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From: "Dennis Cook" <cook@sandgate.com>
Subject: Re: Deactivating TCP checksumming
Date: Wed, 2 Apr 2003 15:47:35 -0500
Organization: Sandgate Technologies
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References: <F91mkXMUIhAumscmKC00000f517@hotmail.com> <20030401122824.GY29167@mea-ext.zmailer.org> <b6fda2$oec$1@main.gmane.org> <20030402203653.GA2503@gtf.org>
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What I was looking for is a general capability to keep the SW transport
stack from
computing outgoing TCP/UDP/IP checksums so that the HW can be allowed to do
it,
similar to Windows checksum offload capability.

"Jeff Garzik" <jgarzik@pobox.com> wrote in message
news:20030402203653.GA2503@gtf.org...
> On Wed, Apr 02, 2003 at 02:22:59PM -0500, Dennis Cook wrote:
> > Using RH Linux kernel 2.4.18, setting "features" bit NETIF_F_IP_CSUM
does
> > not appear
> > to keep a valid IP checksum from being computed in packets presented to
my
> > driver
> > for transmission. So having HW compute outgoing checksum buys nothing.
>
> You are not using sendfile(2), which is required to activate h/w csum.
>
> Jeff
>
>
>