From: Kristof Provost <Kristof@sigsegv.be>
To: Kevin Spiteri <kspiteri@ieee.org>
Cc: netdev@vger.kernel.org
Subject: Re: TCP checksum error on local device
Date: Wed, 9 Jul 2008 15:10:20 +0000 [thread overview]
Message-ID: <20080709151019.GG27741@nereid> (raw)
In-Reply-To: <9a6873fa0807090734ge7ef12lf09e78db44ba77f5@mail.gmail.com>
On 2008-07-09 16:34:32 (+0200), Kevin Spiteri <kspiteri@ieee.org> wrote:
> When I send TCP data from localhost to localhost (either on 127.0.0.1
> or on the public IP of the machine), the TCP checksum is wrong.
>
I suspect this is intended and expected behaviour. The checksum is quite
useless as the packet never travels over the network and can't be
corrupted.
The transmit code in net/ipv4/ip_output.c seems to mark packets for the
loopback interface with CHECKSUM_UNNECESSARY.
I guess the connection over loopback still carries the data like you'd
expect right?
Kristof
next prev parent reply other threads:[~2008-07-09 15:06 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-07-09 14:34 TCP checksum error on local device Kevin Spiteri
2008-07-09 15:10 ` Kristof Provost [this message]
2008-07-09 15:28 ` Kevin Spiteri
2008-07-09 15:38 ` Ben Hutchings
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