From owner-freebsd-net@FreeBSD.ORG Wed Jul 6 21:41:50 2011 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 BA7BF106564A; Wed, 6 Jul 2011 21:41:50 +0000 (UTC) (envelope-from pyunyh@gmail.com) Received: from mail-iy0-f182.google.com (mail-iy0-f182.google.com [209.85.210.182]) by mx1.freebsd.org (Postfix) with ESMTP id 745AD8FC14; Wed, 6 Jul 2011 21:41:50 +0000 (UTC) Received: by iyb11 with SMTP id 11so427272iyb.13 for ; Wed, 06 Jul 2011 14:41:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=from:date:to:cc:subject:message-id:reply-to:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; bh=x8GcH1B6zaS3PetC9UCM9aiRNYqtgxPIobyhOUwCSDA=; b=b4Yi7Dk0gHnxm/fAAXXfi68GD9sSABnBwhdLppxHJSmVJ7IM0Uii6Wo65MW7adIi7K 8EETZWiMi2jiJFyRHylbfjsRQdTx08tekWUqlvQgSonX3cIj7E8Z+FPKYSZe1YKraqGv HAqB/cL/pCzcn1gnUOUp+oQ00ozNVgLCyIqzo= Received: by 10.43.59.80 with SMTP id wn16mr92504icb.67.1309988509456; Wed, 06 Jul 2011 14:41:49 -0700 (PDT) Received: from pyunyh@gmail.com ([174.35.1.224]) by mx.google.com with ESMTPS id c2sm2696479ibd.5.2011.07.06.14.41.47 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 06 Jul 2011 14:41:49 -0700 (PDT) Received: by pyunyh@gmail.com (sSMTP sendmail emulation); Wed, 06 Jul 2011 14:40:16 -0700 From: YongHyeon PYUN Date: Wed, 6 Jul 2011 14:40:16 -0700 To: David Christensen Message-ID: <20110706214016.GB5559@michelle.cdnetworks.com> References: <20110706201509.GA5559@michelle.cdnetworks.com> <5D267A3F22FD854F8F48B3D2B523819385C32D9115@IRVEXCHCCR01.corp.ad.broadcom.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5D267A3F22FD854F8F48B3D2B523819385C32D9115@IRVEXCHCCR01.corp.ad.broadcom.com> User-Agent: Mutt/1.4.2.3i Cc: Charles Sprickman , David Christensen , "freebsd-net@freebsd.org" Subject: Re: bce packet loss X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: pyunyh@gmail.com List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 06 Jul 2011 21:41:50 -0000 On Wed, Jul 06, 2011 at 02:28:19PM -0700, David Christensen wrote: > > You had 282 RX buffer shortages and these frames were dropped. This > > may explain why you see occasional packet loss. 'netstat -m' will > > show which size of cluster allocation were failed. > > However it seems you have 0 com_no_buffers which indicates > > controller was able to receive all packets destined for this host. > > You may host lost some packets(i.e. non-zero mbuf_alloc_failed_count) > > but your controller and system was still responsive to the network > > traffic. > > > > Data sheet says IfHCInBadOctets indicates number of octets received > > on the interface, including framing characters for packets that > > were dropped in the MAC for any reason. > > The IfHcInBadOctets counter says the controller received X bytes > that were bad on the wire (collisions, FCS errors, etc.). A value I thought that too. But other counters such as FCS, FAE, Collisions, Jabbers were all zero. > of 539,369 would equal about 355 frames @ 1518 bytes per frame. > How bad that is really depends on the amount of time the server > was running. The minimum bit-error rate (BER) for 1000Base-T is > 10^-12, so running at line rate you'd expect to see an error very > 1000 seconds according to the following link: > > http://de.brand-rex.com/LinkClick.aspx?fileticket=TFxnnLPedAg%3D&tabid=1956&mid=5686 > > Most vendors design to greater than 10^-12 and you're probably not > running at line rate all the time so you should see fewer errors. > In my testing I can go for days without seeing any errors, but if > you run long enough or have marginal interconnects/cabling the > error rate will rise. > > Dave > >