[Fedora-xen] TCP checksum corruption

[Mike McGrath]

Daniel P. Berrange wrote:
> On Tue, May 08, 2007 at 01:00:32PM -0500, Mike McGrath wrote:
>   
>> Daniel P. Berrange wrote:
>>     
>>> Ok that makes absolutely no sense to me now :-)  Everytime I hit it I was
>>> able to solve it eventually by setting 'tx off' on some combo of devices.
>>> The RHEL-5 Dom0 kernel also already has the neccessary fixes in which is
>>> even odder that it doesn't work for you. 
>>>  
>>>       
>> So the question is where to proceed from here?  I can tcpdump on the 
>> bridge, peth and the domu host to see the errors.
>>     
>
> Actually tcpdump showing errors does not neccessarily mean that there are
> errors! If checksum offload is enabled, then you expect tcpdump to show
> errors, because the checksum is not filled in by the OS - its left up to
> the physical NIC. If you've turned 'tx off' on absolutely every device
> then, tcpdump ought to show correct checksums though.
>   

So here's the core of the problem.  This is actually our koji builder.  
When running:
koji list-tagged --quiet --latest --inherit f7-final

on lan, it takes about 10 seconds, when running it remote to another 
machine it will run 12 minutes +.

    -Mike