From owner-freebsd-net@FreeBSD.ORG Sat Oct 20 11:14:12 2007 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 665E916A417 for ; Sat, 20 Oct 2007 11:14:12 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from fallbackmx03.syd.optusnet.com.au (fallbackmx03.syd.optusnet.com.au [211.29.133.136]) by mx1.freebsd.org (Postfix) with ESMTP id EC82913C448 for ; Sat, 20 Oct 2007 11:14:11 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from mail05.syd.optusnet.com.au (mail05.syd.optusnet.com.au [211.29.132.186]) by fallbackmx03.syd.optusnet.com.au (8.12.11.20060308/8.12.11) with ESMTP id l9JMg0HN003389 for ; Sat, 20 Oct 2007 08:42:00 +1000 Received: from server.vk2pj.dyndns.org (c220-239-20-82.belrs4.nsw.optusnet.com.au [220.239.20.82]) by mail05.syd.optusnet.com.au (8.13.1/8.13.1) with ESMTP id l9JMft7W022464 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sat, 20 Oct 2007 08:41:56 +1000 Received: from server.vk2pj.dyndns.org (localhost.vk2pj.dyndns.org [127.0.0.1]) by server.vk2pj.dyndns.org (8.14.1/8.14.1) with ESMTP id l9JMftEx059975; Sat, 20 Oct 2007 08:41:55 +1000 (EST) (envelope-from peter@server.vk2pj.dyndns.org) Received: (from peter@localhost) by server.vk2pj.dyndns.org (8.14.1/8.14.1/Submit) id l9JMftwB059974; Sat, 20 Oct 2007 08:41:55 +1000 (EST) (envelope-from peter) Date: Sat, 20 Oct 2007 08:41:55 +1000 From: Peter Jeremy To: Len Gross Message-ID: <20071019224155.GI20308@server.vk2pj.dyndns.org> References: <27cb3ada0710172051t536a4d11pfdfdb079ebd98932@mail.gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="liOOAslEiF7prFVr" Content-Disposition: inline In-Reply-To: <27cb3ada0710172051t536a4d11pfdfdb079ebd98932@mail.gmail.com> X-PGP-Key: http://members.optusnet.com.au/peterjeremy/pubkey.asc User-Agent: Mutt/1.5.16 (2007-06-09) Cc: freebsd-net@freebsd.org Subject: Re: Disable Exponential Backoff (retry) on Ethernet? 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: Sat, 20 Oct 2007 11:14:12 -0000 --liOOAslEiF7prFVr Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Oct 17, 2007 at 08:51:34PM -0700, Len Gross wrote: >I'm doing some protocol development and it is convenient to start it on >Ethernet. I will need to send a packet to the Ethernet device and only ha= ve >it be sent once, even if there is a colision. I know we've still got some hubs lying around in a backroom at work but I don't know of anything that will let you disable the retry-on-CD. Have you considered simulating the network at a slightly higher lever: Use ipfw pipes or similar to simulate packet loss (either set a queue length of 1 or probabilistically). This could be done either as a bridge or by tunneling your protocol over IP or UDP. --=20 Peter --liOOAslEiF7prFVr Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQFHGTKz/opHv/APuIcRArusAJ4pMIwKZcAFLFNwyMU3uZfv44JnzACeNiwh nAGneCdvy3oU4yYbp3MTbVI= =/kAs -----END PGP SIGNATURE----- --liOOAslEiF7prFVr--