Re: TCP/UDP Bad Checksum

From: Stephen Hemminger
Date: Thu May 31 2007 - 12:43:00 EST

On Thu, 31 May 2007 06:03:28 -0700 (PDT)
Guillaume Berthelom <guillaume.berthelom@xxxxxxxxx> wrote:

> Hi,
> I've got a problem with my ethernet frames:
> The ping and DHCP client work fine as same as the TCP handshake, so the
> connexion is established fine. But when the frame (TCP or UDP) send by my
> board need a checksum, this checksum failed and the server don't respond me.
> I have adapted the ethernet drivers for 2.4 kernel to 2.6 so it might come
> to it but my ethernet controller don't have checksum offload; and I use a
> 2.6.20 kernel.
> I have no idea where search. So if you could give me some way where might be
> the issue, I'll really appreciate...
> Thanks,
> Guillaume Berthelom

Network driver development should be sent to netdev@xxxxxxxxxxxxxxxx
The packet should be checksummed correctly when handed to your driver.
Check the settings for dev->features, and check the length value. You may
be sending less data than the full socket buffer.

Stephen Hemminger <shemminger@xxxxxxxxxxxxxxxxxxxx>
To unsubscribe from this list: send the line "unsubscribe linux-net" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at