Re: Bad TCP checksum error

From: Rick Jones
Date: Fri Oct 26 2007 - 12:59:56 EST


Checksum Offload on the NIC(s) can complicate things. First, if you are tracing on the sender, the tracepoint is before the NIC has computed the full checksum. IIRC only a partial checksum is passed-down to the NIC when CKO is in use.

So, making certain your trace is from the "wire" or the receiver rather than the sender would be a good thing, and trying again with CKO disabled on the interface(s) (via ethtool) might be something worth looking at. Ultimately, doing the partial checksum modificiations in a CKO-friendly manner might be a good thing.

rick jones
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