netdev - Re: rare bad TCP checksum with 2.6.19?

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Date:	Mon, 15 Jan 2007 20:39:36 +1100
From:	Herbert Xu <herbert@...dor.apana.org.au>
To:	mjt@....msk.ru (Michael Tokarev)
Cc:	netdev@...r.kernel.org
Subject: Re: rare bad TCP checksum with 2.6.19?

Michael Tokarev <mjt@....msk.ru> wrote:
>
> Note there's no funny/interesting hardware involved, like network cards with
> tcp checksumming offload capabilities (this is plain dumb 8139 card).

The 8139 card might be dumb, but the driver isn't :) It emulates
checksum offload in software, meaning that tcpdump will show bogus
checksums.

So please disable hardware checksum offload with ethtool -K and
then try again.

Thanks,
-- 
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <herbert@...dor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
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