From mboxrd@z Thu Jan  1 00:00:00 1970
From: Roland Dreier <rdreier@cisco.com>
Subject: Re: Question regarding protocol specific mtu for FCoE
Date: Wed, 03 Jun 2009 14:21:11 -0700
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Cc: "Zou\, Yi" <yi.zou@intel.com>,
	"netdev\@vger.kernel.org" <netdev@vger.kernel.org>,
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To: Rick Jones <rick.jones2@hp.com>
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In-Reply-To: <4A26E4AE.4020607@hp.com> (Rick Jones's message of "Wed, 03 Jun
	2009 14:01:34 -0700")
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 > So FCoE cannot say "fcoe_mtu = min(OPTIMAL_FCOEMTU,netdev->mtu)" and
 > send-down frames based on that?

I think the point is that FCoE wants to use OPTIMAL_FCOEMTU (2KB + a bit
for headers) even when netdev->mtu is 1500.  (eg datacenter network
supports baby jumbo frames so FCoE traffic that stays within the network
should use OPTIMAL_FCOEMTU, while lots of IP traffic is going out onto a
1500-byte MTU campus and having TCP doing lots of PMTU discovery is a
pain)

 - R.