netdev - Re: incorrect cksum with tcp/udp on lo with 2.6.20/2.6.21/2.6.22

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Message-ID: <20071002104033.GA30281@gondor.apana.org.au>
Date:	Tue, 2 Oct 2007 18:40:33 +0800
From:	Herbert Xu <herbert@...dor.apana.org.au>
To:	Krzysztof Oledzki <olel@....pl>
Cc:	netdev@...r.kernel.org
Subject: Re: incorrect cksum with tcp/udp on lo with 2.6.20/2.6.21/2.6.22

On Mon, Sep 24, 2007 at 11:44:19AM +0200, Krzysztof Oledzki wrote:
> 
> So, with DR mode, packet goes by the lo device (with bad checksum) and 
> then get redirected outside. Unfortunately, when it leaves host it has bad 
> checksum, too. :(

Did you check this by taking a tcpdump on an external host?
Doing a local tcpdump doesn't work as tcpdump won't show the
correct checksum if checksum offload is enabled.

If it's really sending a bogus checksum then it's a bug in
LVS.

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