Wireshark-users: [Wireshark-users] Ang: Re: Large TCP packets
Date: Thu, 26 Jun 2008 14:02:27 +0200 (CEST)
>> 	3) the network adapter on the machine is doing TCP 
segmentation  
>> offloading on the receive side and passing simulated jumbo 
frames to  
>> the host.
>
>As the trace was made on the sending side, I suspect that the 
FTP
>server is indeed offloading TCP segmentation to the NIC. If 
you want
>to be sure, you could make a trace on the server and at the 
same time
>on the client to verify that the large packets are indeed 
segmented
>to normal sizes on the wire.

TCP segmentation offloading (TSO from wikipedia), wow 
something new every day :-)
Tested on the clientside and there the fragments was as 
excpected, so I checked the linux machine.
ethtool -k eth0 and it has TSO enabled. 
So for my testing I can actually turn it off, to get better 
wireshark traces.

Thanks for the help.

/Martin