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Date: Thu, 27 Feb 2014 11:01:18 -0500
Message-ID: <CAFMmRNzTBDD=qhoUPmEkWfuHr-rzFFRi847mXuh4jHmMXUKtug@mail.gmail.com>
Subject: Re: Network loss
From: Ryan Stone <rysto32@gmail.com>
To: Rick Macklem <rmacklem@uoguelph.ca>
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Cc: Johan Kooijman <mail@johankooijman.com>,
 freebsd-net <freebsd-net@freebsd.org>, Jack Vogel <jfvogel@gmail.com>,
 John Baldwin <jhb@freebsd.org>
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On Wed, Feb 26, 2014 at 8:00 PM, Rick Macklem <rmacklem@uoguelph.ca> wrote:
> And please email if you try it and let us know if it helps.
>
> I've think I've figured out how 64K NFS read replies can do this,
> but I'll admit "ping" is a mystery? (Doesn't it just send a single
> packet that would be in a single mbuf?)

ixgbe currently returns an error from its if_transmit function if it
gets an error sending *any* packet that is queued for transmit.  So if
there is a 64K NFS request queued then ping could see an EFBIG error.
I can't explain the packet loss, unless ping is counting errors from
send() as lost packets (which would be completely reasonable).