Subject: Re: e1000 tcp checksum incorrect, x86 64b

From: Rick Jones <[email-masked]>
Date: Fri, 28 Sep 2007 09:35:07 -0700

Herbert Xu wrote:
> Jon Smirl <[email-masked]> wrote:
> 
>>App is writing seven bytes to the socket. Socket write timeout expires
>>and the seven bytes are sent. The checksum is not getting inserted
>>into the packet. It is set to a constant 0x8389 instead of the right
>>value.  App is gmpc 0.15.4.95, Revision: 6794
>>
>>Attached Wireshark packet trace show the problem. e1000 is 192.168.1.4
>>64bit, Q6600. Dell Dimension 9200
> 
> 
> Wireshark is broken.  It needs to know TP_STATUS_CSUMNOTREADY
> means that the checksum is partial and will only be completed
> when the hardware sends the packet out.
> 
> Alternatively disable checksum offload with ethtool.

Or take the packet traces "outboard" of the NIC somewhere/somehow.

What problem(s) led to your taking the packet trace in the first place?

rick jones