From owner-freebsd-questions Fri Feb 28 13:27: 5 2003 Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8AA8737B401 for ; Fri, 28 Feb 2003 13:27:03 -0800 (PST) Received: from gldis.ca (constans.gldis.ca [66.11.169.73]) by mx1.FreeBSD.org (Postfix) with ESMTP id AC7B443FA3 for ; Fri, 28 Feb 2003 13:27:02 -0800 (PST) (envelope-from gldisater@gldis.ca) Received: from gldis.ca (gldisater@localhost [127.0.0.1]) by gldis.ca (8.12.3/8.12.3) with ESMTP id h1SLR1gb083196; Fri, 28 Feb 2003 16:27:01 -0500 (EST) (envelope-from gldisater@gldis.ca) Received: (from gldisater@localhost) by gldis.ca (8.12.3/8.12.3/Submit) id h1SLR0Zs083182; Fri, 28 Feb 2003 16:27:00 -0500 (EST) Date: Fri, 28 Feb 2003 16:27:00 -0500 From: Jeremy Faulkner To: Cliff Sarginson Cc: questions@freebsd.org Subject: Re: full/half duplex Message-ID: <20030228212700.GA83015@constans.gldis.ca> References: <1046381078.2126.19.camel@ka0ttic> <001201c2deb9$2b29a220$1508060a@furrie.net> <20030228192335.GA10452@raggedclown.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030228192335.GA10452@raggedclown.net> User-Agent: Mutt/1.4i Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Fri, Feb 28, 2003 at 08:23:35PM +0100, Cliff Sarginson wrote: > On Thu, Feb 27, 2003 at 11:37:19PM -0000, Chris Phillips wrote: > > Aaron wrote: - > > I have a 3Com 3c900-Combo and ifconfig is reporting that it was in > > half-duplex mode, so I booted up my 3com dos utility book disk and > > checked and it was at half-duplex so I changed it to full. ifconfig is > > still reporting it being half-duplex. Do I need to reinstall the driver > > or something? How would I go about it? > > > > Chris Phillips wrote: > > > Is it plugged into a hub or a switch? > > > A hub will only do half duplex. > > > A switch will do full duplex. > > > Worth mentioning... > > > I don't know what the problem is but I do not think what you say is > correct. A hub can do full duplex, at least in my previous experience. A hub most certainly can not run full duplex. In order to run at full duplex the tx and rx lines have to be separate. A hub is simply connecting all of the tx and rx lines in the ethernet cable together w/ some amplification. Since all of the tx and rx lines are connected a packet transmitted from one machine will be received by all machines on the network. A switch can do full duplex because each port is essentially its own nic card. The switch segments the network and only traffic that needs to go through a specific segment will go to that segment. This division of traffic is decided based on the mac address of the destination. -- Jeremy Faulkner http://www.gldis.ca To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message