From owner-freebsd-stable@FreeBSD.ORG Thu Aug 12 08:00:48 2004 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D1E6116A4CE for ; Thu, 12 Aug 2004 08:00:48 +0000 (GMT) Received: from citadel.nobulus.com (citadel.nobulus.com [212.97.207.19]) by mx1.FreeBSD.org (Postfix) with ESMTP id 260F143D1F for ; Thu, 12 Aug 2004 08:00:48 +0000 (GMT) (envelope-from iva@citadel.nobulus.com) Received: from citadel.nobulus.com (localhost.nobulus.com [127.0.0.1]) by citadel.nobulus.com (8.12.11/8.12.11) with ESMTP id i7C8dWSo079686; Thu, 12 Aug 2004 08:39:32 GMT (envelope-from iva@citadel.nobulus.com) Received: (from iva@localhost) by citadel.nobulus.com (8.12.11/8.12.11/Submit) id i7C8dUwV079685; Thu, 12 Aug 2004 08:39:30 GMT (envelope-from iva) Date: Thu, 12 Aug 2004 08:39:30 +0000 From: Ilya Varlashkin To: "Marc G. Fournier" Message-ID: <20040812083930.GA79672@CITADEL.NOBULUS.COM> References: <20040810173211.V776@ganymede.hub.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040810173211.V776@ganymede.hub.org> cc: freebsd-stable@freebsd.org Subject: Re: em driver worse then fxp driver ... why? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 Aug 2004 08:00:49 -0000 Hi Marc, I'm not subscribed to -net list, so in case you haven't got solution yet, here is some info. On Tue, Aug 10, 2004 at 05:37:28PM -0300, Marc G. Fournier wrote: > > I have 5 servers sitting on a Linksys 10/100 switch ... 4 of the 5 are > running fxp0 ethernet, while the 5th is running em ... and the 5th > performs atrociously: > > neptune# netstat -ni | head > Name Mtu Network Address Ipkts Ierrs Opkts Oerrs > Coll > em0 1500 00:07:e9:05:1b:2e 36915965 10306 28888840 1 > 10858513 > > I've tried in bth half and full duplex mode .. full duplex, Ierrs climbs, ^^^^^^^^^^^^^^^^^^^ This is very typical behaviour when you have one side forced to full-duplex and the other side is in autonegotiation. The side with forced full duplex will experience lots of input error, and the autonegotiation side will see tons of collisions. The later is because autonegotiation side in the absense of autonegotiation bits from the other side will automagically put itself into half-duplex. I see this everytime somebody comes and plugs new server onto the networkr, and it's happens very often. All you need to do is to have either both sides in autoneg or both sides forced into full-duplex 100Mbps. > half-duplex, Collisions climb ... > That's normal - you will always see collisions on half-duplex links. It's not an error, it's just what half-duplex is all about. > Originally, it was explained that unmanaged switches tended to be > problematic, but I'd expect some sort of uniformity in problems, but 'just > the server with the em device' ... > Indeed, unmanaged switches tend to have ports set to autonegotiation > So, is there a bug in the em device driver that doesn't exist on the fxp0 > devices? > I've observed behaviour you described with any card I came by, including those using fxp driver. If you know in advance that physical setup is wrong try to fix that first, don't rely on the driver fixing it for you. Hope it helps. /Ilya