Re: Intel e1000 ethernet device, change in kernel v3.4, and jumbo frames setting DENIED.

From: D. Stussy
Date: Thu Jul 05 2012 - 15:55:50 EST


"Henrique de Moraes Holschuh" wrote in message news:jjGoO-7l0-19@xxxxxxxxxxxxxxxxxxx

On Wed, 04 Jul 2012, D. Stussy wrote:
There has been some changes to the driver such that things like
checksum verification is offloaded from the CPU. However, this
blocks the ability to set a jumbo frame. The kernel does record an
error indicating that checksum offloading need be disabled fro jumbo
frame MTU sizes to be used. My e1000 interfaces use the 82574L
chipset.

1) Was this an intentional change?

Yes, but I understand Intel is trying to come up with a way not to need it.

2) How do I disable that function so I can set jumbo frames with
"ifconfig" or "ip"? I simply don't know what setting I need to
pass.

ethtool can do it. Check its manpage, it can manipulate the various NIC
offload engines, as well as other parameters such as dma ring buffer size,
etc.
=====================
I'll look into it. Thanks.

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