impossible packet length ...

[Peter Jeremy]

On 2009-Feb-08 11:31:45 +0200, Danny Braniss <danny at cs.huji.ac.il> wrote:
>Q: with rxcsum on, and a bad checksum packet is received, is it
>   dropped by the NIC? if not, then it somewhat explains the behaviour

If checksum offloading is working correctly then a bad packet should
be dropped by the NIC.  If checksum offloading isn't working correctly
then you can wind up in the situation where both the NIC and the
driver think the other party has verified the checksum.  It's also
possible that you may be running into corruption during DMA transfer
from the NIC to RAM.  ISTR there have been some issues reported
recently with checksum offloading on some NICs - though I don't have
details to hand - you might like to search the lists.

>changing the nic is tough, but if needed will be done. 

If disabling checksum offloading fixes the problem and the additional
CPU load is acceptable (at least until you find a real fix) then
there's no need to change NICs.

-- 
Peter Jeremy
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