From owner-freebsd-hackers Sat Sep 27 09:48:14 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id JAA01366 for hackers-outgoing; Sat, 27 Sep 1997 09:48:14 -0700 (PDT) Received: from GndRsh.aac.dev.com (GndRsh.aac.dev.com [198.145.92.241] (may be forged)) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id JAA01346; Sat, 27 Sep 1997 09:48:05 -0700 (PDT) Received: (from rgrimes@localhost) by GndRsh.aac.dev.com (8.8.5/8.7.3) id JAA20293; Sat, 27 Sep 1997 09:47:15 -0700 (PDT) From: "Rodney W. Grimes" Message-Id: <199709271647.JAA20293@GndRsh.aac.dev.com> Subject: Re: 'fxp' driver/hardware lossage (was Re: Alexander B. Povol's mail) In-Reply-To: <17057.875363985@verdi.nethelp.no> from "sthaug@nethelp.no" at "Sep 27, 97 02:39:45 pm" To: sthaug@nethelp.no Date: Sat, 27 Sep 1997 09:47:15 -0700 (PDT) Cc: tlambert@primenet.com, hackers@FreeBSD.ORG, stable@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL25 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk > > > That's only true of coaxial media. Over twisted pair, if you see > > > data start arriving on the receive pair while your transmitting then > > > you have to assume that the data is being sent by another station > > > and you've got a collision situation. > > > > Isn't this the hub's responsibility to distinguish and prevent? > > Nope. A hub doesn't do anything with collisions - it just propagates > them bit by bit. The NICs sense the collision. Better go think so more about that... it depends on the hub! Some hubs that have partitioning ability will automagically partition out someone who starts to transmit if the hub is sending data out that port, this is called autopartitioning and is used to stop baligerant (sp) mau's or Jabberers(sp). If you want something that really tries to ``prevent'' this you want a switch and not a hub, and you want full-duplex non-simplex NIC cards in every box connected to that switch, and no I'm not just talking about 100Base stuff here, it applies to both 10 and 100Base ethernet over TP. -- Rod Grimes rgrimes@gndrsh.aac.dev.com Accurate Automation, Inc. Reliable computers for FreeBSD