' interfaces in it. >>> I configged a /31 on both interfaces >>> em0 in box 1 = 10.0.0.1 >>> em0 in box 2 = 10.0.0.2 >> >> As someone else mentioned even if you did a /31, those addresses >> aren't >> on the same network... >> 254 & 1 == 0 >> 254 & 2 == 2 >> >> Hence different networks.. the other thing is that you can't have >> a /31 >> due to the fact that one ip w/ all the node bits set is the broadcast >> for the network causing other sorts of troubles... the smallest >> usable >> network is a /30... >> >> -- >> John-Mark Gurney Voice: +1 415 225 5579 >> >> "All that I will do, has been done, All that I have, has not." >> _______________________________________________ >> freebsd-net@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-net >> To unsubscribe, send any mail to "freebsd-net- >> unsubscribe@freebsd.org" >> > > _______________________________________________ > freebsd-net@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org" > -- Kim Shrier - principal, Shrier and Deihl - mailto:kim@tinker.com Remote Unix Network Admin, Security, Internet Software Development Tinker Internet Services - Superior FreeBSD-based Web Hosting http://www.tinker.com/