Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 6 Jul 2011 14:40:16 -0700
From:      YongHyeon PYUN <pyunyh@gmail.com>
To:        David Christensen <davidch@broadcom.com>
Cc:        Charles Sprickman <spork@bway.net>, David Christensen <davidch@freebsd.org>, "freebsd-net@freebsd.org" <freebsd-net@freebsd.org>
Subject:   Re: bce packet loss
Message-ID:  <20110706214016.GB5559@michelle.cdnetworks.com>
In-Reply-To: <5D267A3F22FD854F8F48B3D2B523819385C32D9115@IRVEXCHCCR01.corp.ad.broadcom.com>
References:  <alpine.OSX.2.00.1107042113000.2407@freemac> <20110706201509.GA5559@michelle.cdnetworks.com> <5D267A3F22FD854F8F48B3D2B523819385C32D9115@IRVEXCHCCR01.corp.ad.broadcom.com>

next in thread | previous in thread | raw e-mail | index | archive | help
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
> 
> 



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20110706214016.GB5559>